| nycavsr2000 |
Hi fellas,
Wife and kids were out the door visiting friends down south so I called up Earl and asked if I could audition his speakers yesterday. For what its worth, here are some speakers I have heard and respect:
Linkwitz Orions++, right at Siegfried's house near San Francisco
NaO II dipoles designed by John Kreskovsky
GR Research OB5's and OB7's
Earl was an excellent host, brought me down to his well treated home theatre room (about 15 feet wide and 30 feet deep with a 10 ft ceiling) where the Summa 15's were in the corners behind curtains and turned in 45 degrees to avoid the side walls. There were also 3 subwoofers setup in the room (all bandpass design!). The Summa's are about 98dB/2.83V/m efficient in full space. His electronics are extremely simple and plain by audiophile standards. A PC and Toshiba CD player as sources, a Pioneer Digital Receiver (100 watts/channel), zip cord wire and zip cord interconnects. Nothing amazing here at all.
First CD we played were various tracks from Bela Fleck & Flecktones, a Live CD.
Wow! We were playing at peaks of 100 dB from my listening position (roughly centered about 10 feet away from the speakers). No compression. Tight clean bass. Performers were in the room. Imaging was very stable over a horizontal axis of an entire sofa. Music appeared from a complete black void.
The most open midrange I have ever heard. This includes the dipole systems I have listed above. There was no real part of the frequency response that was drawing attention, although I was continuously amazed by how clean the bass was and how delineated it was. Treble was just there, never drawing attention to itself but never lacking either.
Image body, intensity were all there. Small instruments sounded small. Close miked, sounded close miked.
Neutral is a great way to describe it.
Next we listened to some cuts from Diana Krall. Her voice was so compelling that she really sounded she was right up there on stage, playing for you. A personal treat if you will.
Next, Geddes played a cut from a DVD from Phantom of the Opera. Dynamics in spades. Everything was released unshackled. And just when you thought the music may lose control, it doesn't. How quickly the Summas start and stop is uncanny. I believe this is as much a product of speaker design as it is the room. The final cut was my favorite. Eagles DVD Live! The guitar solos were electrifying, even soul searching.
I am beginning to understand why some audiophiles say they listen at 80 or 85dB. I think its because of compression. When I auditioned the Orions and NaO II's, I was a little hesitant to crank it up. With the Summas, the music just gets louder but never, ever loses control.
In any case I suggest anybody within a spitting distance of Michigan to call up Earl and give these an audition. Even if you own fancy schmancy loudspeakers, I mean TAD 3 ways, Avante Garde, etc...give it a listen. It will challenge every audiophile belief you have had. Earl was kind enough to let me have one of his books, "Premium Home Theater." I have been leafing through the book and found one paragraph regarding 'subjectivism' that I found quite eye opening (page 249):
"When dealing with subjectively oriented AV issues,I prefer to deal with the science (facts), whenever possible, and not Audio Tarot. My wife coined this wonderful phrase after she first came into contact with the audio community that I work in. She has a background in experimental psychology and knows how easily subjective opinions can be swayed by external factors. She noted that a large amount of audio folklore is accepted by its practitioners purely on faith,i.e. there is no way to either prove or disprove these beliefs. Basically, audio,in these aspects, is a religion. Mankind has always had trouble reconciling facts with their fundamental belief system when the two come into conflict (to wit Galileo). The facts are often suppressed in order to perpetuate the established belief system. The practitioners of Audio Tarot will always prefer to suppress those facts that contradict their established beliefs."
Trust me just like many of you, I am part of the (gulp) Audio Tarot as well. Will I give up some of my fancy schmancy equipment? Probably not terribly soon. But boy was this system an awakening.
What did it teach me? The speaker/room equation is the achilles heal to audiophile aural enlightenment. Until you've solved that issue, you (I mean me) will be in this perpetual audiophile merry-go-round of exchanging equipment, spending thousands of dollars, etc...
Fix that problem first. For if a loudspeaker/room with Pioneer electronics can blast me into an eargasmic orbit, what more do I want? Better question is what more can I have? Will better electronics make a better listening experience? Perhaps. However, the Summa 15's really take you 90% there, so I'm not surprised that a simple receiver can take you so far ahead of everybody else.
A few pictures to follow tomorrow.
Till then,
Anand. |
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| tinitus |
Nice read!
But dont let Earls amp fool you
He has written a lot about it ... its very carefully selected ;) |
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| gedlee |
Anand
Thank you for your kind review. I should point out that we have never met before and that all I asked of you was that you post your impressions. I had no doubt what they would be.
And yes, the loudspeaker room interface is the key, To ignore this is to ignore the essence of audio.
(Well not zip cord interconnects, Radio Shack :))
Thanks again. It was a pleasure meeting you. |
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| publius |
What a FANTASTIC review.
Thanks Anand!
Do you know what frequency the Summas were crossed to the subs? |
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| publius |
| Congrats E.G. These Summas MUST be something very special. |
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| gedlee |
| quote: | Originally posted by publius
What a FANTASTIC review.
Thanks Anand!
Do you know what frequency the Summas were crossed to the subs? |
I don't "cross" to the subs. The subs all overlap with various frequency responses. |
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| nycavsr2000 |
As Gedde said, he has 3 subs, all bandpass design, with different frequency response overlap. First time I have ever heard a bandpass system done right.
In due time, I think Gedde will reveal the details of these bandpass subwoofers as future kits perhaps.
In the meantime, I figure let the Nathan10 run full range and have a low pass set for your sub. Best to do it with measurements. Most subs nowadays whether DIY or commercial are either sealed, ported or dipole based anyway.
Anand. |
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| publius |
| quote: | Originally posted by gedlee
I don't "cross" to the subs. The subs all overlap with various frequency responses. |
So, the rolloff on the mains is sufficiently steep (>=12db/octave)to protect them from any sub-bass in the L-R channels? Then you send a combined L-R channel sum to each subwoofer where you have high and low pass filters and you use each of the three subwoofers to cover a different frequency range? Do you do this to reduce the burden on each subwoofer or to "shuffle" the room modes (or some other reason)?
How would this work for people who are running a home theater? THX assumes second order rolloff at 80hz in the mains to which it adds an additional second order filter to create a net fourth order rolloff. THX rolls off the subwoofer channel at fourth order at 80hz for a smooth transition. |
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| gedlee |
| quote: | Originally posted by publius
So, the rolloff on the mains is sufficiently steep (>=12db/octave)to protect them from any sub-bass in the L-R channels? Then you send a combined L-R channel sum to each subwoofer where you have high and low pass filters and you use each of the three subwoofers to cover a different frequency range? Do you do this to reduce the burden on each subwoofer or to "shuffle" the room modes (or some other reason)?
How would this work for people who are running a home theater? THX assumes second order rolloff at 80hz in the mains to which it adds an additional second order filter to create a net fourth order rolloff. THX rolls off the subwoofer channel at fourth order at 80hz for a smooth transition. |
Each sub does not cover a different frequency range. One does, in my case, but that not necessary. The 15's go down to about 50 Hz, monopoles with a natural rolloff. There is one very LF sub 25 - 50 Hz. one broadband sub 50-100 and another 50 - 150. So at about 50 Hz there are five sources, one below that, four to about 100 Hz, three to 150 Hz and then just the mains.
The subs feed from the LFE channel on the receiver.
My room is a home theater.
THX is not the gospel in audio. |
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| salas |
| quote: | Originally posted by publius
Congrats E.G. These Summas MUST be something very special. |
Bravo Dr. Geddes. Congrats from me too. |
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| publius |
| quote: | Originally posted by gedlee
Each sub does not cover a different frequency range. One does, in my case, but that not necessary. The 15's go down to about 50 Hz, monopoles with a natural rolloff. There is one very LF sub 25 - 50 Hz. one broadband sub 50-100 and another 50 - 150. So at about 50 Hz there are five sources, one below that, four to about 100 Hz, three to 150 Hz and then just the mains.
