I have not, but I may try it with my Driverack PA to see what it sounds like.
Well, it worked, but with a consequence. The output is down 6db
I talked to my EE brother about it and he attempted to share why that is.
Drivers connected in series no doubt has something to do with it. I'd still opt for using a computer between the input of the amp for a test. That way you can connect the speakers in the usual manner. Only the signal it amplifies will change. Plus you get to play with reverb if you want.
Bummer...
Ok Weysayo.......I'm going to give a fullrange array another attempt based on your results.....with a few changes.
For starters, I'll be using a smaller driver for closer C to C spacing. I know you found the combing to be inaudible but sadly I isn't share the same experience. My second deviance will be the addition of a 15" bass module below each tuned to 30hz and crossed to the array at 250 hz.......which will allow for the smaller fullrange limitations. With the added bass module, my array length will be only 16 drivers which will bring me to 6" below ceiling height.
So I'll be looking for suggestions on a fullrange driver, but my attention is already drawn to the FaitalPro 3FE as there's three impedance variations which will allow for easier power tapering.
I'll start a new build thread after all the details are worked out and it will begin with the construction of the bass modules.
For starters, I'll be using a smaller driver for closer C to C spacing. I know you found the combing to be inaudible but sadly I isn't share the same experience. My second deviance will be the addition of a 15" bass module below each tuned to 30hz and crossed to the array at 250 hz.......which will allow for the smaller fullrange limitations. With the added bass module, my array length will be only 16 drivers which will bring me to 6" below ceiling height.
So I'll be looking for suggestions on a fullrange driver, but my attention is already drawn to the FaitalPro 3FE as there's three impedance variations which will allow for easier power tapering.
I'll start a new build thread after all the details are worked out and it will begin with the construction of the bass modules.
Hahaha, Mayhem13, you're a funny man.
You're going to try due to my results and do everything different
.
Just kidding. Personally I wouldn't shade a floor to ceiling line array. And I wouldn't cross over to a point source either. Just my views...
I cannot argue against using smaller drivers. that's a pretty sane choice if you're not going to extend the low frequencies.
Why not add a line of 12" drivers for the low end? I hope you are not talking about a ported enclosure for that 15".
You're going to try due to my results and do everything different
.Just kidding. Personally I wouldn't shade a floor to ceiling line array. And I wouldn't cross over to a point source either. Just my views...
I cannot argue against using smaller drivers. that's a pretty sane choice if you're not going to extend the low frequencies.
Why not add a line of 12" drivers for the low end? I hope you are not talking about a ported enclosure for that 15".
There is no doubt there are some advantages to doing what your suggesting. Maybe at some future point.
For now, I am going back to what I had before. It sounded better. Sure, the drop in ambient SPL played a role. But I find myself thinking about why R-L and L-R were devised in the first place, and why it worked.
One of the things that caught my notice about this was the need to preserve the soundstage. Thus, it made sense to me to cancel the phantom middle. But were talking about assuming ambient speakers in the same room as the mains with a direct physical path to the LP. In my case, neither of these assumptions are true.
When I was listening to the R-L setup, even with reduced levels, the middle of the stage seemed dry and to have less life than my previous setup. I did notice that the extreme left and right did retain some life though.
I suppose I am going to have to forge my own path, for most of the conventional wisdom on the subject applies to in-room ambient speaker location which mine are not. The rules are different apparently.
To be honest, your initial impressions are not that different from my own. As I said before, I had to "leak" a little phantom into the ambient channels to prevent them from sounding too different.
The dry middle stood out against the more wet sides. But this was less of an issue with the added reverb ambience. But after 2 blissful days this third day I get a bit bugged by using L-R and R-L alone. At the listening spot it worked very well. But off axis it annoyed me(*). Not the sound I want to hear in a room. And therefore not acceptable in the long run.
So I also put some center back in, playing with a band pass on that. The L-R and R-L seemed to have more intelligibility in the phantom center. I'm looking to retain that.
(*) very much like using longer frequency dependent windows for my FIR correction at mid or low frequencies. At the listening spot it works, but not outside that sweet spot. I want something that sounds pleasant everywhere and best at the sweet spot.
