AudioCircle

Audio/Video Gear and Systems => Home Theater and Video => Topic started by: SoCalWJS on 30 Sep 2018, 05:37 pm

Title: Multiple Subwoofer Connection & Control
Post by: SoCalWJS on 30 Sep 2018, 05:37 pm
I'm kinda curious to find out how people are hooking up multiple Subs in their HT system if their AVR only has one Subwoofer output. I currently just use an RCA splitter, but I have 3 subs, so I end up using multiple splitters. This seems like a non-optimal solution to me due to signal loss (yes, you can just turn up the gain on the Sub, but not ideal).

I wondered if there was a solution that not only allowed for a single "split" (into the device and that device has multiple outputs) but also might allow for some adjustment to each sub. Not only are mine different brands, but different locations (corner vs not) which leads to widely different in-room responses.

It would be neat in my situation if a manufacturer allowed for Digital EQ for each channel, but I imagine that's pushing it.

I may just need to get a different AVR at some point, maybe one that has multiple Sub outs (3+ would be nice  :green:, but unlikely) with the on board EQ system handling each Sub channel independently.
Title: Re: Multiple Subwoofer Connection & Control
Post by: Jonathon Janusz on 30 Sep 2018, 07:38 pm
I've wondered the same thing too, but from the perspective of 2-channel folks with 2-channel preamps.

I'm starting to believe (and someone correct me if I'm wrong), most of the folks "swarming" subs are sending the subwoofer out signal (or a full range line level signal from a 2-channel preamp) into some kind of DSP/crossover unit, which then takes over management duties for the subwoofers and also adds enough outputs to connect up whatever amount of subs is desired?
Title: Re: Multiple Subwoofer Connection & Control
Post by: Bob in St. Louis on 30 Sep 2018, 10:03 pm
A few years ago, I ran the sub-out to a DCX2496, then I had six (iirc) channels to 'cut up' as I saw fit.
The 'philes will argue about sound quality of the 2496, but when you're talking about <120(ish)Hz, sound "quality" becomes less relevant, especially for HT.
I've been thinking about bringing the unit back into the mix. It sure was fun. I had slope files for music, movies, and various levels of insanity for each one.
Title: Re: Multiple Subwoofer Connection & Control
Post by: jpm on 30 Sep 2018, 10:16 pm
I've recently been thinking about whether it would be viable to try using the two balanced sub outputs at the same time as the two unbalanced sub outputs on my Marantz 7702. Anyone else try anything like this?
Title: Re: Multiple Subwoofer Connection & Control
Post by: SoCalWJS on 30 Sep 2018, 11:56 pm
A few years ago, I ran the sub-out to a DCX2496, then I had six (iirc) channels to 'cut up' as I saw fit.
The 'philes will argue about sound quality of the 2496, but when you're talking about <120(ish)Hz, sound "quality" becomes less relevant, especially for HT.
I've been thinking about bringing the unit back into the mix. It sure was fun. I had slope files for music, movies, and various levels of insanity for each one.
I need to look into "Pro Audio" solutions. After all, this is for HT solution where I'm not really expecting the last word in critical listening.

I took a look at the DCX2496, but if I looked at the right thing, it's all XLR connections. I need RCA's.

Gotta be something out there.....

( I was at a little outdoor concert in the park type thing yesterday and loved the "chest impact" their system was putting out for the Kick Drum & Bass (Electro Voice ekx I think). I'm sure the specs are not "Audiophile", but it was pretty impressive for outdoor use IMO)
Title: Re: Multiple Subwoofer Connection & Control
Post by: Bob in St. Louis on 1 Oct 2018, 12:07 am
Parts=Express has quite a selection of XLR-RCA adaptors for the alternative to making your own cables.
https://www.parts-express.com/neutrik-na2mpmf-3-pin-xlr-male-to-rca-phono-jack-adapter--092-2406
Title: Re: Multiple Subwoofer Connection & Control
Post by: Doublej on 1 Oct 2018, 01:09 am
Something from MiniDSP might work for you.
Title: Re: Multiple Subwoofer Connection & Control
Post by: lokie on 1 Oct 2018, 01:57 am
I send one of two outputs on my 2 channel preamp to a Berhinger 2496. 

Subs are two Infinite Baffle w 2-15" woofers each.  I'm thinking about putting one more in the back of the room and wire up out of phase.
Title: Re: Multiple Subwoofer Connection & Control
Post by: Bob in St. Louis on 1 Oct 2018, 02:26 am
That's very close to what I've got.  :eyebrows:
Title: Re: Multiple Subwoofer Connection & Control
Post by: poseidonsvoice on 1 Oct 2018, 05:24 am
Hi!

A Minidsp solution might work for you.

