How your room impacts how you hear sound

[anarchist]

Apologies Max, I rearranged your post a bit to address it.

I wonder what I have to state to get attacked around here?

I ask myself the same question. Lets look at your statements versus mine. I get attacked instantly while you skate.

I was trying to illustrate that addressing room acoustics on a forum like this is almost impossible.

I said, "Its very simple; making improvements in your sound based on the room is
a very specific scenario whilst generalizations can be made about the
sound of various components."

One side is saying, correctly that the sound produced by the speakers and amps (etc.) is not affected by the room.

The other side is saying that the sound heard from the speakers and amps (etc.) is affected by the room.

This side said both, "The component is producing exactly the same sound. What you hear is
different."

If it is a cheap and horrible system it will sound bad in the best
room. Conversely if it is a massively expensive system in a dreadful
room it will also sound bad.

I said, "If the source
sucks (meaning all the components), there is nothing you are going to
do to make them great by altering the room."

I am called all manner of names for my statements while you make statements which are no different and folks line up to kiss you for the insight. II think it is the greek thing and they are curious. Maybe if I change my screen name to Max...

[maxg]

Robert,

Hilarious post and not a million miles from my assessment either. I dont know - differences of style perhaps. I tend to spend some time selecting my phraseology so as not to offend whilst you....er.....leap in with both feet and a large cudgel?

Rule of life number 32 - you can say anything and get away with it if you phrase it cleverly enough.....

Another handy tip - gainsay your own argument within the post to cover yourself.

Having said that - you know it is actually impossible to prove that the speaker is producing exactly the same sound from one room to another where the resultant sound differs. Think about it a little - kinda reminds me of Schroedinger's cat or one of those logical debates where you ask if a tree that falls in the forrest makes a noise if there is no-one there to hear it.

[colterphoto1]

My comments:

1) We should thank mas for getting us all looking at acoustics. He has pointed out that what we read about large room acoustics does not necessarily apply to small room acoustics. Plus, he beats us to death on the issue - - which is a good thing. Yes, agree completely

2) Many of us have visited the listening rooms at Klipsch Indy. They are heavily treated. The fair conclusion is that Klipsch thinks treatment helps. I listend to K-Horns and other Klipsch in a heavily treated room at a dealer in the 'burbs of Chicago. Nice. Our rooms are too heavily treated for real listening. We are looking to create a room for Customer Service/ Sales that is closer to 'average room'

3) What to do to a room to make it better may be difficult to determine without testing equipment. But I suspect that most rooms are so bad that most treatments (within reason) will improve them. When you're at the bottom, anything is "up." I bought 'up' with my home purchase. 1955 house with 3/4 knotty pine in the hearth room, 1" plasterboard ceilings, then I installed hardwood floors in the gallery. I now have two drastically distinct, but pleasing listening environments.

4) You can do an elementry test on a room. Just clap your hands and listen for the echo. In some cases this will result in an echo which sounds like a science fiction sound effect, a distinct "boooiiinnng". My living room has that and I believe it causes a nasal type influnce on voices and music. Drywall is the worst. The drywall 'ping' is horrible, it is a function of the moderate hardness with the springyness of a bunch of flexible panels all hung 16" oc. In contrast, my hard 1" plasterboard walls have virtually no slapback.

5) I'll repeat my bath tub story because it may show how little you have to do to change things.

I have a tub with two sliding doors on the long wall giving access. I listen to NPR in the morning on a Tap Tunes. With the doors closed, there is a distinct reverberation making voices unclear. Siding one door totally open takes away just half of that long wall. So that is 1/6th of the total wall length. (Consider that the floor and ceiling are still there too, so it is a smaller fraction of total reflecting surfaces. This 1/6th cures the reverb totally. But opening the door halfway, meaning 1/12th of the wall total, is where the cure is just about totally effective.

Granted, this may not apply to a living room. But it could indicate that 10 percent or less treatment will improve things. I think PWK was talking about that figure for treatment with polycylinders. And see Dr. Who's experience with treating the AES room at U of I.