The subs feed from the LFE channel on the receiver.
My room is a home theater.
THX is not the gospel in audio. |
This is the most screwed up system that I have ever heard, but you are E.G. and I am nobody, so I feel compelled to try to understand why you have put it together this way.
Question 1: If you are not crossing any content to your subs and your mains roll off at 50hz, how do you hear content below 50hz that is in the music? I know there is not much content below 50hz, but still, your system would appear to be incapable of reproducing the bottom octave on a piano and I am guessing that is not right.
Question 2: The Dolby LFE channel spec has a brickwall at 120hz, so there is no content above 120hz for the sub that is crossed at 150hz. What is the purpose of the low pass filter on this sub?
Question 3: Given that deep bass requires much more power and displaced air than upper bass, why do you have two subs (and two speakers) covering the upper bass and only one unit covering the deep bass? Seems like the sub that is not playing any content in the LFE channel from 120hz and up could be better deployed assisting below 50 hz.
I am completely baffled by your configuration, I admit that I don't understand your approach, and I apologize if my questions are poor questions. |
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| gedlee |
Question 1: You do misunderstand, there is a sub specifically tuned to do 25-50 Hz. Reread my post.
Question 2: This is not true. The LP filter in the LFE is tunable and on my receiver it can go up to 150 Hz.
Question 3: I use multiple subs to smooth out the LF mode problems in a small room. I have more than enough SPL capability for any situation and in fact the biggest problem with this approach is getting too much low end. Balancing all this out correctly is not trivial and I posted that point elsewhere when we talked about multuiple subs in the "cardiod bass" thread. You should go read that one.
There is no "one right way" to set the subs paramters (gain, filters, phase). You take the subs that you have and set them up in the room with measurements. If you have enough subs you will usually get something satisfactory. Too few subs and you will always be disappointed. |
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| nycavsr2000 |
| quote: | | There is no "one right way" to set the subs paramters (gain, filters, phase). You take the subs that you have and set them up in the room with measurements. If you have enough subs you will usually get something satisfactory. Too few subs and you will always be disappointed. |
Thank you. I wholeheartedly agree.
Anand. |
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| limono |
Seems like this going to be SOTA speaker kit and I only wished dear DR provided plans for proper woofer to compliment satelites.
Somehow I'm not convinced in matching some Costco Booomer to
Summas 80-100 Hz.
Regards, L |
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| Patrick Bateman |
| quote: | Originally posted by gedlee
Question 3: I use multiple subs to smooth out the LF mode problems in a small room. I have more than enough SPL capability for any situation and in fact the biggest problem with this approach is getting too much low end. Balancing all this out correctly is not trivial and I posted that point elsewhere when we talked about multuiple subs in the "cardiod bass" thread. You should go read that one.
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Here's the thread: http://www.diyaudio.com/forums/show...25&pagenumber=1 |
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| gedlee |
| quote: | Originally posted by limono
Seems like this going to be SOTA speaker kit and I only wished dear DR provided plans for proper woofer to compliment satelites.
Somehow I'm not convinced in matching some Costco Booomer to
Summas 80-100 Hz.
Regards, L |
Summas are 50Hz and up. I will supply plans for my subs thats not a problem, but I won't make them as kits since thats just a waste of my time considering the economics. |
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| Patrick Bateman |
| quote: | Originally posted by limono
Seems like this going to be SOTA speaker kit and I only wished dear DR provided plans for proper woofer to compliment satelites.
Somehow I'm not convinced in matching some Costco Booomer to
Summas 80-100 Hz.
Regards, L |
Could someone explain to me the advantage of using a boutique subwoofer instead of a Costco subwoofer?
You might argue that the Costco sub will have lousy power handling. If that's the case, buy four of them. That increases your SPL limit by 12db.
You might argue the Costco sub isn't as handsome as an audiophile sub. That may be true, so hide it! No one wants to look at three subs anyways.
You might argue that the Costco sub has lousy frequency response. While some cheap subs are designed with a hump in the midbass, there are plenty of inexpensive powered subs that measure well and have predictable crossovers and EQ built in.
Last but not least is price. Spending $750 on three Costco subs and pairing them with a $1200 kit seams reasonable. Spending $3000 on three boutique subs seems unnecessary with $1200 mains.
I've always been mystified by the use of exotic subwoofers in the home. In car audio, they make a lot of sense, because box size is king in mobile audio. Also, car subs function in "pressure mode" due to the small dimensions of the cabin. Exotic subs also make sense in pro audio, where dozens of subs are in play and each is being fed thousands of watts.
In the home, not so much. |
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| limono |
Well , sorry but by Summa I meant 10" dIY version which is 80-100 Hz and needs a woofer not subwoofer to be a regular full range speaker. Maybe it's time to name the kit ??I agree that for HT the quality of subwoofer is of no importance ;) and most everything will do. Sorry to add a confusion to already confused thread .
Regards, L |
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| publius |
| quote: | Originally posted by gedlee
Question 1: You do misunderstand, there is a sub specifically tuned to do 25-50 Hz. Reread my post. |
I have read and re-read your posts in this thread. You have a sub tuned to do 25-50hz. BUT, you said that this sub is receiving the LFE channel source. The *LFE channel* is different from the *subwoofer channel*.
Since you have said in a previous post that you "do not cross to the subs", then the only content that your subwoofer array is receiving is that which is contained in the LFE channel. If you are listening to a two-channel source, such as a piano recording, there will be no content in the LFE channel and in your system you will hear not hear the bottom octave of the piano (~27-51hz).
| quote: | Originally posted by gedlee
[B]Question 2: This is not true. The LP filter in the LFE is tunable and on my receiver it can go up to 150 Hz. |
I think that you are confused. The LFE channel and the subwoofer channel are two separate sources of content though they are summed and fed through the same cable to the subwoofer. In a previous post you said that you "do not cross to subs". This indicates that you are running your main speakers full range and that no content is being shifted from the main channels to the subwoofers. In such a system, the subwoofer(s) will receive only the LFE (aka ".1") content. Dolby has a low-pass filter for LFE content at 120hz. There is no slope. All content above 120hz is just filtered out. So nothing is gained by setting the LFE LP filter on your receiver to 150hz.
| quote: | Originally posted by gedlee
Question 3: I use multiple subs to smooth out the LF mode problems in a small room. I have more than enough SPL capability for any situation and in fact the biggest problem with this approach is getting too much low end. Balancing all this out correctly is not trivial and I posted that point elsewhere when we talked about multuiple subs in the "cardiod bass" thread. You should go read that one. |
Thank you for pointing out the cardiod bass thread. I will be sure to read through.
It remains an open question though how you can have "too much lowend" when you are only powering your subs with the LFE content channel.
Perhaps what you are really doing is:
1. running your main speakers full range (and letting their natural rolloff below 50hz protect them from overdrive)
2. using your receiver to SUM content from your main speaker channels below 150hz to the LFE channel, creating what is called a subwoofer channel (which is distinct from an LFE channel).
3. using this subwoofer channel as the input for each of your subwoofers, which you then adjust for frequency and level.
If this is the case, then it would all seem to make some sense.
| quote: | Originally posted by gedlee
There is no "one right way" to set the subs paramters (gain, filters, phase). You take the subs that you have and set them up in the room with measurements. If you have enough subs you will usually get something satisfactory. Too few subs and you will always be disappointed. |
Yes. Parametric EQ can also help as well. Do you have parametric EQ in your subwoofers? If not, how do you deal with room modes?
