I am game!
I agree
I have heard differences in all sound systems when I have moved farther away from the drivers. Should it be only a dB decrease?
I am not perceiving a complete frequency loss like doubtingthomas experienced... ...what I am perceiving is a slight detail loss in the mid-range along with a greater dB decrease relative to the treble, it must be in the 3dB range based on my current EQ settings. Could be a room node. I figured it is the farfeild sound - a law of physics we must work with. The only way to know for sure is to test it...
What do you use for a signal generater? Parts Express sells a Velleman kit for about forty dollars, but I have read that it is not suited for all applications. Any good PC based options? Suggestions anyone?
God Bless,
Allen
I agree
I have heard differences in all sound systems when I have moved farther away from the drivers. Should it be only a dB decrease?
I am not perceiving a complete frequency loss like doubtingthomas experienced... ...what I am perceiving is a slight detail loss in the mid-range along with a greater dB decrease relative to the treble, it must be in the 3dB range based on my current EQ settings. Could be a room node. I figured it is the farfeild sound - a law of physics we must work with. The only way to know for sure is to test it...
What do you use for a signal generater? Parts Express sells a Velleman kit for about forty dollars, but I have read that it is not suited for all applications. Any good PC based options? Suggestions anyone?
God Bless,
Allen
Nothing to lose
I will try that, it will only cost time as I have the hardware for that!
God Bless,
Allen
I will try that, it will only cost time as I have the hardware for that!
God Bless,
Allen
You can download an app for Iphone called Tonegen among others, I think mine was free, there is also free software on the net, i should say that I didn't get a complete frequency loss, but it was close.
Discovery #4 - part II
Good call, fastbike1! - you were right! I finally had a chance to down load a simple tone generater and play a chromatic scale off an old stereophile sampling CD I have. Bottom line: I have some room issues to address...
It may as well be, becuase I understand now, what you heard, it is flat out wrong sounding! Almost out of phase like, only on the listening couch mind you! In fact I huffed my couch out of the room to see if it was the cuase. I am relieved it was not, becuase I do like to sit on something! On the listening couch, or that area of the room, sounds in the 80hz thru 250 Hz region "phase out" I thought maybe this was my problem. This problem was fixed by moving the speakers closer to the TV. But I still notice a loss in detail and "body" in the midrange. To make sure it was indeed a room issue, I put on the TV speakers, and wouldn't you know it, it does the same thing! (just did not notice it, didn't put my heart and soul in that sound system!) So this is a room issue. If I move my couch 3 1/2 feet from the back wall, that problem is solved, and so is the bass node, reguardless of speaker placement. But having my couch 3 1/2 feet into the room is not practical, so I must find a way to deal with this problem. I do not desire to solve it electronically, becuase it is indeed acoustical. It must have something to do with the three walls behind and to the sides of the couch.
Just for the fun of it, I decided to entertain the 3 1/2 feet couch position... The detail and range balance is exceptional and the frontal sound stage is deep and wide. The only sonic shortcoming to this position is it does not have have that cool "behind you" type surround effect I get with the couch closer to the wall. So is that the comprimise, or can I have the best of both worlds? I will need to do a lot of research on room treatments to see what my options might be.
I have to say I have really been enjoying creating this PC based sound system. You can access test tones, scales. or a certain song in seconds and even have more then one item cued up. This is the way to go!
So how did Aveburys do with the chromatic Scale? Great, it is solid down to 40 Hz. It can play a 20 Hz tone, and I can feel it, but it is pretty soft, and think if that low of a signal is important to you, you need a sub-woofer, or move these cabinets right against the wall and EQ down your higher bass. I think it would be best to remove the bass content at about 35 Hz as I believe the lower stuff may cause more harm then good.
The horn plays up to about 250 Hz, there may be a little higher, but hard to tell without setting these up in a padded room. At 200 Hz the horn is putting out about as much sound as the speaker itself, and at 100 Hz, most of the sound is coming form the back and a little from the speaker. Lower then that, the sound is "percievable" at the speaker, but all of what is heard and felt comes out of the horn. I am sorry I do not have a measurement system yet, but this at least give you a good idea of what these cabinets are designed to do. Well done, Scott!
I have a little concern in the 180 Hz thru 250 Hz area, where the front and back horn sounds could possibly interfere with each other. I am guessing this is what the stuffing in the horn throats is for? So Doubtingthomas and Dave, what does the stuffing in the throats do anyway?
I have learned a lot about how I hear and percieve sound aswell. The Aveburys play a chromatic scale relatively even. I hear minor peaks and dips, but nothing significant. I far as I am concerned, these speakers are flat enough. I did all these tests without EQ also. The mid-range has opened up more, and I find I would still like more, but I like the detail and attack of the un-EQ-ed sound. My headphones, are full-range, but mid-range heavy. I like that kind of sound, but is that Hi-Fi? But is Hi-Fi the goal? I think we need that attribute, but there is more to it then that, I am finding! I am close with this system, just not quite there. If I solve the room issues, get a DAC and finish the diffraction-free exteriors for the Aveburys, will I be there?