My basement is concrete block walls, concrete floor, plaster ceiling- really horrid. I had some rolls of fibreglass insulation and bubble wrap- stacked em up in the corner of the long legs of the 'L' shaped room and the diffeence was astounding! Just KILLED standing waves.

Gil

[anarchist]

Having said that - you know it is actually impossible to prove that the speaker is producing exactly the same sound from one room to another where the resultant sound differs.

The electrical signals don't change do they? That tree does make a sound if you have a recorder out there now, doesn't it?

From now on, I will just let you make my points for me so I don't have to be attacked. [:|]

[maxg]

Robert,

At the risk of getting seriously off topic (sorry all) read up on Schroedingers cat. The basis of it is that there is a cat in a box with a loaded gun. At some point the cat will cause the gun to go off and kill the cat. Schroedingers point was that until you open the box to examine whether or not the cat has killed itself it is neither dead nor alive. Its state is determined by the observer.

In our discussion (almost back) the recorder is, in effect the observer - but only once someone listens to the tape. Till then the tree made no sound.

For the loud speaker we are not measuring the electical signal in order to assess the sound it is producing - we can only measure the sound the speaker is making - and that is in the room - which negates the measurement. To be fair we could set up a system to measure the excursion of the drivers in the speaker during playback rather than the sound but even if we have a perfect match it does not mean the same sound is being produced.

Sadly this is going to get worse and worse the more I be-labour the point. Ultimately even if you could measure the sound of the speaker within the room and determine, by eliminating the sonic effects of the room, the original sound produced you are still screwed because I will claim that the measurement devices are now changing the sound back to how it was - but only because I can.[6]

And finally - its not my fault!!! Blame the quantum physicists that came up with their theories - you can apply them to real world situations but there is a danger your head will explode if you do.

[anarchist]

Yeah, yeah, yeah. And this existence only exists because we perceive it as so. [8-)]

I am starting to feel like an atheist at a Southern Baptist revival. []

[sfogg]

"The electrical signals don't change do they? "

Actually... they probably could change somewhat.

What happens when you move a coil of wire through a magnetic field?

It creates electricity.

In other words a speaker can also act as a microphone.

Hook up a driver to a scope or analyzer and clap your hands or something and look at the electrical signal the speaker produces in response.

A room with bad bass resonances could result in moving the coil(s) when they are not supposed to be. That would be a sort of back emf distortion. The electrical signals between the amp and speaker would vary depending upon if the room was resonating or not. Heck, just a higher noise floor in one room compared to another might changethe electrical signal if the drivers were picking up the acoustic signal (noise) and turning it into electrical signal.

Shawn

[maxg]

Sorry Robert - I will leave that one for another day perhaps.

Shawn,

Good point - forgot that one. Gets worse still if you are listening to vinyl where the cartrdige could be picking all this mess up and feeding it back into the signal - so even the signal from the vinyl is not the same - so Jacksonbart was right all along and Robert just diappeared in a puff of logic.

For my next trick.....

[sfogg]

Max,

"Gets worse still if you are listening to vinyl where the cartrdige
could be picking all this mess up and feeding it back into the signal -
so even the signal from the vinyl is not the same -"

Yup, or had a microphonic tube somewhere in the chain....

"just diappeared in a puff of logic"

Douglas Adams fan I take it?

Shawn

[merkin]

But am I suppose to put piles of insulation, plants, wet clothes and blankets in my corners? Should I cover my french doors in carpet? If I leave my shower doors open the floor gets wet. Help i don't know what to do!

[merkin]

In Illinois the cat couldn't have the gun unless he has a firearm owner's identification card. Guess I'd have to put the cat in the box with a sharp knife or bow and arrow.

[maxg]

Shawn,

Huge DG fan - well spotted and wouldnt a babel fish be useful around here at times - or maybe not.

Merkin,

This thread is a bit confusing now - let me help out a little:

You dont put piles of insulation, plants, wet clothes and blankets in your corners - you spread them around the room.

Heavy curtains will be fine for the french windows.