[EDIT: I see (in another thread) that structural methods are used to tame modes. Nice.] |
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| MJL21193 |
| quote: | Originally posted by limono
I agree that for HT the quality of subwoofer is of no importance ;) and most everything will do. Sorry to add a confusion to already confused thread .
Regards, L |
HT is the ONLY place a subwoofer matters. You don't need one for music, providing you have real main speakers.
Good quality subs beat one note boom boxes and over eq'ed, over driven poop producers any day. |
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| gedlee |
| quote: | Originally posted by publius
Perhaps what you are really doing is:
1. running your main speakers full range (and letting their natural rolloff below 50hz protect them from overdrive)
2. using your receiver to SUM content from your main speaker channels below 150hz to the LFE channel, creating what is called a subwoofer channel (which is distinct from an LFE channel).
3. using this subwoofer channel as the input for each of your subwoofers, which you then adjust for frequency and level.
If this is the case, then it would all seem to make some sense.
Yes. Parametric EQ can also help as well. Do you have parametric EQ in your subwoofers? If not, how do you deal with room modes? |
Your discussion is all semantics to me. The output on the receiver is labeled "LFE", but yes in "stereo" it is a mono sub channel, but in DVD it is the LFE "PLUS" which means that LF energy from all channels is also sent to the LFE channel - an ideal situation for what I do. Different receivers do this differently but in mine I can set the LP frequency above 120 Hz in "PLUS" mode.
When you use multiple subs in a room with substantial LF damping there really aren't problem modes that need EQ. Only in a few cases have I found the need for EQ at these frequencies. |
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| gedlee |
| quote: | Originally posted by Patrick Bateman
Could someone explain to me the advantage of using a boutique subwoofer instead of a Costco subwoofer?
You might argue that the Costco sub will have lousy power handling. If that's the case, buy four of them. That increases your SPL limit by 12db.
You might argue the Costco sub isn't as handsome as an audiophile sub. That may be true, so hide it! No one wants to look at three subs anyways.
You might argue that the Costco sub has lousy frequency response. While some cheap subs are designed with a hump in the midbass, there are plenty of inexpensive powered subs that measure well and have predictable crossovers and EQ built in.
Last but not least is price. Spending $750 on three Costco subs and pairing them with a $1200 kit seams reasonable. Spending $3000 on three boutique subs seems unnecessary with $1200 mains.
I've always been mystified by the use of exotic subwoofers in the home. In car audio, they make a lot of sense, because box size is king in mobile audio. Also, car subs function in "pressure mode" due to the small dimensions of the cabin. Exotic subs also make sense in pro audio, where dozens of subs are in play and each is being fed thousands of watts.
In the home, not so much. |
The Costco comment was perhaps somewhat facicious, but John, you get the point and I agree with you. The fact is that I don't use Costco subs, I use bigger units with higher power, BUT I don't use boutique subs just like you say. |
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| gedlee |
| quote: | Originally posted by MJL21193
HT is the ONLY place a subwoofer matters. You don't need one for music, providing you have real main speakers.
Good quality subs beat one note boom boxes and over eq'ed, over driven poop producers any day. |
I don't agree with this and obviuosly neither do the reviewers of my rooms. |
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| MJL21193 |
| quote: | Originally posted by gedlee
I don't agree with this and obviuosly neither do the reviewers of my rooms. |
Which part? The need for a sub for music or the adequacy of the cheap HT in a box subs?
I have always had reasonably good speakers. I've had good subs and I've heard cheap ones. Music, IMO is best through 2 good speakers, ones that cover the frequency range. As it was intended to be. I turn off my sub for music. Likewise, I don't listen to music is surround.
As for HT, I'd rather no sub than a deficient one. |
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| publius |
| quote: | Originally posted by gedlee
Your discussion is all semantics to me. The output on the receiver is labeled "LFE", but yes in "stereo" it is a mono sub channel, but in DVD it is the LFE "PLUS" which means that LF energy from all channels is also sent to the LFE channel - an ideal situation for what I do. Different receivers do this differently but in mine I can set the LP frequency above 120 Hz in "PLUS" mode.
When you use multiple subs in a room with substantial LF damping there really aren't problem modes that need EQ. Only in a few cases have I found the need for EQ at these frequencies. |
Thank you Dr. G. Have you posted the frequency response of your room? I would be curious to see what response you have found to sound best. If not, could you describe it? E.g., do you shoot for dead flat response, rising response in the bass with a 5db peak around 50hz and rolled off below that, etc. |
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| gedlee |
| quote: | Originally posted by publius
Thank you Dr. G. Have you posted the frequency response of your room? I would be curious to see what response you have found to sound best. If not, could you describe it? E.g., do you shoot for dead flat response, rising response in the bass with a 5db peak around 50hz and rolled off below that, etc. |
I go between perfectly flat and about a 2 dB rise at maybe 50 Hz. Some rooms sound different than others, but in general I would say flat is best unless you have a notable lack of bass. If I can dig up my room response I will post it.
I believe, as many others have noted, that true CD sounds bright if EQ'd perfectly flat to 16 kHz. I drop this by a few dB at the top with the curtains that I use in front of the speakers and this seems to yield the best results. If you don't use curtains and you don't use a treble control and you use a flat EQ in the crossover, I guarantee you that you will find this bright as we are just not used to hearing wide coverage at 10 kHz. |
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| gedlee |
| quote: | Originally posted by MJL21193
Which part? The need for a sub for music or the adequacy of the cheap HT in a box subs?
I have always had reasonably good speakers. I've had good subs and I've heard cheap ones. Music, IMO is best through 2 good speakers, ones that cover the frequency range. As it was intended to be. I turn off my sub for music. Likewise, I don't listen to music is surround.
As for HT, I'd rather no sub than a deficient one. |
No one is suggesting using totally incompetent subs. Even the Costco ones are Infinity and Klipsch, not junk.
But only two source locations for the low end will not yield a very good response and then these mains need to be huge to go low enough. The two speaker approach is just not optimum, even for stereo. |
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| MJL21193 |
| quote: | Originally posted by gedlee
But only two source locations for the low end will not yield a very good response and then these mains need to be huge to go low enough. The two speaker approach is just not optimum, even for stereo. |
Funny, but it works for me. Mains don't need to be huge. I have three way speakers with fairly good low end response, fairly good efficiency and capable of fairly high SPL. They sound great for music, and I do like it loud.
By themselves they don't cut it for HT though.
For HT, there is not enough bass production. Also, we need a centre channel and rear surrounds. But, this is HT, not music.
It just seems like your system is optimized for HT, not for music. |
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| gedlee |
| quote: | Originally posted by MJL21193
It just seems like your system is optimized for HT, not for music. |
Thats not what the reviews say. Read them!
REDWINGS RULE!!!! |
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| limono |
Can't we just focus for now on DIY speaker kit which will be 10" with 80-100Hz bottom and options and leave the Summa or 12" 15" out of it? When the first batch will be delivered and when the first (beta??) testers are going to write or report on the sound?
Is there a prototype to listen too? I do like an idea of a curtain at a front of a speaker (it solves speaker finish problem too;)
Regards, L |
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| salas |
| quote: | Originally posted by gedlee
I go between perfectly flat and about a 2 dB rise at maybe 50 Hz. Some rooms sound different than others, but in general I would say flat is best unless you have a notable lack of bass. If I can dig up my room response I will post it.
