This is a review and attempted measurements of the Legacy Audio Wavelet audio pre-amp/processor/DSP/Room EQ. It is on kind loan from a member and costs US $4950.
The industrial design is decent with a dot matrix LED panel. I was shocked to see such an expensive processor come with an external power brick:
That was nothing compared to trying to get the unit on the network to configure it. There is an Ethernet port but no documentation on how to use it. Instead they have a horrible way to configure a wifi dongle (see above the unit). You first go to some website and give it your wifi config in addition to serial number of the device. it then creates a text config file which you put on a flash drive. You plug in the flash drive and pray that it does something useful in the one minute the company says to wait. In my case, that wait finished with "IP error." I guessed that this was due to not having plugged in the wifi dongle. I did that and after a power cycle thankfully it got on line.
Alas, once online I could not do anything to force the unit be in bypass mode. It comes configured with specialized setup for their speakers (?) as you will see in measurements.
Legacy Wavelet DAC Measurements
I attempted to use the USB input to test the DAC but with the cable I had, connection was too loose. It didn't work at first. Then it worked. Then it stopped working when I just touched the cable. After all the frustration of trying to network the thing, I was in no mood for messing with this so opted to conduct all the tests using S/PDIF input.
When I had the dashboard up, I thought I was going crazy because at first I would see this kind of performance:
Super strangely, if you keep increasing the volume, all of a sudden it switches to another gain mode where the clipping disappears! Here is that performance:
Even this is nothing to write home about:
I found the volume control to be very odd in operation. Sometimes it would go backward in level as I continued to dial it forward. It seems to have some kind of fine mode (?). Very frustrating.
Continuing on, this dynamic range at the above output level:
So just 16 bits worth of dynamic range in an application (home theater) where this is clearly insufficient (THX spec is 105 dB).
Before I go further, I decided to run frequency response test to make sure no processing was active:
Clearly we have a high-pass crossover here but also a couple of corrections which I assume is needed for their speakers. I could not find a way to defeat either one of these. I found another measurement in some magazine where they also had to deal with the high pass crossover although they did not see the two boosted ranges. Given this, the measurements will not quite relate to other devices and hence my comment about this being an "attempted" review.
IMD test showed clipping which I did not see in 1 kHz test:
Linearity is not great:
Jitter spikes can be masked by high noise floor:
Strangest results were this:
The rise in low frequencies is because the high pass filter reducing output and increasing noise component. But what is the explanation for the large distortion increase between 300 Hz and 1 kHz???
I could not run multitone test because 192 kHz is not supported on its S/PDIF input (most devices are this way).
Conclusions
It is tough to evaluate a device when it has built-in corrections that you can't defeat. But we have enough data here to not like the functionality of the device. And its performance (which by the way, matches the few bits measured by another site). The volume control/gain staging bug seems quite serious to me. You actually have the unit clipping, then going back to normal operation! You better use an amp that doesn't need more than 2 volts input (balanced) to reach its full output power or you will experience this problem.
Despite the difficulty of measuring the device, I am disappointed enough in its performance to not recommend it. Mind you, its room EQ and PEQ correction for their speakers may be great value add but there is no reason to have the device be this broken otherwise.
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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/
The industrial design is decent with a dot matrix LED panel. I was shocked to see such an expensive processor come with an external power brick:
That was nothing compared to trying to get the unit on the network to configure it. There is an Ethernet port but no documentation on how to use it. Instead they have a horrible way to configure a wifi dongle (see above the unit). You first go to some website and give it your wifi config in addition to serial number of the device. it then creates a text config file which you put on a flash drive. You plug in the flash drive and pray that it does something useful in the one minute the company says to wait. In my case, that wait finished with "IP error." I guessed that this was due to not having plugged in the wifi dongle. I did that and after a power cycle thankfully it got on line.
Alas, once online I could not do anything to force the unit be in bypass mode. It comes configured with specialized setup for their speakers (?) as you will see in measurements.
Legacy Wavelet DAC Measurements
I attempted to use the USB input to test the DAC but with the cable I had, connection was too loose. It didn't work at first. Then it worked. Then it stopped working when I just touched the cable. After all the frustration of trying to network the thing, I was in no mood for messing with this so opted to conduct all the tests using S/PDIF input.
When I had the dashboard up, I thought I was going crazy because at first I would see this kind of performance:
Super strangely, if you keep increasing the volume, all of a sudden it switches to another gain mode where the clipping disappears! Here is that performance:
Even this is nothing to write home about:
I found the volume control to be very odd in operation. Sometimes it would go backward in level as I continued to dial it forward. It seems to have some kind of fine mode (?). Very frustrating.
Continuing on, this dynamic range at the above output level:
So just 16 bits worth of dynamic range in an application (home theater) where this is clearly insufficient (THX spec is 105 dB).
Before I go further, I decided to run frequency response test to make sure no processing was active:
Clearly we have a high-pass crossover here but also a couple of corrections which I assume is needed for their speakers. I could not find a way to defeat either one of these. I found another measurement in some magazine where they also had to deal with the high pass crossover although they did not see the two boosted ranges. Given this, the measurements will not quite relate to other devices and hence my comment about this being an "attempted" review.
IMD test showed clipping which I did not see in 1 kHz test:
Linearity is not great:
Jitter spikes can be masked by high noise floor:
Strangest results were this:
The rise in low frequencies is because the high pass filter reducing output and increasing noise component. But what is the explanation for the large distortion increase between 300 Hz and 1 kHz???
I could not run multitone test because 192 kHz is not supported on its S/PDIF input (most devices are this way).
Conclusions
It is tough to evaluate a device when it has built-in corrections that you can't defeat. But we have enough data here to not like the functionality of the device. And its performance (which by the way, matches the few bits measured by another site). The volume control/gain staging bug seems quite serious to me. You actually have the unit clipping, then going back to normal operation! You better use an amp that doesn't need more than 2 volts input (balanced) to reach its full output power or you will experience this problem.
Despite the difficulty of measuring the device, I am disappointed enough in its performance to not recommend it. Mind you, its room EQ and PEQ correction for their speakers may be great value add but there is no reason to have the device be this broken otherwise.
----------
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/