No, this is my old setup - fullrange driver (Visaton B200) and nearfield dipol sub. The B200 was equalized to have a linear frequency response at 30° which lead to an uniform energy radiation, i.e. linear frequency response of the indirect soundfield.
Elias, mounting the speaker in or on the wall is another method of controlling directivity - maybe even the best one available.
gedlee said:
Yes, at least big enjoyment of all audience on the fence.
markus76 said:
Yeah but *only* for those who buy in text book cooking
Speaker design isn't that way (fully repetitive / relaying on a "no white areas on the map" approach) – hence my reservations about all the cited "science" telling me how *I* have to perceive loudspeakers.
All I can contribute in a discussion is how *I* feel about certain aspects and what correlates from my point of view in simu's or theory.
And again - I'd like to second Scott's point anytime in that this *is* "soft" science actually.
markus76 said:
Not so sure about the goals we should put up in order to stating just another bias / to found just another school – these schools all have a come and a go
Would a 300(100) - 25kHz true dipole operation in the lateral direction - from what I'm exploring with my current design - be good enough for you - just to continue on the topic?
Or should I first advertise it as something like "the groundbreaking SUMMA cum MICHAELIS available soon" at every third posting or so - and write some books before?
ScottG said:
(.."write a book or 2"..makes me want to smack you over the head with a full Klippel suite.
wow - better I'll reconsider that part of book writing
Michael
I've been wanting to post on this thread for a while, but with so many points floating through it, putting together a coherent post is surprisingly time-consuming. So, this may not be coherent
I also think that boundary integration is an under-utilized tool when dealing with real-world rooms. It seems to me that integrating the speakers directly into the wall or corner is a way to reduce the number of variables in play, and if done properly 'should' help to normalize the power response. Of course, it brings it's own set of problems.
[long ramble upcoming]
For the most part, my system is based on Earl's perspective. My speakers (Yorkville U15's) aren't exactly like the Summa, but are basically similar - 60-degree conical horn topping a 15" midbass. My room is *very* problematic - only 7.5' wide, and ~16 ft long. There is simply no way I can get the first lateral reflection out farther than about 6-7 ms, and getting the speakers away from the front wall has major practical problems given the room layout. Trying highly regarded conventional speakers (ACI Sapphire XL) in this room was a complete disaster, with the only even vaguely acceptable results being in a completely impractical near-field arrangement.
My 'solution' is to use highly directive speakers, and put them *IN* the corners. The U15's are perfect for this, as they are highly directive, and they don't have much if any baffle step compensation in the xover as far as I can tell, so the power response in the corner doesn't boom the way a conventional flat-on-axis hi-fi speaker would. This means that my power response broadens gently from a a 60-degree pattern at HF to about a 90 degree pattern at LF which is much better than the free-field monopole case of broadening to 360. I am using EQ, but it's mostly to deal with a couple speaker and room resonances and the HF falloff from my 'Geddes style' foam plug. The speakers are positioned using Earls approach of crossing the main axis in front of the listening position which IMHO works very well for CD style speakers.
Reflection points still needed treatment, though, and I made the choice to use very heavy acoustic treatments on most of the front half of the room resulting in a very dead room by conventional standards.
The results of all this are what I'd term very successful, but exactly what you'd expect. The sound is very clean and imaging is IMHO very good - no localization to the speakers and good lateral spread. Tonal balance is apparently very natural and uniform (though you'd expect this in an eq'd system anyway) However, there is as you'd expect no sense of spaciousness due to the deadened reverberant field.
So, the next step is to use additional synthetic reverberant channels. I'm still very early in this process, but even the first steps are very educational. Since I use a PC running jack/BruteFIR as my source, adding separate reverb outputs is 'easy'. I have a pair of speakers directly to the side of the listening position, and have a simple reverb running to them via a receiver, so I can easily control the reverb-to-main volume ratio via a remote (and/or mute it completely). The early results are encouraging; doing a mute/un-mute comparison it's immediately apparent how the presentation expands and fills in with the reverb, but doesn't really result in degraded placement. I can't measure the level difference between the reverb and main signals, but you have to get your ear right up to the reverb speaker to hear it explicitly, so I'd guess it's at least 20dB down.
Future experiments along this route are to add rear channels for a total of 4 reverb channels, and obviously to play with the reverb characteristics. There is a decent-looking reverb editor (tap-plugins.sourceforge.net) that lets you control things reasonably well that I'm intending to use.
So, in terms of contributing to this thread, I think the take-aways are:
- my experience seems to largely support Earl's ideas since I based my setup heavily on his work, particularly in the approach to keeping the first 10+ ms clean. It wasnt' until I did this that I got anything reasonable in my room.
- I think I split the difference on the monopole-vs-dipole debate by finding an arrangement that inherently normalizes the power response.