I believe, as many others have noted, that true CD sounds bright if EQ'd perfectly flat to 16 kHz. I drop this by a few dB at the top with the curtains that I use in front of the speakers and this seems to yield the best results. If you don't use curtains and you don't use a treble control and you use a flat EQ in the crossover, I guarantee you that you will find this bright as we are just not used to hearing wide coverage at 10 kHz. |
Maybe you use a -2 db slide from 2k to 10k? That sounds good in general. |
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| publius |
| quote: | Originally posted by Ric Schultz
Earl,
Very interesting stuff. The DDS ENG 1-90 Pro waveguide is mentioned a lot for its good sound. Did you design it? Someone mentioned you did. What do you think of it? How low can it xover well? How does it compare with your waveguides? Thanks. |
it loses directional control around 1.5k.
http://htguide.com/forum/showpost.p...3&postcount=274
From what people say, it performs okay, but is a little small for a nice cross to 15" or 12" woofer. Dr. G's will probably be better. |
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| publius |
Dr. G.:
The off-axis plot at the bottom of these pages (which are amazing btw) show the ESP15 has a dip around 1.4khz that gets worse further off-axis and is not present on the ESP10 plot. What is causing that? Is it that the ESP15 could benefit from a slightly larger waveguide or is it something else?
http://www.ai-audio.com/products_esp15.html
http://www.ai-audio.com/products_esp10.html
Also, the off-axis plots on the ESP15 are flat from 1.2khz up, while on the ESP10, they are flat from about 2khz up. What effect does this have on how these two speakers sound? |
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| AJinFLA |
| quote: | Originally posted by nycavsr2000
Will better electronics make a better listening experience? Perhaps.
Anand. |
Better..?? Better how?
cheers,
AJ |
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| gedlee |
| quote: | Originally posted by publius
Dr. G.:
The off-axis plot at the bottom of these pages (which are amazing btw) show the ESP15 has a dip around 1.4khz that gets worse further off-axis and is not present on the ESP10 plot. What is causing that? Is it that the ESP15 could benefit from a slightly larger waveguide or is it something else?
http://www.ai-audio.com/products_esp15.html
http://www.ai-audio.com/products_esp10.html
Also, the off-axis plots on the ESP15 are flat from 1.2khz up, while on the ESP10, they are flat from about 2khz up. What effect does this have on how these two speakers sound? |
I described this before. The ideal waveguide would be more like 18" across. This would elliminate the midrange narrowing that you are talking about.
I seldom if ever make subjective comments. But having listened to the SUMMAs for five years now and comparing them to other speakers and the reviews of other listeners, I'd put those speakers up against any speaker at any price. I have had, at most an hour or two listening to the ESP10 and ESP12. They are more similar to the 15 than different, but they are not quite as "smooth" as the 15. This is reflected in the measurements. Bigger is better in speakers. You want that "ultimate sound" it takes a big speaker and a bit of money. |
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| gedlee |
| quote: | Originally posted by limono
Can't we just focus for now on DIY speaker kit which will be 10" with 80-100Hz bottom and options and leave the Summa or 12" 15" out of it? When the first batch will be delivered and when the first (beta??) testers are going to write or report on the sound?
Is there a prototype to listen too? I do like an idea of a curtain at a front of a speaker (it solves speaker finish problem too;)
Regards, L |
I don't see any reason not to discuss the bigger speaker options.
I am casting the first waveguides this week. The first deleiveries could be next week.
I will probably havea pair here to audition by next week. But they won't have the advantage of the room that the Summas are in. I'm not giving up my SUMMAs!!
Oh, and for a name I'm going to use Nathan10, Abbey12 and Lidia15. Summas will always be the composite cabinet models. There maybe an Abbey plus, 1 12" woofer and 15" waveguide. |
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| MEH |
| Am I reading you correctly, Earl, that in addition to Nathan10 kits, you have now changed your plans and will definitely offer Abbey12 and Lidia15 kits? Or are these still just possibilities awaiting the success of the Nathan10 kits before becoming reality? If the larger waveguide kits are a definite go, do you have any estimate for when they will be available and at what initial price? |
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| gedlee |
| quote: | Originally posted by MEH
Am I reading you correctly, Earl, that in addition to Nathan10 kits, you have now changed your plans and will definitely offer Abbey12 and Lidia15 kits? Or are these still just possibilities awaiting the success of the Nathan10 kits before becoming reality? If the larger waveguide kits are a definite go, do you have any estimate for when they will be available and at what initial price? |
I'd say based on response, the 12" is s deffinite go, I've already started on that one, but the Lidia15 is probably down for the count. No one has shown an interest in that size. There might be an Abbey_plus, a 12" woofer and 15" waveguide. There is a little interest in that, but not enough right now for me to commit to it. |
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| mike galusha |
| quote: | Originally posted by gedlee
I'd say based on response, the 12" is s deffinite go, I've already started on that one, but the Lidia15 is probably down for the count. No one has shown an interest in that size. There might be an Abbey_plus, a 12" woofer and 15" waveguide. There is a little interest in that, but not enough right now for me to commit to it. |
I'm very much interested in the possibility of the Abbey_plus, enough to send in a deposit to get in the queue. Would you want the same $200 per unit as a deposit/earnest money? If not what will the number be? I suspect the final cost isn't known yet but at this point it's the seed number that matters. :) |
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| gedlee |
| quote: | Originally posted by mike galusha
I'm very much interested in the possibility of the Abbey_plus, enough to send in a deposit to get in the queue. Would you want the same $200 per unit as a deposit/earnest money? If not what will the number be? I suspect the final cost isn't known yet but at this point it's the seed number that matters. :) |
I hate to take a deposit on this model as I'm not sure of if or when. Stay in touch though. |
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| nullspace |
Hi Earl --
I'd be interested in the Abbey_plus as well.
Regards,
John |
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| tinitus |
I suppose you know allready that the suggested 200USD would be fore a single waveguide only ... well, I might be in fore a pair :)
We have to make Earl sign them, as they may become collectors items some day :cool: |
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| gedlee |
| A word of warning: I may stop selling only waveguides as I might not be able to keep up with full kits and they will take priority. |
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| mike galusha |
Thanks for the update Earl, I'll definitely stay tuned.
And I was hoping for a full kit for the Abbey_plus. :) |
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| MEH |
| quote: | Originally posted by gedlee
I'd say based on response, the 12" is s deffinite go, I've already started on that one, but the Lidia15 is probably down for the count. No one has shown an interest in that size. There might be an Abbey_plus, a 12" woofer and 15" waveguide. There is a little interest in that, but not enough right now for me to commit to it. |
Please help me out, Earl, because I'm not fully understanding the attraction of Abbey_plus. I'm guessing that a fair approximation of the Abbey_plus performance can be made by essentially grafting the <1kHz portion of the ESP12 measurements to the >1kHz portion of the ESP15 measurements. Close enough, or am I missing something? If that is the case, then it seems clear to me that Abbey_plus will not measure equal to or better than Lidia15, and may also sound perceptibly inferior. To me that means that the significant potential advantages of Abbey_plus are predominantly in size and price, not sound quality when compared to Lidia15. That, of course, raises two immediate questions: 1) Will a 15" waveguide paired with a 12" woofer really result in a package significantly smaller than a 15" waveguide paired with a 15" woofer? 2) Will a 15" waveguide paired with a 12" woofer really result in a package significantly less expensive than a 15" waveguide paired with a 15" woofer?
I'd appreciate it if you could answer those questions with some real numbers, because without those numbers it is hard to evaluate just how much is being traded-off in going from Lidia15 to Abbey_plus, whether Abbey_plus really makes sense, or whether Lidia15's better measured performance is actually worth a little more size and a little more expense. |
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| gedlee |
| quote: | Originally posted by MEH
Please help me out, Earl, because I'm not fully understanding the attraction of Abbey_plus. I'm guessing that a fair approximation of the Abbey_plus performance can be made by essentially grafting the <1kHz portion of the ESP12 measurements to the >1kHz portion of the ESP15 measurements. Close enough, or am I missing something? If that is the case, then it seems clear to me that Abbey_plus will not measure equal to or better than Lidia15, and may also sound perceptibly inferior. To me that means that the significant potential advantages of Abbey_plus are predominantly in size and price, not sound quality when compared to Lidia15. That, of course, raises two immediate questions: 1) Will a 15" waveguide paired with a 12" woofer really result in a package significantly smaller than a 15" waveguide paired with a 15" woofer? 2) Will a 15" waveguide paired with a 12" woofer really result in a package significantly less expensive than a 15" waveguide paired with a 15" woofer?
