Audyssey/YPAO EQ resolution

[highfigh]

In the Salk speaker thread, Sean Olive made a comment that most speakers do well down to about 300Hz, which leads me to ask why receivers with Audyssey, YPAO, etc only have 1 octave resolution for their equalizers. If problems in the ≤300Hz is the hardest range to solve, why don't they use 1/3 octave EQ up to 300HZ, or parametric, with sliding center frequency?

Since they control the EQ with a DSP (Digital Signal Processor), how hard would it be to change this? Having a control at 63Hz is great if that's where the problem is and I know it's a common area, but houses, apartments and condos aren't all built the same way and this has to be a common issue when people use these automated setups.

Thoughts & comments?

 

[BoredSysAdmin]

From my 805 manual about Eq Settings:

You can select: 63 Hz, 160 Hz, 400 Hz,
1000 Hz, 2500 Hz, 6300 Hz, or
16000 Hz. And for the subwoofer,
25 Hz, 40 Hz, 63 Hz, 100 Hz, or
160 Hz.
Each band can be cut or boosted from
–6 dB to +6 dB in 1 dB steps.

But, I'm not sure if Audyssey's limited to same steps or applies it's own EQ engine/processing - I tend to hope for latter.

 

[gene]

Audyssey has more than 1 octave resolution for bass. In fact its the only auto-eq system we've tested that actually does something beneficial for the sub channel when properly used.

 

[highfigh]

Audyssey has more than 1 octave resolution for bass. In fact its the only auto-eq system we've tested that actually does something beneficial for the sub channel when properly used.

That's only on the new models, right? I keep getting into jobs with older models that only have the 63, 125, 250, etc and problems in other areas that aren't controllable, which is seen in the RTA display.

 

[anamorphic96]

The EQ bands being talked about on the receivers are for manual adjustment.

When Audyssey is being used it has the ability to adjust more frequencies. If not all of them. The problem is how many filters it has to work with. As you go up in the Audyssey line more filters are available for it to use. However the filter set for subwoofers is the same on MultEQ and MultEQ XT. The lower end version 2EQ offers no EQ for the sub.

YPAO from my understanding works the same way. More EQ is available when using the automated version and not the manual version.

 

[jostenmeat]

The biggest complaint about the auto EQ systems is the lack of flexibility. You won't know what Audyssey has done except by measuring the results for yourself. Otherwise, it can apply hundreds of filters, so that's got to be much finer than 1 oct rez.

Your mention of 300hz is interesting, because AFAIK Trinnov can have that freq pt as the correction cutoff, but I think I've been led to believe it is the guesstimation of what the Schroeder frequency area for any given room.

ARC is flexible in that the correction cutoff freq is adjustable, but I've been given the impression that most users leave it higher than expected.

MCAAC is perhaps the most adjustable, but AFAIK it does nothing at all for the sub channel, and only down to something like 63hz-ish otherwise. It only exists in Pio receivers, as YPAO only exists with Yam receivers. No pre/pros.

Most Audyssey featured products will offer at least two target curves, Flat and House/Audyssey (HF rolloff). It seems, historically, that Denon offered more flexibility in choosing either depending on the listening mode, as Onkyo's first generation with XT cannot apply Flat to stereo, or so I was taught by nibhaz. Marantz, at least for years, could not apply Audyssey correction to bitstreams of advanced lossless codecs, but could to the decoded PCM.

NAD will offer a third target curve, at least on certain models, as designed by Paul Barton of PSB. I do not know how it compares to the other two curves.

Then who knows what a pro can do with the Audyssey Pro calibration.

edit: I was picking Warpdrv's brains on the ARC with his purty Anthem processor. Here are some thumbnail attachments of the EQ results:
http://forums.audioholics.com/forums/showpost.php?p=567647&postcount=5

 

[selden]

Marantz, at least for years, could not apply Audyssey correction to bitstreams of advanced lossless codecs, but could to the decoded PCM.

They still have that limitation in the nnn4 generation of receivers, and don't have the XT or Pro versions of Audyssey, either. Presumably the limitations are due to them using slower DSPs than what the competition has.

 

[6L6X4]

In the Salk speaker thread, Sean Olive made a comment that most speakers do well down to about 300Hz, which leads me to ask why receivers with Audyssey, YPAO, etc only have 1 octave resolution for their equalizers. If problems in the ≤300Hz is the hardest range to solve, why don't they use 1/3 octave EQ up to 300HZ, or parametric, with sliding center frequency?

Since they control the EQ with a DSP (Digital Signal Processor), how hard would it be to change this? Having a control at 63Hz is great if that's where the problem is and I know it's a common area, but houses, apartments and condos aren't all built the same way and this has to be a common issue when people use these automated setups.

Thoughts & comments?

I'm fairly new to Audyssey, so take my response with a grain or two of salt.

AFAIK, the Audyssey room correction is entirely separate from the receiver's graphic EQ. MultEQ XT can create hundreds of points on its correction curve that it uses to fix room anomalies, not to mention its time domain corrections.

In my Denon, that MultEQ curve can be roughly copied to the equalizer, but of course it is limited to the equalizer's resolution.

To use the equalizer, Audyssey is turned off. So your options are to uses the crude equalizer curve (sans time correction) or the much more sophisticated MultEQ correction, but not both at the same time.