Keep fighting for your dreams
Allen
Good call, fastbike1! - you were right! I finally had a chance to down load a simple tone generater and play a chromatic scale off an old stereophile sampling CD I have. Bottom line: I have some room issues to address...
It may as well be, becuase I understand now, what you heard, it is flat out wrong sounding! Almost out of phase like, only on the listening couch mind you! In fact I huffed my couch out of the room to see if it was the cuase. I am relieved it was not, becuase I do like to sit on something! On the listening couch, or that area of the room, sounds in the 80hz thru 250 Hz region "phase out" I thought maybe this was my problem. This problem was fixed by moving the speakers closer to the TV. But I still notice a loss in detail and "body" in the midrange. To make sure it was indeed a room issue, I put on the TV speakers, and wouldn't you know it, it does the same thing! (just did not notice it, didn't put my heart and soul in that sound system!) So this is a room issue. If I move my couch 3 1/2 feet from the back wall, that problem is solved, and so is the bass node, reguardless of speaker placement. But having my couch 3 1/2 feet into the room is not practical, so I must find a way to deal with this problem. I do not desire to solve it electronically, becuase it is indeed acoustical. It must have something to do with the three walls behind and to the sides of the couch.
Just for the fun of it, I decided to entertain the 3 1/2 feet couch position... The detail and range balance is exceptional and the frontal sound stage is deep and wide. The only sonic shortcoming to this position is it does not have have that cool "behind you" type surround effect I get with the couch closer to the wall. So is that the comprimise, or can I have the best of both worlds? I will need to do a lot of research on room treatments to see what my options might be.
I have to say I have really been enjoying creating this PC based sound system. You can access test tones, scales. or a certain song in seconds and even have more then one item cued up. This is the way to go!
So how did Aveburys do with the chromatic Scale? Great, it is solid down to 40 Hz. It can play a 20 Hz tone, and I can feel it, but it is pretty soft, and think if that low of a signal is important to you, you need a sub-woofer, or move these cabinets right against the wall and EQ down your higher bass. I think it would be best to remove the bass content at about 35 Hz as I believe the lower stuff may cause more harm then good.
The horn plays up to about 250 Hz, there may be a little higher, but hard to tell without setting these up in a padded room. At 200 Hz the horn is putting out about as much sound as the speaker itself, and at 100 Hz, most of the sound is coming form the back and a little from the speaker. Lower then that, the sound is "percievable" at the speaker, but all of what is heard and felt comes out of the horn. I am sorry I do not have a measurement system yet, but this at least give you a good idea of what these cabinets are designed to do. Well done, Scott!
I have a little concern in the 180 Hz thru 250 Hz area, where the front and back horn sounds could possibly interfere with each other. I am guessing this is what the stuffing in the horn throats is for? So Doubtingthomas and Dave, what does the stuffing in the throats do anyway?
I have learned a lot about how I hear and percieve sound aswell. The Aveburys play a chromatic scale relatively even. I hear minor peaks and dips, but nothing significant. I far as I am concerned, these speakers are flat enough. I did all these tests without EQ also. The mid-range has opened up more, and I find I would still like more, but I like the detail and attack of the un-EQ-ed sound. My headphones, are full-range, but mid-range heavy. I like that kind of sound, but is that Hi-Fi? But is Hi-Fi the goal? I think we need that attribute, but there is more to it then that, I am finding! I am close with this system, just not quite there. If I solve the room issues, get a DAC and finish the diffraction-free exteriors for the Aveburys, will I be there?
Keep fighting for your dreams
Allen
Attachments
Other test results
Too high! I really liked the impact of the bass though. I would like to try an 8' stand.
Hardware turned out being defective. I guess there was a reason that RCA cord did not work, I figured it was the wire, it turned out to be the plugs! So this project will have to wait until I place my next order...
Too high! I really liked the impact of the bass though. I would like to try an 8' stand.
Hardware turned out being defective. I guess there was a reason that RCA cord did not work, I figured it was the wire, it turned out to be the plugs! So this project will have to wait until I place my next order...
i havn't got any stuffing in mine now, I had a nasty resonant peak that seems to have gone. I do plan to get a Behringer UltraCurve Pro and will keep you posted. In fact I'll post my whole build with pictures whan I have time.
I had to try this!
Opps, pushed the wrong button, lost it all, got to type it again! Second time around...
Here goes:
I have always liked open baffle speakers so I really had the itch to try alpair 12 in this format...
I started with a mono comparison between Avebury and a not so nice plywood panel. (The baltic birch is worth the extra $$.) Avebury was fuller, more detailed, more dymanic, yet distant. Like sitting in the back half of a concert hall. The panel had only one thing, but it was the one thing I have been looking for this whole time: A deep, present, and big midrange. Avebury was more disreet and the panel was more like a "wall of sound"...
So I set up a second panel for a stereo listen. I was pretty excited, I was sure this would soundstage the room away! Oh, how disappointed I was... It was flat, loud, and shrill! No texture, No dymanics, No third dimision, so therefore no soundstage at all! 😱 I listened to about 5 songs and a selected scene from a movie and decided to bag this deal! I realized why I needed a 4-way system to get the open baffle to work before!
