Integrating mix-matched subs .... Rythmik FV15HP or SVS PC13-U and an older eD A3-300.

[Qwiklap]

This is my first post on AH --but I have decided to start moving off of AVS. Question is in the re line: Is this just a colossally bad idea? Can it work?

I already have the A3-300 and it works (or will work once I get the plate amp back). I am thinking of upgrading the subs in stages -- starting with one new sub (either the Rythmik or SVS), and then getting a second down the line. But for now pairing it with what I have (which seems to do a decent job).

Room specifics: I have a dedicated home theater room that is windowless, dark and relatively tightly sealed. It is 19’ wide x 23’ long x 8’8” high. The screen wall is on the front wide wall. 15’ back from the screen wall is a 16” platform for the second row (platform is 8’ x 19’ x 16”). The platform is solidly constructed and filled with insulation, and does not resonate (at least I can’t hear it). I calculate it to be roughly 3785 cu ft of space. 3572 cu ft if you back out the space the platform takes up (I don’t know if you are supposed to do that or not).

As I thought about it during construction, I believed that the natural place for subwoofers would be along the back wall on either side of the rear row (I took pictures of the areas). So there are two coax connects (that terminate in RCA’s in the media closet) in the two back corners. The room is not sound proof – but it is resistant to sound transference. The ceiling is hung on an Auralex RC-8 channel system, all the drywall is 5/8” thick, double-layered with green glue, recessed cans have backer boxes, wall boxes have putty pads, ceiling and walls are insulated with mineral wool, door is solid core with an acoustic seal threshold. Supply and return to the HVAC system using acoustic ducting, and I have not heard any sound transfer through the HVAC. For the most part – only a small amount of sound (mostly mild hums from the bass unit) transfers to the room directly above – which is the formal living room (which no one is typically in). The room is carpeted with thick carpet and premium 10lbs pad. It is otherwise not yet acoustically treated – but I plan to do so with some DIY treatments. The left rear corner (when facing the screen), foundational corner of the house (the left wall and rear wall are foundation walls). The right wall is shared with the media closet, and the mechanical/storage room. Front wall is half foundation, and half shared with the rec room.

Equipment: I have a Onkyo TX-SR805 (which uses Audyssey MultiEQ XT for correction) and I have a Velodyne SMS-1 -- which I know is good, but cannot correct individual subs.

Let me know your thoughts.

 

[crossedover]

Behinger dcx 2496 or other equivalent will be your best option. Look up some of the papers Dr. Geddes wrote on eq and placement.

 

[Qwiklap]

Thanks.

If I upgraded my receiver/pre-amp to something with MutiEQ XT32 and SubEQ HT -- would that take care of the issue in terms of the two different subs?

 

[crossedover]

Thanks.

If I upgraded my receiver/pre-amp to something with MutiEQ XT32 and SubEQ HT -- would that take care of the issue in terms of the two different subs?

For non like subs I'd go with a unit suggested or similar ie DBX branded

 

[PENG]

Thanks.

If I upgraded my receiver/pre-amp to something with MutiEQ XT32 and SubEQ HT -- would that take care of the issue in terms of the two different subs?

I will be using sub eq ht to eq two different SVS but not 3. Sub eq can in theory do two reasonably well.

 

[crossedover]

Geddes talks extensively about the eq processes, expecially to the mains vs location. The behinger will give superior flexibility in most instances, definitely in the case of 3 subs and with two especially in lack of the audessey xt32 dual sub eq.

 

[Qwiklap]

I will be using sub eq ht to eq two different SVS but not 3. Sub eq can in theory do two reasonably well.

Thank you Peng -- to be clear, when I get the second upgraded sub, the A3-300 would be sold. Two Rythmik or SVS subs for my room should be plenty (although I am sure some would disagree).

 

[lsiberian]

I see no reason to spend 300+ on the DCX when the minidsp will do the job and costs significantly less.

 

[crossedover]

I see no reason to spend 300+ on the DCX when the minidsp will do the job and costs significantly less.

Yes the mini dsp would be an example of "similar " mentioned in my first reply. Significantly would be subjective. As a matter of fine tuning the mini will be slightly easier with the likes of REW, but as mentioned there several solutions. IMHO the DBX is bullet proof but cost over 600, unless used.

 

[lsiberian]

Yes the mini dsp would be an example of "similar " mentioned in my first reply. Significantly would be subjective. As a matter of fine tuning the mini will be slightly easier with the likes of REW, but as mentioned there several solutions. IMHO the DBX is bullet proof but cost over 600, unless used.

Can't say I've used a DCX or DBX, but the minidsp definitely is up to this task. I have 3 of them in my setup running the mains. It's only 100 bucks and they have excellent support.

 

[PENG]

Thank you Peng -- to be clear, when I get the second upgraded sub, the A3-300 would be sold. Two Rythmik or SVS subs for my room should be plenty (although I am sure some would disagree).

XT32/Sub EQ HT should have no problem EQ'ing two identical subs. I also have little doubt that it can do a very decent job equalizing two different subs because I have faith in Professor Kyriskakis and his team. I just moved my SVS sub to the other side of the front wall to make room for the new sub that is larger, re-run XT32, plot my graphs and am now ready for the new sub to arrive. With the new sub in place, I will run XT32, this time with Sub EQ HT engaged, and will plot the graphs again after so I know how well Audyssey does. So now it is Just wait and see..

