This is a review and detailed measurements of the Sonance DSP 2 150 amplifier with digital inputs and equalization capabilities. It is on kind loan from a member and costs US $1075. While you can buy this in retail, bulk of Sonance's business is in Custom Integration (CI) space where it is installed as part of a more complete system. Connectivity and such is optimized for this use as opposed to consumer.
Note: I should know this but I don't. It is possible that our company, Madrona Digital, is a dealer for Sonance. So you are welcome to read bias into my subjective remarks.
The DSP 2 150 has an unusual shape of being narrow but super deep:
The picture is kind of deceiving. It is quite deep.
A single power button is all the controls you have. The needed to reset the unit as the owner had set it to static IP address which I did not know. There was no mention of how to do this in the manual. Fortunately a search showed the answer which was to set the left volume all the way to the left and right, you guessed it, all the way to the right.
Upon powering on it did indeed reset itself with DHCP being on which allowed it to get on my network. I was disappointed that I had to use an IP scanner to find its address rather than supporting multicast DNS or something similar so I could just use its name. Since you are likely to want to mess with the EQ more often, having to keep looking up the IP address is inconvenient.
Anyway, once you suffer through finding the device, you are greeted with a very speedy web interface with lots of control:
I was however disappointed that all settings are global. Unless you see it, I couldn't figure out how to have per-channel settings.
The back panel shows the special connectivity I mentioned:
Notice how there is only digital Toslink/Coax Input and Output. There are no analog inputs. The digital inputs are fed forward on the output ports.
After my testing, the top of the amplifier where the vents are in the center was quite warm. You better allow a lot of room for above it to cool. And don't put it on anything hot. Sadly in a lot of custom installs such luxuries don't exist so I worry about its reliability in such situations.
Sonance DSP 2-150 Measurements
There is no way to see the dials for the input gains so I just set them to something that "felt" right as far as gain:
Two things stand out. One is the timing mismatch between the two channels. We have seen this before in one or two other digital input amps so I wonder if they all share the same platform. There is a delay setting in the EQ pane of the control page but per my intro, I couldn't figure out how to apply it to one channel only. And this is assuming that the delay is fixed which may not be (may be a sample mismatch).
The second problem is the awful spectrum of the signal. It is one thing to have the two harmonic peaks but what is all that grunge around them?
SINAD which ignores those irregularities for the most part is below average at 75 dB:
At first, I measured the signal to noise ratio using traditional methods for analog input amplifiers:
Then I realized since there is a DAC in front of the amp, perhaps I use use dynamic range measurements which don't let the DAC mute to get better response. Here is that result:
So a bit lower but not a lot. Results are pretty good overall so this should be a quiet amplifier.
When I first reset the unit, the EQ panel showed a bass boost. Strange that this is so post factory reset. Anyway, after that, here is the response:
Response at 44.1 kHz was just as flat but cut off much sooner naturally (not shown).
Here is our multitone:
I am puzzled by the high noise floor and rising noise level at mid frequencies. The former is in conflict with the SNR/DNR measurements so perhaps there is a problem where noise floor is substantially shifted up when more than one tone is input.
Crosstalk is nothing to write home about but not bad enough to complain too much:
Here is our power into 4 ohm:
Yet another puzzle. Normally we are noise limited at lower power levels so the graph slopes down. Here it is almost flat indicating a constant noise or distortion in play. Again our DNR/SNR was very clean so this has to be constant distortion/spurious tones of some sort.
Anyway, I got 161 watts which is well shy of company spec of 300 watts. If I pushed the amp any further protection circuit would kick in. Same problem stopped me from getting max power but peak power did work:
So maybe it can get to 300 watts but not with constant tones.
Switching to 8 ohm load we get a similar response except that the distortion level rises slowly as if there is some kind of limiter:
But if there is a limiter, why didn't it do that for 4 ohm???
Finally, here is our response at different frequencies:
Puzzle after puzzle....
Conclusions
Hmmm. What does this net out to? Below average distortion levels. Some kind of bug in channel processing. Good packaging. Good DSP capabilities that don't work on per channel basis. Seems like the whole design needs a proper evaluation and clean up across the board.