The dry middle stood out against the more wet sides. But this was less of an issue with the added reverb ambience. But after 2 blissful days this third day I get a bit bugged by using L-R and R-L alone. At the listening spot it worked very well. But off axis it annoyed me(*). Not the sound I want to hear in a room. And therefore not acceptable in the long run.
So I also put some center back in, playing with a band pass on that. The L-R and R-L seemed to have more intelligibility in the phantom center. I'm looking to retain that.
(*) very much like using longer frequency dependent windows for my FIR correction at mid or low frequencies. At the listening spot it works, but not outside that sweet spot. I want something that sounds pleasant everywhere and best at the sweet spot.
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Related to what I said previously, the content of the ambient energy seems only constrained by how it affects the direct. I cant see any reason to remove the phantom middle IF it doesn't adversely affect the soundstage.
You have gone to one extreme in eliminating the phantom middle altogether. Now it seems, you are poised to dial it back in incrementally. But it may turn out that its not only a question of how much, but when. Playing with the delay may render some help here.
But another word comes to mind, a recent one, DE-correlation. When you add more reverb, the phantom middle seems to be less of a problem. Perhaps this is because it becomes more de-correlated as you add reverb. From a certain point of view, it may also be the case as the delay is longer.
Here is a out-of-the-box idea. Suppose you put a barrier in front of the surround speakers. Maybe a foot out from it. Perhaps V shaped. What this would cause is anything from them to have to bounce at least once before making its way to the LP. It would also spread out the return in space and time. But most importantly, it would break up the direct path to your ears. An acoustic de-correlation tool maybe?
You have gone to one extreme in eliminating the phantom middle altogether. Now it seems, you are poised to dial it back in incrementally. But it may turn out that its not only a question of how much, but when. Playing with the delay may render some help here.
But another word comes to mind, a recent one, DE-correlation. When you add more reverb, the phantom middle seems to be less of a problem. Perhaps this is because it becomes more de-correlated as you add reverb. From a certain point of view, it may also be the case as the delay is longer.
Here is a out-of-the-box idea. Suppose you put a barrier in front of the surround speakers. Maybe a foot out from it. Perhaps V shaped. What this would cause is anything from them to have to bounce at least once before making its way to the LP. It would also spread out the return in space and time. But most importantly, it would break up the direct path to your ears. An acoustic de-correlation tool maybe?
I'am a little late to the party but here is what i had in mind about MS matrix:
Pro Audio Design Forum • View topic - Mid Side M-S Matrix Construction Information
Don't cost this much and as long as you can solder and eventually build a small whitestone bridge to pair some of the resistors it works quite good and line level.
When you use the board l/r>m/s you can vary m content using a pot on the m then you use another board M/S>L/R and then you can have mono content completly cut or any level you want. And using some line level eq/filter you can tailor fr, add reverb,....
Pro Audio Design Forum • View topic - Mid Side M-S Matrix Construction Information
Don't cost this much and as long as you can solder and eventually build a small whitestone bridge to pair some of the resistors it works quite good and line level.
When you use the board l/r>m/s you can vary m content using a pot on the m then you use another board M/S>L/R and then you can have mono content completly cut or any level you want. And using some line level eq/filter you can tailor fr, add reverb,....
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Hahaha, Mayhem13, you're a funny man.
You're going to try due to my results and do everything different
Just kidding. Personally I wouldn't shade a floor to ceiling line array. And I wouldn't cross over to a point source either. Just my views...
I cannot argue against using smaller drivers. that's a pretty sane choice if you're not going to extend the low frequencies.
Why not add a line of 12" drivers for the low end? I hope you are not talking about a ported enclosure for that 15".
A line of 12's???........might as well start looking for divorce attorneys! Lol
I believe one of my biggest problems here is lack of space. I don't have more space available, the line arrays are at the long wall, preferably I would have put them on the short wall in the corners but my room just doesn't allow for that (due to windows etc.) The setup is highly unsymmetrical and as such I had to overcome some problems associated with that.
