I made the experience, that the stereoimaging is better with speakers with a kind of distance to the wall other then wallmounted. The latter measures better (no sbir) but isn't as holographic in stereo. Do you have other experience?
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Are my bass traps not working? Some changes in var smoothed frequency response, but not much in ERB smoothed one.
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This is probably either a trick of the mind, or a characteristic of the different speakers you've heard rather than how they were placed.
The visual depth is real for sure.
But even soffit mounted speakers, it will be a struggle to integrate DBA with an xover at 130/140 Hz. I'm also not sure DBA will work in itself that high. Let us see this successfully done before drawing conclusions.
But even soffit mounted speakers, it will be a struggle to integrate DBA with an xover at 130/140 Hz. I'm also not sure DBA will work in itself that high. Let us see this successfully done before drawing conclusions.
Hopefully the following will not be missunderstood - but this technique is so old and often used (at least in Germany), I'm feeling like someone wants a proof that stereo works
You're right with the visual depth - in my feeling it supports the imagination a lot.
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Is it? I thought, and what I read several times, it is related to (later) reflections (not Bass/SBIR which of course profits from soffit mounting) which supports (based on the amount, as they can also destroy) this imaging. I've always wanted to try an AB-comparison but never was able to do that... Which brings the question to me, If all these freestanding loudspeakers only stand free for managing bass response, when no active or heavy passive absorption is in place.
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Do you understand the concept of polar lobing? How do you avoid that when distance between sources are greater than 1/4 wavelength? The far distance between the woofers such high in frequency is one thing, but the other is the distance between the fronts and woofers furthest away. Especially if the room is wideHopefully the following will not be missunderstood - but this technique is so old and often used (at least in Germany), I'm feeling like someone wants a proof that stereo works
You're right with the visual depth - in my feeling it supports the imagination a lot.
I have yet to see anyone successfully running DBA as high in frequency as you propose. Have you?
If so. please show us measurements of it. Frequency response and waterfall with high resolution should be minimum.
What did I propose? The whole thing started mentioning dba as an reasonable solution tackling (deep) bass issues, which is pretty hard to solve the passive way.
Now we are moving further to discussion areas more easily to attack this concept - of course passive absorption is more easily adopted >100hz then in the deep bass region, nobody denies that hence it is kind of usual to combined exactly this method of combination (which I also do by myself, my roomacoustic was much more expensive then the speaker itself). I mentioned that there are many people running their dbas above 100hz, thats a fact. And no, If you want measurements of that, I'm not doing this work for you, you can research that in so many (home) cinema communities by yourself, as It is a really common thing and so often distributed. Besides, even wikipedia mentions 114hz for vertical room dimension in an 4x3 meters room with only an 2x2 array
Double bass array - Wikipedia
But somehow I still get the feeling of trying to nitpick and propose the own "passive only" solution as superior.
137hz was mentioned from someone else, of course an dba becomes less effective/good the higher it moves in frequency - I guess that's what you want to pinpoint with "polar globing". As I'm not familiar with this word, probably due to translation matters, I assume it's related to directivity and the transforming from omnidirectional to directional of soundwaves, the higher it gets (narrowing beamwith)?
Nevertheless, yes, I'm crossing over at 140hz with an dba placed far far far away from what it should be in theory / textbook (livingroom!), I would say its placed pretty bad but still is able to produce pretty good sound in practice with no issue of aligning the tops/fronts or localization.
As the question was stated twice but not answered yet: what do you mean with most sensitive area?
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Sorry. I was referring to the statement that DBA can work up to 137 Hz, but I see that was juliangst and not you.What did I propose? The whole thing started mentioning dba as an reasonable solution tackling (deep) bass issues, which is pretty hard to solve the passive way.
Now we are moving further to discussion areas more easily to attack this concept - of course passive absorption is more easily adopted >100hz then in the deep bass region, nobody denies that hence it is kind of usual to combined exactly this method of combination (which I also do by myself, my roomacoustic was much more expensive then the speaker itself). I mentioned that there are many people running their dbas above 100hz, thats a fact. And no, If you want measurements of that, I'm not doing this work for you, you can research that in so many (home) cinema communities by yourself, as It is a really common thing and so often distributed. Besides, even wikipedia mentions 114hz for vertical room dimension in an 4x3 meters room with only an 2x2 array
Double bass array - Wikipedia
en.m.wikipedia.org
But somehow I still get the feeling of trying to nitpick and propose the own "passive only" solution as superior.
137hz was mentioned from someone else, of course an dba becomes less effective/good the higher it moves in frequency - I guess that's what you want to pinpoint with "polar globing". As I'm not familiar with this word, probably due to translation matters, I assume it's related to directivity and the transforming from omnidirectional to directional of soundwaves, the higher it gets (narrowing beamwith)?
Nevertheless, yes, I'm crossing over at 140hz with an dba placed far far far away from what it should be in theory / textbook (livingroom!), I would say its placed pretty bad but still is able to produce pretty good sound in practice with no issue of aligning the tops/fronts or localization.
As the question was stated twice but not answered yet: what do you mean with most sensitive area?
This is something I would need to measurements of before I believe it will work. And there will be trouble integrating the front speakers well. I have not seen anyone running DBA higher than 80 Hz/100 Hz. The bass area above 80 Hz is an area we are more sensitive to vs the sub frequencies and lower midrange is also very crucial. So that's why I debating against the comment that this is the best way to deal with bass/room modes.
Polar lobing is frequency deviation that happens when sources are spaced too far from each other. That's what is going to happen when running DBA as high as 137 Hz.
Acoustic treatment is of course superior. It deals with the whole frequency area, always works in the time domain, it can be combined with high quality diffusion and which IMO is absolutely necessary for true high-end result (DBA steals place for that), and it works in all of the room. Not much to discuss really. It can also be much cheaper than DBA. But it takes up more space, and that's not practical for everyone. So it's matter of choosing what works for people. I'm not against neither DBA or multiple subwoofers, but I think it's worth mentioning the weaknesses.
I've never seen a DBA being used up to those frequencies but in theory it should work. Crossover points of 80Hz or 100Hz are more common.
Above that frequency you of course need absorption and bass traps to lower the reverb.
I came up with those 137Hz by using the DBA formula which exactly takes this into account. The higher you want the plane wave effect to work the closer the subs have to be.
The upper frequency to which a SBA/DBA produces a plane wave is c/(2*d) with the speed of sound c=343m/s and the distance between drivers d.
Bass arrays are very common here. When I read german forum posts or watch videos about home theatre setups in dedicated rooms, then 9/10 times they'll use a SBA or DBA.
If I had the space I would rather go for SBA and absorption on the rear wall because it's way cheaper and easier to implement.
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Take into account polar lobing between woofers and front speakers?
Someone asked ... what exactly?
I think the question is if lobing between the DBA and LCR speakers would become a problem.
I never thought about this. I guess it's not an issue if they're close to the subs (as they usually are) and if you use steep low/ high pass filters.
I never thought about this. I guess it's not an issue if they're close to the subs (as they usually are) and if you use steep low/ high pass filters.
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