The best way I can describe the presentation diferences is with the open baffle system, it creates a concert in your living room, where as Avebury attempts to bring you to the concert venue itself. (I'll get to the "attempt part below) The open panel sounds like the instruments are in your room with you, were as the Avebury recreates the venue the instruments were recorded in. This is great for movies and recordings that take Spacialness into consideration. For the close miced recordings, the open baffle may be the better choice. Close mic reproduction is good for live sound, but not sound recording. I have learned this first hand helping several musicans with both performance and CD releases. We have a long way to go with recordings, at least if we are considering "soundstage" as a part of high fidelity. I know I do not stick my ear right under the snare when I listen to a drum solo!
Anyway, another great learning experience! I still would really like to get a little more of that mid-range presentation in the Aveburys. But maybe that presentation is a result of what the room adds on an open panel system.
So the winner is... Avebury! Thank God, I put a lot in this project!
Now to the "Attempt"... I believe Avebury can make the room disappear, and put me at the concert. It is trying, but I believe it is being held back by my Realtek Audio in my computer, some room issues (minor compared to the open panel) and some defractions not having the drivers rebated in the cabinets. The good news is I have some pieces cut for my defraction free cabinet exteriors, I am narrowing down the final design. I have also chosen the AMB y2 DAC. It sounds like that will bring me closer to the mid-range I want. I still have a lot of research to do on room accoustical design, but I have some ideas manifasting.
As you can see, I am really giving the Aveburys a serious run for all they are worth. And they are sounding better everyday, I am close to graduating from the 200 hour break-in period!
I had no idea I would learn so much about myself doing this project!
You all have a fantistic night!
Allen
Opps, pushed the wrong button, lost it all, got to type it again! Second time around...
Here goes:
I have always liked open baffle speakers so I really had the itch to try alpair 12 in this format...
I started with a mono comparison between Avebury and a not so nice plywood panel. (The baltic birch is worth the extra $$.) Avebury was fuller, more detailed, more dymanic, yet distant. Like sitting in the back half of a concert hall. The panel had only one thing, but it was the one thing I have been looking for this whole time: A deep, present, and big midrange. Avebury was more disreet and the panel was more like a "wall of sound"...
So I set up a second panel for a stereo listen. I was pretty excited, I was sure this would soundstage the room away! Oh, how disappointed I was... It was flat, loud, and shrill! No texture, No dymanics, No third dimision, so therefore no soundstage at all! 😱 I listened to about 5 songs and a selected scene from a movie and decided to bag this deal! I realized why I needed a 4-way system to get the open baffle to work before!
The best way I can describe the presentation diferences is with the open baffle system, it creates a concert in your living room, where as Avebury attempts to bring you to the concert venue itself. (I'll get to the "attempt part below) The open panel sounds like the instruments are in your room with you, were as the Avebury recreates the venue the instruments were recorded in. This is great for movies and recordings that take Spacialness into consideration. For the close miced recordings, the open baffle may be the better choice. Close mic reproduction is good for live sound, but not sound recording. I have learned this first hand helping several musicans with both performance and CD releases. We have a long way to go with recordings, at least if we are considering "soundstage" as a part of high fidelity. I know I do not stick my ear right under the snare when I listen to a drum solo!
Anyway, another great learning experience! I still would really like to get a little more of that mid-range presentation in the Aveburys. But maybe that presentation is a result of what the room adds on an open panel system.
So the winner is... Avebury! Thank God, I put a lot in this project!
Now to the "Attempt"... I believe Avebury can make the room disappear, and put me at the concert. It is trying, but I believe it is being held back by my Realtek Audio in my computer, some room issues (minor compared to the open panel) and some defractions not having the drivers rebated in the cabinets. The good news is I have some pieces cut for my defraction free cabinet exteriors, I am narrowing down the final design. I have also chosen the AMB y2 DAC. It sounds like that will bring me closer to the mid-range I want. I still have a lot of research to do on room accoustical design, but I have some ideas manifasting.
As you can see, I am really giving the Aveburys a serious run for all they are worth. And they are sounding better everyday, I am close to graduating from the 200 hour break-in period!
I had no idea I would learn so much about myself doing this project!
You all have a fantistic night!
Allen
Attachments
Oh yeah
And I have to say, those panels just do not look as cool in the room as the Avebury cabinets!😎
Allen
And I have to say, those panels just do not look as cool in the room as the Avebury cabinets!😎
Allen
Opps, some clarifation
I want to clarify some things in regards to my open panel experiement post above, becuase I do not want anyone to get the wrong idea, and think alpair 12 is horrible in an open ballfe cabinet, it is not. In fact Alpair 12 is better then what I used for mid-range in my former system. However, to bring it to the level of Avebury is going to require a lot more work in room treatments and compatible drivers for bass and the such. Avebury has been fully engineered, were as my "crap" wood panels are not too thought out at all. I was just after a taste of the potential Alpair 12 has in an open baffle. The potential is there if you are willing to put in the engineering and work. I been down that path before, I wanted to do something diferent, as in Avebury, and I really enjoyed comparing the two systems. I just hope no one got discouraged to use Alpair 12 in an open system, becuase I believe it would work well. I apologize for any confusion I may have caused.