I'd appreciate it if you could answer those questions with some real numbers, because without those numbers it is hard to evaluate just how much is being traded-off in going from Lidia15 to Abbey_plus, whether Abbey_plus really makes sense, or whether Lidia15's better measured performance is actually worth a little more size and a little more expense. |
You are mostly correct, but posting real numbers is not something that I am prepared to do for a hypothetical situation. I can mate the twelve with 15" waveguide in a simulation, but its different than simply matching the ESP15 > 1 khz to the ESP12 < 1 kHz. Thats only a rough approximation of what really happens.
The Abbey_plus WOULD NOT BE significantly smaller than a Lidia15. The Abbey_plus would be a little less expensive than the Lidia15. The actual numbers here are irrelavent until such time as I decide to actually make a 15" mold. The 15" waveguide is a lot bigger than the 10" and much more difficult to fabricate. The ability to do it myself within my resources is questionable. Having it done elsewhere makes the cost prohibitive.
I ruined my first 10" mold and now I am making two more. But that delayed me a couple of weeks.
The biggest problem with the ESP15 is its size, and the narrowing of the polar response at 1500 Hz. The 12" woofer in a new enclosure helps out both these problems a great deal. But yes, the 12" woofer has some problems that we don't see in the 15". Which is the better tradeoff is not clear and I would not do an Abbey_plus if it is not better than the Abbey. But the bottom line is that the Lidia15 is unlikely to have much appeal to most people. My idea is to keep the Summa available for those people who really want the best - and are willing to pay for it. Maybe a kit - but the enclosure price quadruples when it molded in glass. |
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| MEH |
| quote: | Originally posted by gedlee
But the bottom line is that the Lidia15 is unlikely to have much appeal to most people. |
If we accept that as true, I guess I'm having a hard time figuring out why Abbey_plus would be any more appealing. You say there would be no great difference in size between Lidia15 and Abbey_plus, and only a small difference in price, so just what consumer fault does Lidia15 suffer from that Abbey_plus does not? Why might you choose to offer an Abbey_plus kit and not a Lidia15 kit? I just don't get it. |
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| gedlee |
| quote: | Originally posted by MEH
If we accept that as true, I guess I'm having a hard time figuring out why Abbey_plus would be any more appealing. You say there would be no great difference in size between Lidia15 and Abbey_plus, and only a small difference in price, so just what consumer fault does Lidia15 suffer from that Abbey_plus does not? Why might you choose to offer an Abbey_plus kit and not a Lidia15 kit? I just don't get it. |
If only one of the two is offered, as is likely, then the one with the greater appeal makes the most sense. Thats going to be the smaller and cheaper one. Whats hard to understand?
And, as I said, I have molds for the full Summa if thats what a customer wants, but then its a big jump in size and price. |
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| Patrick Bateman |
Here's some food for thought.
The Summa uses a 15" woofer and a 15" waveguide because this combination is ideal when crossing over from the waveguide to the woofer. The ESP10 uses a 10" waveguide and a 10" woofer for the same reason. Yet there's nothing to stop you from putting the *woofer* in a waveguide. For example, you could use a 15" waveguide with a 12" woofer which is ALSO mounted on a waveguide.
One option I'd considered was an eight inch woofer in a 15" waveguide, paired with a compression driver on a 15" waveguide. This combination wouldn't have the sensitivity of the "real" Summa, due to the inefficiency of the woofer. But the use of an eight inch woofer would simplify the crossover, and would be significantly cheaper. (The woofer in the Summa is uber-expensive.) |
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| gedlee |
| quote: | Originally posted by Patrick Bateman
Here's some food for thought.
The Summa uses a 15" woofer and a 15" waveguide because this combination is ideal when crossing over from the waveguide to the woofer. The ESP10 uses a 10" waveguide and a 10" woofer for the same reason. Yet there's nothing to stop you from putting the *woofer* in a waveguide. For example, you could use a 15" waveguide with a 12" woofer which is ALSO mounted on a waveguide.
One option I'd considered was an eight inch woofer in a 15" waveguide, paired with a compression driver on a 15" waveguide. This combination wouldn't have the sensitivity of the "real" Summa, due to the inefficiency of the woofer. But the use of an eight inch woofer would simplify the crossover, and would be significantly cheaper. (The woofer in the Summa is uber-expensive.) |
John
The part of this that doesn't work for me is that the waveguide would be very short in your example. That makes it kind of unpredictable. The idea could work, but I would suspect that the development to successful implimentation would be massive.
A direct radiator on a waveguide does not have a match to the wavefront that the waveguide wants to see so there will be a lot of HOMs generated. Now in a long horn the HOM do not propagate very far if they are below cutoff. So in a long waveguide the HOM fall off below cutoff to zero, but in a short horn they could reach the mouth as what is called evanescent waves (which deacy exponentially). Bottom line here is that it is just not prediactable what the directivity of a short waveguide on a smaller direct radiating driver would be. A piston driver is highly predictable.
Trial and error could develop this to being a viable approach, but I suspect that it would be a lot of iterations to get it right. First pass success would be shear luck. Development time for a product is the single biggest cost, although the costs of making all those waveguides would also be substantial.
I've thought of this concept myself before, but the development issues scared me away.
I also know how to correct the axial hole in the waveguide, but once again development costs prevent my pursuing that.
A classic example is the new "Arial", its been over a year and nothing has yet been built and tested. I suspect that with usual development iterations it will be another couple of years before we have succesful results from this endeavor.
There is no end of the things that we can "try", but the smart engineer stays fairly close to what he knows "works". Each modification is one step better and in that way we can get to an ideal. The problem here is that big companies, who can readily do this kind of advanced development, don't take any risks and aren't really interested in progress, only profits. The very real problem is that development in a product like loudspeakers is not going to be very fast and sometimes not even at all.
Elliminate the Summas and how much change has there been in the loudspeaker market? Not much. Does that imply that they can't be improved. Hardly. It implies that there is no interest in improving them. |
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| MEH |
| quote: | Originally posted by gedlee
Thats going to be the smaller and cheaper one. Whats hard to understand? |
What is hard to understand is that when I previously asked you whether Abbey_plus would be significantly smaller or cheaper than Lidia15, you said "Abbey_plus WOULD NOT BE significantly smaller than a Lidia15" and "Abbey_plus would be a little less expensive than the Lidia15." As I said before, it is very hard to get a sense of the relative trade-offs with no numbers to work with, but the preference for Abbey_plus over Lidia15 still remains hard for me to understand. If the customer/DIY-builder wants smaller and cheaper, there's Nathan10. If he wants something else, it seems to me most likely that he is willing to accept larger size and somewhat higher price in order to get better sound quality. If Lidia15 is comparable in size to Abbey_plus and not significantly more expensive than Abbey_plus, it doesn't make sense to me that the better measuring Lidia15 would be much less attractive to that I-don't-want-Nathan10 builder than would be Abbey_plus.
