Thoughts on YPAO for hifi?

[existingbrain]

Curious what folks think about Yamahas approach to room correction for hifi, ie, 2 channel stereo listening. See link below for their explanation, but basically the approach is to match the frequency response of both speakers by EQing down the speaker with the higher sound level at any given point along the frequency spectrum to match the speaker with the lower sound level. I own a receiver with this functionality and in my experience it works well for cutting down bass peaks, but I have not noticed any improved stereo imaging, as their marketing material would suggest. Obviously your results will vary depending on the room and speakers, but I’m more curious about what folks think about the philosophy/theory behind this approach compared to that of others such as Dirac, arc, etc.

How YPAO™ Works in Yamaha Hi-Fi Receivers - Yamaha Music - Blog

YPAO™ Yamaha technology analyzes the acoustics of your space to optimize the sound you hear. Here's how it works in two-channel Hi-Fi receivers.

hub.yamaha.com

 

[GXAlan]

YPAO is great for its simplicity and loudness compensation (YPAO volume). It’s not heavy handed with the EQ to full range and is conservative in what it corrects.

 

[JeffS7444]

While using DSP to achieve better left/right channel matching frequency response seems like a worthy goal, I'd be a bit disappointed if it didn't go further, by making both conform better to some target frequency response, and ideally, there ought to be some degree of user configurability of that target response.

And I would not be keen to see a broad dip centered around 1 kHz, because I feel that can make movie dialog harder to understand.

 

[GXAlan]

While using DSP to achieve better left/right channel matching frequency response seems like a worthy goal, I'd be a bit disappointed if it didn't go further, by making both conform better to some target frequency response, and ideally, there ought to be some degree of user configurability of that target response.

And I would not be keen to see a broad dip centered around 1 kHz, because I feel that can make movie dialog harder to understand.

There are some FIR filters that you cannot edit, but at least on the AV products, you can go into the menu to manipulate the PEQ. The frequency and Q are not continuous variables like a MiniDSP but discrete options that still give you some control. There's no Audyssey app or Dirac style target curve.

 

[amirm]

They have always been week in bass optimizations where you need help the most. In their document, they show they only have a handful of filters. If they only allocate one to low frequencies, that is not going to be much especially if its response is too wide.

 

[Smaestro]

Just my experience:

I used YPAO on my setup, Yamaha RX-V479 with two T+A Criterion TMR 160's, in my then assymetrical living room with the supplied microphone. I did everything according to the manual but the resulting EQ was super strange, deep bumps and cuts that didn't make sense to me. I tried it a couple more times in slightly different positions, but every time it was strange in a different way. Not something reproducible with low/high shelves.
See edit below.

Perhaps worth to try again, I have since moved (to another assymetrical living room). If I can still find that darn microphone somewhere..

edit: After discussing with my partner, whose memory is vastly superior to mine, it turns out I remembered wrongly what was up with the YPAO results. It made left and right very different in level, even though the measurement was done in the middle (equilateral triangle). While perhaps some balance was warranted, what it did it was way off.

 

[Keith_W]

YPAO is crude, entry level DSP software. It is as effective as colouring in a postage stamp with crayons between your toes. I am not even sure if it's better than nothing, because DSP that sends the correction the wrong way is worse than no DSP at all. I am sure that Yamaha has hired some decent DSP engineers. I can imagine them going to work dreading the unrealistic requirements imposed upon them by management. The only reason it exists is for marketing. If you care about room correction, don't use it.

 

[GXAlan]

They have always been week in bass optimizations where you need help the most. In their document, they show they only have a handful of filters. If they only allocate one to low frequencies, that is not going to be much especially if its response is too wide.

The AV products are a 7 band “PEQ” *but* you cannot pick your own frequency or Q specifically so it’s not that great.