The surrounds are too close, one way to solve that is to put them up higher. But I cannot sell that concept unless I put them in my damping panel. (I'm seriously considering that)
Due to the ambient channels being point sources the level gets higher the closer you move towards them. Not a problem if you only sit at the listening spot but I want to accommodate more than one listener at times.
By putting them higher up I'd solve some of the distance problems but I'd also have to make them fire directly to the listening spot instead of the more diffused side firing setup I use now.
Compromises, as usual. So for now I'll play with settings to find a good compromise. It's pretty good for what it is. Which was the goal. But I'll always look for ways to improve. I have no idea if I could get away with putting them up high in the damping panel. Working around a fully functional living room isn't easy. Keeping my Girl happy is a big part of that.
I kinda promised no more speakers
.
I believe one of my biggest problems here is lack of space. I don't have more space available, the line arrays are at the long wall, preferably I would have put them on the short wall in the corners but my room just doesn't allow for that (due to windows etc.) The setup is highly unsymmetrical and as such I had to overcome some problems associated with that.
The surrounds are too close, one way to solve that is to put them up higher. But I cannot sell that concept unless I put them in my damping panel. (I'm seriously considering that)
Due to the ambient channels being point sources the level gets higher the closer you move towards them. Not a problem if you only sit at the listening spot but I want to accommodate more than one listener at times.
By putting them higher up I'd solve some of the distance problems but I'd also have to make them fire directly to the listening spot instead of the more diffused side firing setup I use now.
Compromises, as usual. So for now I'll play with settings to find a good compromise. It's pretty good for what it is. Which was the goal. But I'll always look for ways to improve. I have no idea if I could get away with putting them up high in the damping panel. Working around a fully functional living room isn't easy. Keeping my Girl happy is a big part of that.
I kinda promised no more speakers
Thought about moving?
Seriously, the biggest upgrade you could do for yourself at this point would be a larger room.
Would it work better over wider area if frq and phase profile for ambient speakers is corrected so it is same as a diffuse 90º measurement taken in middle of room measuring main speakers only. When ambient speakers is corrected and measured alone they shall in same middle of room at a diffuse 90º measurement show same frq and phase profile as mains (minus LF area) so when later mixed in and delayed they replicate this rooms diffuse mains and make it bigger.
Correction for ambient speakers will probably be very non minimum phase domain so FIR power and processing time will be needed, processing lag should not be a problem in it will just hide itself behind the added delay ambient speaker normal have added.
Correction for ambient speakers will probably be very non minimum phase domain so FIR power and processing time will be needed, processing lag should not be a problem in it will just hide itself behind the added delay ambient speaker normal have added.
While I did correct the FR, I'm now opting to correct the timing as well for the ambient channels. And I'll have to work a bit harder to see if there are any strange peaks. A few more control measurements to get the ambient channels in better shape.
Jim is right about the room, but I'll continue my challenge to get the most out of what I've got. It's a learning exercise as much as anything else. The FR of the kicker is way more important than I figured it would be. The added reverb softens the effect they have somewhat but I just know I can win something here by paying more attention to the ambient channels. They have a bigger influence on the total perception than I had imagined.
I'm nit-picking here though. A few months ago I said I was finished. That wouldn't have been a problem, I really was happy enough. I just can't stop learning and remain curious on how this stuff works, when it gets translated by our weird human brain.
Jim is right about the room, but I'll continue my challenge to get the most out of what I've got
. It's a learning exercise as much as anything else. The FR of the kicker is way more important than I figured it would be. The added reverb softens the effect they have somewhat but I just know I can win something here by paying more attention to the ambient channels. They have a bigger influence on the total perception than I had imagined.I'm nit-picking here though. A few months ago I said I was finished. That wouldn't have been a problem, I really was happy enough. I just can't stop learning and remain curious on how this stuff works, when it gets translated by our weird human brain.
Still playing with this, currently I have a 6 db/octave low pass at 400 Hz on the center channel, gradually filtering out the high frequency content. Mixed in at a lower level, it's more pleasing than without any center in the ambience.
It's also timed a little earlier (3 ms) than the sides. I've had it timed late too but that didn't quite work as well. I've also had it timed the same as the sides but lost too much that way, I haven't measured it but it messed up the balance.
