What is everyone's preference on calibrating multiple subs? One at a time? Both together? Pro's and con's each way? I know this will vary based on placement, so let's assume both subs are equidistant from main listening position. I believe procedures change greatly at different distances.

I've found it really depends on your setup and room acoustics. Both can give good results. There is also a third option which is to use one sub as the "contol" sub and use the other sub(s) to make phase and equalization adjustents. Why do you say procdures change at different distances?

My understanding was if your subs are at different distances from your listening position, and/or not staged near each other the proper way to calibrate was one at a time then turn both on??? My dual subs are both up front between the mains, one on each side of the center channel and each one is the same distance to my LP. I am new at this, and have not p/u a meter or dove into REW yet. Just looking for a good start. Sounds good in my room, but my AVR set the subs(calibrated together & set at 11:oo) at -15. -3 to 0 sounds and feels good to me, so I'm curious as to how this plays into what the rest of the speakers are set to?

"Jakeman" is right when he states that it all depends on your setup and room acoustics. My method is pretty similar in that I have four subs always start off with one sub, set the volume and then individually do the others to match the first in output level. A good SPL meter AND "test disc" is worth the expense here since low bass is harder to balance strictly by ear AND, in my opinion, in comparison to your AVR/Pre-Pros internal test tones, the sound coming from a source piece of equipment like a DVD/BR player gives you a better (and more accurate) idea of what you are going to hear when playing back source material. You then turn them all on and match the volume to "taste" or, if you wish, use the meter to match them with your other speakers.

If your subs are equidistant from your listening position, the distance probably won't be a factor UNLESS, the subs are from different manufacturers and/or different types(down-firing/front-firing). At this point phase "may" have to be adjusted and this could affect overall volume as well. It may take some time but once it's done, it's done. This is, of course, unless you decide to move or replace them with others.

In the end, to me anyway, the TWO most important elements of maximizing sub performance and from the standpoint of your listening position, is balanced volume levels and proper phase relationship. How loud you want to play them in relation to your other speakers and source material, is just a matter of personal taste.

Thanks for the info guys! I have some work to do.

Casey, is a Radio Shack meter sufficient? Or would you recommend something else?

The Radio Shack metre is pretty much the standard.

I would concur.

I would start by placing your sub dB level on the receiver to the neutral position of 0dB. Then calibrate each sub One by One individually to match the same levels as the other speakers, usually 75dB. Adjust the volume (gain) on the sub not the receiver. Then turn off sub 1, and calibrate sub 2, etc...then turn them all on at once at the end. If you have them positioned "around" the room, the peaks and nulls will help cancel each other out for a more flatter response, which is the goal.

How would you go about doing a phase calibration? I have 2 totally different subs, an EP-350 and a 15" 500W DIY downfiring. They are in opposite corners of the room and I notice a big difference in SPL as I move around the room.

Change the setting on your phaser from "stun" to "calibration".

Sorry, I'm especially no help when tired....

Stewie, it's past your bedtime.

PB, if the auto-calibration set the receiver sub trim at -15, that indicates that the 11:00 setting on the sub volume controls is too high and should be reduced so that the result after calibration is closer to 0.

You're no help when you're not tired!

O' course, neither am I.

Thanks JohnK & sirquack. When I ran audyssey with one sub at a time my sub trim was set to +2. When I run it with both subs on it sets it -10 to -15 depending on setting on subs. I can tweak to my personal preference on AVR, but I am still wondering how this affects the trim levels of the other speakers? I going out grab a meter tonight, where can I get a test CD? Does radio shack sell those as well? BB?

I guess I should have added that when my subs are set to 10 or 11:00 & the avr sets trim to -10, When I turn up avr to -2 to 0 it sounds great.

If you run the sub "hotter" than the auto-calibration set it, either by increasing the volume control on the sub or the sub trim control, the other trim levels aren't affected. While some prefer to set the sub a few dBs "hot", the 8-10dB you mention seems a bit high. Keep in mind that a sub isn't supposed to call attention to itself as a separate sonic entity; the impression should be that the sub isn't working but the speakers are putting out more bass.

Pit, I did not use Audyssey to setup my subs initially, prior to running Audyssey. I used a Radio Shack SPL meter from the primary seat at ear level. I used the receivers manual built in test tone (pink noise), leaving the receiver sub level at 0dB to start. Then calibrated each sub one by one to the speakers, then turned them both on. The combined subs all on will have a higher SPL dB reading, but I have found that worked best for me. Some recommend to set them each about 3dB lower than the speakers, then when combined it will bring them up to match the speakers. You will just have to experiment, and may have to retry a few times till it works out. For my setup with an Axiom EP600, I have to have my receiver at -5dB, otherwise my EP600 volume would have to be to low to compensate.

Run Audyssey last. Also, one trick that many don't know. After Audyssey's first sweep, you can calculate and check the settings, without running all 8 locations, just to see what it does to the sub. Once your happy with the results, rerun for all locations.

Thanks for the tip and you're right I think many do not know that.

yeah it saves a lot of time. it is nice whey your trying to get the distances right as well. Since my 600 always comes in at 27ft and my 350's are correct distances. I usually try to get them as close to the same as possible, since there is only one distance setting for the speakers.

Thanks for the advice sirquack. I think my main issue is I've been calibrating both subs together. After reading everyone's suggestions I realize it would be beneficial to calibrate one at a time. You suggest running Audyssey last, but if both subs are dialed in won't Audyssey still trim them down? I gather the goal is to get them set at a point where Audyssey doesn't need to trim down? But if I prefer them to run a little "hot" the key is calibrate one, run Audyssey, then turn the second sub on matching level of 1st??? That will add the "hotness"? Make sense?

sirquack, I need help with this trick. My avr asks for three positions before I can calculate. How do you stop after one?