Sincerly
Allen
I want to clarify some things in regards to my open panel experiement post above, becuase I do not want anyone to get the wrong idea, and think alpair 12 is horrible in an open ballfe cabinet, it is not. In fact Alpair 12 is better then what I used for mid-range in my former system. However, to bring it to the level of Avebury is going to require a lot more work in room treatments and compatible drivers for bass and the such. Avebury has been fully engineered, were as my "crap" wood panels are not too thought out at all. I was just after a taste of the potential Alpair 12 has in an open baffle. The potential is there if you are willing to put in the engineering and work. I been down that path before, I wanted to do something diferent, as in Avebury, and I really enjoyed comparing the two systems. I just hope no one got discouraged to use Alpair 12 in an open system, becuase I believe it would work well. I apologize for any confusion I may have caused.
Sincerly
Allen
Oh yeah Allen. A good DAC will make all the difference in the world. The onboard "Realtek" chip are far from stellar. Also you need to consider everything going on in that computer mainly fan noise.
There is a lot of debate about out board DACs VS. high end sound cards. Personally I wouldn't use the the sound card option myself. To many software headaches.
More Bass Discoveries
Yes, upon farther testing, I have decided that it would be best to remove bass content below around 40 Hz. That seems to be the lowest effective frequency of the horn. This system will play below that, but it is indeed doing more harm then good. First of all, the driver goes into distorn at even moderate levels due to excessive driver movement. And secondly, the bass attained below 40 Hz is bearly perceiveable, as it does not appear to be amplified by the horn. The "felt" bass I perceive is above 40 Hz. It seems this below 40 Hz bass is just wasting amplifier power and dynamic headroom for what this system is good at. It is more noticeable with movies, which have sub-sonic rolls and the such. The interesting thing is the bass that is "loaded" by the horn say between 40 Hz and 250 Hz hardly moves the driver at all, even at crazy loud levels! I believe this sytem is indeed capable of more then its current circumstances allow.
So I am currently seeking information on possible ways to "manage" this wasteful bass. Options I am considering are: Digital crossover placed before the DAC, an analog cross-overb after the DAC, or limiting the frequency response of the chip amps.. Naturally, I desire the method that will effect the 40 Hz thru 20 kHz content the least if that is even possible. Keep in mind, I will more then likely be using an AMB y2 DAC, so if I go the digital route, then all I need is a good digital cross-over. Would mini DSP work for this application? Or would I need a Beringer (and bepass its interal DAC?) Needless to say, it may be better to post this on a separate thread, eventhough I am attempting to optimize the Avebury system we have created. I think I will eventually want a sub-woofer or butt-shaker for the 20-40 Hz stuff, but I am not really missing it now, so a full fledged cross-over may not be necessary.
I am looking forward to getting the DAC, it seems that is really going to bring this system to a whole new level. Need to earn the money first!
Namaste.
Allen
Yes, upon farther testing, I have decided that it would be best to remove bass content below around 40 Hz. That seems to be the lowest effective frequency of the horn. This system will play below that, but it is indeed doing more harm then good. First of all, the driver goes into distorn at even moderate levels due to excessive driver movement. And secondly, the bass attained below 40 Hz is bearly perceiveable, as it does not appear to be amplified by the horn. The "felt" bass I perceive is above 40 Hz. It seems this below 40 Hz bass is just wasting amplifier power and dynamic headroom for what this system is good at. It is more noticeable with movies, which have sub-sonic rolls and the such. The interesting thing is the bass that is "loaded" by the horn say between 40 Hz and 250 Hz hardly moves the driver at all, even at crazy loud levels! I believe this sytem is indeed capable of more then its current circumstances allow.
So I am currently seeking information on possible ways to "manage" this wasteful bass. Options I am considering are: Digital crossover placed before the DAC, an analog cross-overb after the DAC, or limiting the frequency response of the chip amps.. Naturally, I desire the method that will effect the 40 Hz thru 20 kHz content the least if that is even possible. Keep in mind, I will more then likely be using an AMB y2 DAC, so if I go the digital route, then all I need is a good digital cross-over. Would mini DSP work for this application? Or would I need a Beringer (and bepass its interal DAC?) Needless to say, it may be better to post this on a separate thread, eventhough I am attempting to optimize the Avebury system we have created. I think I will eventually want a sub-woofer or butt-shaker for the 20-40 Hz stuff, but I am not really missing it now, so a full fledged cross-over may not be necessary.
I am looking forward to getting the DAC, it seems that is really going to bring this system to a whole new level. Need to earn the money first!
Namaste.
Allen
The discovery that changes it all.
Thanks once again for your grace and patience. Things are going to be very crazy for me over the next couple of months. Things are changing... One of my jobs is ending on April 1st - this is two thrids of my total income and all of my health benefits, so I am to be using that while I have it. Thankfully I have opportunities lined-up after, they might not be eagle, but I can at least settle for crow!
