• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Looking for DSP options with optical out

Bhh

Member
Forum Donor
Joined
Feb 9, 2020
Messages
78
Likes
77
Location
NYC / Hudson Valley
I recently picked up a Umik-1, REW and have disappeared down the wormhole of room correction. I will soon be adding a pair of Rythmik subs to my LR bookshelf speakers so I suppose now is as good a time as any to pick up a DSP but I’m struggling with finding options that will work for my use-case and was hoping to get some recommendations.

Current setup is very simple (like me). Chromecast Audio to Rotel A12 via Toslink. The Rotel has Signal Sense which brings it out of standby mode as soon as it gets a digital signal (does not work with analog signals). My wife loves this since just clicking on LR Speakers in Spotify or asking Google Assistant to play something wakes the whole system up. No fiddling with remotes or anything like that. The subs will supposedly power on automatically with analog-in but I know if things start getting a lot more complicated, she is going to quit supporting the upgrades and this hobby will be banished to the dark basement man-cave.

What I’m looking for is a DSP solution that can handle room eq from REW, send analog signals to the subs and digital to the amp (to wake it up). Alternatively, the entire DSP’d signal could be sent to the amp via digital and the Rotel preamp outs forward the signal to the subs.

If I understand how all this all works (a big IF), the former would allow me to experiment with crossover functions to perhaps limit sending the bookshelf speakers anything below 50-55hz but would use the DSP DAC for the subs. The Rotel has a Wolfson DAC and I really have no idea how that stacks up against the DACs in these DSP units so I don’t know if one option is preferable for audio quality.

Lastly price, even with the subs, I only have about $3k in this system so spending more than $500 or so starts to feel misdirected. I also want to upgrade the bookshelves from B&W to Revel soon as well.

The miniDSP 4x10HD seems to check all the boxes but I’m having a difficult time understanding if this will work and some online reviews seem to indicate that its DSP filters don’t get applied to the digital outs? Worst case scenario is rolling my own with Raspberry Pi/HifiBerry DAC+DSP but I might never crawl out of that wormhole.

Thanks.
 
Last edited:

RayDunzl

Grand Contributor
Central Scrutinizer
Joined
Mar 9, 2016
Messages
13,204
Likes
16,986
Location
Riverview FL
The miniDSP 4x10HD seems to check all the boxes but I’m having a difficult time understanding if this will work and some online reviews seem to indicate that its DSP filters don’t get applied to the digital outs?


That wouldn't make sense to me...

https://www.minidsp.com/images/documents/Product Brief-4x10 Xover plug-in.pdf

1581887281716.png
 
OP
B

Bhh

Member
Forum Donor
Joined
Feb 9, 2020
Messages
78
Likes
77
Location
NYC / Hudson Valley
That was fast!
That certainly appears to suggest the digital outs have every bit the functionality as the analog signals. Perhaps we have a winner.

Thanks so much for posting.
 

Jukka

Active Member
Joined
Apr 24, 2019
Messages
248
Likes
168
To me that looks like digital out is just pass-through. Check with their support before buying. (EDIT: I might be misinterpreting that image, but I really recommend contacting the support first)

NB! Did you think about volume control? If you use dsp to split to the subs, but use Rotel for volume, your subs will be running at max all of time.

I suggest you check out their SHD series, it's more pricey, but ticks all the boxes for stereo 2.2 setup.
 
OP
B

Bhh

Member
Forum Donor
Joined
Feb 9, 2020
Messages
78
Likes
77
Location
NYC / Hudson Valley
@Jukka
That’s an excellent point about volume control I had not considered. I’ve never used the pre amp outs on the Rotel, maybe a stupid question but will volume control attenuate gain to subs if I just send corrected but full-range signals from the DSP to the amp?

The gain on the Rotel is usually set at about 50% and casual listening volume is set via the streaming app. However the amp volume does get adjusted upwards when we want to crank things up a bit. High-pass filtering the main speakers is controversial anyway so that idea may need to get dropped.