At this point I can only make sense of your claims with some combination of the following four: 1) My own sense of value is wildly at odds with most other DIY builders; 2) Abbey_plus really would be significantly smaller than Lidia15; 3) Abbey_plus really would be significantly less expensive than Lidia15; 4) Lidia15 really wouldn't measure any better than Abbey_plus; rather, the two would have similar magnitude variations in frequency response and directivity, just at different frequencies. I must confess that I don't have much of a clue which of these four is the dominant factor making Abbey_plus more attractive than Lidia15 in your estimation of likely customer preferences. |
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| gedlee |
| quote: | Originally posted by MEH
At this point I can only make sense of your claims with some combination of the following four: 1) My own sense of value is wildly at odds with most other DIY builders; 2) Abbey_plus really would be significantly smaller than Lidia15; 3) Abbey_plus really would be significantly less expensive than Lidia15; 4) Lidia15 really wouldn't measure any better than Abbey_plus; rather, the two would have similar magnitude variations in frequency response and directivity, just at different frequencies. I must confess that I don't have much of a clue which of these four is the dominant factor making Abbey_plus more attractive than Lidia15 in your estimation of likely customer preferences. |
Its 1) and 4). I already said that 4 would likely be the case. 1) comes from experience - what customers say they want and what they will actually put down their money to get are usually two vastly different things. I am not willing to take the financial risk on the Lidia15s until I know that I won't be loosing money. DIYs don't particularly care about loosing money - especially not mine. |
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| MEH |
Thanks, Earl, now it makes better sense. If, in terms of sound quality, Abbey_plus isn't so much inferior as just different from Lidia15 while at the same time being a bit cheaper, then it finally makes sense to me to bias your decision toward Abbey_plus.
Two last questions, then I promise I'll shut up for a while. 1) What do you anticipate that the sensitivity of Abbey_plus will be? 2) Is there anything to be gained in a Nathan_plus (12" waveguide/10" woofer) or Nathan_minus (10" waveguide/8" woofer)? |
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| gedlee |
| quote: | Originally posted by MEH
Thanks, Earl, now it makes better sense. If, in terms of sound quality, Abbey_plus isn't so much inferior as just different from Lidia15 while at the same time being a bit cheaper, then it finally makes sense to me to bias your decision toward Abbey_plus.
Two last questions, then I promise I'll shut up for a while. 1) What do you anticipate that the sensitivity of Abbey_plus will be? 2) Is there anything to be gained in a Nathan_plus (12" waveguide/10" woofer) or Nathan_minus (10" waveguide/8" woofer)? |
Nothing is ever gained from going smaller. A Nathan_plus is a cool idea! Once I have a 12" mold this is pretty easy to do
:) |
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| MEH |
| quote: | Originally posted by gedlee
Nothing is ever gained from going smaller. |
I thought we just got done discussing that by going to a smaller woofer than Lidia15, Abbey_plus is a net gain (comparable sound quality, lower price)?
Yeah, I lied. Shoot me. |
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| JoshK |
Just a random thought...a bit OT, but not too much...
Ever considered making a milled throat piece for your waveguides out to say 4" (or whatever gets you to say some episilon from 45º)? The throat piece could be milled from aluminum or something of that nature and have ready made driver attachements. Then the throat could match up to whatever size waveguide you wanted. You'd still need a mold but it would be more interchangeable, etc. |
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| pooge |
| quote: | Originally posted by JoshK
Just a random thought...a bit OT, but not too much...
Ever considered making a milled throat piece for your waveguides out to say 4" (or whatever gets you to say some episilon from 45º)? The throat piece could be milled from aluminum or something of that nature and have ready made driver attachements. Then the throat could match up to whatever size waveguide you wanted. You'd still need a mold but it would be more interchangeable, etc. |
Same asked in
previous post |
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| gedlee |
| quote: | Originally posted by MEH
I thought we just got done discussing that by going to a smaller woofer than Lidia15, Abbey_plus is a net gain (comparable sound quality, lower price)?
Yeah, I lied. Shoot me. |
The gain is in size and price for equivalent performance, but I doubt that woofer smaller than the 12" would yield the same benefit. |
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| chrisb |
| quote: | Originally posted by chrismercurio
I kindly disagree.
IMO, you are better off having NO center channel and sending that information to the LR's than fruitlessly spending money on a speaker that will be oriented incorrectly. This causes detrimental lobing effects, comb filtering, and frequency response anomalies that have nothing to do with the Speaker Dr Geddes has engineered.
It is (one of) the greatest pieces of misinformation that marketing people have provided to the public at large that laying an MTM loudspeaker is OK. Center channels are "supposed" to widen the sweet spot and listening area over a wider space. Laying a speaker on it's side that was not designed for it actually hinders this concept.
Please, save your money and your ears.
Chris |
While I tend to agree with Chris, for those feeling cheated by missing the full home theater multi-channel experience, there is another option.
If the room is wide enough, run an identical pair of enclosures immediately flanking the screen, and wired in mono. The phantom image created will be centered both horizontally and vertically. The trick of course is to maintain the same timbral and dynamic characteristics of the mains, while avoiding the temptation to downsize this pair to fit the room aesthetics / space.
Of course it would be nice to have a pro-grade projector and acoustically perforated screen to allow placement of the entire audio front row out of sight, but few of us have that option. |
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| gedlee |
| quote: | Originally posted by chrisb
While I tend to agree with Chris, for those feeling cheated by missing the full home theater multi-channel experience, there is another option.
If the room is wide enough, run an identical pair of enclosures immediately flanking the screen, and wired in mono. The phantom image created will be centered both horizontally and vertically. The trick of course is to maintain the same timbral and dynamic characteristics of the mains, while avoiding the temptation to downsize this pair to fit the room aesthetics / space.
Of course it would be nice to have a pro-grade projector and acoustically perforated screen to allow placement of the entire audio front row out of sight, but few of us have that option. |
How is running an second pair of speakers on the side any different than using phantom mode? Its the same thing.
"acoustically perforated screen to allow placement of the entire audio front row out of sight" - you mean a bed sheet of course, but why is that not an option? I built a friend an 8 foot screen with a project (720p) for less than $1000. Thats less than a cheap small LCD. Forget about the "pro" projectors. Just get an Optoma in your price range and go to the linens goods store for a $20 screen. AND STAY AWAY FROM SALESMEN! |
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| MJL21193 |
| quote: | Originally posted by chrisb
If the room is wide enough, run an identical pair of enclosures immediately flanking the screen, and wired in mono. The phantom image created will be centered both horizontally and vertically. |
Hi Chris,
I like this idea on two levels: 1/ It's an elegant solution and 2/ it's an excuse to build another speaker. :up: |
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| MJL21193 |
| quote: | Originally posted by gedlee
How is running an second pair of speakers on the side any different than using phantom mode? Its the same thing.
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You send the centre channel to both speakers. ;) |
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| chrisb |
Earl, not all of us have domestic partners understanding enough to tolerate the bedsheet screen
not in my room you don't, dear
And not to make light of the suggestion, but how much would the thread count affect the acoustic transparency? i.e. the coarser (and cheaper) the better? |
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| chrisb |
| quote: | Originally posted by MJL21193
You send the centre channel to both speakers. ;) |
oops, I forgot to type that, and thought it obvious. see what "assume" can do? |
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| gedlee |
| quote: | Originally posted by MJL21193
You send the centre channel to both speakers. ;) |
But thats what "Phantom mode does!!" I must be missing something or you guys are. If I send the center channel signal to both left and right speakers then the phantom image is dead centered. |
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| gedlee |
| quote: | Originally posted by chrisb
Earl, not all of us have domestic partners understanding enough to tolerate the bedsheet screen
not in my room you don't, dear
And not to make light of the suggestion, but how much would the thread count affect the acoustic transparency? i.e. the coarser (and cheaper) the better? |
I don't get it. Your wife doesn't like movies? She likes small screens? My wife uses the theater just as much as I do. How is a TV any better looking than a screen? What am I missing here? My friends wife loved the theater, and most of all she loved the price.
