Same with sub positioning - move it a bit, test and pick the best.
There's actually an easier way to position subs, by doing it backwards: set up the sub where your head will be while mixing, then walk your head around possible locations for the sub while listen carefully... Down on your knees and close to the front wall, mostly, of course. It's a lot easier to move your head around the room, than it is to move the sub around!
True, this method won't necessarily excite exactly the same modal response as having things the other way around, but it can get you in the ball-park, then you can tweak it the final bit the way you are doing it now.
But no matter which combination of position, crossover and volume, I get peaks in the 93-97 hz area and nulls in the 107-114 area
Then those are very likely modal issues, or SBIR issues, and NO amount of EQ or sub-walking is going to fix that. It is a room problem, not a sub problem, so the ONLY way to fix that is to fix the room.
This is why I'm trying two subs. I've read a few things here and there that say two subs set up properly will excite different room modes.
Perhaps, and perhaps not... And that's assuming that your room even
HAS other modes! Most small rooms have only a very tiny handful of modes in the low end, to play with, which is part of the problem.
Exciting more modes is not the solution:
damping all of the modes is the solution, best accomplished with large bass traps in the room corners.
As for treatment, I've got DIY floor to ceiling traps which perform extraordinarily well in all other areas
How were those built? What materials, what technique, and what size.
But the upper lows (95-120) have been difficult to tame. Specifically, 93-97 and 112-117.
94 Hz is your 0,2,0 axial mode, and 9.7 is your 3,0,0 axial, but you also have tangential modes at 88.8 and 99.8, and an oblique mode at 94.9. Not a happy picture!
This isn't a surprise, because these areas correspond to known room modes and quarter-length waves.
It isn't just quarter waves on the room axes that you need to worry about: Harmonics are also an issue, and so are tangential and oblique modes.
Everything above 140 is +/- 3db from the mean and everything below 90 is +/- 1db.
Did you measure that with REW? If not, then please do that. Then post the MDAT file here, so we can analyze it, and try to figure out where the problems are coming from, and how to deal with them.
I have tried running the near-fields at full range via a mirrored output from the interface, but it just didn't produce as even of a response.
That won't work very well! (As I guess you already discovered). Doing that, you'd have multiple sources trying to produce the exact same very long waves, at different locations in the room. That's a recipe for acoustic disaster...
So my question is this: which of these two ways should I connect the subs?
I would go with method #3: if the first sub has a direct out (post-crossover) then use that to feed the second sub, hopefully on an input that does not do any more filtering.
Failing that, go for method #4: Use an external stereo crossover, and pipe the "low" output to both subs in parallel, and the "high" output to each main monitor. In that case, you CAN set the built-in controls on the mains to "no sub" or set the crossover control (if there is one) way down as low as it will go, since you are doing the crossover elsewhere. Ditto for the subs: set the cross-over controls as high as they go, or use the direct input that does not go through any filtering, if there is one.
I can see pros and cons for both scenarios. I understand that placing subs is largely dependent on each rooms unique profile, but was wondering if there was commonly accepted wisdom in this matter.
You'll need to set up the subs symmetrically, tight up against the front wall, and keep them in phase (both set to "0" or both set to "180", whichever works best). So if your left sub is two feet left of the center-line, then the other sub should be two feet right of the center-line.
But anyway, post the MDAT file from REW so we can take a look at that: it will lay bare all the secrets of the room! Then we can try to figure out the best way to deal with the issues.
Also please post some photos of the room, so we can SEE what it looks like, and how you have it set up. That helps a lot to understand what you are dealing with.
- Stuart -