I did have to rebalance the tonality. More towards a flat gradually sloping FR curve than what I had initially. Not a bad sign, to me it means the room sound is probably more even trough out the room than it was before the added ambience. I need to confirm that though.
Still more experiments needed, it's very rewarding to play with though. It definitely shows what a big influence a room can have. If you want better sound? Start with the room!
It's also timed a little earlier (3 ms) than the sides. I've had it timed late too but that didn't quite work as well. I've also had it timed the same as the sides but lost too much that way, I haven't measured it but it messed up the balance.
I did have to rebalance the tonality. More towards a flat gradually sloping FR curve than what I had initially. Not a bad sign, to me it means the room sound is probably more even trough out the room than it was before the added ambience. I need to confirm that though.
Still more experiments needed, it's very rewarding to play with though. It definitely shows what a big influence a room can have. If you want better sound? Start with the room!
While I did mention using a different kind of pré EQ I don't think I've shown it here yet.
I measured the raw response at the listening position. Next step was to export a minimum phase IR of that measurement in REW. Re-import the minimum phase IR and let REW calculate PEQ filters based on a 1/6 octave FDW. Manually tweak it here and there afterwards and use that EQ as pré EQ.
The difference in pré EQ in graphics:
A few broad strokes of EQ with low Q
The new pré EQ:
Much more action here, leaving less to correct for the FIR filter
Still need to revisit this some day, the old EQ had a slight advantage in the midrange (around 500-800 Hz), the new EQ having the advantage in the top end. Not shown is a 3 dB high frequency shelf I used on the top end. Some day I'll see if I can get the best of both worlds... Not in a hurry though, I was quite pleased with the outcome.
Just something I always wanted to try. When I made the move to JRiver 21 I figured why not do it...
The right EQ is even more "busy" (though, notice the difference in scale of the plot):
Some of that boost is removed in post-EQ
There's more cut than boost though, notice I'm only using boost below 60 Hz. It seems the only real difference was the high shelf boost at higher frequencies that made the difference. There's no difference in boost in pré EQ at those frequencies in the old and new setup beside that shelf. So did I win anything? Only that a high shelf does work when I let the FIR filters eat away the excess boost.
I still use some manual PEQ correction after that. Based on all of the different tests I've done over the past year.
I measured the raw response at the listening position. Next step was to export a minimum phase IR of that measurement in REW. Re-import the minimum phase IR and let REW calculate PEQ filters based on a 1/6 octave FDW. Manually tweak it here and there afterwards and use that EQ as pré EQ.
The difference in pré EQ in graphics:
A few broad strokes of EQ with low Q
The new pré EQ:
Much more action here, leaving less to correct for the FIR filter
Still need to revisit this some day, the old EQ had a slight advantage in the midrange (around 500-800 Hz), the new EQ having the advantage in the top end. Not shown is a 3 dB high frequency shelf I used on the top end. Some day I'll see if I can get the best of both worlds... Not in a hurry though, I was quite pleased with the outcome.
Just something I always wanted to try. When I made the move to JRiver 21 I figured why not do it...
The right EQ is even more "busy" (though, notice the difference in scale of the plot):
Some of that boost is removed in post-EQ
There's more cut than boost though, notice I'm only using boost below 60 Hz. It seems the only real difference was the high shelf boost at higher frequencies that made the difference. There's no difference in boost in pré EQ at those frequencies in the old and new setup beside that shelf. So did I win anything? Only that a high shelf does work when I let the FIR filters eat away the excess boost.
I still use some manual PEQ correction after that. Based on all of the different tests I've done over the past year.
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I'm still on the ambience path... there is a lot to like there.
Playing with levels and timing and having a good time listening to 2 channel recordings. Every now and then I try something different like a 5.1 recording and compare.
The more I get things to work as I want, the more I like what it does. It really works well to "hide" the room. And it gives me a much more involving 3D soundstage, in both width and depth with the true feeling of envelopment.
So I encourage everyone reading this to give it a try. Don't forget to absorb all early reflections to -20 dB or more, for at least the first 20 ms.
I get a better balance in the room, on top of the 3D space effect. Enhancing the "you are there" experience. So far it works with more and more recordings, discovering new gems between my records.
