Dirac Live Bass Control with mixed subwoofers

[Deckard71]

Hello. I have 3 subwoofers:

Two 10” 300w (BK XLS mk2)
One 12” 500w (SVS SB2000 Pro)

I have the 2 small subs connected with an Y cable. I do this because my AVR manages only 2 subs independently, so the AVR “sees” the two small subs as one, but also because it is known that the smaller sub limits the output of the total LFE, capping the big subwoofer output. As the small subs are summed up, this limitation is not big, as the AVR sees the 2 small ones as one big sub

With DLBC would it be possible to manage the 3 subs independently, despite two of them are smaller, or should I continue to sum the 2 small subs and continue to treat the subs as two?

I know that someone will say that Id better remove the 2 small subs and get another SVS SB2000Pro, but I need the 2 small subs as they are connected to the front speakers via HF to make them full range

Thanks

 

[Axelpowa]

I tried exactly this witt my RZ70. Manages only 2 subs.

I tried 2 SVS SB2000 connected with Y as one
Other sub is a Dayton Ultimax 18"

Dirac sees them as 2 subs

Worst idea I could have. The SVS delivered a horrible sound, boomy bass, lots of trebble. Tried different positions.
Also tried 1 SVS only with same result...

I checked with rew the response and was very good, but the sound not.

Hope you have better luck!

 

[Deckard71]

And you didnt try to manage the 3 subs independently because your Onkyo only manages 2, right?

Audyssey manages well the trick of having 2 small subs summed and 1 bigger sub. The response is good, measured with REW. I will buy an AVR with 4 subs out (probably Marantz C40) and my doubt is if for DLBC it would be better to continue like this or treat the 3 subs independently

 

[Willem]

How about equalizing your three subs independently using Multi Sub Optimizer and a miniDSP 2x4HD? I have done that with three different subs, and I am very pleased. In your case you can then use the AVR equalization on top of that, and including the main speakers. I hope this makes sense in your system. The biggest drawback of MSO is that it is hard work.

 

[Deckard71]

How about equalizing your three subs independently using Multi Sub Optimizer and a miniDSP 2x4HD? I have done that with three different subs, and I am very pleased. In your case you can then use the AVR equalization on top of that, and including the main speakers. I hope this makes sense in your system. The biggest drawback of MSO is that it is hard work.

Well, miniDSP 2x4 HD has 2 inputs, and I'd need 3. Apart from that, I am not sure if that solution would solve the problem of the smaller sub capping the bigger sub, which Dirac seems to manage

 

[Willem]

The 2x4HD has four outputs to a maximum of four subs. With MSO you use the subs as mono, so I use the rca output of my RME ADI-2 into the 2x4 HD, and the xlr output of the ADI-2 into a passive HP filter and then to my power amp.

 

[Deckard71]

So you feed a single RCA input in the miniDSP, all the three subs together? with a signal coming from 3 different distances and woofers? And in this case the small subs are not limiting the big? I do not understand it, sorry

Anyway, my doubt is between keeping Audyssey as it is (1 sub and 1+1 sub) which works well (measured with REW) or upgrade to DLBC, and in this case, treat the 3 subs independently or use the 1 and 1+1 path

 

[Willem]

Yes the subs are fed from one mono signal that goes into the 2x4 HD which applies different filters to each of the four potential subwoofer outputs. Timing etc is dealt with by the MSO filters in the 2x4HD. MSO optimizes not only multiple subs (and main speakers if you want to) but also for multiple listening positions. I do think there is nothing more sophisticated, but it is quite an effort. First, you have to measure reponse for each subwoofer and for each listening position (so 15 measurementst in my particular case) and then you have to input those measurements into MSO, which takes a bit of learning. I was very pleased with the results across my entire listening space. My smallest sub (a KEF kube 8) currently does indeed hold back the bigger SVS SB2000 and my B&W PV1d, but I have not yet had time to increase its level and make new measurements. And to be honest, the three of them have quite enough power already.