I have a lot to type in, so sit back and enjoy. I have been doing a lot of reading on these forums to help move me forward on this project. I found this interesting post on audiophile classifications: http://www.diyaudio.com/forums/everything-else/109586-problem-james-randis-pear-cable-expose.html
I am not one to put myself in a catagory, as I have been in all those catagories at one point, but it will help you all out when you read my posts. I am a "subjective" type. So take that with a grain of salt, it is all about the music and movies sounding good to me. That is why I am building a system, becuase I do not like the ones in the stores!
Okay, lets get down to business...
Thanks Dave, now I know the best option, if I do go this route...
I played with an old Optimus EQ destined for my garage sale this summer. Do I even need to mention anything about the harm this does to the sound, just even having it hooked up on bypass? I noticed a difference on my old system, but what I hear on this system, we just do not need to go there! I just wanted to play with the idea of taking out that lowest octave of bass. It helped but it did not do enough. I had to take out the 62Hz band also, it was even better with the 125Hz out at the loudest levels - laser disc player run line in full into the amps without any attentuation. Good sound stage, a little grainy though. Thru the TV pre-amp, a little less sound stage, more noise, same grain. Realtek Audio (motherboard) is still the quietest at the expense of "meat". I do not need this system any louder then it was during this test. So crossing at 40Hz would not be enough, still a lot of driver movement, which could indeed be distortion from the chip amps, which according to the maths max out at about 40 watts per channel. At these levels Alpair is moving at about 1 cm each way, it is not popping, but the sound is compressing and the amp is clipping. Take out the bass as stated with the EQ, and all is fine - huge sound stage, dynamic, even thru the Raeltek! And I am hearing that mid-range I like... And it is big too... Wait a minute... What is going on?..
I turn things down to where nothing distorts and bypass the EQ which is still plugged in. Mid-range dies. You remeber a detail loss I spoke of on post #284? When I remove the bass at about 200 Hz this is minimized about 85% - I can live with that, but what is going on?
I take the EQ out completely, and use the EQ's in both Foobar and Windows media player to do the same thing. Bands are different, so the sound was a little different, but the results where the same: bass crossed out = full deep midrange, minimal detail loss on listening couch. System run Full-range = hollow mid-range and significant detail loss on listening couch. So the mid-range issue I have been having is not an amp issue or an Alpair 12 issue, or even an open baffle issue. It is a bass issue.
In post # 284 I also mention a 80 Hz to 200 Hz bass "phase shifting?" on the listening couch area. I was able to fix that by putting the speakers two feet from the side walls and at least two feet form the back wall, leaving only 4 feet between the cabinets. They really should be placed farther from these walls, but that is not practical for my room. In this position, the bass is better, but the sound stage is narrow and I still experience a detail loss on the couch. take the bass out, and the detail loss is less apparent. It is safe to say these cabinets are very room dependent!
For the fun of it, I turned the cabinets around, so the horns where shooting out into the room and the Alpair 12 was bouncing off the back and side walls. No bass "phase shifting", yet the bass did not sound as low either. Got me thinking about the Chang designs.
I started to do some research...
http://www.diyaudio.com/forums/multi-way/203306-sense-depth-loudspeaker-soundstage.html
http://www.diyaudio.com/forums/ever...y-lateral-movement-vs-speaker-seperation.html
I found the answers here:
http://www.diyaudio.com/forums/markaudio/157768-pensil-12-b-w-matrix-802-a-6.html
The bottom line: my current room is too small for this design. They do not have enough room in the front for the bass to "wrap around" the cabinets, and my listening position is not far enough away for the front and back sounds to blend together. It seems that the back sounds are interfering with the front sounds.
I am sure you all are wondering at this point several things- one of which is: if I had read this information in the begining would I have built this design - you bet I would, I love big sound! This design seemed to be the most cost effective, as it did not need a subwoofer. But it does create some time alignment?interference issues? in a room like mine. I really like this design, especially asteticly and figured it would work. I have certailly learned a lot, esp about room acoustics.
So what next? I am going to do a little more research, but I have always wanted to try a spherecial cabinet. The Alpair 12 is the perfect canidate for that. I am thinking more of a leaky sealed design -vs- ported, although I will look into the concept behind Pensil. I am not interested in extending the bass of Alpair 12, I would perfer at this point to allow it to have it's headroom for what it is good at: 200Hz on up! I am thinking subwoofer for the lows. I can then have it all and play it loud! The challenge is getting this bass to sound as good as the Avebury bass, it is that good!
So, who would be interested in a pear of Avebury Cabinets?
Believe me, I am just as surprised as you! I put my heart and soul into this. You can understand why it has taken me so long to post! Not an easy decision to shallow! It has debunked many of my beliefs. God forbid you can have Big 3D sound in my room with a six inch full-ranger and sub on each side positioned correctly in this room. It requires the right driver, the right treatment (Enable), right amp, and right cabinet! How about solid maple and oak spheres? Time for a new thread!
Who wants to continue this thread? Anyone?
God Bless you all!
