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


I've been trying out speakers in a complicated shoot out, both bookshelves and towers — all in my home with my gear. I'm looking for speakers obtainable up to about $4k but could go up (or down) a bit if the right thing came along.

Basic facts: All speakers were run in at least 100 hours. Room is 27 x 14 x 6.5 ceilings. Powering with all QS tubes, 60w, NOS, tube R2R dac, and decent cables. No terrible reflection points; room not overly live or dampened. REL R 328 sub available but I did most listening without it.

Recent auditions, type:

Klipsch RP 600-M (budget singleton of the group)
Fritz Rev Carbon 7 mk II (bookshelf, 2 way, soft dome)
Focal 936 (tower, 3 way, inverted metal)
Martin Logan Motion 60s XTi (tower, 3 way, AMT)

Coming soon:

Salk SS 6M (bookshelf, 2 way, beryllium)
Dynaudio Evoke 30's (tower, 3 way, soft dome)

Let me speak just to the problems, rather than what was good about the speakers. So far, I've found the Klipsch, Focal, and especially the Martin Logans were all too bright — forward, aggressive, "turn it down" treble.

The ML's were the most impossible to tame and hardest to listen to on more tracks. (I did a lot of hanging of towels and other dampeners and other soft things to try to see if I could bring them to heel. I varied the recordings used. Changed cables/wires. No luck.)

The Focals were occasionally too bright; their bigger problem was a bit too much energy in my small listening space. They were better when I plugged their ports with socks.

I'm looking forward to how the next two speakers sound. The Dynaudio towers, I notice, are 10 inches shorter and half the weight of the other towers; not sure what that might mean, but it could just be right size for my space. I'm looking forward to seeing if the Salks bring more detail to the treble without also being too rolled off or harsh.

Hearing is very personal for physiological and taste reasons. However, if anyone has any thoughts about why I might be experiencing some of the phenomena I am (harsh treble, especially) based on my room or gear, etc., that might help me understand factors I'm not fully appreciating. Thanks.


128x128hilde45

Showing 2 responses by lemonhaze

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.


Hi hilde45, you mentioned, I think that you only hear to 14KHz. I only hear to 12K but it does not matter. The very high freq's are harmonics and for realistic sound it's essential that the tweeter is able to reproduce them.

Transients are rich in harmonics, they provide the leading edge and spatial clues. This stems from man's survival in the wild. The sharp crack of a breaking twig  gives the direction and even height of possible danger. We need those high freq's man.

Consider some musical instruments, a sax, a violin and a piano, robbed of all harmonics playing middle C. What will be heard is only the fundamental freq. a sine wave (261Hz), the instruments sounding exactly the same. It is the associated harmonics with the fundamental that allows one to recognise the piano say. The better and more complete the harmonics the more the piano will sound like a piano and listening fatigue is delayed.

Last year attending the XFI Premium Show in Holland I managed to have a lengthy. informative chat with Max Townshend from the UK. He was lecturing and demonstrating his super-tweeter. When hooked up the sound opened up with improved imaging and rhythm. Rim shots, snare,  the whole drum kit and mid range improved. Understandable because of a more complete harmonic structure.Still thinking about that tweeter, expensive though. The sound was not brighter, just cleaner and a lot more fun.

Some links that may interest you. The first one is excellent with much on REW. Plus a bunch of other very useful links. The second link has a short video on powder on a plate being excited by a sweep tone.  Enlightening. This is essential reading for anyone wanting to inexpensively take their system to the next level. A level that I don't believe can be attained by endless upgrading of components.

https://www.gearslutz.com/board/studio-building-acoustics/610173-acoustics-treatment-reference-guide...

https://ledgernote.com/columns/studio-recording/acoustic-treatment-guide-for-panels-and-foam/