The problem with absorption panels- it kills the fine details


If you’ve ever removed your absorption panels, you’ll find that you’ll hear a lot more detail and there is more openness. Truth is all those fine pressure amplitudes that add so much to enjoyable listening are considerably extinguished with absorption panels. The room seems quieter with absorption panels because all the fine detail is diminished.

It sounds different, so people think it sounds better. Absorption panels can kill good sounding music. I removed most of the absorption panels, and things actually sounded better. All the furniture in the room and the bookshelves were doing their thing in a great way. So I’ve concluded I really don’t need all that crap on the walls.

emergingsoul

@rick_n

I have been looking for possible new speakers and focused on Sonus Faber as a possible source. Their most recent speakers just don’t sound as good to me as their speakers from 10 years ago,  Their newer software-designed systems do not seem to me to have the same time alignment and immediacy. The Wilsons are pretty good, but to my ear have never tamed their tweeters (the inverted Audax cannot be managed effectively).

In general, it’s getting to the point that people need to learn how to design, built and customize their OWN speakers for their OWN rooms. Or find someone who can,

.

 

Let's get right to the point here.  OP why didn't you offer a pic of the room you're trying to optimize?  That would have been helpful and much more productive.  Here are two things to keep in mind that are mostly universally accepted:  1-you can over damp a room with absorption  2-you have to work really hard to over-diffuse a room.  With that in mind, try some different treatments and see what works for you.

 

Sonus Faber just updated their Homage line (Amati etc.) and they said that they are becoming more and more software modeling dependent.  Look around YouTube and you will see some cool interviews with the designers and understand their process to get optimal sound.  It's software driven.

 

The same can be done to optimize a room.  The big treatment co's like Viacoustic and Artnovian will take you room specs and recommend exactly what you need to optimize your room.  I took that route and am very, very pleased with the results.  I don't buy into what some have said in the thread about just moving furniture etc.  I guess they're not math fans.  Sound waves are math.  Start there and them tweak it to suit your ears.  Everyone hears things differently.  Good luck and cheers.  

Geez, never expected to see the word 'horrifying' so much in an audiophile thread.

Now I'm a little horrified to listen to my system!

I agree with everyone mentioning judicious use of the correct panels. In most listening rooms bass is biggest problem. Most retailers make bass traps that scatter/diffuse over a certain frequency to help keep rooms from being over dampened.

The room is the most critical part of a system. I was reminded of this recently when listening. The door behind my listening position that I usually keep open, I closed. This moved the reflection off the back wall behind me up about 10 feet. Sound was horrible. Soundstage collapsed, and the sense of openness disappeared. Opened the door, back to normal.

I’m sure the door closed with the correct application of panels could minimize the difference. For now, I’ll just keep the door open.

 

I'm stuck with a 16 x 16 1/2 square room.So yes I need some of "that crap" on the walls.

My above opinion is mostly in regards to smaller rooms where the challenges are greater. 

Of course every room is different with different needs. It seems to me that reflections will alter the sound you were supposed to hear as mentioned above. Not wanting to play the guessing game I had my room designed by a professional and I built it. It is virtually all absorption on every wall and ceiling. There is no drywall in the room. It is definitely considered a dead room and I was nervous about how it would sound. After everything got broken in I was blown away by how good it sounds. I hear mostly the direct sound from the speakers and I don’t feel I’m missing anything. I have been fortunate to have a few members with more experienced ears over for a listen and I believe they were pleasantly surprised how good it sounded. If anyone else here would like to come over for some listening I’d be glad to have you. 

So I’d say and over damped room is better than an under damped room. Happy listening! 
 

Ron 

Measure your room...hmm...how about simply listening to your system? Move the speakers...never rely on the opinions of anybody else as your earballs are attached to your head. My speakers are horns and my sweet spot  for critical or optimal listening is around 8 or 9 feet from the speakers...interestingly, further out in the room (long room with 18' ceilings, huge stone fireplace along one wall, huge euro style windows...blah blah) it sounds like real musicians are playing from one end, and that also sounds great. I thought when we bought the place a couple of years ago, that room would be Horribilus El Reflecto...it's not, sounds great. A great live music room also...who knew? 