- corners CAN work, contrary to conventional audiophile wisdom.
- overly dead rooms are bad, and even what is IMHO a very good setup won't sound right without the correct blend of room sound.
- there may be solutions for even the worst rooms if you are OK with bringing in electronic help.
Sorry for the somewhat OT ramble, but I think it touches on enough points of discussion that at least some will find it interesting.
markus76 said:
I also think that boundary integration is an under-utilized tool when dealing with real-world rooms. It seems to me that integrating the speakers directly into the wall or corner is a way to reduce the number of variables in play, and if done properly 'should' help to normalize the power response. Of course, it brings it's own set of problems.
[long ramble upcoming]
For the most part, my system is based on Earl's perspective. My speakers (Yorkville U15's) aren't exactly like the Summa, but are basically similar - 60-degree conical horn topping a 15" midbass. My room is *very* problematic - only 7.5' wide, and ~16 ft long. There is simply no way I can get the first lateral reflection out farther than about 6-7 ms, and getting the speakers away from the front wall has major practical problems given the room layout. Trying highly regarded conventional speakers (ACI Sapphire XL) in this room was a complete disaster, with the only even vaguely acceptable results being in a completely impractical near-field arrangement.
My 'solution' is to use highly directive speakers, and put them *IN* the corners. The U15's are perfect for this, as they are highly directive, and they don't have much if any baffle step compensation in the xover as far as I can tell, so the power response in the corner doesn't boom the way a conventional flat-on-axis hi-fi speaker would. This means that my power response broadens gently from a a 60-degree pattern at HF to about a 90 degree pattern at LF which is much better than the free-field monopole case of broadening to 360. I am using EQ, but it's mostly to deal with a couple speaker and room resonances and the HF falloff from my 'Geddes style' foam plug. The speakers are positioned using Earls approach of crossing the main axis in front of the listening position which IMHO works very well for CD style speakers.
Reflection points still needed treatment, though, and I made the choice to use very heavy acoustic treatments on most of the front half of the room resulting in a very dead room by conventional standards.
The results of all this are what I'd term very successful, but exactly what you'd expect. The sound is very clean and imaging is IMHO very good - no localization to the speakers and good lateral spread. Tonal balance is apparently very natural and uniform (though you'd expect this in an eq'd system anyway) However, there is as you'd expect no sense of spaciousness due to the deadened reverberant field.
So, the next step is to use additional synthetic reverberant channels. I'm still very early in this process, but even the first steps are very educational. Since I use a PC running jack/BruteFIR as my source, adding separate reverb outputs is 'easy'. I have a pair of speakers directly to the side of the listening position, and have a simple reverb running to them via a receiver, so I can easily control the reverb-to-main volume ratio via a remote (and/or mute it completely). The early results are encouraging; doing a mute/un-mute comparison it's immediately apparent how the presentation expands and fills in with the reverb, but doesn't really result in degraded placement. I can't measure the level difference between the reverb and main signals, but you have to get your ear right up to the reverb speaker to hear it explicitly, so I'd guess it's at least 20dB down.
Future experiments along this route are to add rear channels for a total of 4 reverb channels, and obviously to play with the reverb characteristics. There is a decent-looking reverb editor (tap-plugins.sourceforge.net) that lets you control things reasonably well that I'm intending to use.
So, in terms of contributing to this thread, I think the take-aways are:
- my experience seems to largely support Earl's ideas since I based my setup heavily on his work, particularly in the approach to keeping the first 10+ ms clean. It wasnt' until I did this that I got anything reasonable in my room.
- I think I split the difference on the monopole-vs-dipole debate by finding an arrangement that inherently normalizes the power response.
- corners CAN work, contrary to conventional audiophile wisdom.
- overly dead rooms are bad, and even what is IMHO a very good setup won't sound right without the correct blend of room sound.
- there may be solutions for even the worst rooms if you are OK with bringing in electronic help.
Sorry for the somewhat OT ramble, but I think it touches on enough points of discussion that at least some will find it interesting.
dwk123 said:
Yes, I found your findings interesting - thanks.
Do you use SIR for reverberation?
Most concerns I have is – don't you find it problematic to overlay the same reverb all the time.
I assume you don't exactly model a small room – like yours - with the reverb.
In my experience it is hard to get intimate recordings right at concert hall room signature – though I admit its a *pleasing* additive .
Michael
Originally posted by mige0 Yeah but *only* for those who buy in text book cooking
Speaker design isn't that way (fully repetitive / relaying on a "no white areas on the map" approach) – hence my reservations about all the cited "science" telling me how *I* have to perceive loudspeakers.
All I can contribute in a discussion is how *I* feel about certain aspects and what correlates from my point of view in simu's or theory.
And again - I'd like to second Scott's point anytime in that this *is* "soft" science actually.