In the highly unlikely event that it does not work well enough, then I will also the 3rd party systems that Crossedover and Isiberian suggested. Your room seems big enough to justify 2 SVS or Rythmik. Mine does not, but I am doing it anyway. May be we can compare notes in a few weeks.

 

[AcuDefTechGuy]

I already have the A3-300 and it works (or will work once I get the plate amp back).

Or you could get some passive subs and never have to worry about the plate amps again.

I've always love passive subs - NHT, RBH, Funk, Velodyne, etc.

 

[herbu]

I paired a Rythmik FV15HP with an SVS PB13U, and used MultEQ XT32 to match them. To me, they sound great! I cannot discern direction or separation... (one is in the front of the room, the other in the back). If I remember correctly, I set the FV gain at about 9:00, and the PB at -20dB before running Audyssey. Audyssey set the volume of the FV at -3dB, and the PB at -4dB.

After my tinkering, for music I use -3dB for both, and for movies I use 0dB for both. The VERY noticeable peaks and nulls I had with a single sub are gone. Our 2 main listening positions, (my chair and wife's chair), are ~5ft from each other, and with one sub the difference between them was huge. Could surely have mitigated w/ sub placement, but acceptable positions for large sub were limited.

 

[shadyJ]

I had an A3-300. No way would I try to mix it with a FV15HP or PB13 Ultra. By doing so, you are reducing the overall sound quality of the bass system to that of the ED, and it will not be as good. Trust me, I have closely compared an A3 to other subs, it is not bad, but I don't think it is on the level of some of these others. You will be throwing away money by trying to mix a higher end sub with it. The difference in sound quality that you pay for will be lost.

 

[PENG]

I paired a Rythmik FV15HP with an SVS PB13U, and used MultEQ XT32 to match them. To me, they sound great! I cannot discern direction or separation... (one is in the front of the room, the other in the back). If I remember correctly, I set the FV gain at about 9:00, and the PB at -20dB before running Audyssey. Audyssey set the volume of the FV at -3dB, and the PB at -4dB.

After my tinkering, for music I use -3dB for both, and for movies I use 0dB for both. The VERY noticeable peaks and nulls I had with a single sub are gone. Our 2 main listening positions, (my chair and wife's chair), are ~5ft from each other, and with one sub the difference between them was huge. Could surely have mitigated w/ sub placement, but acceptable positions for large sub were limited.

I am happy to know Sub EQ HT works for you. I know their theory is sound, not I have even less doubt it will work for me too.

 

[herbu]

I had an A3-300. No way would I try to mix it with a FV15HP or PB13 Ultra. By doing so, you are reducing the overall sound quality of the bass system to that of the ED, and it will not be as good.

I'm not sure about that. Chris at Audyssey seems to indicate otherwise in the Ask Audyssey section... https://audyssey.zendesk.com/forums/84181/entries/76175.html

Question:
I own 2 subwoofers. One is in the front right corner and other is in the back left corner.
Will any of the multieqxt AVRs EQ each sub individually?

Reply:
Yes, if the AVR with MultEQ XT provides individual control of the two subwoofers then MultEQ XT will create filters for each sub separately.

Question:
So it filters for each sub seperately. However, does it consider each sub then working together?

Reply:
No, it doesn't consider the subs together.

My experience w/ one very good sub and one lightweight, is the very good sub dominates. Especially so if you can control the volume of the 2 subs separately. You can lower the volume of the lightweight and mainly use it to temper the peaks/nulls a bit, and depend on the good sub for your primary listening pleasure.

I started with the lightweight... it was OK. I added the FV15HP... it was great. I replaced the lightweight with a PB13U and it was magnificent!!! I would not hesitate to suggest someone add a good sub with their lightweight, especially if their AVR has 2 sub outputs and Audyssey XT32.

 

[shadyJ]

The overhang from the lesser sub will kill the sound of the transient response from the higher performing sub. I have run through this scenario before with the exact model sub the OP has and also a Rythmik sub, trust me, you don't want to mix these subs.

 

[crossedover]

The overhang from the lesser sub will kill the sound of the transient response from the higher performing sub. I have run through this scenario before with the exact model sub the OP has and also a Rythmik sub, trust me, you don't want to mix these subs.

Have you tried proper eq and if so describe

 

[PENG]

I'm not sure about that. Chris at Audyssey seems to indicate otherwise in the Ask Audyssey section... https://audyssey.zendesk.com/forums/84181/entries/76175.html

Question:
I own 2 subwoofers. One is in the front right corner and other is in the back left corner.
Will any of the multieqxt AVRs EQ each sub individually?

Reply:
Yes, if the AVR with MultEQ XT provides individual control of the two subwoofers then MultEQ XT will create filters for each sub separately.

Question:
So it filters for each sub seperately. However, does it consider each sub then working together?

Reply:
No, it doesn't consider the subs together.

Chris was talking about the Sub EQ, that EQ two subs separately. Sub EQ HT is different, it first set the level and distance (delay) for each sub individually, after that it EQ the two as one acoustically. I believe Chris referred to that (Sub EQ HT) as best of both world.

 

[shadyJ]

Have you tried proper eq and if so describe

Didn't EQ them, but they were level matched and placed right next to each other for fast A/B switching.