Speaker shootout update; aggressive treble eliminating some (fairly?)

@pelletfan Thanks for your post. So far so good, but I’m going to put them through their paces. 
Your suggestion of a stand is SUPER helpful. 

ONCE UPON A TIME I had a pair oof B&W-801 Matrix speakers (upgraded). I had always thought the tweeters sounded a little "hot" especially on CD's as they were 1st coming out in droves. I had an excellent Levinson amp (23.5's) and I was pretty happy anyway with the sound. But then after I sold the speakers to a friend I heard them driven by Pass Aleph 1.2 mono blocks. Of course they were $14K and all that, but all of the sudden the B&W's sounded astonishingly good, smooth and as delicious as a chocolate malt. Just an example of how good the speakers really were all along. But I wonder if and when you were able to hear an audition at a dealer where you "knew" right then and there this is what you were after (with the cd's you brought in yourself)? Then you make a careful note of everything they were using along with the room, etc. Since your hearing is obviously very good, you should be able to find what is right and not so right about your own set-up. It may take some time (and unfortunately money) to find equipment that gets you closer faster to your personal goal. BTW, I replaced my B&W's with Eggleston Andra's and never looked back, but they weren't cheap and it took a lot of time for me to be able to to make the changes I wanted, including different amplifiers (Levinson 33H's- wonderful amps).

There have been some good suggestions here. I recommend you become familiar and comfortable with REW. It is a positive step in the right direction. Also free and really useful is HolmImpulse  I am using Omnimic from Parts Express but is not free, about $300, because it also allows me to measure Thiele/Small parameters. This provides tone bursts and measures room response in a second.

I have found the ability to read CSD plots (waterfall) very useful when adding acoustic treatments. Not only in how the frequency is altered but more importantly how the decay time is shortened. An untreated room has sound bouncing around with early and later reflections, confusing the information leading to smear and congestion, ruining soundstage and imaging.

All rooms suffer from this and taming these long decays makes a such a difference that unless you have heard it, is difficult to conceptualise. You have a room with reasonable dimensions that can be sorted out. No need to be overly concerned with a low ceiling unless you use a trampoline to keep fit!

A statement you made earlier about matching speaker to room or room to speaker is, I feel, not the way to approach this. There is a scientific target to strive for with room treatments and measurement is the only way to achieve this. Some of the advice offered here is well intentioned but misleading. EQ can not sort out overly long decay nor dips in the response. If you increase the power into a dip/null it will just cancel with the same power, leaving the problematic dip there but sapping the amplifier's power and driving it towards clipping. Taming the peaks by reducing power will flatten the response, but the sound is still taking to long to decay.

People often suggest drapes and wall to wall carpeting. They often do more harm than good. These are narrow-band absorbers, where what is required is broad-band absorbers. Take wall to wall carpet. It is thin with no air gap so it becomes a high-Q narrow-band absorber, and because there is a lot of it those freqs. are mostly lost. A nice thick rug in the listening area is fine. To sort out the floor to ceiling reflections consider the idea below. Absorption is needed on either the front or back wall or on both. The third axis to consider is the two side walls but in your case they are far away and not so troublesome. Dispersion/ diffusion would work well here. Drapes can help and also blend in nicely with the decor but a single thin drape will not do much. Use a 2 or 3 rail set up with thick material. The multirail provides a lot more material and, importantly, spaces the layers at different distances from the wall, broadening its freq. of absorption.

You mentioned a blanket positioned on the ceiling. If you replaced this with a proper broad-band absorber about 4ft X 8ft X4" thick and filled with OC73 or equivalent, you would hear an immediate improvement and see it on the response plots. There are many DIY articles for building these and bass traps on the net. Check out super-chunk bass traps. Simple and cheap if you are at all handy.  Bass traps are the true stars when treating a room. Can't really have too many.

Sound propagates in different ways depending on frequency. below the Schroeder freq. it is modal, transitioning to a reverberant field above that. When low freq's are present in a room, there is combining, some constructive and some destructive resulting in peaks and nulls. If its a full null then that is information missing and as previously mentioned EQ can't get it back. But bass traps can. They will smooth out the response, which again can be seen and heard.

It may have occurred to you that how do you know when to stop with treatment. It is not guesswork and there are tables that will give you a target to aim for. The aim is to achieve a reduction in decay time across the full freq. spectrum. In your size room it will be about 400ms. where the sound is required to decay by 60dB. Known as T60. This is great fun to do. As you introduce some bass traps you will notice on the waterfall plots that some previously missing information (nulls and partial nulls) is now starting to return and that some problematic peaks are being tamed. The audible result defies credulity.

One last thing, Take no notice of Kenjit, I think his lobotomy went wrong.

@lemonhaze71
I'm glad you say the low ceiling is not a disaster. A lot of things have sounded quite amazing, so perhaps I've just figured out where the low ceiling factor becomes a major issue, untreated.

I will try to learn REW, and HolmImpulse also. It's helpful to hear what you're using the software for, as I don't really know how to go about with analysis. This is probably why folks keep telling me to contact GIK — because there's a lot to this, and my fumbling around isn't going to get me that far. Still, knowing what I can use a *few* things the tools for to help my room (and speaker choice) a little bit is something I can seek out for the moment. I can at least seek to learn something about the major problems getting in the way of the test speakers' having a fair hearing. I have already taken some steps to soften the rooms reflection points, though I have not used measurement to know exactly how it helps. In this way, I am effectuating your comment about not trying to match "speaker to room or room to speaker is," though I am not yet on the way toward a scientific target.

Regarding this basement's floor, the room has a concrete floor with thin wall to wall carpeting, but also several thicker area rugs, other furniture (couch, leather chair, bed, wooden chest covered with a blanket), so there's quite a range of absorbtion and diffusion going on.

Regarding ceiling reflections, I may look into replacing the blanket and getting an OC73 absorber but I'd hope I can just mount it temporarily without getting into a DIY project at the start. Given that I'm not sure how far apart the speakers should be, ultimately, I'm not sure whether or not 4ft X 8ft will cover the correct area, though maybe there's a lot of wiggle room in something 8 feet across?

Bass traps — noted. I'm not finding any problems with the bass that make me want to set up traps *before* making a speaker choice. Still, if as you say there could be issues with frequencies *above* the bass which are affected by peaks or nulls, then some home-made experimentation may be in order. I appreciate you mentioning some targets to shoot for, such as 400 ms and T60. I bought a miniDSP mic that I can put at my listening position or at other places in the room (I obviously need to read about how to go about this), and see if I can figure out the software.

FYI, the rear wall is actually a built in bookshelves above cabinets that run the entire length of the room, with books of various heights all along. The two side walls are far away though I will confess that the speakers are not the same distance from either side wall. A bit hard to explain. My electrical setup has limits which necessitate this arrangement.

Anyway, super helpful post. Thank you.

@jtcf  Good luck with your search, too!

@pelletfan Thanks for your post. So far so good, but I’m going to put them through their paces.
Your suggestion of a stand is SUPER helpful.

Select the stand height so that the tweeters are at or just above your ear level where listening.