I need help with my room


Rooze came over yesterday with a TACT room analizer(?) which showed the frequency response of my system in my room. I will try to post pictures of the results, but suffice it to say that the entire frrequency response is muted. I have one spike at about 40Hz but everything is an average of 6db below what it should be.

There are pictures of my system so you can see some of the room, although I have taken down all my room treatments. This did help, but not enough. The room is carpeted and has a cheap acoustic tile ceiling. I was wondering if fire rated tiles would help in the midrange and treble?

Any ideas for getting me to where I should be? HELP!
128x128nrchy
It is easy to forget how little information I included with my posts. I figure since I know what I did, that you must too!

The measurements were taken many times. I think it was a total near seven. The microphone like type thing was placed on the back of the listening chair within inches of where my own ears would be located while listening. The speakers are about three feet out from the back wall and on the left side about two feet out from the side wall. On the right side this is not possible since there is a door on the side wall, and a little farther out into the room is a staircase going up. No room is perfect and mine is as imperfect as the best of them.

The measurements were taken with all room treatments in place, with the speaker placement adjusted, and then again with some, and then all treatments removed.

I should probably mention that I had Rooze’s Cary V12 monoblocks driving my speakers rather than my Krell FPB 200. I’m not sure how much difference that will make as far as measurements are concerned.

Sean, you need to keep in mind that there is a fine line between bravery and stupidity. Be careful not to give me too much credit. Carl is correct when he describes the listening room as a near nearfield. The speakers are about eight feet apart (I’m not home now, so I can’t give exact dimensions) and the listening chair forms a triangle with the two speakers with the chair, of course at the apex of the triangle.

I realize that most peoples systems don’t sound as good as they think it does. I was concerned about the accuracy of my system, hence the attempt at quantifying it. No audiophile worth his/her salt would say that they have wild frequency swings, or phases issues, and not feel the urge to hang their head, or at least, their salesman.

I probably have not taken enough measurements, but I’m wondering if I can do anything with the amount of information I have at the moment.

I admit that it is difficult to determine whether the frequency issues are speaker, room, or speaker and room interactions. Does it really matter what the source of the flaws is though? If I were willing to replace my speakers, or my room, neither of which is an option, then that would be more relevant, but I’m not in a position to do either, so I need to fix the interaction as much as possible.

Onhwy61, I have asked myself the question: how important is a flat frequency response at the listening chair. I just want to assure myself that I am getting a reasonable facsimile.

We did use the TACT in correction mode, and actually I preferred the sound without it, but I will readily admit that just because I like something, or even worse, am used to a certain sound doesn’t make it right. My goal in ‘opening this can of worms’ was to get a little better sound from my system as opposed to just having it sound like I want it to sound.

I don’t know if this makes any or much sense to anyone else, but that’s where I am.
Nrchy, in another post titled How Important Is Flat Response you wrote:

It is possible to love a system that is not musically accurate. Just because a person likes the sound of their system doesn't mean it's accurate, and just because a system is accurate doesn't mean you will like the sound of it!

Has the measurement experiment altered your views. I hope not.

Also in that same thread I posted a link to a site run by Ethan Winer. There he has a graph of the bass response in his personal listening room. Ethan makes a living selling and advising people on acoustic treatments, yet the response in his own room doesn't measure flat.
I'm not necessarily trying to get a flat response, I just want my system to sound better.
Nate: Easy mistake to make when posting on a complex subject i.e. assuming that we know what you know. Other than that, i agree with what you said. That is, you left out just a few "small" details : )

My thoughts are that you would have gotten VERY different results if you would have taken the measurements with your Krell in the system. The high output impedance that Cary amps demonstrate will typically introduce very measurable divergences from "flat" frequency response in most systems. On top of that, those divergences from neutrality will vary in frequency and amplitude with the different loudspeaker / cable combinations that they are mated with. This is not to say that Cary amps don't or can't sound good, but that the results of mating this type of amp with any given speaker / cable interphase is most assuredly a "crap-shoot" at best. With components like this, it is strictly a matter of "system synergy" as the predictability factor based on science is very low.

As a side note, those that own Cary products and think that i'm slapping them in the face / stepping on your toes, please review some of my previous posts where i mention this brand. While i personally believe that Cary amps are not a very "linear" device, they are quite capable of producing very "musical" sound that is highly enjoyable and projecting vast amounts of spaciousness into a recording. Funny thing is, one of my other "favourites" when it comes to mass-produced tube gear would be Atma-Sphere amps, which measure VERY differently from Cary amps. Completely different ends of the sound and design goals spectrum, so go figure... : )

Other than that, if it were my system and knowing what i know now about the test conditions, i would consider the test runs that you did to be nothing more than an experiment and "learning session". If you wanted to do this "right", you really need to get your amp back in there ( or the amp that you intend to use in the near future ) and give it another series of test runs. Sean
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PS... If i remember correctly, Stereophile actually tested a Krell amp in the same issue that they did a Cary amp. John Atkinson said something to the effect of "If one of these amps is right, one of them is VERY wrong". Obviously, it all boils down to a matter of personal preferences : )