How would you handle tuning 3 subs?

[madpoet]

I have an Onkyo 5008 which has XT32 and 2 sub outs. I know I will have to split 1 sub out, but I'm wondering how well it will handle that when it comes time to calibrate.

[craigsub]

Paul .... Assuming all three subs were the same, and you had the same power to each, you may have an issue with XT-32 boosting the single unit sub too much in an effort to match the duals that would be on the other output.

Of course, depending on how many microphone positions you used, and proximity to your listening areas, and this may even be preferable, if the "duals" were in a part of the room that needed more output than where you put the single.

[madpoet]

Who knows Craig, I might just have to go to 4 ;)

[craigsub]

That is totally unwarranted, eight 18 inch drivers in one system. Makes sense to me! :biglaugh:

[Mktheater]

That is totally unwarranted, eight 18 inch drivers in one system. Makes sense to me! :biglaugh:

It just does not make sense, it should be required! I have always used a one to 4 splitter for the processor to see one sub. I always set each sub to 75 dB's alone and made sure it went up at least 3-4 dB's when I combined another sub. The best you can ask for is 12 dB's of gain but make sure that the phase is correct because If not you will get peaks or nulls with placement. Then let th EQ do its thing.

[madpoet]

Did you just set 2 of the four to 180 phase and move on, or did you actually measure and decide which two to set that way :)

[Mktheater]

Did you just set 2 of the four to 180 phase and move on, or did you actually measure and decide which two to set that way :)

2 were out of phase 180 degrees. Just measure and see what does what. Once you get a flat response don't touch a thing except the processor gain.

[madpoet]

Yeah.. measure... guess I need to get me something besides the black box XT32 then ;)

[madpoet]

Found this great post which even a novice like me could follow, so I ordered up some gear to try REW :)

http://polaraudio.blogspot.com/2012/01/calibration.html

Be a while before my new towers of terror arrive, plus I have to get the clone amp shipped over. But in a few weeks my house may be lifted into orbit! If I can get output and a smooth line anywhere near what Mk got I will be in heaven, but my room is complete crap so I am not expecting perfection. Just a ****load of bass! :angel:

[madpoet]

It just does not make sense, it should be required! I have always used a one to 4 splitter for the processor to see one sub. I always set each sub to 75 dB's alone and made sure it went up at least 3-4 dB's when I combined another sub. The best you can ask for is 12 dB's of gain but make sure that the phase is correct because If not you will get peaks or nulls with placement. Then let th EQ do its thing.

Hey Mk how did you set phase on your subs? I know you were using 1 out to a 4 way splitter (and what kind of splitter?) and then to your 10kQ. I will be doing much the same just with 3. But since I am using a single output, where am I setting the phase? Does the amp allow you to?

[sbdman]

Ok, you've got the FP10000Q, the 3 18.2's, all hooked up and running? A near MKtheater setup...

I'm dying to hear what's going on! Throw a dog a bone?

[madpoet]

Yesterday was something of a disaster... lot of rewiring :) Headed down in a minute to get started on today's run. Going to take some before graphs with REW. I TRIED to place mine using the Geddes suggested layout. So I'm hopeful to have a nice response right out of the gate. And then we can see what XT32 does.

[sbdman]

Jumping up and down like a little school boy...
But, what's it sound like?

Yesterday, hope you didn't shutdown the local power lines and cause a cascade effect?