If looking at small screens with poor sound is your idea of entertainment then I guess thats up to you. The money that I save NOT going to a theater for good viewing easily paid for all the equipment in a year or two. Movies on a small TV just don't do it for me. Sorry.
I mean if you live in a very small appartment with only one room or two then you do have a problem - you have the wrong hobby, but other than that I just can't see how my approach is not possible. Its worked well for everyone that I've done it for. One guy even did it in his one bedroom apartment. |
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| chrisb |
| quote: | Originally posted by gedlee
I don't get it. Your wife doesn't like movies? She likes small screens? My wife uses the theater just as much as I do. How is a TV any better looking than a screen? What am I missing here? My friends wife loved the theater, and most of all she loved the price.
If looking at small screens with poor sound is your idea of entertainment then I guess thats up to you. The money that I save NOT going to a theater for good viewing easily paid for all the equipment in a year or two. Movies on a small TV just don't do it for me. Sorry.
I mean if you live in a very small apartment with only one room or two then you do have a problem - you have the wrong hobby, but other than that I just can't see how my approach is not possible. Its worked well for everyone that I've done it for. One guy even did it in his one bedroom apartment. |
There is of course no "correct" reply to any of this, nor if I may say so without petulance, is there the need for any of us to justify the degree to which we pursue the goals of our entertainment.
Like many forum posters, I've played in this sandbox for most of my life (over 40yrs), and have had the opportunity to own an experience a wide range of gear, name dropping from the list is totally pointless.
Are my expectations different from those of yourself and your clients? Apparently - but never have I had as much fun listening or tinkering as in the past 5yrs. So, no this hobby is not wrong for me - indeed it has never been more right.
If it matters, I don't reside in an apartment. There are a couple of TV's in the house, the most recent upgrade was a 42" HD Plasma - just the right size for the room decor, and good enough for me -and no we don't watch a lot of movies. Indeed since installing the HD cable box over a year ago, the DVD player hasn't even been plugged in. My wife has a very stressful job, and would far rather be in the garden or doing yoga in her personal time than investing the emotional energy required to fully enjoy the home theatrical experience. For her TV is mostly pre-bedtime hypnotherapy, and I've certainly learned to give her that time & space. |
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| chrisb |
| quote: | Originally posted by gedlee
But thats what "Phantom mode does!!" I must be missing something or you guys are. If I send the center channel signal to both left and right speakers then the phantom image is dead centered. |
um, isn't that exactly where it should be? Perhaps you missed that we were talking specifically about creating a phantom with the Center Channel of the front 3 - the L&R mains are still used as well * (so there are indeed 4 speakers on the front row, plus as many subs as the room requires, plus the surrounds, et al)
Every conversation I've ever heard on the subject of location of a CC enclosure relates to the compromises derived from placement on a different vertical plane than the main L&R channels.
Of course, after about 5yrs of trying to tolerate a 5.1system, I trashed it all in favor of HT2.0 (i.e. vanilla stereo) - with teeny little FR drivers to boot, so we're obviously talking a different language.
* edited for "clarification" - at least I thought it was
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| MJL21193 |
| quote: | Originally posted by gedlee
But thats what "Phantom mode does!!" I must be missing something or you guys are. If I send the center channel signal to both left and right speakers then the phantom image is dead centered. |
My setup has the centre channel going to the centre channel speaker. This is currently on a 5 gallon paint bucket, in front of the equipment unit that has the TV on top.
I wouldn't even consider sending centre channel to the left and right mains.
With 2 centre channel speakers, one on either side of the screen, the image is projected to the centre of the screen. Beautiful!
| quote: | Originally posted by gedlee
I don't get it. Your wife doesn't like movies? |
The words out of my first wifes mouth would be: "not in my room you don't, Fokker. What's next? Confederate flags as window curtains??"
:joker: |
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| Pallas |
| quote: | Originally posted by chrisb
[B]If the room is wide enough, run an identical pair of enclosures immediately flanking the screen, and wired in mono. The phantom image created will be centered both horizontally and vertically. The trick of course is to maintain the same timbral and dynamic characteristics of the mains, while avoiding the temptation to downsize this pair to fit the room aesthetics / space. |
That sounds like a really bad solution to me, on sonic, aesthetic, and budgetary grounds. Sonically, two speakers doing the same thing in close proximity can only lead to comb filtering and an attendant narrowing of the sweet spot. Sure, it might sound better than a toppled-MTM center, but realistically, what doesn't sound better than a toppled-MTM center?
Aesthetically, it means yet another big box in front. Who wants that?
Budget-wise, there's that whole superfluous speaker to build.
So I wouldn't do double-centers under any circumstances I can conceive.
I don't know if it'll work as well with Dr. Geddes' kits as it does with the speakers I use - 12" Tannoy Dual Concentrics, though I wouldn't be using those if the Nathan10 kit had come out ~18mos ago! - and I'll leave that to people who have measured and heard the design to answer, but what I do is to have all three front speakers up high. The midpoint of my Duals is roughly 60" off the ground, and the TV* fits nicely just under and slightly behind the bottom of my center channel's baffle. The image doesn't sound like it's way above my head, and as an added bonus the highs sound just as good when I'm standing as when I'm sitting.
But I also have a question for Dr. Geddes. Admittedly, this thread might not be the right place to ask, but it has the virtue of having your attention. I'm curious about your use of bandpass subs. Assuming your subs are as big as the AI ones, that makes each of them larger than my sealed ULF sub, which uses an 18" driver in a closed 24" cube. Moreover, one of AA bandpass subs is bigger than all three of the 12" + 12" passive radiator subs I am planning to build (I have the parts on hand from a previous project) to smooth out room response in my room, to be placed per your guidance on a couple threads here. (Big one in the corner, others placed randomly, as far apart from each other as possible with one above the floor-ceiling centerline.) Are there audible benefits to using bandpass subs thusly (as opposed to sealed/vented), beyond the built-in top end rolloff and possibly the efficiency gain? Moreover, were I to make my "BB" subs bandpass designs, it seems they would be much bigger than the PR designs, with lesser extension and only a little bit more efficiency. (At least 4th order; I don't know of a Mac-compatible program that will model 6th order bandpasses.) In addition to the receiver's crossover, the amps I use have a DSP built in that provides flexible crossovers, shelf-filters, and 5 or 6 bands of parametric EQ for each driver, so shaping the top end of the "BB" subs' response is pretty easy. The drivers themselves (Peerless's XLS12, aka 830500) are low-inductance and have clean measured performance to ~500Hz, so I'm not convinced that distortion would be much reduced with a bandpass enclosure, either. (Though I could be wrong.) Still, is there an important part of the picture I'm missing that makes bandpass enclosures a superior choice for a multichannel music system that occasionally is used to watch movies and such?
*Said TV is a 46" Sony LCD. The right-side wall of my living/listening room of my condo has a double-door to a balcony that's usually only partially draped. I borrowed a decent projector from a friend and tried it with with a sheet before buying it but even in daylight CNN viewing. Maybe something coarser than the Frette I ripped from atop my bed would've done better, but it was really washed out. The LCD does fine day or night, and though it's 2+ feet smaller than the THX screen size recommendation it seems sufficient to me. |
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| gedlee |
| quote: | Originally posted by chrisb
There is of course no "correct" reply to any of this, nor if I may say so without petulance, is there the need for any of us to justify the degree to which we pursue the goals of our entertainment.
Are my expectations different from those of yourself and your clients? Apparently - but never have I had as much fun listening or tinkering as in the past 5yrs. So, no this hobby is not wrong for me - indeed it has never been more right.
