Down4Sound JP95 Car Amplifier Review

[Palladium]

Does -71 dB noise matter in a car?

Between driver THD, panel resonances, a 60dB background noise floor and 85dB safe hearing limit? Unlikely.

 

[milosz]

What is the typical background noise level in a moving car? You are NEVER going to hear the noise component in a 69 dB SINAD from a car amplifier! Yes it's worthwhile to mention that the amp doesn't perform like a home amp - but keep in mind that it DOESN'T NEED TO!

An important part of engineering is to consider the real world use case - and design to match that goal within the economic envelope available. Money spent to develop an autosound amplifier with a 100 dB SINAD would be R&D money wasted, although it would impress Amirm

 

[Multicore]

Looks like the consensus here is: not great on the bench but the price per pound is unbeatable.

 

[Multicore]

What is the typical background noise level in a moving car? You are NEVER going to hear the noise component in a 69 dB SINAD from a car amplifier!

But typical listening conditions is not generally how we judge amp noise. At home or on the desk we judge the noise by running the amp chain at typical gain with silent input signal, moving your ears close to the speaker and if there's no hiss then it's ok. I don't see why similar shouldn't apply in a car. A lot of people have cars that are objects of pride and very comfortable, luxurious even. So why wouldn't it be reasonable to sit in it and listen? A lot of cars, even those with an ICE, are quiet when it is idling and a lot turn off the ICE when the car is stopped. And in cars the tweeters are sometimes within 1 meter of the ears in the normal listening configuration, without moving your ears close to them.

 

[Roland68]

I wonder what the noise-level is in a car. I guess very good performance are wasted in a car compared to ones living room. Does an amp for a car have to be better than this?

The noise level in a car depends on the speed and also on engine speed, wind, tires and ground conditions.
The amplifier doesn't have to be better, but it does have to be louder, depending on the above.
The ambient noise was significantly more overpowering the music signal than the amplifier's poor noise levels. But if you are stationary and the ignition is off, then it can make a difference.

 

[elberoth]

Nice to see some car audio amps tested!

 

[Alice of Old Vincennes]

Forced perspective can have a tendency to play tricks on one's perceptions. Do you really believe that that guy's hands are as big as his head?

Ask the House of Windsor.

 

[Bob101]

Does -71 dB noise matter in a car?

When you're parked in the woods.
It is something you can notice as hiss in sensitive tweeters. In modern cars tweeters are also pretty close to your ears. But once you're driving? Not really, at least in your or my car. If you drive a Rolls or a Maybach you're simply not going to pimp your ride with this. I hope.

 

[Adaboy4z]

JP sells these amps like Hot cakes. They produce large amounts of power for bass heads who just want to be the loudest and paying little money. Just think 30 years ago this amp would be $1000!!

 

[JDS]

It is surprisingly high: most cars at 70 mph read between low 60 to 75 dB, not counting the noise from the traffic around you

And that noise is dynamic, varying with speed, road surface, weather, etc. This is why I am a bit puzzled by concerns about THD, S/N, etc. in car stereos. If peaks are (dangerously) at 100dB, and background noise is at, say, 70dB, you have only 30dB of audible range to work with. That's about 3% THD. Isn't everything below that going to be inaudible?

 

[AdamG]

This thing is huge! Amazing value for the price.
View attachment 358374
Specs.>
View attachment 358375

I was going to post up the Specs but you beat me to it. Thank you Sir for your incredible support and assistance.

 

[dtaylo1066]

Why not just battery power some of the inexpensive but good measuring amps like Fosi if you want great sound? Of course in a car...

 

[amirm]

And that noise is dynamic, varying with speed, road surface, weather, etc. This is why I am a bit puzzled by concerns about THD, S/N, etc. in car stereos. If peaks are (dangerously) at 100dB, and background noise is at, say, 70dB, you have only 30dB of audible range to work with. That's about 3% THD. Isn't everything below that going to be inaudible?

You can't use single number SPL numbers to determine audibility. You have to have its spectrum. Directional noise from a tweeter will be more audible than diffused noise. And speaker noise multiplies with number of speakers you have.

 

[pseudoid]

@amirm,
*Thank you for the review, but you are still making me wait until you 'recommend' a similar 4+1 channel amp (@<$500) that can motivate me to go full OCD tearing-out the whole OEM audio system... down to every single single cable and connector..., in my '06 GTO.

