This is a review and detailed measurements of the JBL DS4086 8-channel car audio amplifier with same number of DSP channels. I bought it for US $440.
This is a highly compact unit that is about half the volume of any competing amplifier plus this many channels of DSP. This was a major advantage in me selecting it as I look up upgrading the audio system in our Mercedes Sprinter camper van. Here is the side view and connectivity:
You can see cost savings in the form of captive RCA cables, no power terminals (comes in a dongle), etc. Despite that, feature set is quite good including full parametric equalization:
You see the indicator saying "Disconnected." No matter what I did, it would not connect. I messed with the included driver from 2014 (!) but problem remained. After an hour of this, installed the same on my laptop (both running Windows 11) and it worked instantly. Installation of the software is mandatory as you need to at least program the matrix mixer to get sound. Note that only filter is a PEQ. No other types which is not a huge limitation but it is there. You do get typical crossovers which is one of my main application as I implement active crossover (and hence the number of channels I needed -- at least 6).
FYI the filter defaults to "graphic" which made me go crazy as I could not figure out why I could not set the Q. As it turns out, JBL's notion of graphic eq is to use the parametric EQ but fix the frequencies and Q as you see. Kind of interesting hack but I wish they would make the PEQ mode default and have more colorful indicator of which is active.
Note that this DSP lacks "OEM integration" meaning it is not easy to take out the EQ/delays out of modern automotive head units. Products with this "de-EQ" feature, have separate tuning/EQ for that mode to flat line the response of the source before applying acoustic EQ. You can do that here but it will be harder. I don't need this feature so doesn't matter to me.
Design is a few years old, making me worried that it will be discontinued and at any rate, the software may get out of date and not supported in the future.
For testing, I hooked up my custom built Lithium battery bank. I kept the voltage between 13.6 to 13.7 volts throughout the testing. As I was trying to fix the software installation issues, I left the amplifier on. I was very surprised to see how hot it got just sitting there:
You could barely keep your hand on it. This is unacceptable in my book as it is only going to get hotter in a car (my room temp was just 22.8 degrees C as you see). Fortunately it doesn't get much hotter (picture right) after all of my testing.
JBL DS4086 DSP Amplifier Measurements
Let's start with our usual dashboard:
Noise floor and distortions are high by home audio standards, but slightly below average for all car audio products tested:
I worry that once you add the noise from the head unit, it will sink to unacceptable levels and produce hiss.
Notice the 21 watts idle power consumption which explains the thing cooking just sitting there.
Gain seems quite low. Max I could get was with setting the gain to 6 dB and having the selector switch set to "LO." Otherwise, the gain dips as low as 10.5 dB as indicated. It is not much of a problem in practice because it doesn't product a lot of watts:
Any head unit should be able to produce that 1.35 volt without distorting much.
Frequency response shows, as expected, class D load dependency:
And digitization of input with sampling rate of 44.1/48 kHz.
Channel separation was pretty poor:
As were multitone and 19+20 kHz but again, in the category, less so:
Power delivery has a strange kink in distortion showing up both early and jumping before clipping:
While better than a stock head unit, not much power is available as I feared (but hoped otherwise):
Note again that all of this testing is with 2 channels. You likely get less if you drive more channels. 40 Hz power is about the same which is good:
FTC like sweep shows some variation but nothing too crazy:
I should note that design was robust in that the amp would go into full clipping and keep going which made above tests possible.
Here is 8 ohm power:
Here is the response relative to frequency:
The last quarter of output power is delivered at quite high distortions which are likely audible. I put the cursor before that happens.
There is potential for audible pop although not extreme:
The amp was warmed up before I got a chance to run the warm up test:
Conclusions
For the price and amount of functionality, the measurements are not too bad. The main issues then for me is software support/stability and heat generation. On latter, I no longer can stuff it in a hole in the dash like I was planning to do. I can put it under the seat but then I can get a larger unit. I went ahead and ordered an Audison DSP amp. It cost more than twice as much. Hopefully it will do better (it has a key feature which I am hoping will be a major advantage). That review, should be out by end of the week if it arrives on time.
If you can keep the JBL DSP4086 cool and can accept some risk on software functionality/support, you may be fine with this unit.