Love, Allen
Thanks once again for your grace and patience. Things are going to be very crazy for me over the next couple of months. Things are changing... One of my jobs is ending on April 1st - this is two thrids of my total income and all of my health benefits, so I am to be using that while I have it. Thankfully I have opportunities lined-up after, they might not be eagle, but I can at least settle for crow!
I have a lot to type in, so sit back and enjoy. I have been doing a lot of reading on these forums to help move me forward on this project. I found this interesting post on audiophile classifications: http://www.diyaudio.com/forums/everything-else/109586-problem-james-randis-pear-cable-expose.html
I am not one to put myself in a catagory, as I have been in all those catagories at one point, but it will help you all out when you read my posts. I am a "subjective" type. So take that with a grain of salt, it is all about the music and movies sounding good to me. That is why I am building a system, becuase I do not like the ones in the stores!
Okay, lets get down to business...
Thanks Dave, now I know the best option, if I do go this route...
I played with an old Optimus EQ destined for my garage sale this summer. Do I even need to mention anything about the harm this does to the sound, just even having it hooked up on bypass? I noticed a difference on my old system, but what I hear on this system, we just do not need to go there! I just wanted to play with the idea of taking out that lowest octave of bass. It helped but it did not do enough. I had to take out the 62Hz band also, it was even better with the 125Hz out at the loudest levels - laser disc player run line in full into the amps without any attentuation. Good sound stage, a little grainy though. Thru the TV pre-amp, a little less sound stage, more noise, same grain. Realtek Audio (motherboard) is still the quietest at the expense of "meat". I do not need this system any louder then it was during this test. So crossing at 40Hz would not be enough, still a lot of driver movement, which could indeed be distortion from the chip amps, which according to the maths max out at about 40 watts per channel. At these levels Alpair is moving at about 1 cm each way, it is not popping, but the sound is compressing and the amp is clipping. Take out the bass as stated with the EQ, and all is fine - huge sound stage, dynamic, even thru the Raeltek! And I am hearing that mid-range I like... And it is big too... Wait a minute... What is going on?..
I turn things down to where nothing distorts and bypass the EQ which is still plugged in. Mid-range dies. You remeber a detail loss I spoke of on post #284? When I remove the bass at about 200 Hz this is minimized about 85% - I can live with that, but what is going on?
I take the EQ out completely, and use the EQ's in both Foobar and Windows media player to do the same thing. Bands are different, so the sound was a little different, but the results where the same: bass crossed out = full deep midrange, minimal detail loss on listening couch. System run Full-range = hollow mid-range and significant detail loss on listening couch. So the mid-range issue I have been having is not an amp issue or an Alpair 12 issue, or even an open baffle issue. It is a bass issue.
In post # 284 I also mention a 80 Hz to 200 Hz bass "phase shifting?" on the listening couch area. I was able to fix that by putting the speakers two feet from the side walls and at least two feet form the back wall, leaving only 4 feet between the cabinets. They really should be placed farther from these walls, but that is not practical for my room. In this position, the bass is better, but the sound stage is narrow and I still experience a detail loss on the couch. take the bass out, and the detail loss is less apparent. It is safe to say these cabinets are very room dependent!
For the fun of it, I turned the cabinets around, so the horns where shooting out into the room and the Alpair 12 was bouncing off the back and side walls. No bass "phase shifting", yet the bass did not sound as low either. Got me thinking about the Chang designs.
I started to do some research...
http://www.diyaudio.com/forums/multi-way/203306-sense-depth-loudspeaker-soundstage.html
http://www.diyaudio.com/forums/ever...y-lateral-movement-vs-speaker-seperation.html
I found the answers here:
http://www.diyaudio.com/forums/markaudio/157768-pensil-12-b-w-matrix-802-a-6.html
The bottom line: my current room is too small for this design. They do not have enough room in the front for the bass to "wrap around" the cabinets, and my listening position is not far enough away for the front and back sounds to blend together. It seems that the back sounds are interfering with the front sounds.
I am sure you all are wondering at this point several things- one of which is: if I had read this information in the begining would I have built this design - you bet I would, I love big sound! This design seemed to be the most cost effective, as it did not need a subwoofer. But it does create some time alignment?interference issues? in a room like mine. I really like this design, especially asteticly and figured it would work. I have certailly learned a lot, esp about room acoustics.
So what next? I am going to do a little more research, but I have always wanted to try a spherecial cabinet. The Alpair 12 is the perfect canidate for that. I am thinking more of a leaky sealed design -vs- ported, although I will look into the concept behind Pensil. I am not interested in extending the bass of Alpair 12, I would perfer at this point to allow it to have it's headroom for what it is good at: 200Hz on up! I am thinking subwoofer for the lows. I can then have it all and play it loud! The challenge is getting this bass to sound as good as the Avebury bass, it is that good!
So, who would be interested in a pear of Avebury Cabinets?
Believe me, I am just as surprised as you! I put my heart and soul into this. You can understand why it has taken me so long to post! Not an easy decision to shallow! It has debunked many of my beliefs. God forbid you can have Big 3D sound in my room with a six inch full-ranger and sub on each side positioned correctly in this room. It requires the right driver, the right treatment (Enable), right amp, and right cabinet! How about solid maple and oak spheres? Time for a new thread!
