Bass management for 8 passive subwoofers?

[Mattias]

I wonder what suggestion there is for bass management/dsp for 8 subwoofers? Most I have seen (like minidsp 2x4HD) is for max 4 subwoofers.
Any suggestion?

 

[lovinthehd]

How about the miniDSP 4x10HD?

 

[lovinthehd]

What subs and amps are they?

 

[TLS Guy]

I wonder what suggestion there is for bass management/dsp for 8 subwoofers? Most I have seen (like minidsp 2x4HD) is for max 4 subwoofers.
Any suggestion?

What the "H" to you want 8 subs for?

 

[AcuDefTechGuy]

Just pretend that you have 4 subs.

Each Y-Cable connects 2 subs, so pretend that each Y-Cable = 1 sub.

 

[shadyJ]

What the "H" to you want 8 subs for?

Because 9 is too many.

 

[BoredSysAdmin]

Because 9 is too many.

This reminds me of a story from 2010. Location: Fancy NYC Hedge Fund. A trader already has PC(s) with 12 displays.
The ask is to have a TV dedicated to CNBC/Bloomberg tv etc.
The conversation goes
IT Guy: Why not just add another monitor?
Trader: 13 Monitors? That's just crazy !!

 

[Mattias]

How about the miniDSP 4x10HD?

Old and discontinued as I understand. Would prefer something that are still in production.

 

[lovinthehd]

Old and discontinued as I understand. Would prefer something that are still in production.

Yes, looking at their site its no longer there....too bad the flex8 doesn't have analog inputs....

 

[Mattias]

Yes, looking at their site its no longer there....too bad the flex8 doesn't have analog inputs....

Yeah, I could get a ADC before flex8 but would be nice to skip this unnecessary step.

 

[ryanosaur]

Perhaps a silly question, but why not run two 2x4?

 

[Mattias]

Perhaps a silly question, but why not run two 2x4?

Yes, it is a choice and the cheapest one right now.
Just for bass management, are there anything better in Flex than 2x4HD?
And any problems with having two 2x4HDto set-up the subwoofers?

 

[ryanosaur]

Yes, it is a choice and the cheapest one right now.
Just for bass management, are there anything better in Flex than 2x4HD?
And any problems with having two 2x4HDto set-up the subwoofers?

No problems I am aware of running multiple miniDSP devices. They even told me if I wanted 11 or 13 channels of DL management I could use 2 ea DDRC88-A to do it. That would give 16 channels of processing, all with DL and the possible addition of the Bass Control Module, too.

The Flex 2x4 seems like a seriously good option just short of something like a QSC Digital Processor (like Core110f). You can get it Balanced with TRS. ASR gave it a pretty outstanding review as I recall.

I'd prefer a more simple 1-box solution, myself, but hitting that number of Subs is pretty Epic-level and not much gear will give you control over that at the level you may want. Marani DSP is very good, but their Center Frequency is limited to 20Hz at the lowest setting for any filter.
Dunno if the DDRC-88 is being discontinued... they still have it on the website at minidsp.com but listed as out of stock.

 

[lovinthehd]

Yeah, I could get a ADC before flex8 but would be nice to skip this unnecessary step.

It'd still be a step with any dsp, but it might be built into the same box. I was going to say something about using dual 2x4s but Ryan beat me to it. Or maybe just try four pairs of subs on one 2x4.

 

[ryanosaur]

Or maybe just try four pairs of subs on one 2x4.

This becomes tricky depending on how they are arranged.

With that many Subs, OP is either a complete junky or is doing a DBA, perhaps.

???

@Mattias ? Care to enlighten us?

In the end, if pairing Subs, they would need to match and be colocated or symmetrical placement in a regular shaped room. Frankly, I would opt for individual channels if it were me as that gives the best control. An extra Grand for DSP is nothing depending on the rest of the equipment.

 

[lovinthehd]

This becomes tricky depending on how they are arranged.

With that many Subs, OP is either a complete junky or is doing a DBA, perhaps.

???

@Mattias ? Care to enlighten us?

In the end, if pairing Subs, they would need to match and be colocated or symmetrical placement in a regular shaped room. Frankly, I would opt for individual channels if it were me as that gives the best control. An extra Grand for DSP is nothing depending on the rest of the equipment.

