The argument for/against room treatment

[Tim Link]

I've already demonstrated more than once via my in-room videos the best room you'll ever hear. The room that's been so overshadowed with music, the room all but gone. What more could you possibly ask for than a room (filled with acoustic anomalies) that for all intensive purposes no longer exists when listening to music?

I could ask for tighter bass. I could live without it, but it'd be really sweet if I could get it. It's one of those things where you don't know how much you're going to like it until you hear it. You can hear it by listening to headphones, but it's a much more compelling experience to hear it filling your listening room.

 

[stehno]

I could ask for tighter bass. I could live without it, but it'd be really sweet if I could get it. It's one of those things where you don't know how much you're going to like it until you hear it. You can hear it by listening to headphones, but it's a much more compelling experience to hear it filling your listening room.

Hey, Tim. Who wouldn't want tighter bass? But when bass becomes tigher, it's never just tighter bass we're getting. All areas of the bass become more well-defined, deeper, more natural, more musical, a bit closer toward the live event, etc.

And yes, in-room videos are generally but a fraction of actual in-room listening experiences. But if there is any magic or voodoo in high-end audio, my hunch is it's with the bass. There are no hard and fast rules toward achieving a truly musical bass because every speaker, subwoofer, and/or room and every combination thereof is so vastly different. In fact, I'm embarassed to say how many years I went without a musical bass since my previous room and my current room. I eventually gave up but still every so often I'd try something else. And it only takes a tiny move in the right direction or perhaps the turn of some knob or toggle switch (on a sub) and suddenly we've crossed over into the promised land. When this happens, it's quite a game changer for the entire presentation. But it seems to be free to all who are willing to work for it.

 

[pjwd]

The measurements are from the same room and same position. No gating used in the mesurements.

Pictures of speakers below.
2-way design with no vertical lobing but doesn't avoid floor reflections
View attachment 75621

CBT36 which avoids floor reflections:
View attachment 75622

Horn speaker that minimizes floor reflections:
View attachment 75625

Take note that I didn't imply that floor reflections were more detrimental than other reflections. I only suggested that adding broadband treatment to the floor makes an importance difference and improvement to my ears with traditional speakers. A benefit of treating the floor broadband is that one also begins to deal with vertical modes and bass is improved. But obviously not very practical with thick absorption on the floor! But even a 2" absorbent on the floor is an improvement to my ears.

Thanks bjorn that is an interesting range of results from each speaker type
You only need a dipole to complete the set
I will now have to try some floor absorbers and see if i can hear the difference. I agree with all you have stated excepting a subtle difference on first reflection points
The idea is that at first reflection points the best option is a reflector that redirects the sound away from the listener .. this reflector can be absorbant if you need to make the room less bright
This avoids the problem of a first reflection that does not correlate with the direct sound either from a different frequency spectrum in the case of absorbtion or altered phase in the case of a diffuser .
I have done elaborate diy qrd and broadband absorbers and while they give an improvement , the reflector is the most satisfying.
I developed this working with a thoughtful acoustic engineer on a number of projects .. its wonderfull to take a first principals approach to these issues
Acoustics is such an interesting area .. when its done right no one notices .. but a poor result really stands out
Phil

 

[Bjorn]

I use reflectors too. Mostly to redirect the energy to the rear of the room where there are diffusers. That's better than absorption if the energy is redirected in a good manner and especially if combined with low frequency absorption behind the redirection panels.

 

[wil]

You are correct, well sorta'. This part of the playback vineyard belongs to the speaker and/or a subwoofer's interaction with a given room (i.e. optimal placement and tuning). IOW, a playback system's noise floor level has very limited influence in this regard. But this has already been discussed earlier.

But where you are incorrect is thinking that it is beneficial to once again deal with the effects (room modes, flutter, etc) with acoustic treatments rather than dealing with the cause - which in this case is inferior speaker / subwoofer placement and tuning.

Bass has a noise floor not too dissimilar to a playback system's noise floor. Move a speaker 1/2-inch here or there or tune a subwoofer here or ther and bass notes become audible or inaudible. That's a mechanical energy / acoustic noise floor of sorts. In contrast, every playback system starts off with a much raised noise floor and each time it is lowered a notch, more and more music info becomes audible at the speaker. This is primarily an electrical energy noise floor.

