Minidsp C-DSP 8x12 V2.0 Review

[carlosmante]

Unless it can DSP away vibrating sheet metal, which I doubt, seems like a waste of $700+. It also seems silly to quibble over a few dB SNR in an automotive environment.

IMHO The high noise floor in the average motor vehicles make DSP not a priority in sound improment.

 

[amirm]

IMHO The high noise floor in the average motor vehicles make DSP not a priority in sound improment.

DSP has been *the key* in improvement in stock premium car audio for the last two decades. You want good tonality across multiple seats. Even if you have perfectly flat speakers, the small cabin will cause modal regions up to many hundreds of hertz as I mentioned. This means up and down frequency response that needs to be corrected. DSP is also helpful in making sure drivers are not pushed too hard resulting in distortion. Cars have also become much quieter over the years. And there is such a thing as EVs.

A DSP based active crossover also gives you tons of control over building you a multi-way speaker in a car.

There was a time when car audio was junk and aftermarket was just about boomy bass. But no longer. My car's premium sound systems put a smile on my face in how good they sound. So let's not spread generalizations here.

 

[Rottmannash]

It's been many moons since I bought my last head unit (new cars make it well nigh impossible to replace the HU) so do newer head units have coax and/or optical out much like home streamers, CD players, etc? When I was buying them they only had RCA outs.

 

[kencreten]

Why is this 760 for some chips in a box? Is there special diamond sauce or something?

@kencreten Not sure what cheaper alternative there is if if you want a very flexible multichannel DSP. $550 seems like a good deal. You can use it as a 2 in 3 or 4 out xover with a sinad of 105. Yes, yes, not 123dB... we'll just set aside that...105dB is still very good. If you accept the hit of the ADC you get even more flexibility.

You can do this in software, but then you need a pc controlling everything. You can jury rig some dsp chips and DAC chips together, but you will waste way more than $500 dollars of time and still may not have as well an integrated solution.

I'm not using it for car audio. I'm going to use in an HT application. I think that, with a midrange HT that has preamp out, not sure what other multichannel dsp there is available for ~$500 bucks. Sure, I want the ADC to have 10dB more SINAD headroom, (mainly to stop the forum whining...whoops, did I say that out loud?), but I think I can live with it for the price. Yes, if it was a grand or more I'd expect a bit more. (and, perhaps minidsp will come out with v3 in a couple years that has better analog conversion...)

$500 sounds much better to me. Thanks.

 

[kencreten]

Do you know many units that offer 12 channels of Digital ins AD-DA, DSP, Volume control etc for less?

I understand the price should be more like $500. Well... it's still chips in a box.

 

[kencreten]

Don’t look up the cost of a BSS BLU-100…

Now I'm curious. heheh

 

[jhaider]

Yes, I do. I split the 12V+ from the power source into two wires, one connected to DC IN +, the other connected over a relay and then to REMOTE IN. I then connected the trigger from my Denon receiver to control that relay. So when the trigger from the receiver goes on, the relay short the second 12V+ to the REMOTE IN.

I'm still a little confused (or dense). Is there any chance you could draw the configuration out? Your relays sound like they have more taps than the ones I've used in the context of converting the remote port on a pro amp (e.g. Crown XLS, Crown DCIn) to work with a home hifi 12V trigger (see below). Are you saying that you parallel both the hot leg of the PS and the hot leg of the 12V trigger into the relay "+" input? Also, do you connect the common pin on the relay to the "DC IN -" terminal with the PS cold leg, as shown below (green wire)

Also, is tapping the relay's N/C output correct, as one would on a pro amp?

I tried a few switched adapters first, but none of the did it. I then ended up using this one, but I guess any sufficiently well filtered or clean 12V source would do.

FWIW, I tried mine with the above PS (amazon) and the un-triggered chain (AirPlay2 over WiiM Pro -> RME ADI-2 Pro FS -> C-DSP 8x12DL -> KH 80 DSP + subs) did not seem notably noisier than my previous chain (miniDSP SHD Studio -> Topping E50 to KH 80, SMSL Sanskrit to subs). Perhaps the 6dB attenuation of going from RCA to XLR helps. Despite losing that 6fB It seems to have sufficient of voltage to drive the KH 80 to my limits.

 

[tktran303]

I understand the price should be more like $500. Well... it's still chips in a box.

Doesn’t matter if it’s chips in a box. If it provides a novel purpose or useful product or service and there is a market for it then you’ve got a product/service.

It’s not like they are selling a bajillion of these.

As @amirm says; stock vehicle OEM is actually very good these days.

In the 20th century you really had to add your own DIY sound system.

Now it’s worlds better as standard, and for a few thousand €/£/$ sounds kind of fantastic.