In my enthusiasm I've tried some quad recordings. But that only made me aware of the tiny back channels. Even on regular 5.1 program they do a much better job. Ah well, you can't have it all I guess.
Playing with levels and timing and having a good time listening to 2 channel recordings. Every now and then I try something different like a 5.1 recording and compare.
The more I get things to work as I want, the more I like what it does. It really works well to "hide" the room. And it gives me a much more involving 3D soundstage, in both width and depth with the true feeling of envelopment.
So I encourage everyone reading this to give it a try. Don't forget to absorb all early reflections to -20 dB or more, for at least the first 20 ms.
I get a better balance in the room, on top of the 3D space effect. Enhancing the "you are there" experience. So far it works with more and more recordings, discovering new gems between my records.
In my enthusiasm I've tried some quad recordings. But that only made me aware of the tiny back channels. Even on regular 5.1 program they do a much better job. Ah well, you can't have it all I guess.
I am glad your liking things
But I did want to comment on this. A lot of people say it, but in the data ive been able to view, I haven't seen anyone achieve it. Not down to the transition frequency (about 250hz).
Even my room misses it in the strictest sense.
Perhaps the bigger problem is full agreement on what chart data actually indicates this the best. Certainly a full range ETC does not though.
You're absolutely right, Jim. Even though I mention it (and kind of assume people will look at the standard ETC presentation) I'm not there by a long shot. Not going to get there completely either. So I definitely don't mean it in that strictest sense.
How many measurements do we get to see here, taken at the listening position. It's still a trend to measure a speaker up close to figure out the crossovers etc. Look at it with gating to see the speaker. Yet I believe that's only the start of it. Once the speaker is at it's final position we need to see/learn what the room is doing to explain the sound we hear.
But we need a goal to shoot for, in order to get a potential of a pleasant result with ambient channels.
I'm not going to try and state what those real numbers we would need are. So first looking at that ETC plot alone is definitely a start. Personally I like the spectrum plots to get an idea of what's happening, along with looking at the filtered IR tab with use of the filters there.
That alone will burst most bubbles of thinking you're actually 20 dB down.
But what I'm trying to say is get aware of the peaks in your impulse, try and treat first reflections and breaking up the intensity of those reflections will go a long way towards better potential of sound in your room.
It will spread out the energy instead of a broad wideband peak. It will change the sound heard in the room. Some may even start to miss hearing that energy. Depending on where it comes from it could actually add to the current enjoyment level.
The only way to get a grip on things is to measure at that listening position. Start with the ETC graph as presented in REW and figure out where the largest early peaks come from. Treat them as best you can (or are allowed to).
Sadly we can't all build a dedicated room like yours, that room is by far the best I've seen in REW with real measurements, browsing trough the plots of the IR's you posted. I've seen a lot more room measurements but none that compare.
I did see rooms with a lot of potential, but with worse behavior than my own living room with minimum treatment.
The choice for absorbing as much as possible was an obvious choice for me to be able to run the ambient channels later on. I'd love to add more damping here and there though. But it's not going to happen. I bet many can relate to that.
Some speaker designs obviously work better to avoid early reflections. Horns come to mind, but usually there is a wall behind the listening position that get's in the way before we have passed that mentioned 20 ms.
My choice for arrays was to avoid floor and ceiling reflections, but that did mean I needed to work on the side wall(s) (and the front wall if I want even better results) and the wall behind my listening position. It looks pretty clean on a 10 dB spectogram, first signs appear at 15 dB down that I definitely don't make it all the way down to that 20 dB I mentioned. But the focus of the reflections is mostly gone by treating those early places the waves hit.
So this is a lot more words to get people to measure at the listening spot, after all that hard work to build their speakers, whatever they may be. And think about what they see.
I firmly believe the IR shows us what we hear. What it doesn't show is how we hear it.
Record your room and listen to it on headphones. It will make you quite aware of the room's signature. (not addressed to you Jim)
The added ambient channels/energy can help to influence and change that perception of that room. It doesn't need to be perfect to work, but don't expect great results without any effort.
