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Alpine PDX-V9 Review (car amplifier)

michaelahess

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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!;)
Don't track it so, why not!
 

michaelahess

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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.
Also had an unmodified 2013 Mustang GT CS, had the power desire down. The way I looked at it, nobody ever road in the BRZ with me "it's too small" so it was the same as having a passenger, but being "all mine."
 

pseudoid

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Jesus Christ dude.
Keep his name off this discussion. ;)
"HE" was probably too busy to enjoy audio like us.
I think even HE would choose performance audio over a bit lost performance from a BRZ.
I hope you are using no more than 17" wheels on your Z.
 

michaelahess

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Keep his name off this discussion. ;)
"HE" was probably too busy to enjoy audio like us.
I think even HE would choose performance audio over a bit lost performance from a BRZ.
I hope you are using no more than 17" wheels on your Z.
Probably also best not to bring religion into a forum about science. Such irony!
 

CoryGillmore

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Keep his name off this discussion. ;)
"HE" was probably too busy to enjoy audio like us.
I think even HE would choose performance audio over a bit lost performance from a BRZ.
I hope you are using no more than 17" wheels on your Z.
Nah it's got the 19-inch factory forged Rays though, so very light as far as 19-inch wheels go.
 

typericey

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Thanks for the review Amir. Made me miss my younger car audio days. Though at the same time I blame it for whatever tinnitus I have now. :facepalm:

Back then I also preferred Alpine head units and had one of these PDX amps. Measurements of this amp is more than enough for car audio where the road noise levels are much higher anyway.
 

restorer-john

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Back then I also preferred Alpine head units and had one of these PDX amps.

I just loved those Alpine head units. That gorgeous crystal blue/green button array and silent controls. Ah, the good old days.
 

Head_Unit

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View attachment 171569
Respect to alpine for not making the usual garbage in the car audio world
That car is just inside the entrance to their headquarters...not far from a head unit which a disgruntled customer shot a bullet into. That sits there as a reminder about providing quality to the customer. I don't recall Pioneer headquarters having anything quite as interesting ha ha.
 

Head_Unit

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Aw darn, you did test the sub channel? I'd have liked to see if it met rated power...
Really @Amir would need a 2 ohm load for that...though come to think of it he could parallel his 4 ohm I'd think.
 
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I am running several of these amplifiers myself. I upgraded recently and I will tell you, I have fallen in love with the PDX amps. The sub channels actually make north of 900W at 2 ohms when set with a scope, so don’t be too concerned with the “regulated power supply” that is advertised as doing the same amount of power at both 4 and 2 ohms. I own 6 of them. 2 each of the V9’s, F6’s, and M12’s. They just sound so good and the test data shows why. And that slight power variance between the two channels on the same pair, it’s really not difficult to overcome that when using a proper DSP and being able to adjust the channel volume. A mere 1dB difference in channel volume to match the two will hardly be aubible as far as SNR goes. So, the ONE minor disappointment there was with these is easily fixed. Like Amir said, they are well above average for a HOME audio amplifier, let alone car audio. Alpine really has found ways to overcome the normal limitations that are faced when developing an amplifier for a car. I live in a condo with neighbors nearby and with common walls, so I don’t really get to enjoy a really nice home audio system. My car is where I have to enjoy my music. I know for a long time a lot of people were shying away from Class D Amplifiers because they didn’t make the same sound as Class A/B amplifiers. With modern technology, that’s no longer the case and the Class D amplifiers actually come out on top in cases of the top shelf ones once you figure in efficiency, heat, footprint, and cost. Alpine is one of the FEW SQ mainstream brands today. Yeah, you might have some others but they aren’t mainstream and are more for the elite members of society. I have not found another brand that delivers this kind of quality for the cost. There are many other brands that make more power for the cost, but they are not nearly as clean. An audiophile is going to choose cleanliness over power every time and not all of us have the money to afford Mosconi or Brax. For an amplifier to be mass produced and have a price tag under $1,000 US while still performing THIS well is an unbelievable feat. And with this kind of efficiency on top of it. I’ve run my amplifiers HARD for HOURS on end and reached back to feel them barely warm to the touch in my pickup truck. Supposedly this technology has filtered down into their current “S-Series” amplifiers and the ones that came from the Korean plant seem to make a LOT more power than advertised. I’d like to see the test results from one of those amplifiers. I’d actually like to see more car audio amplifiers under the microscope in general. Not a lot of people test them in this manner. You see it all the time for home audio, but not nearly as much for car audio. Keep up the good work, Amir! Look forward to seeing more reviews from you!
 

