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!
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Nate, i'll start off by saying that you are a brave individual. You've laid your heart, soul, system and room along with all of its' non-linearities out for all to see and criticize. Kudo's to you for having the guts to do that. Having said that, i think that most folks would be utterly stunned if they saw the response of their system when obtained from testing like you did. I know i was when i first had access to upscale test equipment. Even just listening to the image shift when playing the Cardas sweep tone told me that something was VERY wrong. The funny thing is that moving over just one foot to either side and playing that same frequency sweep will produce DRASTICALLY different results. As mentioned above, that's why averaging of results becomes important.

In order for one of these devices to work and be properly interpreted, you have to take GOBS of readings. Something that most folks don't understand is that, if the speaker isn't very linear to begin with, you can't compensate for that with room treatments. That's why i've stressed speaker designs that take into account real world room acoustics with typical in-room placements. Most speakers, especially a lot of higher priced "audiophile approved" designs don't do this.

Other than that i don't know if you took any nearfield measurements of your speakers, but you should do that if / when you get a chance. This will tell you how much of what you are measuring is room based and how much is speaker based. As you get further away from the speaker, the room becomes a bigger factor. This is why some folks absolutely love and "preach the gospel" of nearfield listening i.e. less room interaction.

Other than that, your in-room response from appr 125 Hz up to appr 15 KHz varies +4/-5 dB's. This is actually not that bad compared to some that i've seen but could obviously use some help. Once again though, i don't know if you are fighting speaker problems, room problems or a combo of the two ( most likely ).

As to bass response, most rooms look absolutely horrible to say the least. Poor speaker design along with poor acoustics make for VERY "non-linear" response. For a peak at what the measured response is of someone else's system that has taken a lot of time in setting things up, take a gander at Joe's measurements regarding his "Critical Q subwoofer" installation. As a side note, i would encourage those that are interested in learning about woofer design and / or the "sealed vs ported" debate to give this entire article a read. It is quite educational and deals with real world situations and the design goals / trade-offs that we have to deal with.

Back on topic now, Joe's system actually measures quite good, yet it is something like +6/-5 dB's from 20 Hz to appr 15 KHz. It should also be noted that Joe chose to use a very revealing method to test his system, so it would look much "flatter" if he had used the standard 1/3 octave method that many others use.

As such, Nate has nothing to be ashamed or embarrassed about. While his system looks "rough", part of that has to do with the size of the graph used. If we were viewing a smaller graph length-wise with a narrower vertical gradient scale, the in-room response could have been made to look "much better". Obviously, his system isn't perfect and needs work, but the scaling of this graph somewhat exaggerates the results compared to what we are used to looking at.

Having said that, I have a lot of respect for anyone that would have both the guts and humility to post potentially "embarrassing" measurements ( only to those that aren't well versed in actual in-room response measurements ) and then ask for help in resolving those problems.

Not to single him out, and i know that he won't take this the wrong way, but even with the calibre and cost of gear that he's using, one can see how easy it is to end up with a "non-linear" system. On top of that, it is also easy to see how one could have a very different "sonic conclusions" when making comparisons from one system to another. That is, each system is going to produce unique deviations in frequency response ( and associated observations in timbre and transient response as they are all inter-related ). This is why i and many others strive to promote "neutrality" in both electronics and speakers, as a neutral response removes as much of the individual deviations out of the equation from system to system as is possible. Obviously, minimizing the deviations from a "flat" response can be a LOT of work and very frustrating to say the least.

With that in mind, my suggestion is to NOT make any brash decisions until you can make some very thorough tests and analyze the results. That is, IF you ( or anyone else in a similar situation ) aren't happy with what you are hearing. Obviously, some folks are content to listen to what they have and think that it is "as good as it gets" without really knowing what they are dealing with whereas others strive to achieve the best results possible. It would appear that Rooze and Nate are folks that fall into the latter category. As mentioned though, when one first takes steps like this, the "shock to the system" that you get as results may be enough to scare one away from seaking the "sonic grail of neutrality".

If you were to "quit" now and simply enjoy your system, i would understand. At the same time, i know that once someone sees this type of information about their system and know what is going on, it is a hard thing to forget about. As such, i would advise others to NOT take the steps that Nate did UNLESS you have the heart, soul and courage of a warrior. I say "warrior" as you'll have one helluva fight in front of you once you see what you're really dealing with. Sean
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Could you please describe how the measurements were taken.

From looking at the graphs I don't see how you could describe the response as muted. The most prominent features show a recessed lower bass/midrange and an elevated upper midrange with a smooth treble. If anything, I suspect your system sounds slightly forward.