That's just plain wrong. Obviously you missed a couple of studies by Olive that have proven that objective assumptions on the quality of a certain speaker can be made by utilizing high resolution measurements.
Am I the only one that sees an antilogy in refusing to read existing scientific studies and claiming at the same time that there's no scientific aspect in louspeaker building?
dwk123 said:
Be careful, you're asking for trouble here.
Scott - you are often critical of me so here is one for you. You argue like a lawyer making every attempt to derail the opponents argument by bringing in a whole list of "what-ifs" or "what-abouts" without addressing the discussion directly. I don't care to argue with you because, not being a lawyer, its not my expertise. Its obviously yours.
You were correct in pointing out my "unreasonable" comment about Elias, and I appologize because that was not what I meant. I said that I thought my approach was "reasonable and practical" and that Elias was taking a contrary position. I did not mean to imply that his position was unreasonable, I only meant to say that it isn't necessarily the most "practical" and he doesn't seem to care about practicality. And thats fine, we differ on that point. I will say again that I don't disagree with the use of dipole in the range of below 500 Hz, I just don't see any advantage, and I take the "practical" approach of doing what is the most efficient.
"Perception" to me is always scientifically based, otherwise its an "subjective opinion". This IS NOT the Webster deffinition, but it is the one that is generally held in the Psychoacoustics community. I
f I care to continue the discussion I will start a new thread because this one is no longer going anywhere.
DWK
I have often thought about the "practicalities" of embedding the speakers in the corners. There is some attraction to this for me and in certain situations I can see it being the most effective approach. Toole likes this approach also. But that requires more work than just placing the speakers and it makes the installation rather fixed. But in the right situation it is exactly what I would do.
markus76 said:I liked my dipol sub - now I have this very expensive Gedlee speaker that I have to love
An externally hosted image should be here but it was not working when we last tested it.
Selling always is an option....
do you also have a pix of your setup you made the measurements in # 275 with
http://www.diyaudio.com/forums/showthread.php?postid=1626200#post1626200
gedlee said:
Don't think so - as long as he states *his* impressions and doesn't force anybody to join some ones "universal truth".
BTW – we all can see that you have a strong tendency to draw as much attention towards you as possible, Earl, but consider that:
Teaching – as you once stated you'd really like to do – is way more about supporting one's personal development – wherever this person may heading for – much more than to just plant *your* seed.
In fact, teaching is an art and you haven't gone under the surface right now IMHO.
In that sense I would really like you to open your mind (and slightly change habits / allow for moods to let also *yours* perception change / grow) as I'm confident you have way more to offer than can be seen now
"Summa cum Laude" is OK - but not enough.
You got the picture?
gedlee said:
No, *Percception* never is nor will be " an completely objective domain" its always subjective
Michael
mige0 said:
Well the basic idea is to create a planar wave front coming from the front wall and from the back wall. The one at the back wall is phase inverted and time delayed. The delay matches the room length so the two waves meet at the back wall where they neutralize each other. The planar wave is generated by multiple subwoofers evenly distributed on the front and back wall. The more subwoofers the more planar the wavefront stays to higher frequencies. Horizontal and vertical modes are eliminated by the buildup of the planar wave front.
markus76 said:
If you would read my posts carefully, you would notice I'm talking more generally than just monopole vs dipole.
It's a comparison between a source with no directivity (i.e. monopole) against a source with directivity (i.e. dipole, cardioid, second order cardioid etc).
It just happens to be that at low freqs monopole and dipole are the most easiest directivity patterns to achieve. But there is no reason to limit yourself to just dipole when you need the directivity.
Hence the question is to find the psychoacoustic reasons so that we know how to select the correct directivity pattern for different freq bands to gain the ultimate.
- Elias
Hello,
Since they has been discussion about 'practicality' of using dipoles I'll make a comment on that. Actually one could apply the 'practicality' claim more generally to all sources with directivity at low freqs if one is too narrow minded and not considering all the aspects that we are trying to achieve.
It is true dipoles at low freqs have lower efficiency. Sure I would like to have my dipoles having 100dB/1W/1m output at 20Hz, but it's not going to happen. Size can be big but not always, W frame is very compact actually. Active crossover and multiamping is needed for best results. One can talk about other tehcnical issues like distortion and so on, but they are points to be tackled by engineering.
After correct implementation these technical issues have no psychoacoustic relevance.
What is relevant is what psychoacoustic benefits the _directivity_ of the source can bring. Monopole have no directivity no mather how you engineer it. Thus directivity of the source brings _extra freedom_ in design to allow to be used.
The psychoacoustic benefits directivity will bring will outperform the engineering issues when we are after the ultimate. Engineering is just a straight forward implementation when you know the goal.
Most paractical directivity source is a dipole. And it is very practical for home livingroom usage.