Jdunk54nl

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Just a quick update for all, I was having some weird very intermittent audio drop outs on my right side (even channels for the amp), I thought it was my truck wiring since it is common for the wiring entering the door to break. I did not think it was this amp. This was happening when I sent the amp in.
Well, after much trial and error of eliminating what was causing it, it was the amp.

Sent it out to alpine for a flat rate repair fee of $95. Turned out to be a bad pre amp flex cable in the amp. So, this amp still did that well with a bad flex cable inside. Probably why the channel difference was measured too!
 
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Just a quick update for all, I was having some weird very intermittent audio drop outs on my right side (even channels for the amp), I thought it was my truck wiring since it is common for the wiring entering the door to break. I did not think it was this amp. This was happening when I sent the amp in.
Well, after much trial and error of eliminating what was causing it, it was the amp.

Sent it out to alpine for a flat rate repair fee of $95. Turned out to be a bad pre amp flex cable in the amp. So, this amp still did that well with a bad flex cable inside. Probably why the channel difference was measured too!
I was actually wondering if there was something going on with the amp that he tested and I was going to offer him to send him one of mine to test to double check everything. I hope that you are able to send it back to Amir for another run on his test equipment to see how she REALLY does!
 

Jdunk54nl

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I was actually wondering if there was something going on with the amp that he tested and I was going to offer him to send him one of mine to test to double check everything. I hope that you are able to send it back to Amir for another run on his test equipment to see how she REALLY does!
I won't be sending it back anytime soon. Too many things going on to have to retune my truck again once I'd get it back.

I'd imagine it would measure very similar to the f6 I sent in and was measured around the same time.
But maybe I could get some ap measurements on it via a friend locally, but that won't happen soon either.
 
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I won't be sending it back anytime soon. Too many things going on to have to retune my truck again once I'd get it back.

I'd imagine it would measure very similar to the f6 I sent in and was measured around the same time.
But maybe I could get some ap measurements on it via a friend locally, but that won't happen soon either.
I understand. Just out of curiosity, how long did he have it? Maybe I can send him one of mine to see how it does if it wasn’t gone too long.
 

Jdunk54nl

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I understand. Just out of curiosity, how long did he have it? Maybe I can send him one of mine to see how it does if it wasn’t gone too long.
A little more than a month total time if I remember correctly.
 
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A little more than a month total time if I remember correctly.
That’s really not horrible. I’m sure he has other things he does with his life other than test amplifiers, lol. And then he also has other amplifiers in line to be tested, so retesting an amplifier that already did very well wouldn’t be on the top of his priority list, even though the tested unit ended up having a degraded component. However, I am personally VERY interested to see how it measures up to the F6 now that it’s 100%. I was reading through the JL HD900/5 Review and I was honestly very disappointed. 50% higher cost (the V9 was $999.99 at the time of its discontinuance) and performance that was WELL under the V9 even with a bad component. The PDX’s all maintained 0dB within the human spectrum while the JL started sloping downward at 100Hz on the low side and 10kHz on the high side. That’s HARDLY “HD” as the model number suggests. The distortion was also MUCH higher than the V9, again, even with the V9 having something wrong with it. The more you think about something like that, the more incredible it is. Really goes to show you don’t have to spend $4k+ on hand built amplifiers that need a ton of real estate to get superior audio. Some guys just spend money for the sake of spending money. It’s really sad to say that it looks like the SQ competitions have become more about who has the “status symbol” equipment rather than who has the knowledge of how to select the right components for what they want and how to tune their system. Anyway. What speakers are you running off your PDX’s? I’m personally running the old Scan-Speak made Alpine SPX speakers.
 

Jdunk54nl

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That’s really not horrible. I’m sure he has other things he does with his life other than test amplifiers, lol. And then he also has other amplifiers in line to be tested, so retesting an amplifier that already did very well wouldn’t be on the top of his priority list, even though the tested unit ended up having a degraded component. However, I am personally VERY interested to see how it measures up to the F6 now that it’s 100%. I was reading through the JL HD900/5 Review and I was honestly very disappointed. 50% higher cost (the V9 was $999.99 at the time of its discontinuance) and performance that was WELL under the V9 even with a bad component. The PDX’s all maintained 0dB within the human spectrum while the JL started sloping downward at 100Hz on the low side and 10kHz on the high side. That’s HARDLY “HD” as the model number suggests. The distortion was also MUCH higher than the V9, again, even with the V9 having something wrong with it. The more you think about something like that, the more incredible it is. Really goes to show you don’t have to spend $4k+ on hand built amplifiers that need a ton of real estate to get superior audio. Some guys just spend money for the sake of spending money. It’s really sad to say that it looks like the SQ competitions have become more about who has the “status symbol” equipment rather than who has the knowledge of how to select the right components for what they want and how to tune their system. Anyway. What speakers are you running off your PDX’s? I’m personally running the old Scan-Speak made Alpine SPX speakers.
Amir and I had an arrangement to expedite the amp testing. Otherwise it could be way longer.