Each of these two noise floors has its area of responsibility within the playback vineyard and with very limited overlap into the other's part. When both sectors are sufficiently addressed any such NEED for acoustic treatments and/or custom rooms is either greatly diminished or gone. But both take much work. BTW, there are numerous other NEEDS/folklore that are greatly diminshed or gone when these two areas are sufficiently addressed. Rooms being the most important component and the need for acoustic treatments are but two of them. For example. If you study my 2 components carefully you might realize they are among they most humble components found within this forum which should not only provide more evidence to substantiate my claims but also sufficiently address yet another very popular folklore.


Perhaps all of these influence the sound greatly when an unresolving playback system is in use and/or little work has been performed to place and/or tune speakers and/or subwoofers. But for a truly resolving playback system where much attention has also been given to speaker placement and/or subwoofer tuning, there is little if any influence.


Agreed, there is no magic whatsoever as I've tried to share that. I'm just sharing information which includes the results of my efforts focused on the causes rather than the effects, etc. If you choose not to believe what I share and prefer to keep doing what's been done for decades to bandage bleeding playback systems that is your perrogative. But I can assure you such status quo strategies offer very little relief in comparison.

To test if what I'm saying is true, use your smartphone to record a few in-room videos just for your own personal viewing and then compare to those I've shared.


Lucky? Hardly, this is my 3rd room in 21 years and this is by far my worst room to work with and though I consider my bass quite musical, it still isn't quite on par with my first two rooms both in which I did not use a subwoofer.


As I've mentioned before, most anything can be made to sound more musical. It's a journey, not a destination and it's an imperfect world and we're all dealing with imperfect rooms, power, equipment, etc. Any given recording contains exactly 100% of all the music info we're able to hear and all we can do is strive to make as much of that 100% music info audible at the speaker. Either we can deal with the effects, e.g. tubes, formats, acoustic treatments, custom rooms, multi-channel, omni-directional speakers etc. or we can focus on the causes. One strategy makes all the difference in the world while the other strategy consumes much resources while providing very little benefit.

As for for lack of experience? I've no doubt you have experience but I'm guessing your experience is limited to the status quo which never got anybody very far regardig real levels of musicality. My experience happens to reside in a couple of areas that others have taken for granted or gave very little attention. Or when they have given these neglected areas their attention it seems to have always been with little more than token efforts and/or employing inferior designs, materials, principles, and/or methods. But with regard to experience, at what point should our ability to discern / interpret what we hear enter into this discussioin?


Assuming for sake of argument that I am wrong, it should take little effort on your part to provide an in-room recording that meets or exceeds the musicality as these videos below or above. BTW, I'm using an iPhone 12 pro and Shure MV88 stereo condenser mic.

Room modes?


I've already demonstrated more than once via my in-room videos the best room you'll ever hear. The room that's been so overshadowed with music, the room all but gone. What more could you possibly ask for than a room (filled with acoustic anomalies) that for all intensive purposes no longer exists when listening to music?

Stehno, You make some good verbal arguments, imo. And you've posted a lot of videos on different threads inviting readers to compare recordings in their own systems. I can see how this could be useful, however I think for that to be so, you need to add some additional information:

1- source of the recording.
2- SPL range in db-c at the mic position.

While it appears a lot of your videos are pretty compressed recordings, do they really fall between 98-102 db as stated on your YouTube site?

 

[Tim Link]

I suspect one of us prefers dealing with the effects rather than the cause.

One of the causes is that bass bounces around a room for longer than desirable. It can do this no matter how cleanly and precisely the rest of the playback equipment works. The effect is that it sounds less than optimal. It has to be absorbed faster by the walls and ceiling or something else in the room if you want it to die down faster. Active or passive absorbers, or just big openings like open doors and windows can all help. Leaky walls that let bass escape outside help. Speaker type and position can have some effect too but there is only so much you can do. Sitting very close to the woofers is one way to get a better signal to noise ratio. Positioning the speakers to disrupt a major room mode might help, but only on notes that are played long enough to stimulate that mode.

