TOPIC:

Dear Friends,

I recently added a DDRC-24 to my existing 2 ch. system consisting of a pair of loudspeakers and an integrated amp (and a digital source connected to toslink on DDRC-24). I have the master volume on the DDRC-24 set to 0dB and instead I use the volume control on my integrated amp. I've set up and activated the Dirac filters and everything works fine.

Now, I am considering adding a sub-woofer. The minidsp application notes suggest that I connect the sub to the third output on the DDRC-24 and configure the crossover between the mains and the sub in the minidsp setup tool, then derive the Dirac filters etc. However, this must necessarily mean that the volume controls must be done on the DDRC-24 and no longer on my amp which effectively would take the role of a simple power-amp.

I am not keen on this since I prefer to have the physical volume control on my integrated amp rather than a "blind" volume control on the DDRC-24 which can only be set with a remote control.

The only way I see around this is to connect the sub to the amp instead. However, then I loose the ability to set the crossovers in the minidsp software and I will instead have to use the various knobs on the sub to configure these. Once that is done, I suppose I can run Dirac software which in this case would treat the mains and the sub as a single set of speakers (which I guess there is as such no problems with).

Perhaps someone can confirm that my thinking as described above is correct. Is there a better way to go about this? I know that some devices such as the SHD have a physical volume control and a display to indicate the level, but I would like to avoid having to replace my DDRC-24.

Thanks,
-s

I think you've summarised the situation well .

I've used a 2x4 HD (like your DDRC-24 but without Dirac) to integrate a subwoofer into a stereo system, which worked very well. I did it with the miniDSP acting as a digital pre-amp to control volume, feeding a power amp for the main speakers and an active subwoofer. As you say, not being able to see the volume was not ideal and was a key reason I have now upgraded to an SHD. I would suggest you try this approach though as you lose two key features with you second option of connecting to the sub output:

1. (As you correctly identified) you can't use the miniDSP to act as a crossover, the real benefit of which comes with applying a high-pass filter to your main speakers rather than just a low pass filter to your sub. You will only be able to do the latter with the controls on your sub, and generally speaking with a slower roll-off than you could achieve with your miniDSP.
2. You won't be able to set a time delay between the mains speakers and subwoofer. Typically main speakers are closer than the subwoofer will be and so what is needed is to delay the signal to the main speakers. The phase control on a subwoofer cannot achieve the same thing.

You have all you need to experiment with different options though, so I'd just try things out .

Thank you Ultrasonic, that's very helpful. I didn't think of the ability to set the time delay.

/s

I realize that there is another option which is to connect the miniDSP between the pre-out and main-in connections on my integrated amp. In this way, I obtain the ability to control the volume physically on the amp while keeping the full DSP feature set. However, this adds one A/D conversion and subsequently a D/A conversion to the signal chain. How much of a negative impact on the signal would you reckon this has?

I currently run my digital source directly into the optical input on the miniDSP and from there the L/R channels directly to the main-in on my amp. The third output goes straight from the miniDSP to the LFE input on the sub. In this setup I rely entirely on the miniDSP (software) volume control which is not ideal. On the other hand, I have the shortest signal path possible with only one D/A conversion.

Thanks!

/s