Dirac Live 3 room-correction software Dirac Live Bass Control

Sidebar 1: Dirac Live Bass Control

With Dirac implementations in AVRs or pre-pros, bass management has long been the responsibility of the host device; it was not included in Dirac—until now, or anyway, soon. Dirac Live Bass Control (DLBC) is an important new feature, providing bass management with potential to better integrate subwoofers with each other and with the main speakers. DLBC has already been implemented in a few AVRs, and Dirac sent me a beta version for Windows. I added three SVS subs—two SB-3000s and an SB-2000 Pro—to create a 5.3 system. Because that configuration isn't included in the current DL3 distribution, they sent along a config file. These brief comments, then, are based on beta software and an ad hoc configuration.


With DLBC-enabled installation of Dirac Live 3, the menu on the right of the Filter Design screen offers the following additional options:

Off (no bass management) is for those who have only large, main speakers and no subs or who prefer to use their subs for only the LFE channel.

Upmix Only is akin to traditional bass management but with the ability to visualize and control the crossover parameters and apply speaker/room correction based on target curves. Multiple subwoofers for the redirected bass are summed, but without consideration of the interaction between the subs or the subs with the main speakers.

Full Bass Optimisation (Euro spelling) optimizes both the subwoofers (using a single allpass filter for the redirected bass) and the individual allpass filters for the full-range channels, taking into consideration the acoustical interactions among the subs and the groups of speakers.

While both Off and Upmix Only have their uses, Full Bass Optimisation resulted in much better integration of the subs with each other and with the main speakers—to the point where the subs disappeared but the main speakers seemed to have prodigious low-frequency extension and control. DLBC is still in development, but it promises to be a major advance that will greatly improve the integration of subwoofers in stereo and multichannel systems, particularly with small main speakers.—Kalman Rubinson

Dirac Research AB
Stationsgatan 23-25
753 40 Uppsala, Sweden
+46 18 4108210

Mike-48's picture

Kal, I enjoyed the review and am thankful for your continued interest in DSP applied to audio. To clarify what you wrote about DLBC, my impression is that it sums bass to mono?

Kal Rubinson's picture

EDIT:Ah. DLBC is a bass management system and it will take the bass from each channel and distribute the sum to all the subs. If you want to control what signal goes to each sub (e.g., stereo subs), you need to do that yourself (e.g., in JRiver) and use an alternative mode of DL.

It treats as many subs as you have channels for as independent sources. Note that each sub must have its own channel independent designation and wire connection.

For example, I am using 5 main channels (L,R,C,Ls,Rs) and three subs, so I use an 8 channel layout L,R,C,Sub1,Ls,Rs,Sub2,Sub3).

Mike-48's picture

Thanks for the reply, Kal. I have been running 2 subs in stereo, on the theory that if the bass on a recording is in mono, it will be reproduced fine, and if in stereo, any added ambiance will be nice. If I had to bet, I'd guess they are very hard to distinguish. Indeed, a recently added 3rd sub is run in mono with no decrease in ambiance to my (ageing) ears.

Bob Loblaw's picture

I wish there was more hardware on the market that could be placed between a source and a DAC to provide room correction. I have a Paradigm PW Link which uses Anthem's ARC room correction, but it has some idiosyncrasies to the way it works.
MiniDSP makes the DDRC-24, but it only has analog outputs, and they also have the DDRC-22D, which is exactly what I'm looking for, but expensive in Canada at $1,170 for just room correction. Hopefully more hardware will come to market to fill this niche.

Mike-48's picture

If you mean digital only, stereo only (including 2.1 or 2.2), the miniDSP SHD Studio is a little cheaper than the unit you mentioned and runs Dirac.

Bob Loblaw's picture

That's interesting. I use Squeezeboxes around the house still, but it looks like you can run Squeezelite on the SHD Studio which could eliminate an extra box. Thanks for the heads up.

thatguy's picture

That PW Link could be great if they could fix the little bugs to it.

I would also like a quality 2 channel hardware option that was a bit more affordable for adding Dirac Live3 to my signal chain.

thatguy's picture

I think room correction is the next frontier in 2 channel audio. Articles like this are very helpful; especially the tips on the Harmon curve.

How do the hardware based options (miniDSP) with it built in compare to the PC setup?

Mike-48's picture

One audiophile's opinion: Both hardware systems and systems run on a PC have their advantages. For stereo, dedicated hardware can be easier to set up in terms of connections and abilitites. For example, the miniDSP SHD or Anthem STR have four outputs, 2 for mains and 2 for subs. That can be tricky to configure on a PC (not impossible by any means). Hardware solutions might be incorporated into a preamp with source switching, ADC, volume control, and possibly tone controls for quick adjustments. (When I was looking into a PC-based solution years ago, source selection was a stumbling block.) Finally, dedicated audio units don't require having a PC in the listening room, which some find a distraction.

I think PC-based solutions have the advantage in maximum flexibility and configurability and the ability to add more processing power in the future. You can even change DSP system, if you want, without changing hardware. I suspect also they can be more cost-effective. But to my mind, they are a little more towards the DIY end of the spectrum.

partain's picture

I've been chasing "flat" response for 50 years , and now I find a little bass and treble boost is good ? Back when tone controls existed I used a bit of boost on both ends but I was soon educated out of that nonsense . If I stray too far from flat now I'm afraid I'll feel guilty . Old habits .
Will you get the bass thingie later for free if you buy in now ?
And what about Tidal ?

Kal Rubinson's picture

I've been chasing "flat" response for 50 years , and now I find a little bass and treble boost is good ? Back when tone controls existed I used a bit of boost on both ends but I was soon educated out of that nonsense.

Time marches on but it is a little bass boost and a little treble roll-off.


Will you get the bass thingie later for free if you buy in now ?

Possible but I doubt it.


And what about Tidal ?

Tidal (which I do not use) is just another app. I am guessing that it will work with DL3 the same way that Qobuz does.

doxsoundlv@gmail.com's picture

Running a 2.2 system in my office control room style. Elac Unifi UB5's and Klipsch RPW10 subs fed from my near 20 year old Denon 3802, via a Parasound ZDDAC and J River. With Dirac installed the focus and imaging is much better, and the bass is not so boomy (these are inexpensive subs after all). I think it's a kickass system for very little money and probably about as good as it's going to get in my tiny room. I did the calibration with a DBX RTA mic I had from my pro days, and an ART mic pre to USB, but have a Focusrite on the way that might make a difference...we'll see.

luh3417's picture

For several months, Dirac has been developing a new version for the Mac, that doesn’t use plugins, and instead simply works as a kind of virtual sound card, for all audio output. I’ll buy it then, since I want to use it with Amazon Music, which doesn’t support plugins.

(There’s probably a complicated poorly documented rain dance I could undertake, to make the current version work with Amazon Music, but I’m thinking to just wait for the new version.)

(I think the Windows version is already there and doesn’t need this new architecture).

Here’s instructions for installing the Mac beta https://confluence.dirac.services/display/DLS/macOS%3A+Standalone+Beta

They are updating regularly, latest version is here

Kal Rubinson's picture

Yes, the Windows version is already there and the new Mac version (which I cannot test) has been announced.

luh3417's picture

Is the new Mac version for sale yet? Have they announced a target date? I don’t see it on their website. I have to say I still find their product offerings beyond confusing. OK I see “Plugin and Standalone for Windows and I see Plugin for Mac” so yes what I’m waiting for will be called “Standalone for Mac”.

Some of the new Onkyo AVRs will come with Dirac. Saw that announced somewhere. Ought to give Denon with Audyssey a run for its money. I don’t see this on their website either though.