How to diagnose the need for room treatment?

Al wrote: "Particularly once you get above bass frequencies, tuning the room for flat frequency response using a test cd, microphone, etc., is not necessarily going to get you the best sound, and in fact probably won't. The microphone is not going to discriminate very well, if at all, between early arrival sound (the direct path from the speakers to the listening position) and later arriving sound (reflected off of walls, ceiling, etc). But your ears will!"

I think your comments apply better to the bass frequencies, not above bass frequencies. In the bass, the arrival/decay times are more easily measured and corrected whereas at higher frequencies room mode interactions approach randomness. Thus, at those higher frequencies, only FR adjustments are feasible.

Kal

Bob wrote: "I take exception to those statements. The REW (Room EQ Wizard available at the Home Theater Shack) is sophisticated and does time domains. It is for FREE FREE FREE FREE FREE"

Yes, yes, yes...................but REW is a measurement tool, only. It cannot implement a correction even if it defines it. One needs an additional tool to use the results.

Kal

In the bass, the arrival/decay times are more easily measured and corrected whereas at higher frequencies room mode interactions approach randomness. Thus, at those higher frequencies, only FR adjustments are feasible.

Yes, at higher frequencies only FR adjustments are feasible, but the point I was trying to convey is that making those FR adjustments on the basis of measured flat frequency response, in response to continuous tones monitored only in the frequency domain, will not provide best results. Listening to music provides the last (and most important) word in that part of the spectrum, it seems to me.

Arrival times in the deep bass assume importance particularly because of reinforcement and standing wave issues, as everyone probably realizes. Which causes the measured (and heard) amplitude of deep bass to vary as a function of frequency and location in the room, and which can be more easily corrected on the basis of measurement, as you indicated.

Regards,
-- Al

Hi KR4, That is true. But first one has to identify the problems. How you correct it and how much you wish to achieve is up to each audiophile.

The problem I see is that, very few know what they are dealing with, as far as in room response is concerned.

Bob

FWIW, in my post I referred to 'smooth FR' but I purposefully did not say 'flat FR'. Flat suggests to me hearing all frequencies at the same SPL, and when I have heard sounds in a room that were measurable as flat (especially from speakers which allegedly had a flat FR) the result was too much upper-mid and high frequency energy, where as a 'smooth' albeit tilted FR could be much more realistic for most installations.

Personally I really detest peaky mid-range and upper midrange FR, and it is easy thru measurements to determine whether this is attributibutibe to the speaker or the room (or both) by doing both near field and listen position measurements. Am I wrong, or am I missing the point?