 

[Deckard71]

Thanks. This part "My smallest sub (a KEF kube 8) currently does indeed hold back the bigger SVS SB2000 and my B&W PV1d" is my doubt with DLBC. Can DLBC prevent the smaller sub for limiting the rest of subs?

 

[theREALdotnet]

I think DLBC needs each sub to be its own channel, otherwise I’d imagine their acoustical modelling gets confused. You might get away with placing the two Y-cabled subs close to each other, like on top of or next to each other, effectively working as one speaker.

 

[theREALdotnet]

Can DLBC prevent the smaller sub for limiting the rest of subs?

If the subs are independent channels, DLBC will use each to their best ability, and as required for the overall best bass response.

 

[Deckard71]

If the subs are independent channels, DLBC will use each to their best ability, and as required for the overall best bass response.

So the limitation of the smaller sub is solved with DLBC? Thanks

 

[Willem]

Thanks. This part "My smallest sub (a KEF kube 8) currently does indeed hold back the bigger SVS SB2000 and my B&W PV1d" is my doubt with DLBC. Can DLBC prevent the smaller sub for limiting the rest of subs?

Mind you, the Kube 8 is a very small sub indeed. Even so, I still have enough power for the system as a whole. The issue is that you set the volume control on each of the subs by what you think will be appropriate, and MSO then decides how much to attenuate the sub or subs that it thinks are too loud. So my next step will be to increase the volume control on the Kube 8, and see where that gets me. Will I push my Kube 8 too hard? If that is the case, my best course of action will be to add a fourth sub.

 

[Deckard71]

Mind you, the Kube 8 is a very small sub indeed. Even so, I still have enough power for the system as a whole. The issue is that you set the volume control on each of the subs by what you think will be appropriate, and MSO then decides how much to attenuate the sub or subs that it thinks are too loud. So my next step will be to increase the volume control on the Kube 8, and see where that gets me. Will I push my Kube 8 too hard? If that is the case, my best course of action will be to add a fourth sub.

So MSO limits the output of the big sub to balance it with the output of the weaker sub. This is what I want to avoid and that's why I have the 2 small subs aggregated as one, but was wondering if DLBC can handle the 3 separately without limits

 

[droid2000]

What theREALdotnet said is correct - throw away the y-cable and let DLBC control every speaker independently. That is how you will get the best sound.

 

[Willem]

But volume is not the only relevant variable. As long as you have enough of it, there is no issue. If you have enough, extension is more important. Earl Geddes recommends one big sub in the front corner, primarily for the deepest frequencies, and two smaller ones in the back and on the side, and that is what I did. In my case, I think the smallest one on the side is perhaps a bit too small, but I shall see what happens if I increase its volume. If that does not work I shall have to add another one on the opposite side.

 

[Deckard71]

What theREALdotnet said is correct - throw away the y-cable and let DLBC control every speaker independently. That is how you will get the best sound.

Yes, I do not have DLBC yet, I am still on Audyssey. I wanted to confirm that DLBC could manage mixed subwoofers without the smaller ones limitating the big one. Now it is clear, thanks

 

[droid2000]

Yes, I do not have DLBC yet, I am still on Audyssey. I wanted to confirm that DLBC could manage mixed subwoofers without the smaller ones limitating the big one. Now it is clear, thanks

During the setup process they have you equalize the volume levels of all speakers. If your smaller subs are inadequate, it will be revealed during this step. But I'd be very surprised if you can't make them work.

 

[Butter]

I ran DLBC multi-sub on my setup which has 3 fairly different subs, each on their own channel, and far as I can tell, it aligned them all to the MLP and managed levels, delays, and so on. Sounds dope. Didn't measure post-results yet.

 

[makalister]

Hi,
I've got an Arcam avr10 + DLBC and 2 subs (svs sb 1000). The avr and DLBC license are for just single sub, so it is like having connected in Y. I don't have any chance to manage subs separately. Minidsp can solve this, but should I, first equalize the subs with minidsp and after pass DLBC; or fist DLBC and after minidsp? Would second equalization treat down the first one?