If you put dry towels in front of the shower with the shower door open you get free wet towels and keep the floor dry.

Its all so easy when you know how.....[]

[colterphoto1]

Max, you're a genius! [8-|]

[DrWho]

If you genuinely cant measure the effect of a persian rug (not that thick but high density) on a marble floor (such as I have) then we have a problem with the device.....

I am sure proper acoustic devices do a lot more - one would certainly hope so as they are designed for the job supposedly but that does not pre-suppose that using more normal bits of furnishing cannot make a big difference in comparison to a bare room, for example.

Empty my living room rings like a bell. Furnished it doesn't. Most audiophiles who have visited have expressed real envy over the room's accoustic properties. I would say it is probably amongst the best in the club and I do not own a single audiophile treatment.

I said you can barely measure the difference [] And that difference really resides above 8kHz (you're limited by the 1/4 wavelength thickness of the carpet). I just guess how you and I define big is very different, but nothing wrong with that. The few times I've measured rugs like this, it's been about 1dB above 8kHz both times at the listening position. The decay of the semi-reverberant field pretty much stayed the same (likely due to be swamped by the low frequency resonances). One of which was that room we set up for the AES...and we layed a crap load of carpet too (yea, even despite the theory I wanted to see how much of a difference it made). If you're going to change the perspective of your hearing and focus on changes, then I'd argue any amount of change is going to be percieved as "big". It's just basic psychoacoustics and something I use to my advantage when mixing live sound (guide the focus to the changes so that they don't need to be large to achieve the same effect).

Furnishings like couches and end tables and bookshelves however have a much larger influence...and it's simply because they're much larger and can affect a broader range of frequencies. With a big fluffy couch, you're talking on the order of up to 10dB and frequencies as low as 90Hz.

Btw, don't take my comments as saying your room sounds like crap or that you're not hearing anything. I would be stupid to argue with one's perceptions. You are obviously enthralled with your room and ultimately that's all that matters. However, from the few pics I've seen it can't be perfect (again, not saying it's crap). If you get the chance sometime, I would love to read your impressions of a well-treated room. Of course, if you don't like it I'll probably say it wasn't very well-treated []

[anarchist]

So Max, you and your cohort are stating an amp placed in a hallway closet will produce an electrical signal entirely differently from that amp if placed in a bedroom. And an amp in my bedroom (where it is subjected to various, uh, vibrations) will produce an electrical signal entirely different from that same amp located in your bedroom.

With those facts firmly established, you both agree that offering any advice on anything - whether it be a preamp, amp, speaker or room improvements - is an utterly worthless enterprise and we are all just wasting our time. Therefore, the entire premise of this thread - why don't we argue more about room improvements rather than discuss equipment - is a red herring because there is no point in making any suggestions because ultimately they have no bearing.

So we can put up a FAQ to respond to any and all requests for opinions that states: our opinions mean nothing and whatever choices you make are of little consequence because the audio signal will never be the same. There is no good, there is no bad, there just is... unless you are in the other room and then it may or may not be.

[colterphoto1]

'Fluffy couch' [] thanks for the giggle Doc!

[anarchist]

I said you can barely measure the difference []

Given the logic presented by Max and Shaun, why do you even measure? None of it provides any indication of what the equipment will sound like if anything changes.

Drape blew open, oops, equipment is suddenly producing an alternate signal. Wife walked into the room, oops, her energy field just played havoc on the signal.

No wonder you weren't impressed by Nos's Lascalas or any Lascalas. You walked into the room and your negative energy (a result of your supposition Lascalas have no bass) caused the speakers to immediately get shy and the woofer tried to hide itself instead of reaching full extension. You say your measurements back up your subjective opinion. Ha! Only because the amplifer felt sympathetic to the woofers distress and that sympathy led to an altered audio signal compounding the issue.

[6]

[DrWho]

lol!

I'll be sure to remind the laptop to compensate for my negative energy next time []

[colterphoto1]

when my hair enters the room the energy is drastically altered! []

[dkp]

when my hair enters the room the energy is drastically altered! []

lol