So many years went by since I bought my Alpine PDX-V9 and things have not evolved much I see. Except for price. But still.

Alpine PDX-V9 Review (car amplifier)

This is a review and detailed measurements of the Alpine PDX-V9 four channel amplifier plus subwoofer amp. It is on kind loan from a member and costs US $999. Despite having one more channel than PDX-F6, The V9 is in the same box: Let's see if it measures as well as the F6 did. Alpine PDX-V9...

audiosciencereview.com

*Have you given up posting the comparison bar-graph? (the Alpine review had it)

 

[DMill]

Fun review. I don’t spend much time critically listening to music in my car any more. And the whole market has changed since I was a kid. It used to be a thing to install an Alpine deck in your car. Now everything is so packaged up by what the manufacturer offers it’s hard to imagine cutting apart your dashboard for good sound. My guess is this amp is more than capable of delivering Zeppelins Kashmir at ear splitting levels in your old El Camino. With road noise probably completely transparent. Might want to ask your girlfriend first though.

 

[Doodski]

Fun review. I don’t spend much time critically listening to music in my car any more. And the whole market has changed since I was a kid. It used to be a thing to install an Alpine deck in your car. Now everything is so packaged up by what the manufacturer offers it’s hard to imagine cutting apart your dashboard for good sound. My guess is this amp is more than capable of delivering Zeppelins Kashmir at ear splitting levels in your old El Camino. With road noise probably completely transparent. Might want to ask your girlfriend first though.

The factory power rating is 400 W RMS /ch @ 4 Ohms stereo output. (With the voltage delivered @ clipping = ~ 56.6 V peak @ ~ 14.1 A peak.)

In 2 channel bridged mode into 4 Ohms at clipping results in:
Channel A @ 545 W RMS @ 4 Ohms with 14.44 V DC supply @ ~139 A DC draw. Note: The voltage delivered @ clipping to the load = +/- ~66 V peak @ ~16.5 A peak.
Channel B @ 509 W RMS @ 4 Ohms with 14.54 V DC supply @ ~139 A DC draw. Note: The voltage delivered @ clipping to the load = +/- ~63.8 V peak @ ~16 A peak.

Yes, this thing will go to deafening thumping levels for sure...LoL.

 

[kelesh]

I wonder what the noise-level is in a car. I guess very good performance are wasted in a car compared to ones living room. Does an amp for a car have to be better than this?

No, a car is one of the worst acoustic environments possible. All that reflecting glass and you can never really sit centrally in the right spot. I gave up on car audio years ago, news/weather is about all it's good for.

 

[amirm]

*Have you given up posting the comparison bar-graph? (the Alpine review had it)

Oh, had forgotten that I made a category for it. Will post that a bit later.

 

[ROOSKIE]

A lot of votes for 'waste of money' and 'not terrible'. I'm really curious if folks who voted that way have any actual experience with car audio.

Personally I'd rather use slightly smaller amps that fit very easily under more various car seats but it will fit under my CRV seats. This still seems like a very decent option to me for low money. I have installed many car audio systems including several very excellent sounding fully custom hifi set-ups. The environment is very different from a living or listening room at home.

No, a car is one of the worst acoustic environments possible. All that reflecting glass and you can never really sit centrally in the right spot. I gave up on car audio years ago, news/weather is about all it's good for.

Weather? Roll those windows down and rock out friend.
Sure, it has challenges, yet one can get very good sound in a car.
Also with DSP you can have several tunings saved for things like windows up vs down. 2 front passenger vs just the driver.
If tuning for solo driver focused, DSP and time alignment can make it sound exactly like being in the middle of two monitors.
Even some higher oem options are pretty stellar ones.
I'd like to hear what KEF came up with for the new Lotus cars. Harmon via Revel, Mark Levinson and also AKG have done a few oem systems as well that I'm curious about.

Why not just battery power some of the inexpensive but good measuring amps like Fosi if you want great sound? Of course in a car...

You can and some do this. The car only outputs 12-14volts so that can be an issue as any car(or other type of amp) amp needs to draw very high amperage to make high power in 12volt systems, not all amps can do this.

 

[oscar_dziki]

Forced perspective can have a tendency to play tricks on one's perceptions. Do you really believe that that guy's hands are as big as his head?

Yes. I also believe sun hangs few hundred meters above the clouds