Who wants to continue this thread? Anyone?
God Bless you all!
Love, Allen
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It really sucks to be so sensitive to phasing over a wider than normal BW, doesn't it? Now you know why some of us have been lifelong fans of compression horn systems. Small rooms need either mass quantities of damping and/or highly directional speakers that can keep early reflections delayed until ~behind the listener with either bass traps or a multiple speaker sub system, ergo the smaller the room, the larger the driver or horn required. Studying up on recording studio design seems a good plan at this point before building more speakers.
Bummer about the job, hope you're able to get back on top in the not too distant future.
GM
Bummer about the job, hope you're able to get back on top in the not too distant future.
GM
This is really happening, isn't it!?!
Actually, I always thought people prefered horns for the dynamic headroom and their sound presentation. I have only heard and worked with PA type horns, not heard one designed for the home. You mention about multiple speaker sub systems, are you speaking of line array sub systems or multi-channel, as in one sub on each channel in a 5.1 system? I have been curious about line arrays, but concerned about the comb filtering interference. But maybe the "nearfeild" listening would solve some of the room interference issues. So what is the lesser evil - comb filtering or room interference? I like the idea of bigger systems, in the sense that they move a larger area of air a little bit, that seems more true to nature then cranking up a "home theatre in a box" type of system! Avebury has big bass, not so big mid-range, atleast when it is "interfered" out by my room! I would really like to hear these cabinets in the right room.
I think Alpair 12 has some potential for me also, becuase of the bay window and archway notches I can use to eliminate early reflections. It is not a good idea to intentionly bounce sound of the walls! Yet I do enjoy the scale of big drivers also.
It seems we are limited when it comes to bigger drivers for full-range use. There is Hammer Dynamics, Hawthorn, Phy-PH, BG RD-75, or Eminince beta (which I tried and could not get past its restrained sound). Yeap, I am back to the drawing board. It is a good thing I like to draw!
So GM, what is your latest creation?
Allen
Actually, I always thought people prefered horns for the dynamic headroom and their sound presentation. I have only heard and worked with PA type horns, not heard one designed for the home. You mention about multiple speaker sub systems, are you speaking of line array sub systems or multi-channel, as in one sub on each channel in a 5.1 system? I have been curious about line arrays, but concerned about the comb filtering interference. But maybe the "nearfeild" listening would solve some of the room interference issues. So what is the lesser evil - comb filtering or room interference? I like the idea of bigger systems, in the sense that they move a larger area of air a little bit, that seems more true to nature then cranking up a "home theatre in a box" type of system! Avebury has big bass, not so big mid-range, atleast when it is "interfered" out by my room! I would really like to hear these cabinets in the right room.
I think Alpair 12 has some potential for me also, becuase of the bay window and archway notches I can use to eliminate early reflections. It is not a good idea to intentionly bounce sound of the walls! Yet I do enjoy the scale of big drivers also.
It seems we are limited when it comes to bigger drivers for full-range use. There is Hammer Dynamics, Hawthorn, Phy-PH, BG RD-75, or Eminince beta (which I tried and could not get past its restrained sound). Yeap, I am back to the drawing board. It is a good thing I like to draw!
So GM, what is your latest creation?
Allen
Allen,
First of all sorry to hear about the job situation - wish you all the best and hope you find great opportunities going forward.
The spherical things sounds interesting.... diyaudio forum member Doug Ingram has something in the works!
For my room sizes I've found this design quite suitable - another one from Scott Lindgren and P10:
http://homepage.mac.com/tlinespeakers/Woden/downloads/MarkAudio-A12-DBR-290610.pdf
I also built the Super Pensil 12 which I felt was a bit overpowering for my rooms (170-250 sq ft) - will try them again some time soon when time allows. Also feel that the Alp 12 works best with single strand Cat5 wire interconnects vs multi strand variants on my system, though I must admit I have none of the exotic cables to compare, just common/generic multi-strand.
-Zia
First of all sorry to hear about the job situation - wish you all the best and hope you find great opportunities going forward.
The spherical things sounds interesting.... diyaudio forum member Doug Ingram has something in the works!
For my room sizes I've found this design quite suitable - another one from Scott Lindgren and P10:
http://homepage.mac.com/tlinespeakers/Woden/downloads/MarkAudio-A12-DBR-290610.pdf
I also built the Super Pensil 12 which I felt was a bit overpowering for my rooms (170-250 sq ft) - will try them again some time soon when time allows. Also feel that the Alp 12 works best with single strand Cat5 wire interconnects vs multi strand variants on my system, though I must admit I have none of the exotic cables to compare, just common/generic multi-strand.
-Zia
Well, controlled directivity is part and parcel of its sound presentation. 😉
I was referring to Dr. Geddes's approach to multiple subs system. I tried similar to deal with the floor/ceiling modes and stumbled onto a much better way, though I assume he has a mathematical solution covering many more modes than just the first couple as I did.
I've also messed with corner arrays, though preferred one at the sound wall/floor junction spaced across the room to also act as an equipment platform.