I can't recommend the Sonance DSP 2-150. Too much irregularities for my taste despite the fact that I really like the idea of an amplifier with DSP in it.
----------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
Note: I should know this but I don't. It is possible that our company, Madrona Digital, is a dealer for Sonance. So you are welcome to read bias into my subjective remarks.
The DSP 2 150 has an unusual shape of being narrow but super deep:
The picture is kind of deceiving. It is quite deep.
A single power button is all the controls you have. The needed to reset the unit as the owner had set it to static IP address which I did not know. There was no mention of how to do this in the manual. Fortunately a search showed the answer which was to set the left volume all the way to the left and right, you guessed it, all the way to the right.
Upon powering on it did indeed reset itself with DHCP being on which allowed it to get on my network. I was disappointed that I had to use an IP scanner to find its address rather than supporting multicast DNS or something similar so I could just use its name. Since you are likely to want to mess with the EQ more often, having to keep looking up the IP address is inconvenient.
Anyway, once you suffer through finding the device, you are greeted with a very speedy web interface with lots of control:
I was however disappointed that all settings are global. Unless you see it, I couldn't figure out how to have per-channel settings.
The back panel shows the special connectivity I mentioned:
Notice how there is only digital Toslink/Coax Input and Output. There are no analog inputs. The digital inputs are fed forward on the output ports.
After my testing, the top of the amplifier where the vents are in the center was quite warm. You better allow a lot of room for above it to cool. And don't put it on anything hot. Sadly in a lot of custom installs such luxuries don't exist so I worry about its reliability in such situations.
Sonance DSP 2-150 Measurements
There is no way to see the dials for the input gains so I just set them to something that "felt" right as far as gain:
Two things stand out. One is the timing mismatch between the two channels. We have seen this before in one or two other digital input amps so I wonder if they all share the same platform. There is a delay setting in the EQ pane of the control page but per my intro, I couldn't figure out how to apply it to one channel only. And this is assuming that the delay is fixed which may not be (may be a sample mismatch).
The second problem is the awful spectrum of the signal. It is one thing to have the two harmonic peaks but what is all that grunge around them?
SINAD which ignores those irregularities for the most part is below average at 75 dB:
At first, I measured the signal to noise ratio using traditional methods for analog input amplifiers:
Then I realized since there is a DAC in front of the amp, perhaps I use use dynamic range measurements which don't let the DAC mute to get better response. Here is that result:
So a bit lower but not a lot. Results are pretty good overall so this should be a quiet amplifier.
When I first reset the unit, the EQ panel showed a bass boost. Strange that this is so post factory reset. Anyway, after that, here is the response:
Response at 44.1 kHz was just as flat but cut off much sooner naturally (not shown).
Here is our multitone:
I am puzzled by the high noise floor and rising noise level at mid frequencies. The former is in conflict with the SNR/DNR measurements so perhaps there is a problem where noise floor is substantially shifted up when more than one tone is input.
Crosstalk is nothing to write home about but not bad enough to complain too much:
Here is our power into 4 ohm:
Yet another puzzle. Normally we are noise limited at lower power levels so the graph slopes down. Here it is almost flat indicating a constant noise or distortion in play. Again our DNR/SNR was very clean so this has to be constant distortion/spurious tones of some sort.
Anyway, I got 161 watts which is well shy of company spec of 300 watts. If I pushed the amp any further protection circuit would kick in. Same problem stopped me from getting max power but peak power did work:
So maybe it can get to 300 watts but not with constant tones.
Switching to 8 ohm load we get a similar response except that the distortion level rises slowly as if there is some kind of limiter:
But if there is a limiter, why didn't it do that for 4 ohm???
Finally, here is our response at different frequencies:
Puzzle after puzzle....
Conclusions
Hmmm. What does this net out to? Below average distortion levels. Some kind of bug in channel processing. Good packaging. Good DSP capabilities that don't work on per channel basis. Seems like the whole design needs a proper evaluation and clean up across the board.
I can't recommend the Sonance DSP 2-150. Too much irregularities for my taste despite the fact that I really like the idea of an amplifier with DSP in it.
----------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