One question you really need to ask yourself is whether you really want flat response at the listening position. Smooth response, yes, but flat will sound very bright. If you're adventurous I recommend you get a parametric EQ and experiment. Use it to reduce the peaks in the room response and play with shelving the treble response to see what you think.
I hope Nate doesn't mind me posting this, I don't want to 'steal his thunder' but there are some points that need to be added to help understand the measurements that we took in his room.
Firstly, I think it takes a brave person to look at a frequency respones curve and try to correlate that to how a system might actually sound. I'm barely familier with Nate's system but it sounds like one of the most 'together' and neutral systems I've ever heard. So to look at the graphs and assume specific sonic weaknesses requires a degree of courage and knowledge that I don't have.
A bit more about how we took the measurements:
I don't have actual distances from the listening chair to the speakers, distance between speakers etc, but Nate has the system setup for what I would describe as fairly 'nearfield' perhaps 8' or so from the speaker line to the chair....so as pointed out above, room/speaker interactions become a little less significant.
Also, the room to my ear is very 'dead' sounding with a good amount of diffraction and absorbtion, which I believe accounts for much of the neutrality. Later in the measurement process, Nate removed some of his acoustic treatments, and I felt that was a negative move and that the stage sounded at little more confined and that the tonal balance edged a little away from neutral and more toward bright. Anyway, I'll leave the rest of the room setup description to Nate, since that's his baby not mine.

We used the Tact RCS 2.0 for measurements, and used it in fully digital mode, that is without the need for using it's analog inputs and/or outputs.
Tact recommend setting up the unit to take 20 impulse measurements per channel, more if ambient noise is an issue. I set the unit up to take 35 measurements per channel, and we took several different sets of measurements from the same position, which I later overlayed to verify consistency.
I should have exhibited more foresight whilst taking the measurements however, by having Nate seated in the listening chair, or had cushions or something there to simulate the presence of a person. In larger spaces, these subtle details may not be significant, but it may have made an impact in Nate's room, I'm not sure.....
If you look at the overlay graph showing room treatments in place, versus room treatments removed, there are clearly some significant measured differences. Given that Nates room treatments were not physically large in terms of reflective/absorptive surface area, and 'volume', it could stand to reason that not having a person in the listening chair during the measurement stage could have 'fudged' the results to some degree.
I agree with Sean that Nate is a brave man, hanging his gonads out for all to kick. However, this approach might be missing one fundamental factor, and that is: 'what is it about the sound that I (Nate) am trying to change or improve?'

When I bought the Tact for use in my own system, I had some very specific goals - reduce some treble glare, add a little mid-bass warmth, extend the bass a little, cure some bass 'suck-out' problems at the listening seat.
Nates system, to my ear, doesn't have any of these issues, and doesn't really have anything that I can detect that is the result of poor speaker/room interaction. I think a clearer objective is needed to derive anything valuable from this experience....or, and this is a question not a statement - 'is it acceptable to approach this exercise like experimenting with new cables, for example - I don't really have anything to achieve specifically, I'm just look for all-round 'better'?
I agree with your post Rooze. That is, enjoying one's system and knowing that it is as neutral as possible are two different things. That's why i said that i could understand if Nate or anyone else in a similar situation "quit while they were ahead". That is, stopped working and spending while they were still happy and not quite as broke.

It all boils down to personal preferences, perspectives and goals. Having said that, i think that doing something like this and then seeing the results is VERY frustrating, dis-heartening and will tend to eat at most folks from the inside out. It's a tough call as to what to do and how to go about doing it. That's why i applauded Nate's willingness to bare his soul in such a public manner and his willingness to ask for help.

Other than that, i agree that he needs to be more specific about what it is he wants to achieve i.e. more neutral in-room response, particular changes to tonal balance, etc... If he's happy with the system but not happy with how it measures, and he pursues the correction of the latter, the system may measure flatter. The question is, will he still enjoy the presentation of the system as much as he does now???

Given that most people think that their system is much "better" or "more accurate" than they think it is, they really don't know what they are getting into when they start looking at the testing of their system in this manner. This type of situation is typically a MAJOR can of worms that most folks are afraid to open. I don't blame them either as it gets very complex.

By the way, while you guys were doing all of this testing, did you use the TACT to as a correction device at all? If so, I have to wonder if Nate preferred the system in stock vs corrected form? I'm sure it sounded VERY different. Depending on which he preferred, that might give him a better idea of whether or not he should "mess" with his system or not. Sean
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Sean, i was worried about getting Nate onto the measurement bandwagon and leading him on a downward spiral - but I made him do it anyway!!!(kidding).

I think if things are maintained in a certain context then there will be no permanent damage done. For example, setting a reasonable goal to ameliorate some of the obviously extended peaks and troughs, without striving for complete and utter perfection (the unattainable), is the safest way to approach this. The problem is that once the seed of doubt is planted, it tends to grow and get in the way of what we are ultimately trying to achieve - as you say, opening the proverbial can of worms.
It's over to Nate, but I think my approach right now would be to restore the listening room to its former state, with treatments in place, then to acquire a measurement tool that would allow him to see the result of each small change that he implements. Then slowly, perhaps over a period of a year or more, make subtle step changes, controlled and measured, to move him more towards a linear response, at the same time, allowing his ears to be the ultimate arbitrator between measurement and enjoyment.

Alternatively, given that Nate probably has more 'data' than most, perhaps take advantage of the Rives service, and have a professional assessment undertaken?
Rooze