The SHD series is very nice but that is more than I paid for any single component in this setup, including the main speakers so it just doesn't feel like the best use of that money. I do plan to upgrade those 600 series B&W speakers soon but an extra $600-$700 would probably payoff more at the speaker level at this point. Frankly , the 2x4 HD is all I need from a DSP perspective so I’m paying more than 2x the cost just for the convenience of bringing the amp out of standby mode when it receives a digital signal. Is there another way of doing that short of leaving it on all the time? It is class A/B.
 
Last edited:

Absolute

Major Contributor
Forum Donor
Joined
Feb 5, 2017
Messages
1,084
Likes
2,125
4x10hd will do what you ask. I used it for that exact purpose with the Kii Three and subs. Keep in mind that 5 PEQs per channel will limit your potential for room EQ, but I don't think room EQ above a few hundred hz is advisable unless it's just a broadband tone adjustment.
 
OP
B

Bhh

Member
Forum Donor
Joined
Feb 9, 2020
Messages
78
Likes
77
Location
NYC / Hudson Valley
@Absolute Thank you for confirming.
Yea, sort of sucks about only the 5 PEQs on the 4x10 vs 10 I think on the 2x4. Really, if they just made a 2x4 HD+ that had a few digital outs, they could charge an extra $100+, we could bypass the DAC and it would be the perfect room correction device for 2-channel audio.
 

Jukka

Active Member
Joined
Apr 24, 2019
Messages
248
Likes
168
@Bhh That Rotel looks very nice, if only it had built in dsp :) The "pre out" means that it's under the volume control. Max volume output is usually labelled "fixed out" or "tape out". So yes, you can use pre out for subs. That way you lose high-pass from main speakers, but it's a trade off for usability. If you used the DSP before Rotel to control volume, you gain sound quality, but may lose usability.

I for myself ditched the idea of everything working automatically, since not many products exists in reasonable price range that do all this. I have to resort to building everyhting from multiple pieces of hardware in order to maintain some budget. The miniDSP SHD, although expensive, is actually the cheapest DSP I've found so far that functions as a fine preamp.
 

Davelemi

Active Member
Forum Donor
Joined
Feb 13, 2019
Messages
104
Likes
235
Location
Western Massachusetts
One of the benefits of Roon is the ability to include the corrections provided by REW and also include convolution. You could pay for 4 years of Roon and buy a MiniDSP 2x4 (for the subs) for the cost of the 4x10. I feel your pain though. Although I'm using REW/Roon for room correction, my sub and speakers are fed by my DAC (no crossover)
 
OP
B

Bhh

Member
Forum Donor
Joined
Feb 9, 2020
Messages
78
Likes
77
Location
NYC / Hudson Valley
One of the benefits of Roon is the ability to include the corrections provided by REW and also include convolution. You could pay for 4 years of Roon and buy a MiniDSP 2x4 (for the subs) for the cost of the 4x10. I feel your pain though. Although I'm using REW/Roon for room correction, my sub and speakers are fed by my DAC (no crossover)

Hmm, that's an interesting idea. A regular old 2x4 will work fine to smooth out the subs, don't even need the digital inputs of the 2x4HD. Yea, I'm considering Roon but don't have a digital music collection to speak of so I'm not sure if its worth it to just stream through.

Edit: I just took another look at the miniDSP site. Is anyone familiar with the nanoDIGI 2x8 B?
https://www.minidsp.com/products/minidsp-in-a-box/nanodigi-2x8-b

It is all digital inputs and outputs. My amp has digital coaxial inputs that also work with the Signal Sense feature to wake the amp up out of sleep mode. The cost of this is much less than the 4x10HD and it appears to have 8 PEQ channels.
 
Last edited:

Soundstage

Active Member
Joined
Jan 10, 2020
Messages
294
Likes
216
Hmm, that's an interesting idea. A regular old 2x4 will work fine to smooth out the subs, don't even need the digital inputs of the 2x4HD. Yea, I'm considering Roon but don't have a digital music collection to speak of so I'm not sure if its worth it to just stream through.

