How to diagnose the need for room treatment?

Hi Ghstaudio, I assume you are using the Radio Shack microphone/Spl meter (although you did say a good microphone so its probably not Radio Shack). But If you are buying a microphone and you need a SPL meter, just buy the Radio Shack unit. It is more than adequate and the freq correction is done by the REW set up. Also many/most use this combination, myself included, and help in setup is freely available.

Point it straight ahead. It mut be on a tripod at where your head is.

When you get your Freq response graph, waterfall and RT60, please post them here for interpertation. That will be interesting.
Bob

If you are trying to assess room acoustics based on system throughput, aiming the mic forward, or at any speaker, biases the results to the performance of that speaker. Pointing it upwards makes for the least biased results. Also, averaging more than one mic position helps.

Kal

Make sure you have a measurement microphone - an omnidirectional condenser type. For example the Behringer ECM-8000. An ordinary microphone is not suitable

I will first use the RS microphone. I was going to try an AKG CK-32 cartridge (good omnidirectional mike). Finally, I have a rane RA-27 with a measuring microphone that I could try (requires me to build a small interface).

Most likely, I'll never get past the RS.

The human hearing mechanism tends to some degree to "latch on" to the leading edges of transient waveforms, and give them greater emphasis than what may follow a few milliseconds later.

Re my earlier comments on this issue, in a post in a different current thread Shadorne referenced a Wikipedia writeup on the "Haas Effect," which is what I was referring to without knowing its name:

http://en.wikipedia.org/wiki/Haas_effect

A brief excerpt from that article:

When two identical sounds (i.e., identical sound waves of the same perceived intensity) originate from two sources at different distances from the listener, the sound created at the closest location is heard (arrives) first. To the listener, this creates the impression that the sound comes from that location alone due to a phenomenon that might be described as "involuntary sensory inhibition" in that one's perception of later arrivals is suppressed.

The Haas effect occurs when arrival times of the sounds differ by up to 30–40 ms. As the arrival time (in respect to the listener) of the two audio sources increasingly differ beyond 40 ms, the sounds will begin to be heard as distinct.

Thanks, Shadorne!

Regards,
-- Al