Frequencies you can choose for each of the 7 Bands: 15.6 Hz, 19.7, 24.8, 31.3, 39.4, 49.6, 62.5, 78.7, 99.2, 125 Hz, 157.5 Hz, 198.4 Hz, 250 Hz, 315.0 Hz, 396.9 Hz, 500.0 Hz, 630.0 Hz, 793.7 Hz, 1.0 kHz, 1.26 kHz, 1.59 kHz, 2.0 kHz, 2.52 kHz, 3.17 kHz, 4.0 kHz, 5.04 kHz, 6.35 kHz, 8.0 kHz, 10.1 kHz, 12.7 kHz, 16.0 kHz

Q Values you can choose for each Band: 0.5, 0.63, 0.794, 1.0, 1.26, 1.587, 2.0, 2.52, 3.175, 4.0, 5.04, 6.35, 8.0, 10.08

Then FIR filters that are hidden from the user which result in some correction if you turn YPAO on but zero out the EQ .

But if you look at Audioholics, this is what they got in flat mode

And

Yamaha YPAO R.S.C – Take Two

This post explores what YPAO R.S.C. is really doing under the hood!

simplehomecinema.com

I agree that it’s probably among the weakest of the room correction tools but if you look at those REW measurements, it’s definitely better on compared to off. Even though it has full range correction capability, it really doesn’t do much above the transition frequency unless you manually edit the PEQ yourself and that is probably better that it defaults that way.

 

[Smaestro]

It's important to note that there are 5 different versions of YPAO, the lower tiered ones level match and set speaker delay, but do not EQ.

How to Calibrate Your AV Receiver with YPAO™ - Yamaha Music - Blog

Learn how to calibrate your audio system with Yamaha Parametric room Acoustic Optimizer (YPAO) technology.

hub.yamaha.com

 

[GXAlan]

YPAO is crude, entry level DSP software. It is as effective as colouring in a postage stamp with crayons between your toes. I am not even sure if it's better than nothing

The measurements strongly suggest differently (see my post above). It is entry level, but I think the mantra that "entry level DSP is worse than no DSP" is a bit of an audiophile myth.

 

[Kevin1956]

It's important to note that there are 5 different versions of YPAO, the lower tiered ones level match and set speaker delay, but do not EQ.

How to Calibrate Your AV Receiver with YPAO™ - Yamaha Music - Blog

Learn how to calibrate your audio system with Yamaha Parametric room Acoustic Optimizer (YPAO) technology.

hub.yamaha.com

FWIW, I have several RX-V385 receivers with what I believe is the lowest tier YPAO. It definitely does some PEQ. However, it does not show you what was done, or give you any ability to alter the YPAO settings. I also have a RX-A780 with YPAO-RSC. It does show the changes made and allows you to alter them.

 

[Kevin1956]

Unfortunately for the OP, it doesn't appear that thus far anyone has any experience with the 2 channel YPAO they asked about. The description provided makes it seem like a completely different implementation than that in the Yamaha AVR’s. It certainly seems unique.

 

[GXAlan]

Unfortunately for the OP, it doesn't appear that thus far anyone has any experience with the 2 channel YPAO they asked about. The description provided makes it seem like a completely different implementation than that in the Yamaha AVR’s. It certainly seems unique.

Yamaha says it’s the

• YPAO™-R.S.C. (Reflected Sound Control) and precision EQ for ideal listening environment

But I don’t believe you can choose the tuning which makes me think it’s focusing below the transition frequency.

That means it’s version 4. Precision EQ was introduced with the CX-A5100. You don’t need 3D for two speakers

 

[dougi]

It's not clear if the OP is interested in YPAO for stereo in a multichannel AVR, or a stereo receiver. I believe YPAO on their receiver products (even the RN-2000A) only measure at a single position, so not sure how effective that could be. At least the AVR versions measure over 8 or so.

I have YPAO RSC on an A2A AVR. It doesn't do much correction in the bass, as has been discussed. Luckily my sub has PEQs which I measure and setup before running YPAO.

 

[Kevin1956]

Yamaha says it’s the

• YPAO™-R.S.C. (Reflected Sound Control) and precision EQ for ideal listening environment

But I don’t believe you can choose the tuning which makes me think it’s focusing below the transition frequency.

That means it’s version 4. Precision EQ was introduced with the CX-A5100. You don’t need 3D for two speakers

I agree that YPAO-RSC is what the Yamaha website says. However, the implementation described in the link provided by the OP is clear in stating that it is not the same as in their AVR’s. It says it matches the speakers to each other, not room correction to a target frequency response. So far, all we have been talking about is AVR implementation.