@emergingsoul 

+1

A little anecdote. My local retailer sells megabuck equipment. Over the years, I have auditioned Wilson, Gryphon, Spectral, Rockport, etc. Many systems approach $100K. I have never once been engaged by any of their systems. The culprit was an acoustically dead room. Recently, a friend got the audiophile bug, and we auditioned a system for him consisting of KEF LS 50 Metas and a Primaluna integrated. The dealer's room was minimally damped, but the sound was some of the most engaging "toe-tapping" sounds I have heard. I would have easily guessed at least a $50K system if I was blindfolded. That dealer's philosophy is to replicate a customer's listening room, which they do an excellent job of. 

Hire a professional to measure your room and make specific recommendations or, get a semi professional measurement job done with the help of GIK or another of the many vendors who serve this space.

 

Room correction programs like Dirac or similar help a room to suck less, not sound better. It is also unlikely to be of any use EVER to someone with an analog setup.

 

It isn't hard to achieve the desired result but it isn't inexpensive to do it correctly.

I’m interested in online acoustical calculators. There have been a few listed here but the interfaces seem challenging. And they all have to be done on a desktop or laptop. iPads are taboo in this world these days for acoustical testing even if you connected it to a microphone which is absurd.

Is there something that can be purchased that could be plugged into a microphone and you can see the measurements displayed on a graph of your current room status before you start doing all the room correction work.

dirac won’t do that and it’s very difficult to figure out the original acoustic profile of a room. They’re interface is horrifying and there’s so many noise signal errors when you do the testing it is the most unpleasant experience in the entire world. And now I hear higher end speakers create problems for Dirac testing which leads to noise Signal errors. Wtf? Macintosh has a very expensive box that does a lot of stuff but it doesn’t provide a graph of your current situation Nor a graph when it’s all over. Wtf?

There has to be a simple way to evaluate a room without going nuts. Dirac has a very outdated app on the iPad which hasn’t been updated for several years, it’s horrifying and unusable. So good luck doing room correction with a nad processor

OK, it's clear a little clarification on acoustics is needed here. Not trying to mansplain, but just to provide some context.

1) Speakers provide input into the listening space. What you hear is the direct sound from the speakers plus the reverberant output of the room. This is why equalization, graphic or automated DSP is a mixed bag - it can only change the input to the room, not the output of the room.

2) In every room there is a point where the direct sound level equals the reverberant field level. This is called 'the critical distance'. Listening inside the critical distance is listening in the nearfield. Beyond the critical distance you hear mostly reflected 'far field' sound - mostly the room output. In a 2000 ft3 room, depending furnishings, the critical distance will typically be 3 to 5 feet (!). Extending that distance to hear more of the speaker and less of the room is a function of speaker angular coverage and acoustical treatment. This is why you see directional horns in recording studios and live sound, and why nearfield monitors like KEF LS-50s and venerable LS3/5a designs get lost in larger rooms - they are tuned for nearfield listening.

3) Acoustical panels (2" thick) absorb sound, mostly from 200 Hz and above. Diffusers, well, diffuse the reflected / reverberant field, normalizing the level and reducing 'hot spots. Placing either to reduce first reflections is the first objective of any acoustical treatment plan.

4) Below 200Hz is the province of bass traps. Since the fundamental frequencies of most musical instruments and the human voice are under 200Hz,the importance of bass traps cannot be overstated.

5) The acoustical requirements for a listening room, home theatre, and recording studio are all quite different, as are the requirements for recording a large symphonic work versus a small jazz quartet versus a multi-tracked pop or rock track. Home theaters in particular benefit from being the most damped, as you are replacing the entire reverberant field with the surround sound mix.

Overdamped 2-channel listening rooms, as noted, can sound 'dead', but left untreated they too often suffer from mid and upper mid-range 'glare' and lack of definition as well as boomy, uneven bass because the listening area is well beyond the critical distance, leaving your ears at the mercy of the sum of all room reflections and anomalies.

6) There are lots of online acoustical calculators to help begin the process of tuning a room for your specific requirements and listening taste. These are a starting point, not an end point. Also, there are numerous online advisors on the subject, some are quite skilled and others quite arrogant, most with a product or service to sell. Hey, gotta pay the rent. 