Imagine if you could have a house built and have an excellent music room added for a small cost without having to knowing a single thing.

People can have a walk in robe or upgraded kitchen or outdoor area or bathroom. But an acoustically treated room for playing or listening to musical instruments?

I’d pay for that.

 

[amirm]

It's been many moons since I bought my last head unit (new cars make it well nigh impossible to replace the HU) so do newer head units have coax and/or optical out much like home streamers, CD players, etc? When I was buying them they only had RCA outs.

Yes, some do. See this example: https://www.clarion.com/gb/en/products-personal/multimedia/NX807E/profile/index.html

 

[IamJF]

Sorry but that's typical MiniDSP. You loose 20dB Sinad with the analog input!
The datasheet tells us 115dB SNR, THD+N 0.0007%. It doesn't deliver.

As much I like their software they regularly do deceptive datasheets.

 

[K man]

I'm still a little confused (or dense). Is there any chance you could draw the configuration out?

In your own diagram change COM — DC IN - into COM — DC IN + (and make it black instead of green) and you should be set.

 

[mdsimon2]

Sorry but that's typical MiniDSP. You loose 20dB Sinad with the analog input!
The datasheet tells us 115dB SNR, THD+N 0.0007%. It doesn't deliver.

As much I like their software they regularly do deceptive datasheets.

Care to share an actual example of a deceptive datasheet?

0.0007% THD+N = 103 dB SINAD, Amir measured 104 dB SINAD at 2 V output and it does even better at higher output levels.

I agree that their SNR spec is a bit unclear as it does not state bandwidth or weighting but assuming it is a-weighted which is rather typical that would be about 112 dB unweighted which is what Amir measured.

Personally I wouldn't put too much stock in the analog input measurements as no effort was made to adjust the input sensitivity as described here -> https://www.audiosciencereview.com/...dsp-c-dsp-8x12-v2-0-review.44742/post-1593610. They also do not provide a spec on the input and the AK5556 ADC used is good but not SOTA.

Michael

 

[markk]

I think "deceptive" is a bit harsh.

Often manufacturers are "aspirational" in their specs. And, it's not like they pulled it out of thin air. It's just paste and copy from the akm datasheet which claims 115 dynamic but 105 signal/noise. Which is about right for the digital in side.

Granted, that's why I sent it to Amir to test. Do I think minidsp was "deceptive?" No. We all knew it would probably not test to 115 with Amir's testing. and 105 is, frankly, really good. Yes, a bit disappointed it didn't do a bit better with analog in. I was hoping more for 90's. But, as Michael mentioned, under different testing conditions it might fair a bit better.

And, to repeat... no one is offering a comparable product for $500 bucks, so I'm fine with it.

After all, I'm writing this post on a monitor that the manufacturer is telling me has a 10 million to one contrast ratio. Right?

 

[Beng]

Thanks for the review. Any measurements of sinad with various filters engaged. I have observed a degradation of snr which high q filters. I assuming to has to do with the bitlength of the compute engine.

 

[tktran303]

@markk

Thanks for sending this in to be measured.

BR,
Thanh

 

[Trell]

As to SNR, you sure as heck don't want a tweeter 2 foot away from your ear hissing

There are some monitors for near field use that do have some hiss, including my Genelec 8330A.

That said, my room is far more quiet than a car.

 

[HooStat]

Would you expect the high-level analog inputs to be any different from the low level in terms of SNR? Just curious since I have this unit in my car and I connected the high-level (speaker-level) signal to the unit (it was my only signal source).

 

[jhaider]

In your own diagram change COM — DC IN - into COM — DC IN + (and make it black instead of green) and you should be set.

So tie the COM output to the hot leg of the PS, like this?

That doesn't let magic smoke out of the C-DSP, or the PS, or both?

 

[kencreten]

Doesn’t matter if it’s chips in a box. If it provides a novel purpose or useful product or service and there is a market for it then you’ve got a product/service.

It’s not like they are selling a bajillion of these.

As @amirm says; stock vehicle OEM is actually very good these days.

In the 20th century you really had to add your own DIY sound system.

Now it’s worlds better as standard, and for a few thousand €/£/$ sounds kind of fantastic.

Imagine if you could have a house built and have an excellent music room added for a small cost without having to knowing a single thing.

People can have a walk in robe or upgraded kitchen or outdoor area or bathroom. But an acoustically treated room for playing or listening to musical instruments?

I’d pay for that.

Sounds reasonable.

 

[K man]

So tie the COM output to the hot leg of the PS, like this?

Yes, positive to the COM input.

The DC IN - is a common negative/ground, so if you want to use the REMOTE OUT it’s also positive and you then need to connect the negative to DC IN - (or corresponding on the power supply).