 

[pjwd]

I use reflectors too. Mostly to redirect the energy to the rear of the room where there are diffusers. That's better than absorption if the energy is redirected in a good manner and especially if combined with low frequency absorption behind the redirection panels.

exactly ! - there seems to no commercial devices that do that type of thing - I guess they have to be quite specific to the room.

Also would be quite a trip hazard on the floor

I presume from the link you provided you are an acoustic engineer, do you follow the work of Tapio Lokki from Finland. I think his comparative work in concert halls is fantastic - as you have stated its not all applicable to small rooms but some of the fundamentals apply in all cases.

I wonder if @MadFloyd has had his question answered yet

 

[stehno]

Stehno, You make some good verbal arguments, imo.

Thanks, Wil. I try. I lack much of the intellect to sufficiently describe things other than in layman's terms. But intellect itself can get in the way sometimes so hopefully I'm good. I've tried sharing some of this years ago without in-room recordings. Without in-room recordings readers were more apt to jump all over me, try to mock me, etc, but with in-room recordings some of those types just stay mum - perhaps laying in wait for the right person with more credentials to jump in before they do. In the end the videos don't really seem to help much. I suspect some-to-many can only associate with what they are used to hearing or expect to hear.

And you've posted a lot of videos on different threads inviting readers to compare recordings in their own systems. I can see how this could be useful, however I think for that to be so, you need to add some additional information:

1- source of the recording.

Absolutely. I've got a number of 60's, 70's, 80's sampler / greatest hits type CD's so in some cases I'll have two or 3 versions of the same song and if I encounter that, one will usually sound a bit better than the others. Obviously, I proceed with the one I think sounds better. But nobody's really comparing videos anyway, so at the moment anyway I doubt that it matters much.

2- SPL range in db-c at the mic position.

db-c? My listening chair is about 10 ft in front of the speakers so that puts the recording mic/iPhone about 3 ft in front of me. Which I presume is a sonic compromise of what actually is captured at the mic since the bass and overall presentation are a bit superior at the 10ft distance.

While it appears a lot of your videos are pretty compressed recordings, ...

Sound pretty compressed? How so? Can you provide an example?

do they really fall between 98-102 db as stated on your YouTube site?

Actually, I'm sure the 98-102 is a bit understated. I wrote that template a while back just rough guessing it. I've still never confirmed with an SPL meter but in reality, I'd venture an in-room volume level of 100 - 104db range when recording is more accurate. Tiny condenser microphones don't seem to do very well capturing the dynamics and overall gestalt of the in-room presentation so it's important to try to capture at least a fraction of that in-room experience.

IME with the Shure MV88 mic, it seems the in-room volume levels need to be in the 100 - 104db range. Otherwise the recordings slip into boredom pretty quickly. With a drastically lowered noise floor, my system has no difficulty playing at those volume levels but at those volume levels, I'm also flirting with overloading the recording mic so it's a a fine line.

BTW, I'm only using my macbook pro or iPhone and wired Apple earbuds that come packaged with iPhones to confirm what I've recorded which seems in most cases to be good enough. Though I'm expecting a knock at the door any minute now for Amazon to drop off a hopefully reasonable set of inexpensive AKG headphones to see if that gives me any comfort.

 

[PeterA]

Stehno, I have done direct comparison videos on my system thread. Tango has also done some, particularly with cartridge comparisons.

 

[stehno]

Stehno, I have done direct comparison videos on my system thread. Tango has also done some, particularly with cartridge comparisons.

Oh sure, Peter. I meant anybody comparing theirs to my own. But yes, I wish others would at least play with their smartphones a bit with some sample recordings and just for their own personal playback. Just for the experience and getting to know what their smartphones are capable of as well as their limitations. IMO, there's much the industry could benefit.

 

[pjwd]

Stehno, I have done direct comparison videos on my system thread. Tango has also done some, particularly with cartridge comparisons.