This isn't fully up to date, but close enough.
 
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Amir and I had an arrangement to expedite the amp testing. Otherwise it could be way longer.

This isn't fully up to date, but close enough.
I’ll have to do a detailed write up on my setup once I get into it to rebuild it. I bought my 2011 Nissan Frontier when I was 90% finished with the build that was designed to go in my old Ranger, but I didn’t scrap the project; I simply adapted it to fit. I have a ton more room now so I’m designing and printing the parts I need now so that I can commence the overhaul in the spring. A LOT of CAD and 3D Printing time involved, but it will be epic when I’m finished. I always enjoy seeing other musically-oriented systems because it’s a nice break from the norm of just flat out loud! Not many people in the US care about QUALITY anymore. They just want to rattle their cars to pieces with big power. That’s not enjoyable to me. I was 17 years old when I bought my first 4-channel amp after installing a little Bazooka Bass Tube in my first truck. It wasn’t anything special and I ran some Alpine Type-S 6x9’s in the rear with some Infinity 3.5’s in the dash. It was just one of the original Alpine V-Power amps, the MRP-F200, and it wasn’t a powerhouse by any means nor was it anything high end. The clarity after installation was IMMEDIATELY noticeable over head unit power and I learned VERY early on that a 4-channel amp is an extremely essential part of a car stereo. I’ve always been the musical kind and wasn’t the normal kid who just wanted to blow my doors off their hinges with huge subs. After I installed that F200, I haven’t done a single stereo that didn’t have a 4-channel amp. Today, I’ve graduated to full competition SQ systems with multiple amplifiers and fully active networks. One of the things I really like about the new Alpine head units are the built-in “3-way” crossovers with 13-band PEQ’s per channel and individual time alignment. You could build a very respectable and simple 2-way front stage system plus subwoofer on only a single 5-channel amp (such as the PDX-V9) without a standalone DSP. Would probably do very well in a novice class competition. I would take something like that over 6 15’s in the bed with 3 6000W amps any day of the week. I see a lot of the PDX’s used on eBay, Marketplace, OfferUp, etc and most of the time they are beat up and people don’t want them anymore because they weren’t “loud enough”. When I was searching for my M12’s, I kept getting people saying “oh, man, this thing hits so hard.” So many people don’t know what those amps were really designed to do. I didn’t buy M12’s to “hit harder” lol; I bought them to give myself overhead so that I don’t accidentally clip them and I will be running them under rated power. In other words, I bought them for cleanliness. Needless to say, when someone would tell me it “hit hard” I passed because I knew they had used the gain as a volume control and likely had done damage to the internals of the amp by running it beyond the clipping point. Anyway, good luck with your build. I’ll keep you updated on mine as I start the overhaul process.
 
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Just a quick update for all, I was having some weird very intermittent audio drop outs on my right side (even channels for the amp), I thought it was my truck wiring since it is common for the wiring entering the door to break. I did not think it was this amp. This was happening when I sent the amp in.
Well, after much trial and error of eliminating what was causing it, it was the amp.

Sent it out to alpine for a flat rate repair fee of $95. Turned out to be a bad pre amp flex cable in the amp. So, this amp still did that well with a bad flex cable inside. Probably why the channel difference was measured too!
I was meaning to ask you, do you think your F6 might have a bad preamp cable also since it had a channel imbalance as well? I don’t know if you bought yours new or used, but if you bought them used, maybe someone was pushing more preamp voltage through them than what they should have a maybe damaged both of those cables. Would be good to know if that was an out of spec part causing that or if they just inherently had some channel imbalance issues that, honestly, are pretty easy to overcome with a DSP. If that’s the only thing that isn’t the best on them, I think we’re doing pretty good, lol. I’d rather have the rest of the outstanding performance and have that be where there was a slight compromise. With a good DSP, it’s easy to just dial back the more powerful channel by 1dB to balance the output. And, honestly, when you’re doing the channel balancing with REW, the channels aren’t ever going to be the same volume anyway, so that makes that rather irrelevant.
 

devil84

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Hi guys

Couple of questions on this amp:

1) if I bridged the 4 channels, what power would it give to an 8 ohm speaker (bearing in mind these are 200wrms at 4 ohms

2) is possible to bandpass the bridged channels? Or is bandpass only available on channel 3/4 unbridled

3) can this amp take 2 channel input but then feed all 5 channels
 
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