------------
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/
This is a highly compact unit that is about half the volume of any competing amplifier plus this many channels of DSP. This was a major advantage in me selecting it as I look up upgrading the audio system in our Mercedes Sprinter camper van. Here is the side view and connectivity:
You can see cost savings in the form of captive RCA cables, no power terminals (comes in a dongle), etc. Despite that, feature set is quite good including full parametric equalization:
You see the indicator saying "Disconnected." No matter what I did, it would not connect. I messed with the included driver from 2014 (!) but problem remained. After an hour of this, installed the same on my laptop (both running Windows 11) and it worked instantly. Installation of the software is mandatory as you need to at least program the matrix mixer to get sound. Note that only filter is a PEQ. No other types which is not a huge limitation but it is there. You do get typical crossovers which is one of my main application as I implement active crossover (and hence the number of channels I needed -- at least 6).
FYI the filter defaults to "graphic" which made me go crazy as I could not figure out why I could not set the Q. As it turns out, JBL's notion of graphic eq is to use the parametric EQ but fix the frequencies and Q as you see. Kind of interesting hack but I wish they would make the PEQ mode default and have more colorful indicator of which is active.
Note that this DSP lacks "OEM integration" meaning it is not easy to take out the EQ/delays out of modern automotive head units. Products with this "de-EQ" feature, have separate tuning/EQ for that mode to flat line the response of the source before applying acoustic EQ. You can do that here but it will be harder. I don't need this feature so doesn't matter to me.
Design is a few years old, making me worried that it will be discontinued and at any rate, the software may get out of date and not supported in the future.
For testing, I hooked up my custom built Lithium battery bank. I kept the voltage between 13.6 to 13.7 volts throughout the testing. As I was trying to fix the software installation issues, I left the amplifier on. I was very surprised to see how hot it got just sitting there:
You could barely keep your hand on it. This is unacceptable in my book as it is only going to get hotter in a car (my room temp was just 22.8 degrees C as you see). Fortunately it doesn't get much hotter (picture right) after all of my testing.
JBL DS4086 DSP Amplifier Measurements
Let's start with our usual dashboard:
Noise floor and distortions are high by home audio standards, but slightly below average for all car audio products tested:
I worry that once you add the noise from the head unit, it will sink to unacceptable levels and produce hiss.
Notice the 21 watts idle power consumption which explains the thing cooking just sitting there.
Gain seems quite low. Max I could get was with setting the gain to 6 dB and having the selector switch set to "LO." Otherwise, the gain dips as low as 10.5 dB as indicated. It is not much of a problem in practice because it doesn't product a lot of watts:
Any head unit should be able to produce that 1.35 volt without distorting much.
Frequency response shows, as expected, class D load dependency:
And digitization of input with sampling rate of 44.1/48 kHz.
Channel separation was pretty poor:
As were multitone and 19+20 kHz but again, in the category, less so:
Power delivery has a strange kink in distortion showing up both early and jumping before clipping:
While better than a stock head unit, not much power is available as I feared (but hoped otherwise):
Note again that all of this testing is with 2 channels. You likely get less if you drive more channels. 40 Hz power is about the same which is good:
FTC like sweep shows some variation but nothing too crazy:
I should note that design was robust in that the amp would go into full clipping and keep going which made above tests possible.
Here is 8 ohm power:
Here is the response relative to frequency:
The last quarter of output power is delivered at quite high distortions which are likely audible. I put the cursor before that happens.
There is potential for audible pop although not extreme:
The amp was warmed up before I got a chance to run the warm up test:
Conclusions
For the price and amount of functionality, the measurements are not too bad. The main issues then for me is software support/stability and heat generation. On latter, I no longer can stuff it in a hole in the dash like I was planning to do. I can put it under the seat but then I can get a larger unit. I went ahead and ordered an Audison DSP amp. It cost more than twice as much. Hopefully it will do better (it has a key feature which I am hoping will be a major advantage). That review, should be out by end of the week if it arrives on time.
If you can keep the JBL DSP4086 cool and can accept some risk on software functionality/support, you may be fine with this unit.
------------
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/
