Assistance with dual subwoofer integration to mains needed

[darklordenron]

Hey all, new member here.

Like many, I am finding integration with my subs to my mains to be a bit..problematic.
I'll start with the room dimensions, layout and description first.
This room is 21ftL x 13.5ftW x 9ftH. It has a small open area in the front which will be covered with a wall and door this week.
I'm running a 5.2 system currently, down from a 7.2 (just too much sound in such a small room, I found..) Here's a picture to give you an idea of what I'm working with.
I've added some absorption in the vein of OC703 2" batt panels to the first and second reflections as well as behind the MLP due to a studio space being back there behind the MLP. Those panels are at the first reflection point of the studio monitors being used there. Some light cheap foam that doesn't do much other than (hopefully) reduce a bit of flutter echo is present on the side walls and that left front corner area in the first photo.

Mains are Paradigm Monitor SE 6000F's
Center is a Paradigm Monitor SE 2000C
Surrounds used to be Paradigm Monitor SE Atoms, but I ended up swapping those for some old Polk RTI8's which I feel like spread the sound in a more diffuse manner and they're currently being utilized. They also play a bit lower so there's that too
Subwoofers are a Paradigm V10 and a Martin Logan Dynamo (the older version 1 with higher output)
I definitely don't have fancy gear probably like many of you guys, and part of the reason is because right before I purchased this system, we bought a new construction home right at the start of the pandemic so.. yeah, funding was a bit on the tighter side Using bits of what I had before plus bits that I bought more recently at present.

Anyways.. The main issue is that I can't get the subwoofers integrated with the mains. The reason for the location was to kill a NASTY +20db 50hz peak and a huge -30db 80hz null that I was experiencing with both subs up front due to room modes at their prior 1/3 front wall placement. This is reflective of AMROC calculator when I punch my room dimensions in there, telling me that indeed there should be a gnarly peak at precisely 53hz. That 50hz peak seems to be inherent to the MLP area, front wall and rear wall, though I was able to squash it by moving the subs forward along the two side walls, right under the first reflection point. Just getting them to be non-localizable is the only real thing left to do at this point it seems. They just make themselves obvious at this stage being closer to the MLP than any other speaker I assume. I've attempted to turn them down a bit but it hasn't seemed to do much other than limit the output of the bass, sometimes to a laughable degree.

I have the system x'ed over at 80hz currently, running the 'full flat' setting in my Sony DN1080. The speakers seem to have a small peak around 100hz but appear to have a slight valley under 60hz and then rise again at 50hz with that stupid room mode. I chose 80 so I could avoid that 50hz peak, mainly.
I've level matched the subs to the mains and all other speakers at 75db using pink noise and utilized a Rat Shack SPL meter as well as confirmed this with REW's internal pink noise generator using the UMIK-1 in the MLP's.
I've measured the room at the Left Seat, Right Seat and Center for L, R, and LFE. Here is my graph data to pour over in case that's interesting to see.

Not sure how exactly to upload this .mdat file since i need 10 posts in order to post links. I have it sitting in my google drive at the moment so I guess just pm me if interested and I'll send that over.

Can't wait to get this bass thing better. I only just recently got my UMIK, I haven't actually even noticed with my eyeballs how badly room modes screw with my sound, though in the back of my mind I always knew it was happening.
Thank you!!

 

[darklordenron]

Figured out how to attach REW data

 

[Sonnie]

Welcome to AV NIRVANA

It will help to label the measurements so we know what's what... assuming the first one is front left, etc.

Are you measuring only the MLP at this point?

That is what I would focus on for now... don't try different seats yet. Get the MLP right and then go from there, if you really need/want to mess it up and try to get several seats marginal.

Are all the distances correct from each speaker to the MLP?

Does the Sony have two sub pre-outs to keep each time aligned with the mains... or are they summed together?

Two different subs are always going to be more difficult because at one level they may be in tune with one another, but as you increase or lower volume, one or the other is louder, therefore they won't be balanced with each other very well.

You have a LOT of variables going on with you setup... so it may end up being a challenge to get it right.

 

[Sonnie]

I apologize... after looking again, I do see you labeled the speakers in the comments.

 

[darklordenron]

Thank you!
I could have sworn I labeled them correctly. the first one in each block of three is the subwoofers only. The next is the left seat, next is right seat.

When I download that file from this site and load them up, they definitely have some labeling. ‍

I measured the mlp and right seat as well as the central position, in an attempt to average the responses. I really want both seats to have a decent response since well.. there are only two.

The Sony does have dual sub outs but I’m unsure if they sum or if they’re independent. I do not see any options for adjusting individual delays, so I would bank that they sum.

The speaker distances to the MLP from the speakers seem correct, yes.

 

[Sonnie]

I was assuming your MLP was centered... if not, I would initially work off of what centered looks like. It will be very difficult to see a good looking response from both seats. You might get them acceptable at best.

Ignore what any simulation tells you and try placing one sub in the front left corner and one in the right rear (or vice-versa), then measure. Then move one sub at a time about 2ft from the corner up the side wall, measure each time.

You could try adjusting the phase on one or the other subwoofer at each of the locations and taking measurements each time.

There's really no super easy way to do it... lots of trial and error. ... OR... get a miniDSP for the PEQ filters for the subs. Or get an AVR with Audyssey or Dirac Live to fix it all.

 

[darklordenron]

Yeah, I know it’ll be near impossible to get both seats perfect. A decent level of acceptability is what I’m after because that’s my expectation.

I’m also aware that non-matched subs are much harder to get right.. it may well push me to upgrade them both sooner rather than later.

I measured all the positions just to give everybody an idea of the space and how it reacts to the different seats. I feel like the speaker response looks quite good for what’s going on in that space, almost as if I did something wrong, hah! Subs leave a bit to be desired but at the end of the day that may well just boil down to the room itself and there will be only so far I can go before much more invasive methods of bass trapping start taking place.

Ok, I’ll try going with the corner load method and see if that resolves it. Will report back, thank you!

 

[BenToronto]

When it comes to bass, the more heterogeneity the better. Locations (mid-wall and corner), BR and sealed, floor and wall.... Ignore path length differences. But all need same XO, of course.

Very nice looking room but deadly for being so live, square, and hard surfaced (drywall much better than concrete, ditto for floor).

Needs REW plotting, each sub alone and then together. Be sure subs aren't producing much above 130 Hz, either fundamental or harmonic distortion products.

With music, never found better than just mixing the bass channels.

 

[darklordenron]

I did try the opposing corner method and all that gave me was very one-noted bass stuck around 50hz. It seemed to excite that modal response quite badly, which is why initially I placed the subs under that first reflection point. I am going to go back to that location today to resolve that, even my wife commented that there was “no impact and gunshots sound one-noted.” OOF, .

I’m adding a bit more treatment in the form of reflectors and more absorption to the mix once that door is installed (contractors have been tied up recently with other jobs and waiting on door options. Apparently solid doors are in demand) afterwards, I’ll post some measurements of the subs alone and working together.

 

[darklordenron]

Very awesome, I’ll try them out of phase in the front corners, this time firing AT the front wall (though that doorway corner is still very open until these contractors get back in here and build this wall for me..) and then try opposing corners again out of phase. Firing into the room, I assume? I reverted back to the mid side wall placement and they’re good, I just think they still display some audible peaks and bulls which can be addressed with better placement.