# Sub advize



## Zepplin72 (Aug 12, 2014)

I have 2 sub in my home theatre set up one at the front right and one at the back last diagonal I am confused on what I should have the phase on both sub ples advise me


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## willis7469 (Jan 31, 2014)

I would use a test tone at the crossover freq, with only the front sub and mains. Adjust the phase till you get the most output (spl). Then run the rear sub and adjust its phas til you get the most output again. If you don't have test tones, use the lfe tone in the AVR. Start with the front subs phase at "0", and set the rear subs phase to get the most output. Phase is a moving target, but this is a good way to start. Rew is the best tool for this but if your not equipped yet this will be better than blind lol


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## Zepplin72 (Aug 12, 2014)

I have the front on 0 phase should I rev the rear sub so the 2 sub don't cancel out


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## willis7469 (Jan 31, 2014)

It will depend on how they react to the room. You might be able to tell by ear, but I'd at least use an spl meter. Do your subs have variable phase, or 180deg?


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## Zepplin72 (Aug 12, 2014)

One only had 0 or 180 I have the filter on 55 should I have the filter on off or set it to 55 or few more options 35 45 55 65 75 85


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## willis7469 (Jan 31, 2014)

I forgot to ask what kind of subs they are. So?
In a typical install, you'd set the crossover in the AVR to 80hz and send everything lower to the subs. Smaller speakers will need to be crossed higher. Some subs automatically bypass their own internal crossovers(I think this is what you meant by filter) when you connect to the LFE input. Otherwise just turn the crossover all the way up, and they will only see what the AVR sends to them. (Below the crossover point). As far as phase, if you only have "0" and "180" that makes it easier to compare. If you don't have an spl meter, play some music that you know really well, and that has solid low end and compare. I would start with the front sub at 0 because I think being close to the same distance as the main speakers,they will share similar phase response. It's really hard to tell without measurement tools. But you should still trust your ears too.


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## Zepplin72 (Aug 12, 2014)

Ok thanks I will leave it on 0 and set the crossover to 85 the odyssey set my main speakers at 40 Hz I have the onkyo 929 so I guess that the amp auto filters my sub low freq is that correct


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## willis7469 (Jan 31, 2014)

That is correct. Audyssey sets mine to 40 also. I've run them at 50 & 60, and now I'm trying 80. It seems to helping fill the dip I've got at about 55hz. I haven't run REW yet but it sounds really good to my ears.


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## Zepplin72 (Aug 12, 2014)

What Hz are your main speakers on


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## willis7469 (Jan 31, 2014)

Set to 80 now. That's what THX calls for, and seems to be the status quo. I've liked mine lower in the past, but 80 is working now. No reason you can't experiment. Mostly all the "rules" you'll find are just guidelines. No room/equipment/listener/,etc are the same. 
Have you been able to notice any differences in your testing so far? Anything standout? Good or bad?


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## Zepplin72 (Aug 12, 2014)

Well I have 7.2 I do like how odys has set it up I don't have thx speakers so I don't go in those guid lines


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