Wasn't sure what the configuration is in any case. Four stacks of two might be a great way to go. Or if each pair at least equidistant....

 

[TLS Guy]

This becomes tricky depending on how they are arranged.

With that many Subs, OP is either a complete junky or is doing a DBA, perhaps.

???

@Mattias ? Care to enlighten us?

In the end, if pairing Subs, they would need to match and be colocated or symmetrical placement in a regular shaped room. Frankly, I would opt for individual channels if it were me as that gives the best control. An extra Grand for DSP is nothing depending on the rest of the equipment.

It is not just tricky it is bad engineering. By adding all those subs, you are just increasing the variability of the sound seat to seat, as with change in positions phase, and therefore time anomalies will just proliferate. As you know I am firmly in the camp of phase coherency, and dotting subs about the place drives a coach and horses through that concept.

However, on this I am certain my approach to this is correct, and current wisdom wrong.

I have played my system to many, and all universally say that this room has the best and most natural bass they have ever heard. As I have said before, Ted Jordan looked at this issue didactically and this was a major portion of his life's work and research.

All the current experts need to dust off Ted's body of work. I know for certain it is valid.

My AV room follows his precepts as far as it is possible to do so, and in my view to stunning effect. Putting 8 subs in a room violates petty much all Ted's precepts.

 

[ryanosaur]

It is not just tricky it is bad engineering. By adding all those subs, you are just increasing the variability of the sound seat to seat, as with change in positions phase, and therefore time anomalies will just proliferate. As you know I am firmly in the camp of phase coherency, and dotting subs about the place drives a coach and horses through that concept.

However, on this I am certain my approach to this is correct, and current wisdom wrong.

I have played my system to many, and all universally say that this room has the best and most natural bass they have ever heard. As I have said before, Ted Jordan looked at this issue didactically and this was a major portion of his life's work and research.

All the current experts need to dust off Ted's body of work. I know for certain it is valid.

My AV room follows his precepts as far as it is possible to do so, and in my view to stunning effect. Putting 8 subs in a room violates petty much all Ted's precepts.

I can't say I am a proponent for it as I have no true experience, but I have seen a lot of discussion for Double Bass Array (DBA) placement for Subs. In general, the discussion is very positive for those who can do it properly. With all things, this includes proper engineering of the whole system and not just throwing a collection of second hand subs together. All should match and there is a formula for how they are placed on the Front and Back Walls. If correct, this arrangement should be very effective at eliminating room modes and phase issues.

Again, I'm not an expert here, just putting the theory out there as I've seen it. I certainly don't have the right room to try it out, either.

Just for sake of simple introduction:

Double bass array - Wikipedia

en.wikipedia.org

 

[TLS Guy]

I can't say I am a proponent for it as I have no true experience, but I have seen a lot of discussion for Double Bass Array (DBA) placement for Subs. In general, the discussion is very positive for those who can do it properly. With all things, this includes proper engineering of the whole system and not just throwing a collection of second hand subs together. All should match and there is a formula for how they are placed on the Front and Back Walls. If correct, this arrangement should be very effective at eliminating room modes and phase issues.

Again, I'm not an expert here, just putting the theory out there as I've seen it. I certainly don't have the right room to try it out, either.

Just for sake of simple introduction:

Double bass array - Wikipedia

en.wikipedia.org

The papers on that are all in German. However a theater has seats and the furniture, especially the seating will upset that plan. But even worse it is not only the troublesome frequencies that are out of phase, but all of them are, substantially reducing overall efficiency.
So in practical terms, more downsides than upsides.

 

[Mattias]

Sorry for the delay for answering.
First, the passive subwoofers are not in a double bass array. 6 of them are at the front wall on the floor and 2 are in the back on the room but up in the ceiling. The 6 in the front have a possibility to move a little, but the room is a "normal" living room so the possible movment is just sideways at the front wall.

Right now I have a analog active filter (same company as the speakers + subs so it works perfect for them) but was thinking if a minidsp flex could be used as a active filter (and some EQ for the speakers up till around 300 hz) between the front speakers + subwoofers and then use two miniDSP 2x4 HD for the 8 subwoofers on the output from the flex.

Any problem with a set-up like that?