Furniture is far too vague a term to generalize. Suffice to say a sleek italian leather sectional is at best a diffuser while an overstuffed Victorian fabric sofa is quite an effective, if not optimally placed absorber. 

More than an other component, your room and it's acoustics will return more on your investment than any other changes you can make. A modest rig in a well controlled room will be more enjoyable than a mega-buck system in a poor room.

My impression is that over-deadened rooms are extremely detail revealing. It sounds dead, not my cup of tea, but you can actually hear more detail in the recording. "Air" and "detail" are not the same thing to me. I like some "air" in the room and to my ears it always comes at the expense of some detail, but it’s a worthy trade because it’s just more enjoyable. Now if it’s unevenly deadened, which is typically the case, you might end up with reduced apparent level in the upper treble with the lower midrange and upper bass still reverberating like crazy, so in that case you can end up with a muffled sound. But if you over-deaden a room broadband it sounds exquisitely detailed, perhaps painfully detailed. Diffusion can have differing effects, depending on how it’s done. Diffusers that have long wells or cavities will absolutely smear detail if they are too close to speakers.

The thing is, somebody might still find that to their liking, and the word "detail" can mean different things to different people. Generally it has been found that listening rooms are preferred with an RT 60 of around 0.3 seconds. The RT60 should be shorter in in the mid range and longer in the highs and lower bass. A lot of home listening environments end up just the opposite. The walls and various room openings often leak the lower bass pretty quickly, and the carpet and furniture sop up the upper treble very quickly, leaving a lingering midbass and lower midrange. Typically the absorption should be focused there, where it’s most needed and not where it’s not needed. A midbass to lower midrange absorber with a treble reflector/diffuser ends up making a lot of people happy. I’ve had people tell me,( and I’ve experienced it myself), that if you put a TubeTrap too close to a speaker with the treble reflector pointing toward you it can actually make the sound in the room too bright.

The consensus SHOULD BE, if we are honest with ourselves, is that most audiophiles slap some stuff on the walls without knowing what they are doing, why they are doing it and without a desired outcome in advance.

 

In other words, we apply acoustical treatment like we test cables, we A-B a bit, experiment a bit and then proclaim it "done". If we want a professional outcome, hire a professional. Most professionals though don't get called in until its a clusterph&*% of homemade, DIY or ordered off the internet random "solutions". Talk to a few pros and you will find they are most often in the business of trying to fix a bad haircut.

 

Random outcomes and hope are rarely the best strategy.

I think the consensus is that most rooms don’t need much acoustical treatment as long as there is a furnished room.

All the listening rooms we see with all the really really fancy gear only have all the really really fancy gear in them. It’s ridiculous it’s not normal.

I also think the consensus is diffusers make more sense than absorption panels because they scatter the waves and reduce lots of the reverberation affect. But they don’t diminish and absorb all the detail. So if only the world would create better looking diffuser panels then the crap they have now. Some look nice but many of the so-called absorption diffuser combo panels which are ridiculous look horrifying, with a few exceptions here and there.

I would buy diffuser panels in a minute if they looked nicer, but frankly they are a pain in the ass to buy because the marketing and the availability and the design and the size is so difficult to deal with with on all those damn websites that do a terrible job marketing this product. And the ease at which you can mount them on the wall is absolutely horrifying, it could be a lot easier.

where is a good place to begin to find out how to properly treat a specific room?

I have a fairly large area (media room over a 3 car garage) with wood floors.  Just picked up some new (to me) La Scalas and not getting the wow factor I was hoping for.  

We have plans to put a big heavy area rug in between the speakers and main listening position and wouldn't mind putting a couple panels up, but I'd like to avoid the look of panels everywhere if possible.

@avanti1960 

Its not usually about reflections giving fake detail though they create a sense of space. It's normally about absorption causing suck out in the room response whether you can hear the direct or not. Detail is not only first arrival it's subtle details in sustain, etc.  Get suck out and you get masking from louder sounds at other frequencies.

