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Alternative to miniDSP DDRC24 DIRAC

asrmem

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Hello All.
End of last year I bought the miniDSP DDRC24 DIRAC.
My intention was to do some room correction and also to build a new active speakers.

I connected the miniDSP my current setup.
I own an ONKYO P-3000R preamplifier and the M-5000R power amplifier.
So I connected the miniDSP between preamp and power amp.
Sadly, I got very loud noise.
I reduced the master level in miniDSP software to -20dB, the noise was still hearable.
I disconnected the preamp from the miniDSP, so the input of the miniDSP was open, the noise was still there.
As soon as I removed miniDSP, no noise was hearable.
I was very disapointed about my results.
Maybe I did something completely wrong. No Idea.

To be clear: The noise was very easy to hear. The difference between with connected miniDSP and without was like: Switch the Light on and off.

I would like to build some new active speakers and I'm searching for some alternatives to the miniDSP.
In the profi area, as far as I have seen, the DSPs are built in the power amplifier. So, this is not an alternative for me.
Standalone DSP are rare....


Do someone know some alternatives to the miniDSP at best with also such a room correction possibility like DIRAC?


Thank you for reading.
Best Regards
 

csepulv

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Hello All.
End of last year I bought the miniDSP DDRC24 DIRAC.
My intention was to do some room correction and also to build a new active speakers.

I connected the miniDSP my current setup.
I own an ONKYO P-3000R preamplifier and the M-5000R power amplifier.
So I connected the miniDSP between preamp and power amp.
Sadly, I got very loud noise.
I reduced the master level in miniDSP software to -20dB, the noise was still hearable.
I disconnected the preamp from the miniDSP, so the input of the miniDSP was open, the noise was still there.
As soon as I removed miniDSP, no noise was hearable.
I was very disapointed about my results.
Maybe I did something completely wrong. No Idea.

To be clear: The noise was very easy to hear. The difference between with connected miniDSP and without was like: Switch the Light on and off.

I would like to build some new active speakers and I'm searching for some alternatives to the miniDSP.
In the profi area, as far as I have seen, the DSPs are built in the power amplifier. So, this is not an alternative for me.
Standalone DSP are rare....


Do someone know some alternatives to the miniDSP at best with also such a room correction possibility like DIRAC?


Thank you for reading.
Best Regards
I've been using a miniDSP DDRC24 and haven't experienced the noise you describe, but my miniDSP goes directly to my AVR, as opposed to being in between a preamp and amp.

I would wonder if your unit might be defective. Did you reach out to miniDSP support? If so, what did they say?

In regards to your question, I looked for alternatives before I settled on miniDSP DDRC24. There is the miniDSP SHD, that was well reviewed here on ASR, but costs a lot more.

For room correction, Dirac's website lists their hardware partners. But they are mostly integrated amps, AVRs or AV processors. https://www.dirac.com/live/home-audio-for-audio-lovers/

There is DEQX, which has room correction. https://www.deqx.com/products/. But I don't think they are available till 2022.

On equalizers, I've seen discussions/recommendations in these threads

Hope some of that helps.
 

Sharpi31

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Can you put the DDRC before your preamp, instead of after it? That way any inherent noise is attenuated by the preamp (the same way the signal is). I tried an active setup year ago with a 2x4HD feeding two stereo power amps, and the noise was bad.

Edit: it’s much better to let your DDRC24 work with a full line level input signal, rather than a heavily attenuated out from a preamp. Another reason to put it upstream of your preamp, after your source.
 

Sharpi31

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I’d be cautious about recommending a DDRC24 / 2X4HD as the preamp in all situations. With a high gain power amp and higher sensitivity loudspeakers there will be a lot of hiss (more than many people would tolerate).

Thread 'Review and Measurements and miniDSP 2x4 HD DSP and DAC'
https://audiosciencereview.com/foru...urements-and-minidsp-2x4-hd-dsp-and-dac.2674/

 
Last edited:

holbob

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I use my ddrc-24 with hypex amp and elac dbr62, and everything is silent - not even a hint of hiss.
 