Peter i think that is the best ( only ?) use of phone videos as there are so many variable room to room .. and its quite interesting
I also expect that a phone recording would be a bit more reverbarent than what you hear ( microphone vs ear that interprets via brain) has that been you experience ?
Phil

 

[PeterA]

Peter i think that is the best ( only ?) use of phone videos as there are so many variable room to room .. and its quite interesting
I also expect that a phone recording would be a bit more reverbarent than what you hear ( microphone vs ear that interprets via brain) has that been you experience ?
Phil

Phil, I don’t know what you mean by the system video being more reverberant than listening to the system live. I don’t understand how that would manifests itself when listening over headphones to the computer recording.

 

[PeterA]

Oh sure, Peter. I meant anybody comparing theirs to my own. But yes, I wish others would at least play with their smartphones a bit with some sample recordings and just for their own personal playback. Just for the experience and getting to know what their smartphones are capable of as well as their limitations. IMO, there's much the industry could benefit.

Perhaps people have compared their own system videos to the sound of your system videos and they simply don’t want to comment publicly.

Personally, I don’t have the music in my collection that you are presenting through your videos.

 

[stehno]

.... Positioning the speakers to disrupt a major room mode might help, but only on notes that are played long enough to stimulate that mode.

I dunno, Tim. Positioning a speaker is perhaps what one chooses to make of it. Positioning a speaker can range from pulling it out from the front wall to finding AN optimal location or THE perfect optimal location for maximum benefit as well as anything in between.

I've had 3 rooms in the past 21 years.

- In my first and seemingly best room, I stumbled across AN optimal location purely by accident, not even knowing such things existed. Here I think it worth noting that some semi-pro bass player was visiting one evening and he pointed at the 18-inch subwoofer and exclaimed that subwoofer is sure getting a good workout. And then I walked over to show the sub's power cable was unplugged. Also, just prior to moving from this house, a local reviewer was visiting and among other things he said, good luck trying to find another room like this one.

- In my 2nd room, it took me over 9 month to actively search for AN optimal location moving my speakers around maybe once or twice a week on average. This room was in some ways much inferior to my first room. End result the bass was a tad more musical but for some reason it seemed I also lost 1 or 2 Hertz in the bottom end.

- In my 3rd and seeminlgly worst room (but not the smallest), I'm too embarrased to say how long it took to find SOME optional location / tuning. I eventually gave up but I will say at least 2 US presidents have come and gone during that dry spell. And even with a subwoofer, this bass is not quite on par with the bass of the first two rooms. But it's darn close.

How does one know they found THE perfect optimal location? I've no clue.

The point being is, when you say positioning a speaker, are we really talking apples to apples here regarding speaker placement and extracting most or all that's possible toward achieving a superior musical bass? Because when I've eventually found some superior location, it's quite an incredible even thrilling experience every time I listen and though there's always always opportunity for little improvements and though I continue to experience improvements to this day with little adjustments at the sub, the last thing on my mind is that I'm lacking anything or that I need to shore up any part of the bass with something. It just hasn't happened in my very limited experience.

On the other hand, prior to finding some optimal speaker placement, I will encounter bass suck-outs, heavy, thick, woolly, over-emphasized, and otherwise ill-defined bass off and on throughout the journey. But once the speakers and/or subwoofer are dialed in or as I call it, crossed over to the promised land, most/all such bass quirks are long gone.

Based on my limited experience and based on what I've read or heard from only one or two others, my hunch is that every speaker has an optimal placement for perhaps any given reasonable room and it's just a matter of how much time one is willing to invest finding it. But I've been wrong before.

 

[cal3713]

I just read through this thread and there's lots of good information. One piece that got missed a little bit is how incredible the culminating room in the RPG slide show posted by @microstrip is. I want to hear this approach so badly...

https://www.prosoundnetwork.com/recording/studio-showcase-blackbird-studio-nashville

 

[pjwd]

Phil, I don’t know what you mean by the system video being more reverberant than listening to the system live. I don’t understand how that would manifests itself when listening over headphones to the computer recording.

