I did not send this one in, but this is from Audio Science Review

SounDigital SD 600.1D

https://www.audiosciencereview.com/f...plifier.11521/

Below is copied and pasted from ASR

This is a review and detailed measurements of the SounDigital SD600.1D Nano car audio amplifier. It is on kind loan from a member. The SD600.1D seems to come in different versions (this one is the 2 ohm revision) and costs somewhere between US $150 to $180 depending on seller.

Despite the high power rating, the unit is tiny:



A tiny and noisy fan runs at full speed to provide the needed cooling. Two ultra-cheap pots that are difficult to turn set some kind of low and high pass. There is both line and speaker level inputs.

Specs are hard to believe:



700 watts for something that fits in the palm of your hand for this little money? I guess we will have to find out!

I don't have a car battery setup in my audio lab so I powered the unit using my switching high-power power supply that is rated at 30 volts and 50 amps. I set the output voltage to about 14.5 volts. I adjusted the gain for typical level I use for testing of amps. And tried to set the tone controls so that they would have least impact.

Car Audio Amplifier Audio Measurements
Let's start with our usual dashboard of 1 kHz tone into 4 ohms:




Good grief. Distortion is so high that I can see the sine wave itself being distorted!

The unit is specified to have only 0.01% THD+N at 60 watts so let's go up there and see what we get:




Well, no. We are not even in the same planet with nearly 3% THD+N. And almost all of that is dominated by high harmonic distortion.

Frequency response is not good:




Here is the power output using 4 ohm load:




Ugly distortion curve but over 200 watts of power.

Switching to 2 ohm load gets us more:




Nasty distortion level but we get up to 334 watts. The internal LED started to blink so it may be running out of juice. Not sure we will ever get to 700 watts but more power is there to be had I think.

I could not run my peak and max power ratings as the amp would constantly go into protection given the supply I have.

Conclusions
One look at the unit and you know you have an "ebay special." The car audio market is the wild west of audio where every claim is made, the truth be damned. Here, we have that easily in the form of rated distortion. This is an ugly, ugly amplifier. All effort is put in there to put out power, quality to be damned.

Needless to say, I cannot recommend the SounDigital SD600.1D in any form or fashion.