Sharpi31

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The DBR-62 is around 85dB efficient (= low). I’m just saying that a digital preamp with higher noise floor isn’t going to work well with all amp/speaker combinations. Nothing controversial about that :)
 

mdsimon2

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It looks like the M-5000R has a gain of ~31 dB based on the 150 watt @ 4 ohm power rating and the 0.7 V input sensitivity. That gain is somewhat on the high end and may cause noise issues with the DDRC-24. I agree with others that for best noise performance you either want to eliminate the preamp or use it downstream of the DDRC-24. You definitely do not want to use it upstream of the DDRC-24 as the DDRC-24 ADC will add at least 3 dB of noise compared to using the digital inputs.

Michael
 
OP
A

asrmem

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Hello.
Thank you all, for your thoughts and suggestions.

@csepulv thank you for your links.
I know the list at Dirac. I hoped someone will show some other possibilities.

After Sharpi31's answer, I remember to my days, when I do Car HiFi.
Some years ago I had a setup with an Audison BitOne DSP and some amplifiers.
I still have the devices stored in my basement.
I looked at the level settings of the amplifiers.
They were limited at the half of they maximum possible level.
So this would be the same setup, as here at home.
In the datasheet of the DDRC-24 is this setup also shown: Datasheet DDRC-24
My thinking is now, that I can setup the volume of the preamp at nearly maximum level, and reduce the master level in the DDRC-24 at that level, that I can hear music very loud.
Then I can reduce the level at the pre amp to normal hearing level.
I think that with this setup the noise shouldn't be noticeable.
The only disadvantage, as far as I can see is, that I need to put the level knob in the near of its possible scope.
When I remember correctly at my Car, where I had the above described setup, I had exactly this setup.
Hopefully my description is understandable.

Removing the Preamp is for me definitive not an option.
To connect the DDRC-24 in front of the Preamp is also not an option, because I would like to use the DDRC-24 also as crossover, not only for room correction.

I need to think again about how to proceed...
I don't know, if the above describe solution is a good solution.
Maybe only a good passive loudspeaker is the solution?

Best Regards.
 

Sharpi31

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A key problem is that your power amp will always be amplifying the noise floor of the DDRC-24 (this won’t change with the DDRC or preamp volume control setting - but there are reasons to set those two optimally). I was going to suggest trying a fixed resistor voltage divider (or passive preamp) between your DDRC-24 and power amp (to attenuate the signal and noise by the same dB - allowing you to boost the signal while leaving the noise at the attenuated level), but you ideally need a low source output impedance and high load impedance for that to work well - the Minidsp output impedance is 560ohm (higher than ideal) and the power amp input is 10Kohm (lower than ideal). All in all it isn‘t an ideal scenario for passive attenuation.

You could try a 10K resistor inside the RCA connector (at the amp end) between the plug centre pin and your signal wire. Not ideal, but it would reduce the hiss by 6dB and let you see if that level of hiss reduction ’solved’ the problem (and left you with sufficient volume range etc.).
 

Weeb Labs

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An NJW1194-based volume controller such as this one should work very well.
 

tvrgeek

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I forgot about behringer DEQ2496. A variety of folks on ASR have it and seem to like it. (I have no experience with it, but noting it as I've seen it referred to on several occasions)

Some do. I tossed mine in the trash. Horrible noise. Took forever to boot. I would not even put up with if for a cheap band PA system. Now, some have put in all new analog, power supplies etc and are much better. The DBX is only a hair better.
 

rcstevensonaz

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An NJW1194-based volume controller such as this one should work very well.
Thanks. I was about to suggest this approach, which will allow for sending reference line-level output to the MiniDSP from the preamp (which is now just used as source selector / AVR processor); but did not have any idea what to use for remote-controlled volume.

I actually have a very similar situation and volume control on the MiniDSP is a non-starter; but the NJW1194 (or similar) would solve my issue as well.
 
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