Fair enough .. I thought a few phone recordings that I listened to sounded reverbarent and put it down to the fact that, when recording, you are adding the second space of the room to the original reverbarent field of the recording . The difference being is that your brain filters out the effect of that room but not when its captured on a recording and replayed. Much like when your first hear a suspended curved line array PA above the stage fire up you immediatly look up but after while your brain tells you its coming from the performers on the stage
If your phone recordings reverbarent field sound like your room thats great

 

[pjwd]

I just read through this thread and there's lots of good information. One piece that got missed a little bit is how incredible the culminating room in the RPG slide show posted by @microstrip is. I want to hear this approach so badly...

https://www.prosoundnetwork.com/recording/studio-showcase-blackbird-studio-nashville

View attachment 75767

Ha when i first saw this room I bought a recording by dawn langstroth ( one of the early artists) and it was dull and lifeless which on reflection made sense .. that much difusion starts to absorb a lot of energy
I have heard that recording engineers dont like the space and if you look at images of recording sessions you will see blankets etc over the diffusers
Dammed impressive looking though
Dont imagine the cleaners would agree

Cheers
Phil

 

[cal3713]

I have heard that recording engineers dont like the space and if you look at images of recording sessions you will see blankets etc over the diffusers

Ouch, that's unfortunate. Guess I'll cancel that $10,000 1/2" x 1/2" wood piece order.

 

[wil]

Thanks, Wil. I try. I lack much of the intellect to sufficiently describe things other than in layman's terms. But intellect itself can get in the way sometimes so hopefully I'm good. I've tried sharing some of this years ago without in-room recordings. Without in-room recordings readers were more apt to jump all over me, try to mock me, etc, but with in-room recordings some of those types just stay mum - perhaps laying in wait for the right person with more credentials to jump in before they do. In the end the videos don't really seem to help much. I suspect some-to-many can only associate with what they are used to hearing or expect to hear.


Absolutely. I've got a number of 60's, 70's, 80's sampler / greatest hits type CD's so in some cases I'll have two or 3 versions of the same song and if I encounter that, one will usually sound a bit better than the others. Obviously, I proceed with the one I think sounds better. But nobody's really comparing videos anyway, so at the moment anyway I doubt that it matters much.


db-c? My listening chair is about 10 ft in front of the speakers so that puts the recording mic/iPhone about 3 ft in front of me. Which I presume is a sonic compromise of what actually is captured at the mic since the bass and overall presentation are a bit superior at the 10ft distance.


Sound pretty compressed? How so? Can you provide an example?


Actually, I'm sure the 98-102 is a bit understated. I wrote that template a while back just rough guessing it. I've still never confirmed with an SPL meter but in reality, I'd venture an in-room volume level of 100 - 104db range when recording is more accurate. Tiny condenser microphones don't seem to do very well capturing the dynamics and overall gestalt of the in-room presentation so it's important to try to capture at least a fraction of that in-room experience.

IME with the Shure MV88 mic, it seems the in-room volume levels need to be in the 100 - 104db range. Otherwise the recordings slip into boredom pretty quickly. With a drastically lowered noise floor, my system has no difficulty playing at those volume levels but at those volume levels, I'm also flirting with overloading the recording mic so it's a a fine line.

BTW, I'm only using my macbook pro or iPhone and wired Apple earbuds that come packaged with iPhones to confirm what I've recorded which seems in most cases to be good enough. Though I'm expecting a knock at the door any minute now for Amazon to drop off a hopefully reasonable set of inexpensive AKG headphones to see if that gives me any comfort.

My point on making the video's most useful would be to use streaming sources (best Qobuz or Tidal) as that's the most easily accessible apples to apples source comparison.

On my iPhone db meter there are two settings: db-a and db-c. db-c is best for measuring SPL's of music, where db-a is good for measuring low level ambient room noise level.

As far as dynamic range, I'm not sure if your stated db level of 98-102 is the range of your peaks? It seems too narrow, even if a recording is compressed, to be the average to peak db readings. My reference in what I listen to (all genres) is typically a 10 to 20 db (avg to peaks) range, so it's hard for me to relate to a 4 db range.

 

[pjwd]

Ouch, that's unfortunate. Guess I'll cancel that $10,000 1/2" x 1/2" wood piece order.

Can you imagine the work putting it all together
... "hey you got the second stick wrong ..your going to have to do it all again"