At the frequencies typically involved, one is inside the near-field, so room modes dominate unless you XO them well above ~70-80 Hz for an 8 ft ceiling.
Well, if all your music is the type played in large concert halls, then wall reflections can be a good thing.
Yes, very limited in the inexpensive line. Once one moves to a two-way, I prefer low Fs, Qts, high Vas 15" duplex [co-ax] drivers with horn loaded tweeters. With a properly designed XO with T.D., it gives up nothing to the most expensive 'FR' drivers available other than possibly the sheer bulk required to go low at high efficiency, besting it in every way to mine and many others for 80+ years now.
Well, if life ever let's me get back to DIYing speakers, then assuming nothing better comes along it will be a three way DSL Synergy concept horn system with some type of multiple horn bass and multiple driver crawl space IB sub systems.
GM
I was referring to Dr. Geddes's approach to multiple subs system. I tried similar to deal with the floor/ceiling modes and stumbled onto a much better way, though I assume he has a mathematical solution covering many more modes than just the first couple as I did.
I've also messed with corner arrays, though preferred one at the sound wall/floor junction spaced across the room to also act as an equipment platform.
At the frequencies typically involved, one is inside the near-field, so room modes dominate unless you XO them well above ~70-80 Hz for an 8 ft ceiling.
Well, if all your music is the type played in large concert halls, then wall reflections can be a good thing.
Yes, very limited in the inexpensive line. Once one moves to a two-way, I prefer low Fs, Qts, high Vas 15" duplex [co-ax] drivers with horn loaded tweeters. With a properly designed XO with T.D., it gives up nothing to the most expensive 'FR' drivers available other than possibly the sheer bulk required to go low at high efficiency, besting it in every way to mine and many others for 80+ years now.
Well, if life ever let's me get back to DIYing speakers, then assuming nothing better comes along it will be a three way DSL Synergy concept horn system with some type of multiple horn bass and multiple driver crawl space IB sub systems.
GM
Oh yeah, the wire!
Thanks for reminding me Zia, I have played with the speaker wire and had a revisit tonight. You remember in post #248 I mentioned I would compare four strands of 24 guage to one strand for each signal wire. I acquired these individual strands from Cat-5 wire. The first time I compared the two, I had about 150 hours on the Alpairs, and was just learning about getting the best sound out of my computer. At that time, I prefered the four strand, as it had "more" sound to it, and back then, that is what I was looking for. One strand sounded more "whole" but that wholeness was naked also. Like being in a cold room after a shower! Here I go again with my subjective audiophile outlook...
A lot has changed since then, so I revisited this today. The difference I hear today is diferent. With four strands, I hear more unneeded mid-bass. The diference is subtle, but with one strand, the mid-range and treble shine thru more, creating a slightly more 3 dimisional soundstage. So you know I prefer the one strand arrangement. Using my metaphore above, you could say that with four strands is akin to being naked before the shower and with one strand is being clean after the shower, of course in a warm room! Things have gotten better, between the 300 + hours I have on Alpair and the system improvements I have made with all your help. And quite honestly, I have not completely given up on Avebury either. Now I know the mid-range is there along with the soundstage I am desiring. The question is, can I fix the bass problem, now I know that is the problem and an acuostical one at that... More on that below.
Zia, how did the Super Pensil sound overwhelming? Was this in a bass sort of way?
Thanks for relighting some hope! I was taking some detailed pictures of the flaws in the cabinets, so I can show a potential buyer what they will be dealing with. I have to say, that was quite an emotional experience. Not quite ready to let go yet... The adventure continues.
Allen
Thanks for reminding me Zia, I have played with the speaker wire and had a revisit tonight. You remember in post #248 I mentioned I would compare four strands of 24 guage to one strand for each signal wire. I acquired these individual strands from Cat-5 wire. The first time I compared the two, I had about 150 hours on the Alpairs, and was just learning about getting the best sound out of my computer. At that time, I prefered the four strand, as it had "more" sound to it, and back then, that is what I was looking for. One strand sounded more "whole" but that wholeness was naked also. Like being in a cold room after a shower! Here I go again with my subjective audiophile outlook...
A lot has changed since then, so I revisited this today. The difference I hear today is diferent. With four strands, I hear more unneeded mid-bass. The diference is subtle, but with one strand, the mid-range and treble shine thru more, creating a slightly more 3 dimisional soundstage. So you know I prefer the one strand arrangement. Using my metaphore above, you could say that with four strands is akin to being naked before the shower and with one strand is being clean after the shower, of course in a warm room! Things have gotten better, between the 300 + hours I have on Alpair and the system improvements I have made with all your help. And quite honestly, I have not completely given up on Avebury either. Now I know the mid-range is there along with the soundstage I am desiring. The question is, can I fix the bass problem, now I know that is the problem and an acuostical one at that... More on that below.
Zia, how did the Super Pensil sound overwhelming? Was this in a bass sort of way?
Thanks for relighting some hope! I was taking some detailed pictures of the flaws in the cabinets, so I can show a potential buyer what they will be dealing with. I have to say, that was quite an emotional experience. Not quite ready to let go yet... The adventure continues.
Allen
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