I know that there are posts questioning/criticizing the usefulness of the auto calibration/equalization features of these kinds of units, but since I just recently obtained the Denon 3805 A/V Receiver for other reasons, I thought I'd give it a go and let you know what I found out.

Bottom Line: Pretty good for calibration. Totally sucky for equalization.

Admittedly, I used the microphone from my Radio Shack meter (and would like to hear your thoughts with respect to the impact that this [the quality, or lack thereof, of the microphone] might have had on my results), but my 'equalized' receiver caused the speakers (M60's, QS8's, and a VP150, with a HSU sub) to sound muted. Without equalization, I can describe the sound as clear, three dimensional, and warm. When I turn the equalization on, however, it's like I put a wad of cotton in my ears. Just horrible.

As I mentioned above, I'm wondering if the dramatic difference in quality has anything to do with the microphone I used (which, if so, makes me wonder whether it is worth buying a real microphone for the job).

Thoughts?

I believe folks like Alan think of the broad-band auto-EQ in the 3805 and 1400/2400 as not detailed enough to be helpful (as suckouts are generally narrow-band).

If it had double the bands then, maybe - 4x, then probably. I don't think it has to do with your mic.

I don't think the feature is useless, but it doesn't do as much as one would like it to.

The equalization certainly isn't going to be any better than the mic you used---if you used one that has no low or high response (common in cheap mics), you'll get proportionately bad equalization.

Denon sells a mic they recommend using. I think someone on avsforum got the specs for it from Denon. I think it's a condenser with flat response from 60Hz to 10Khz.

Bruce

It was me (on AVSForum) who got the specs from Denon. :-)

Here they are, straight from Denon. Notice a 29dB microphone amp is also required.

"The specs for Non-Denon microphones and required mic amplifier for use with the AVR-3805 auto setup and room EQ function are as follows:

Required Microphone Specifications

Element: Electric Condenser Microphone
Polar Pattern: Omni-directional
Sensitivity: -40dBV (0dB = 1V/1Pa)
Frequency Response: 20~20kHz Flat Response (Ex: Behringer ECM-8000)

Required Microphone Amplifier Specification

Gain: 29dB
Frequency Response: 10~30kHz Full Flat "

Re broad band EQ, both Denon 3805 and Yamaha RX-V1400/2400 have parametric EQs, so technically the frequency width of each band can be adjusted from broad to narrow. Just because there's only 7 or 8 bands doesn't automatically mean they're broad. It's not like a graphical EQ where you divide the entire audio spectrum by the number of bands.

With the Yamaha, there's a separate 7-band parametric EQ for each channel. IOW the center frequency and width of the 7 EQ bands can vary individually for each channel -- LF, Center, RF, R Surround, L Surround all get their own unique 7 band parametric EQ. Also there's a frequency bias control so all 7 bands can be confined to the low, mid or high spectrum.

That said, I've played with YPAO a lot, and when I turn the EQ on/off while listening to material I can't say which sounds better. It certainly sounds different. Some material sounds better with EQ and other sounds better without it. Also I don't completely trust YPAO -- it often picks a 160Hz or 200Hz crossover. It's sometimes applied a boost and a cut to the same band on the same channel. Maybe it's a display limitation, but it seems like a mistake.

To me the biggest current drawback is it doesn't work for multichannel analog in (SACD and DVD-A). But certainly more bands would be better. I'm sure manufacturers will improve this in the future.

The Yamaha ships with its own calibration mic. Re the Denon calibration mic, I'd suggest Ockham get a good mic, not use the Radio Shack mic. EQing with a non-flat mic is like wearing colored glasses when painting a picture.

I did not know- thanks for the tip.

Awesome information. Thanks, guys, for your help on this. I'll probably end up getting the Denon mic from Crutchfield sometime in April and will let you all know my thoughts.