Honestly, you don’t need any of this crap. If your room is avg, meaning normal furnishings ( carpet, upholstered furniture, some hard surfaces, pillows & throws, maybe a wall tapestry, etc....u get the point...).

over doing it with acoustic panels can deaden the sound too much.  however unless the panels block the direct radiating sound of your speakers you are not losing detail.  what you are losing is sound reflected by adjacent surfaces mixing with the direct sound, slightly out of phase causing a bit of distortion that sounds like added detail. 

my room has 4 absorption / diffusion panels on the wall behind the speakers.  i left 1 foot gaps between the panels to allow some reflection.  

i have no side or ceiling panels, my speakers are far enough from side walls to avoid side reflections.  i hear plenty of detail and have a smooth response.  

rooms that have panels on every open inch of wall and ceiling space are over doing it.  

I agree. In a recording or broadcast studio is one thing but in the home setting I think they suck the life out of the music. The same things apples to carpeting in the home. My opinion. 

It's true, a room can be over-damped.  None of us would like to listen in an anechoic chamber.

But think on this.  A performance properly recorded for stereo presentation will contain all the artifacts of that performance in that room.  We should hear it as if we were in that room.  But if we listen to it in our rooms we will hear reflection artifacts of our room on top of those of the performance venue.  It seems to me that will confuse and complicate the performance we are trying to listen to, even distort it.

If we want truth in playback, may I make a plea for a bit more damping, rather than a bit less.

I'm among the "room sound" fans...there are a few of us (more than a few actually) out there who believe that most rooms generally sound fine with their furnishings providing all the damping you need. Plenty of pro reviewers are in that camp, as rooms, unless you live in a bare shipping container or a dumpster, often have a live-ish reality tone, or at least a tone of their own. Fear not. I use 2 subs to cancel or at least manage low bass standing waves, but my rugs and other crap somehow manage to make my listening room (large-ish living room) sound great.

Any room treatment first requires identifying the problem.  If absorption panels remove detail then you have applied the wrong solution, probably in the wrong places. Rooms can be over damped or over diffused, actually sometimes they can be both. My particular room has a massive bass problem at 63Hz, damping helped greatly, but dampened too much, however the intermediate solution was more bass, in the form of 2 subwoofers. This stopped critically high localised bass nodes whilst absorption calmed down the rest, diffusion behind, at the sides and rear were also beneficial. Interestingly the most effective resolution, in the end, was to buy a lower powered tube amplifier, great bass without excess, so 150 watts down to 25 watts provides much better bass and crisp high end, the mid range is of course a bonus.

Sounds like you overdid it with the panels.  I’d start just treating first-reflection points and see how that works and maybe some diffusion behind the speakers.  A careful mix of absorption and diffusion seems to be key. 

Room treatment is not something that can be guessed at nor something easily done by ear. It is difficult to tame reflections, get a good room response, and maintain on axis speaker response if you are using DSP. That does not mean DSP is bad. It is a tool and must be used responsibly.  I expect you absorbed too much mids making other frequencies more pronounced which further masks the mids. That wrecks your detail.

Room treatments are not tweaks, they're meant to solve specific problems created by the listening environment. 

@pedroeb 

It would be so helpful to see your system and listening room. It might help understand your disdain of room treatment better. 

So I’ve concluded I really don’t need all that crap on the walls.

It might be necessary in the recording studio where microphones are employed. The human brain is capable of amazing things the microphone cannot. Don't make the mistake of thinking the microphone is at all relevant in the listening room. This is why room correction, especially software fails miserably. Ditch room correction as unnecessary academic garbage.

A recording studio never makes a good listening room.

@emergingsoul 

That's why after you take care of the resonance in your room with the absorbing panels, you need to install diffuser panels to regain the clarity you just lost, but you are now achieving that without any resonance! I know, it's a difficult process that many audiophiles rather do without. However not my case, check out my house of stereo system, it was not easy but ultra rewarding in the end.

Absorption panels can be very helpful if used judiciously and appropriately. 

Many listeners overdamped their rooms. The entire room doesn't need to be treated, areas of reflections can help to keep music lively and realistic.

As many responders to your previous thread mentioned, you need a combination of diffusion and absorption to achieve optimal results. Absorption panels can be very helpful if used judiciously and appropriately. 

Interesting, I noticed when I had absorption on the front wall it sucked out the highs, on the back wall behind the MLP is totally different. I started with the side walls and after the third panel it sounded dead. That is when I found a good resource and changed it up, interleafing absorption with diffusion, Now it is the way I like. Totally get it though, dead rooms are painful to listen in.