Edit: I just took another look at the miniDSP site. Is anyone familiar with the nanoDIGI 2x8 B?
https://www.minidsp.com/products/minidsp-in-a-box/nanodigi-2x8-b

It is all digital inputs and outputs. My amp has digital coaxial inputs that also work with the Signal Sense feature to wake the amp up out of sleep mode. The cost of this is much less than the 4x10HD and it appears to have 8 PEQ channels.
Well I cannot connect it to my transport (raspberry streamer) because I have usb out and not optical...
 
OP
B

Bhh

Member
Forum Donor
Joined
Feb 9, 2020
Messages
78
Likes
77
Location
NYC / Hudson Valley
not screwed but what are you doing with the USB out now? You could go out to a DAC and then feed the analog out of the DAC to a regular miniDSP 2x4. Just depends on what is down stream from your streamer.
 

Soundstage

Active Member
Joined
Jan 10, 2020
Messages
294
Likes
216
not screwed but what are you doing with the USB out now? You could go out to a DAC and then feed the analog out of the DAC to a regular miniDSP 2x4. Just depends on what is down stream from your streamer.
Thanks for the reply but that sounds like an overkill because of ADC DAC in the mini DSP no? Why bother with a decent DAC (Topping D70)?

The alternative I am thinking of is a USB to SPDIF converter:

https://www.audiophonics.fr/fr/inte...e-toslink-spdif-xmos-24bit192khz-p-11929.html

or:
https://www.audiophonics.fr/fr/inte...tale-usb-vers-spdif-24bit-192khz-p-11048.html

How bad to the signal is that kind of device?

Then I would feed the MiniDSP NanoDigi with the output on the Topping DAC if that makes sense.
 

QMuse

Major Contributor
Joined
Feb 20, 2020
Messages
3,124
Likes
2,785
To me that looks like digital out is just pass-through.

Look again. 2 digital outputs are connected to 4*10 matrix switcher which means any input can be routed to them.
 

QMuse

Major Contributor
Joined
Feb 20, 2020
Messages
3,124
Likes
2,785
One of the benefits of Roon is the ability to include the corrections provided by REW and also include convolution. You could pay for 4 years of Roon and buy a MiniDSP 2x4 (for the subs) for the cost of the 4x10. I feel your pain though. Although I'm using REW/Roon for room correction, my sub and speakers are fed by my DAC (no crossover)

You can use REW/Roon for room correction and still use MiniDSP 2x4 to implement low-pass and high-pass digital crossovers for your subs and mains. If you want to avoid additional AD/DA use MiniDSP 2x4 HD and send your audio to it via USB.

Process is described here: https://www.minidsp.com/application...-2x4hd-application/282-2x4-hd-sub-integration
 
Last edited:
OP
B

Bhh

Member
Forum Donor
Joined
Feb 9, 2020
Messages
78
Likes
77
Location
NYC / Hudson Valley
Thanks for the reply but that sounds like an overkill because of ADC DAC in the mini DSP no? Why bother with a decent DAC (Topping D70)?

The alternative I am thinking of is a USB to SPDIF converter:

https://www.audiophonics.fr/fr/inte...e-toslink-spdif-xmos-24bit192khz-p-11929.html

or:
https://www.audiophonics.fr/fr/inte...tale-usb-vers-spdif-24bit-192khz-p-11048.html

How bad to the signal is that kind of device?

Then I would feed the MiniDSP NanoDigi with the output on the Topping DAC if that makes sense.

the miniDSP doesn’t have a great DAC but you haven’t really given us enough information to really help you. You need to describe everything downstream from your streamer and what you are trying to accomplish. Presumably you have a DAC downstream already so one of the digital converters above should work fine but I have no idea if they will be detrimental to the signal. I suspect not.
 
Top Bottom