In my setup, I have an AV Processor. From the front outputs, I have a short XLR splitter. 1 set of XLR’s to the front L/R amp channels.

The next set of XLR’s go to the input of the DCX2496, which I have set to combine into mono (to have max signal voltage).. My DCX 2496 is completely modified. The DACs are upgraded, the clock is upgraded and the analog output board is completely differential with the power supplies using tricked out regulators such that any of the switching supply nasties are pretty much null and void. 6 output channels, all differential XLR so the 4 subs are integrated well. 150Hz and below is pretty much distributed to the subs. Subjectively, I have no idea where the bass is coming from except from my main speakers. Which is how it should be. No localization.

My mains are run full range, no DCX for them. Keeps the signal path clean and integration clean as well.

That being said, the single most important point is knowing how to measure, what to measure, and using  REW properly. Understanding the psychoacoustics helps enormously.

Best,
Anand.
Title: Re: Multiple Subwoofer Connection & Control
Post by: artur9 on 1 Oct 2018, 12:46 pm
I tried a Minidsp 2x4 but it didn't work out for me.  I think my unit was buggy/broken and it eventually died (happy day for me).

I used a Xilica DCP-3060.  With the 3 inputs I put in L-lo/R-lo/LFE and split the signal to 4 subs.  My Lyngdorf DPA-1 preamp already does the crossover duties for L/R.

Individual filters and delay for each channel, several memories and all kinds of other goodness in that Xilica I never used.
Title: Re: Multiple Subwoofer Connection & Control
Post by: mcgsxr on 1 Oct 2018, 02:38 pm
Dayton has a new ~$150 USD DSP that the car audio guys are all over.

Can be used in home as well.  I think it is a 2 in 8 out device with individual EQ and passband per output.

Could work well for a multi sub solution.
Title: Re: Multiple Subwoofer Connection & Control
Post by: Bob in St. Louis on 1 Oct 2018, 02:51 pm
This one?
https://www.parts-express.com/dayton-audio-dsp-408-4x8-dsp-digital-signal-processor-for-home-and-car-audio--230-500
Title: Re: Multiple Subwoofer Connection & Control
Post by: poseidonsvoice on 1 Oct 2018, 03:13 pm
Certainly looks promising - perhaps a few bugs need to be ironed out (see the comments in the Dayton link).

A word of caution. A good colleague of mine in the industry experienced noise issues with the older Minidsp products which hopefully have been rectified. Sometimes it is better to stick with a proven design/company, like Xilica. That being said the Dayton product looks great and their refund/exchange policies with Parts Express are generous and fair imho.

Also, if properly implemented, a multi sub system should be an asset for not only HT but 2ch as well. I haven’t seen much or any benefit to using the latest high end dac chips in the <200 Hz range. On the other hand, having ample DSP configurations, and measurement capability has been of great benefit and more of a marker towards success.

Best,

Anand.
Title: Re: Multiple Subwoofer Connection & Control
Post by: mcgsxr on 1 Oct 2018, 03:13 pm
That is it yes.  It can function in the house or in a 12v environment.

Pretty cool device, and well priced compared to some other options.

Still considering one as I have built some DIY active speakers and at present am using a pro line level Xover.  This would be more powerful for sure.
Title: Re: Multiple Subwoofer Connection & Control
Post by: poseidonsvoice on 1 Oct 2018, 03:47 pm
That is it yes.  It can function in the house or in a 12v environment.

Pretty cool device, and well priced compared to some other options.

Still considering one as I have built some DIY active speakers and at present am using a pro line level Xover.  This would be more powerful for sure.

mcgxsr,

Hi!

Having attended Burning Amp yesterday, I would suggest dialing in your active design with the Dayton/Minidsp equivalent and then consider Pass’ newer diy all analog XO that he has been working on. 1st design was for an analog active XO equivalent to replace the Minidsp 4X10 in a Linkwitz LX Mini (+1 sub), and I found the system very nice to listen to. He will be coming out with more active all analog XO’s for Linkwitz’s other designs and with instructions to configure them for others as well.

Best,
Anand.
Title: Re: Multiple Subwoofer Connection & Control
Post by: SoCalWJS on 4 Oct 2018, 11:14 pm
Since MiniDSP got mentioned a few times, I've been reading up on them.

The MiniDSP 2x4 looks like it would do what I want (connection wise) since it would work for up to 4 Subs.

Then I noticed they have the DDRC-24 that adds Dirac Live to the equation. Wonder if it would be worthwhile....

https://www.minidsp.com/products/dirac-series/ddrc-24

I can't find out the specifics for certain, but it looks like it's 2 channels of Dirac applied to 4 outputs. Seems like that's a shortcoming IMO.

Anybody have any experience with this thing? Looks like a bit of work to get the Dirac run through Computer to the DDRC-24.