- Elias
Since they has been discussion about 'practicality' of using dipoles I'll make a comment on that. Actually one could apply the 'practicality' claim more generally to all sources with directivity at low freqs if one is too narrow minded and not considering all the aspects that we are trying to achieve.
It is true dipoles at low freqs have lower efficiency. Sure I would like to have my dipoles having 100dB/1W/1m output at 20Hz, but it's not going to happen. Size can be big but not always, W frame is very compact actually. Active crossover and multiamping is needed for best results. One can talk about other tehcnical issues like distortion and so on, but they are points to be tackled by engineering.
After correct implementation these technical issues have no psychoacoustic relevance.
What is relevant is what psychoacoustic benefits the _directivity_ of the source can bring. Monopole have no directivity no mather how you engineer it. Thus directivity of the source brings _extra freedom_ in design to allow to be used.
The psychoacoustic benefits directivity will bring will outperform the engineering issues when we are after the ultimate. Engineering is just a straight forward implementation when you know the goal.
Most paractical directivity source is a dipole. And it is very practical for home livingroom usage.
- Elias
gedlee said:
Earl, I'm critical of everyone - especially myself. But at the same time I accept a great deal of limitations, because frankly - that's just a part of life.
I do accept the limitations you impose on yourself, but I do NOT accept the limitations that you try to impose on others without their consent (..it started with the definition of "spaciousness" on this thread and progressed from there). Nor do I accept certain instances when you (or others) make definitive claims. Finally, (something you have personally *vastly* improved on over the last 4 years IMO), I do not accept it when someone dismisses another (in that it belittles their existence). (..common example: "If it doesn't meet a strict definition, then it hasn't happened - what you propose hasn't happened". -Jmmlc ran into this on this thread.) If I seem to be especially critical of you, and yes I'd say I am, it's specifically because you violate one or more of these conditions *frequently* - and even then I try to be accommodating.As far as my "arguments" - I try to *specifically address* most if not all points that a respondent has made. That's just thorough, AND polite to that respondent (..rather than "cherry picking" specific points "you" think are more tenable to your own argument). Please, go back and find a response of mine where you would like me to more directly respond. On at least one occasion in this thread alone you asked me for clarification on a response of mine, I'm happy to comply. Do note however that there are occasions when I'm not on the forum - if it seemed that I left a question unanswered then its likely that the discussion had not only "moved on" from that topic, but that at the time I could respond it appeared moot.
When I pose "what ifs" or "what abouts" (which was what - 2 or 3 posts of mine in 24 pages?), its typically because the respondent has chosen an argument that is not only marginal (at best) - but often is so simplistic that I feel it needs some "fleshing-out". This is particularly true if that "fleshing-out" fits within the thread's purpose. Its not my fault that the respondent denies that, or has no interest in responding. Still, point-noted: I'll try to keep this type of response even more limited.
As for perception:
I'll certainly accept that for you, you pose a very limited definition. The fact remains though that while you may dislike the subjective responses of others generally, most especially ones that don't agree with your particular references, that for the most part YOU ARE QUITE WILLING TO ACCEPT THEM WHEN THEY DO *AGREE* WITH YOU (or your references). I don't mind the latter, but its that particular *combination* that's "irksome".
If the whole "dipole" thing is a "non-starter" for you, then a suggestion: don't "start". I've suggested several areas where they could well be better (audibly, not necessarily practically), but you obviously had no interest in discussing anything positive. You were however *more* than willing to repeatedly attempt to quash any meaningful, (to other forum members), discussion on it based on your own limited definition of "practical" in a design format.
I appreciate the apology, but really - it shouldn't be directed to me.
markus76 said:I liked my dipol sub - now I have this very expensive Gedlee speaker that I have to love
An externally hosted image should be here but it was not working when we last tested it.
Dipole sub? Where..?
Oh, THAT! It's so small and practical I didn't notice it at first
P.S. Visaton B200 on the wall, how can you bear them like that not pointing to listening spot? They beam like h*ll.
- Elias
Hello,
One can make the most naive assumption that all the people are the same in their perception. When human is inserted into the equation science can only talk about statistics. There can be the 'average' of population, but it does not warm you much if YOU fall outside the confidence limit of gaussian distribution telling YOU should hear some specific thing in a particular way. What happens if YOU don't hear it? What will YOU do then? It can happen to anyone.
- Elias
P.S. YOU is not pointed to any person particularly.
gedlee said:
One can make the most naive assumption that all the people are the same in their perception. When human is inserted into the equation science can only talk about statistics. There can be the 'average' of population, but it does not warm you much if YOU fall outside the confidence limit of gaussian distribution telling YOU should hear some specific thing in a particular way. What happens if YOU don't hear it? What will YOU do then? It can happen to anyone.
- Elias
P.S. YOU is not pointed to any person particularly.
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