Subwoofer distances

[herbu]

setting distance and phase are the same thing.

Right. Think about it.
I'm still a bit confused over the lengths you're willing to go to make the YPAO distance read the same as actual, especially after Swerd's explanation.

What's the difference between:
> One polarity and the effective distance moved farther away
> Another polarity and the effective distance moved closer

Your initial result involved changing one parameter, (distance).
Your new result will include changing 2 parameters, (distance & polarity).

To my way of thinking, the fewer changes made within the AVR, the better.
But that's just me. If all this is just an academic learning exercise, then good on you. Always interesting to poke, prod, and learn.

 

[KEW]

Yep, this is where we are:

If your sub has a polarity switch on it, you might try the YPAO routine with reversed polarity on that sub. It may or may not work differently.

 

[JOHN FICKEL]

I wasn't really trying to make the YPAO read the actual measurements. I just have heard so many different things as to what is better I just wanted to see for myself. I've heard people say that the actual measurements for SUBS are by far a lot better sounding than the measurements the microphones come up with. This exercise for me was to figure out why the receiver would put the subwoofer so much further back than the actual distance. after the testing I've done today, I put the polarity in my Yamaha receiver to normal, after various tests left reverse has always sounded better to me, yielding more bass. I've tried right reverse, left and right reversed, and again left reverse sounds best. So again in the (Yamaha receiver) I put the polarity to (normal)I went over to my front subwoofer which is the left sub woofer and I put its polarity on the subwoofer 180° The back subwoofer which is the right subwoofer The polarity was left normal. I basically did all the recommendations that the Yamaha receiver made I put the levels and the polarities the way the Yamaha receiver had them set . While listening to bass intensive music The only thing I did was put the sub woofer at 12 feet away in the receiver and then adjusted it to the 19.6 ft away... while listening to bass music . there was a HUGH difference , The Yamaha receiver was RIGHT, while listening to rap music I could easily hear what I preferred . The Yamaha receiver the (distance ) that it set was the best setting for my room, if I adjusted either of the subwoofer's (distances) from what the Yamaha receiver recommended you could tell that the subwoofer's were not working together and I did not have a cohesive bass response. once I put the distances back to where the Yamaha receiver had made the recommendation it was like bliss. So the microphone did in my case set the subwoofers up correctly. I made a huge change, I took the sub from 8 feet away, up to
19.6 feet away, up through the different Distances you could definitely hear the difference while listening to bass intensive music. There is no question, that what the (Yamaha receiver ) had chosen for my room, was (accurate) distances Depending on the model receiver people have maybe a $500 receiver wouldn't do this as accurately but if anybody has a flagship receiver I would hugely recommend letting the microphone set the distances on the subs. The only thing I did was adjust levels of each sub to my liking .

 

[PENG]

John, I know YPAO is not the same as Audyssey, but some of the principles behind the sub distance thing is the same so you may want to read this:

https://audyssey.zendesk.com/entries/177817-Subwoofer-Distance

I prefer to follow instruction to set phase of both sub to 0, crossover to maximum, disable all sub EQs and just let Audyssey (YPAO in your case) do its thing.

Another point, your Z9 should be more accurate than you Radio Shack SPL meter, even if you did use the correction table/file.

 

[herbu]

John,
Your original post said YPAO was ~6ft off in its distance assignment. Relative to what it's doing, (phase matching), do you understand how much 6ft really is?

Think about this. To completely reverse the phase of a soundwave, you shift it by half the length of the wave. Here are the lengths of some bass soundwaves:
20Hz = 56.5ft
40Hz = 28.25ft
60Hz = 18.8ft
80Hz = 14ft

So assume a normal crossover in your AVR of 80hz. The highest freq soundwave sent to your sub is 14ft. To completely reverse its polarity, YPAO would move the effective distance of your sub by 7ft. And if you average all the bass frequencies, the shift would be closer to 12ft. So your 6ft shift was really not extreme.

I'm with Peng. Follow the directions, then adjust each sub volume up/down if desired. Period.

 

[JOHN FICKEL]

John,
Your original post said YPAO was ~6ft off in its distance assignment. Relative to what it's doing, (phase matching), do you understand how much 6ft really is?

Think about this. To completely reverse the phase of a soundwave, you shift it by half the length of the wave. Here are the lengths of some bass soundwaves:
20Hz = 56.5ft
40Hz = 28.25ft
60Hz = 18.8ft
80Hz = 14ft

So assume a normal crossover in your AVR of 80hz. The highest freq soundwave sent to your sub is 14ft. To completely reverse its polarity, YPAO would move the effective distance of your sub by 7ft. And if you average all the bass frequencies, the shift would be closer to 12ft. So your 6ft shift was really not extreme.

I'm with Peng. Follow the directions, then adjust each sub volume up/down if desired. Period.

thank you for your response. It all makes sense now . So I should put that sub back to normal polarity and change it back in the Z9?

 

[JOHN FICKEL]

I believe my Subs were crossed over at 60hz at that time I ran (Distance) and leveling. So I'm going to make sure I have the crossover back to 80hz, only because I def perfer 80hz over 60 HZ. My Z9, I know why it's always reversed that sub, to phase match. It never messed with the other. At any rate I understand now why YPAO does what it does . It make total sense now . So it's better to have the receiver doing the polarity ? Not on the Sub? Thank you !!