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I meant no disrespect to your lifestyle decisions, but then your original comment "Earl, not all of us have domestic partners understanding enough to tolerate the bedsheet screen" wasn't really the point, was it? You aren't interested in Home Theater, thats the issue. If you and your wife were interested then there are very practical solutions as I pointed out. If your not interested thats fine too. But MY wife has nothing to do with it either way. |
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| chrisb |
| quote: | Originally posted by Pallas
That sounds like a really bad solution to me, on sonic, aesthetic, and budgetary grounds. Sonically, two speakers doing the same thing in close proximity can only lead to comb filtering and an attendant narrowing of the sweet spot. |
At what frequencies would drivers separated by the width of a "big" screen start to develop these issues?
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Sure, it might sound better than a toppled-MTM center, but realistically, what doesn't sound better than a toppled-MTM center? |
no argument there
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Aesthetically, it means yet another big box in front. Who wants that?
Budget-wise, there's that whole superfluous speaker to build.
So I wouldn't do double-centers under any circumstances I can conceive.
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Perhaps since the CC doesn't have the same spectral power requirements as the mains, they wouldn't have to be as large, and since this is a DIY forum, as John said earlier, I personally never overlook an excuse to build another enclosure.
but enough OT prattling from me |
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| Pallas |
| quote: | Originally posted by chrisb
[B]
At what frequencies would drivers separated by the width of a "big" screen start to develop these issues? |
That would depend, of course, on the width by which the drivers reproducing the same spectrum are separated. But generally, probably starting in the lower mids.
| quote: | Originally posted by chrisb
[B] Perhaps since the CC doesn't have the same spectral power requirements as the mains, they wouldn't have to be as large, and since this is a DIY forum, as John said earlier, I personally never overlook an excuse to build another enclosure. |
The center, if anything, has greater demands placed on it than the left and right speakers. And I don't see why one would possibly want to build non-identical speakers up front, assuming a coherent sonic image is the goal. Should the left and right speakers be of different designs, too?
And the way I see it, the more building one does the less listening one can do. |
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| gedlee |
| quote: | Originally posted by Pallas
That sounds like a really bad solution to me, on sonic, aesthetic, and budgetary grounds.
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I agree, but I'm done arguing this point.
| quote: | Are there audible benefits to using bandpass subs thusly (as opposed to sealed/vented), beyond the built-in top end rolloff and possibly the efficiency gain?
[b] |
I would think those attributes sufficient, but its LF extension that is more my reason for using them.
| quote: | [b]
Moreover, were I to make my "BB" subs bandpass designs, it seems they would be much bigger than the PR designs, with lesser extension and only a little bit more efficiency. (At least 4th order; Still, is there an important part of the picture I'm missing that makes bandpass enclosures a superior choice for a multichannel music system that occasionally is used to watch movies and such?
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I have not found it possible to make a smaller sub than bandpass that operates over the same bandwidth - assuming a given driver of course. Remember that a bandpass designs response is symmetrical about the drivers Fs in its rear box, but a ported or PR system has the drivers Fs at the lower edge. Thus the bandpass will virtually always go further down in frequency than the ported solution for the same total volume. This is what I have found. The bandpass in this configuraton tends to be less efficient than the ported, but its -6dB point is lower. Its the bandwidth extension that I am looking for not the efficiency. I use several subs so efficiency is not a big deal. Wide bandwidth with a low HP in a small box is where these designs work well.
An 8 ft^3 sub is pretty big. One of our BB subs is a 15 and is larger (about 2 ft^3), but the 12" sub is pretty small (maybe 1 ft^3). My recollection of the sizes and what you are saying don't seem to jib |
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| MJL21193 |
| quote: | Originally posted by Pallas
That would depend, of course, on the width by which the drivers reproducing the same spectrum are separated. But generally, probably starting in the lower mids. |
I doubt that. We aren't talking about 12" B&W TV here.
| quote: | Originally posted by Pallas
The center, if anything, has greater demands placed on it than the left and right speakers. And I don't see why one would possibly want to build non-identical speakers up front, assuming a coherent sonic image is the goal. Should the left and right speakers be of different designs, too?
And the way I see it, the more building one does the less listening one can do. |
This site is about building! Listening is a side benefit!
I don't believe the centre(s) need to be the same as the mains. The centre, IMO, needs to be especially good in the vocal range, and well placed. |
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| Pallas |
| quote: | Originally posted by gedlee
I would think those attributes sufficient, but its LF extension that is more my reason for using them. |
It also seems to me, though, that the port resonances are a big reason not to go that route. As I understand it, you use multiple ports of varying lengths to spread out the port resonances
| quote: | Originally posted by gedlee
[B]I have not found it possible to make a smaller sub than bandpass that operates over the same bandwidth - assuming a given driver of course. |
Hmm. Using the drivers I have on hand (Peerless's XLS12) the best 4th order BP design Unibox comes up with has a total volume of about 32.5L, F6's of about 25Hz and 90Hz, but exceeds xmax with 250W below 26Hz.
My passive radiator design (which, to be sure, is basically Peerless's design from their application note for this driver, but tuned a little lower) is 35L with an Fb of 20Hz. has a natively higher F6 (35Hz) but roughly the same modeled output with 250W at 30Hz (~104dB) and overall more area under the curve down to 20Hz, with the driver not reaching xmax until 16Hz with 250W and the PR hitting xmax at 24Hz. So, with the same power and an amp that provides shelf filters and parametric EQ bands, it would seem that the PR system could both go lower and get louder at LF before hitting xmax. Maybe I need to play with the BP parameters more, but it seems to me that, for this woofer at least, a PR might be the better option. (At least assuming one already has the PR's on hand, because with the dollar collapse and such Danish drivers have gotten pretty pricey.)
| quote: | Originally posted by gedlee
[B]An 8 ft^3 sub is pretty big. One of our BB subs is a 15 and is larger (about 2 ft^3), but the 12" sub is pretty small (maybe 1 ft^3). My recollection of the sizes and what you are saying don't seem to jib |
The AI website list all of the BB and ULF subs as measuring 31.5"H x 23.6" W x 23.6" D, though looking at the pictures that does not make any sense and on further reflection those specs are probably erroneously cut-and-pasted from the ULF18's dimensions. But those are the numbers I was using. If your 12" is about a cube, than each one would be smaller than what I was planning (1.25 ft^3). |
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| Pallas |
| quote: | Originally posted by MJL21193
I doubt that. We aren't talking about 12" B&W TV here. |
I know. The further apart the speakers are, the lower negative effects start. Look at the size of the wavelengths of different frequencies. Think about a toppled-MTM. They sound awful because two points are playing the same signal from different points. A typical 7" toppled-MTM probably has those two sources about a foot apart, and the power response starts to fall apart above ~1.5kHz. Put the sources closer together, and that point will go up. Spread them out, and it will go down. Fundamentally, there's no difference between having the two sources playing the exact same signal in one box (the toppled-MTM we both agree sucks) and putting them in different boxes.
| quote: | Originally posted by MJL21193
[B]I don't believe the centre(s) need to be the same as the mains. The centre, IMO, needs to be especially good in the vocal range, and well placed. |
All speakers need to be especially good in the vocal range, and well-placed! From my experience, even the better "matched" prefab home theater LCR sets (Paradigm, Revel, KEF, Tannoy, etc.) sound like incoherent mush compared to simply using three of the same speakers across the front. Even if the center is "better" than the mains. |
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| gedlee |
| quote: | Originally posted by Pallas
It also seems to me, though, that the port resonances are a big reason not to go that route. As I understand it, you use multiple ports of varying lengths to spread out the port resonances
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They can be in the ULF subs, but never in the BB subs.
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Hmm. Using the drivers I have on hand the best 4th order BP design Unibox comes up with has a total volume of about 32.5L, F6's of about 25Hz and 90Hz, but exceeds xmax with 250W below 26Hz.
The AI website list all of the BB and ULF |
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