Alpine PDX-V9 Review (car amplifier)

[amirm]

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 Measurements
Here is our usual dashboard:

As with PDX-F6, there is some channel mismatch but not as much. Distortion though varies between the two with one channel weaker now. It lands the V9 slightly below the F6 as a result:

This theme continues in SNR test:

As well as crosstalk:

Frequency response is improved though (although not in an audible way):

There was ringing above audio band with PDX-F6 which is gone now with V9.

Multitone shows slightly more distortion again:

But very respectable in grand scheme of things.

I had a hell of a time getting consistent power vs distortion curve. I tightened all the connections and messed around for a couple of hours and this is the best I could get:

It seems to be a power delivery issue. Same shows up with 8 ohm load:

And dramatically as we change the frequencies:

FFT spectrum shows more messiness than F6:

Power output was a bit higher though than F6:

Conclusions
It appears that in the process of adding another amplifier module with high power output for the sub, the overall performance is degraded some compared to last generation. What we see here is still quite good for a car audio amplifier but we were spoiled with how good with the PDX-F6.

I am going to recommend the Alpine PDX-V9, just not super enthusiastically.

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As always, questions, comments, recommendations, etc. are welcome.

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[JSmith]

I always used to use Alpine amps and head-units to deck cars out with nice audio systems... good to see my choice was wise.

Based on this I might go back to the days of old and replace the inbuilt items in my car.



JSmith

 

[KxDx]

Aw darn, you did test the sub channel? I'd have liked to see if it met rated power...

 

[Jdunk54nl]

I purchased this amp used a couple years ago now for $200 used on offerup.

Here is the birth sheet for this amp

 

[GWolfman]

I tightened all the connections and messed around for a couple of hours and this is the best I could get

(emphasis added)

Thanks for your dedication for trying to provide reliable and accurate test results, even when the equipment doesn't want to behave.

 

[GWolfman]

Here is the birth sheet for that amp
View attachment 171497

@amirm What's the measurement (Vout) of your voltage source? From a previous review, IIRC, it was 13.8x? This might explain why we're coming up a bit short on measurements.

What's an alternator Vout supposed to be? Or does it vary?

 

[Jdunk54nl]

My truck always is about 14.2volts to 14.4volts according to my OBD tool that provides real time gauges (sct x4 device). That is also a 240amp alternator.

 

[capslock]

Clearly a dodgy power supply design, but I woudn't vouch for the four main channels using exactly the same design as in the F6. We have -78 dB to -85 dB for the third harmonic and -90-95 for the others whereas the F6 had them all at -102 or better dB. The F6 had also nearly frequency independent distortion while the V9 gets poorer a HF. This is not a power supply issue, it means there is less loop gain at high frequency, hence a different design.

 

[pseudoid]

What type of output (speaker) connectors are these (red circled)? Never had the pleasure to have worked with them...
Another ignorant question: When mobile amps are tested, is the nominal 'battery' power at 14.4Vdc or is it the customary (what is referred to as) "12.0Vdc"?
The two 40Amp fuses also confuse me >> is the 2nd fuse solely for the sub?

 

[Jdunk54nl]

They use these little speaker plug things that go into the red circled holes.

 

[KaMiKaZeCATS]

Respect to alpine for not making the usual garbage in the car audio world

 

[Matias]

Ah what a shame it did not reach the full potention of the F6. Still good though.

PS: @amirm the power x THD+N graphs are written ICEpower instead of PDX-V9.

 

[Jdunk54nl]

I also wonder if something could be slightly messed up with the amp. I am at least the second owner of it.

 

[michaelahess]

I've had this amp in my BRZ since I bought it new in 2012. Cost around $460. It runs a single 10" sealed sub and bi-amped Morel Elates. It's been very good to me. Along with the 200+ pounds of dynamat and thinsulate I installed to deaden the car.

 

[amirm]

PS: @amirm the power x THD+N graphs are written ICEpower instead of PDX-V9.

Oops. That is the default name in the template and I must have forgotten to update them.

 

[pseudoid]

....Along with the 200+ pounds of dynamat and thinsulate I installed to deaden the car.

Ouch!
That is the act of one resolute and dedicated audio nerd.
You are willing to take a >10% weight penalty (~10% performance reduction[?]) on your BRZ!
Truly admirable and a die-hard audio decision over performance hit!

 

[amirm]

@amirm What's the measurement (Vout) of your voltage source?

I indicated them on the graphs:

As you see, it says 13.4 volts. I started with 14 volts but during the previous testing it drew it down to 13.4. On some amps, I can leave my lab supply connected so it can charge the batteries back up between tests. Here, it causes power supply spikes to show up so I could not do that and hence the power supply drain. I did charge the battery in between the power measurements but as I noted, stability was poor and I had to keep repeating the tests, causing the battery to droop.

So yes, companies do rate these amps at higher voltages (often 14+ volts). I think you need dedicated and strong feed to get that kind of voltage at the amplifier in a car. In my RV with its real-time volt meter, I only see 13.7 volts for example.

 

[Jdunk54nl]

Ouch!
That is the act of one resolute and dedicated audio nerd.
You are willing to take a >10% weight penalty (~10% performance reduction[?]) on your BRZ!
Truly admirable and a die-hard audio decision over performance hit!

Some of us are a little bit crazy…

2009-2014 (12th Gen.) Ford F150 – Full Vehicle Sound Proofing – Submitted By Jacob D. – ResoNix Sound Solutions

resonixsoundsolutions.com

 

[pseudoid]

Some of us are a little bit crazy…

I gave up my union card!
My last Dynamat exercise was with a '96 Supra, and with great results but all my performance-minded cohorts grilled me for the sub (rear deck), amps, DSPs, etc.
Recently some of my left-over Dynamat was used to quiet down an Intel NUC10 (inside the A/V cabinet), which I use for serving us movies.

 

[CoryGillmore]

Along with the 200+ pounds of dynamat and thinsulate I installed to deaden the car

Jesus Christ dude....you added 200lbs of material (not including speakers, sub, wires) to your sports car for better car audio? I think you're doing sports car all wrong...

I drive a 370Z and I spent $1200 on two-piece brake rotors that save 10lbs per wheel. Reading your post gave me a twitch.