All that I try to warn for is don't even start trying this in a bare untreated room and expect great results. Learn your room behavior, try to make it behave with your speaker of choice. Make them work together. After that it can be very rewarding to play with that room's signature sound. My room is small, close your eyes, listen and you'd never now it is.
So for what I meant, the 20 dB down is loosely based on that ETC plot for starters. Hunting down the room will give you a lot of input on why it sounds like it does now.
How many measurements do we get to see here, taken at the listening position. It's still a trend to measure a speaker up close to figure out the crossovers etc. Look at it with gating to see the speaker. Yet I believe that's only the start of it. Once the speaker is at it's final position we need to see/learn what the room is doing to explain the sound we hear.
But we need a goal to shoot for, in order to get a potential of a pleasant result with ambient channels.
I'm not going to try and state what those real numbers we would need are. So first looking at that ETC plot alone is definitely a start. Personally I like the spectrum plots to get an idea of what's happening, along with looking at the filtered IR tab with use of the filters there.
That alone will burst most bubbles of thinking you're actually 20 dB down
.But what I'm trying to say is get aware of the peaks in your impulse, try and treat first reflections and breaking up the intensity of those reflections will go a long way towards better potential of sound in your room.
It will spread out the energy instead of a broad wideband peak. It will change the sound heard in the room. Some may even start to miss hearing that energy. Depending on where it comes from it could actually add to the current enjoyment level.
The only way to get a grip on things is to measure at that listening position. Start with the ETC graph as presented in REW and figure out where the largest early peaks come from. Treat them as best you can (or are allowed to).
Sadly we can't all build a dedicated room like yours, that room is by far the best I've seen in REW with real measurements, browsing trough the plots of the IR's you posted. I've seen a lot more room measurements but none that compare.
I did see rooms with a lot of potential, but with worse behavior than my own living room with minimum treatment.
The choice for absorbing as much as possible was an obvious choice for me to be able to run the ambient channels later on. I'd love to add more damping here and there though. But it's not going to happen. I bet many can relate to that.
Some speaker designs obviously work better to avoid early reflections. Horns come to mind, but usually there is a wall behind the listening position that get's in the way before we have passed that mentioned 20 ms.
My choice for arrays was to avoid floor and ceiling reflections, but that did mean I needed to work on the side wall(s) (and the front wall if I want even better results) and the wall behind my listening position. It looks pretty clean on a 10 dB spectogram, first signs appear at 15 dB down that I definitely don't make it all the way down to that 20 dB I mentioned. But the focus of the reflections is mostly gone by treating those early places the waves hit.
So this is a lot more words to get people to measure at the listening spot, after all that hard work to build their speakers, whatever they may be. And think about what they see.
I firmly believe the IR shows us what we hear. What it doesn't show is how we hear it.
Record your room and listen to it on headphones. It will make you quite aware of the room's signature. (not addressed to you Jim
)The added ambient channels/energy can help to influence and change that perception of that room. It doesn't need to be perfect to work, but don't expect great results without any effort.
All that I try to warn for is don't even start trying this in a bare untreated room and expect great results. Learn your room behavior, try to make it behave with your speaker of choice. Make them work together. After that it can be very rewarding to play with that room's signature sound. My room is small, close your eyes, listen and you'd never now it is.
So for what I meant, the 20 dB down is loosely based on that ETC plot for starters. Hunting down the room will give you a lot of input on why it sounds like it does now.
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I agree with most of your post. Good advice and insight. But the above brings up something mentioned in my thread over at Gearslutz.
What the IR does NOT show is the directionality of reflected energy. Knowing what reflections you have in terms of magnitude, spectra, and timing is useful for sure. But the direction of incidence is also, and the IR gives us no clue to it.
Here is a quote from my page:
In my way of thinking, what we would like to know regarding late arriving energy is:
1) Frequency Magnitude
2) Arrival time (by frequency)
3) Direction
4) Ipsilateral - Contralaterial ratio
5) Specular or diffused/de-corralated
Of these, only 1) & 2) are clear in the measurement data we get in a one mic typical measurement.
But thanks to psycho-acoustic studies, we do have some idea what we want these things to be.
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