[Auto]

Was first going to buy a JL Audio A6450 but got suggestion about the Alpine PDX-5 and I'm now inches from buying one. Before I do that I wanted to check that there is nothing better out there for the same money?

JL Audio A6450 - 350USD w/ shipping to Sweden.
Alpine PDX-5 - 450USD w/shippging to Sweden.

[ianbiz]

JL 500/5
but im becoming a bit of a JL fanboy, but i used to be crazy about alpine's higher end stuff. the PDX amps are really cool, and the size makes them even cooler.

[sageashton]

I say the pdx.5, but that is because the size is fantastic. I will not say that it sounds BETTER than a JL, but it sounds as good to me, coupled with alot more power, in a smaller size that can be hidden away from thieves and everything else, thats the seller for me - oh and it is nearly twice as efficient (so they say) as a traditional class AB.

That being said, I do think JL's are really awesome and sound great. You would not be bad off either way in IMO.

[jonywalker]

Actually, I thought over too to use such class-D amps like PDX-5 or the new JL HD600/4 since they are so compact and consume much less power than class A/B amps. Some articles said it was not easy for class-D amps to reach high damping factor, but there are manufacturers like alpine and jl claimed to be able to make high-end amps in class-D already. I think you have already read the post from user badfish. There were however two points I noticed:
1. the lowest input sensitivity of 4 volts is running lean to the radio output (max. 4 volts)
2. it was reported the system didn't get bass deep enough until an equalizer was added to it.

Since I already installed jl 300/2 to drive the subs I could comfirm the jl has at least very deep bass, also the frequence that I can not hear but just feel After hours of running it doesn't get hot at all, just slight warm.
If the size is not the fact to you the jl 500/5 could probably be a better choice, also to the point of view in design and material treatment, the jl gives me a better impression. Since its sub channel works in class-D too it would not consume much more power than the PDX. There are still some other advantages for jl
1. more configuration probabilties from A - D, summing of front and rear channel for sub-channel, no 3rd input is required, but PDX does.
2. switchable 12dB and 24dB crossover, PDX has only 12dB
3. higher S/N value 105dB to 86dB
4. frequence response 5Hz - 50kHz to 20Hz - 20kHz
5. input sensitivity 0,2v - 8v, PDX 0,2v - 4v

Therefore, excepting the size the apline pdx has no advantages, my opinion.

[badfish]

The PDX-5 is a great amp. The sub bass not getting low enough wasn't really a problem with the amp so much as it was with the subwoofers. I used the earthquakes and I discovered recently that the spacer was thick (I started another thread on that). So the foam surround was getting pushed on by the carpet. Plus you can't expect really good low end considering that the subs are in tiny little ported boxes. I will add an EQ to make it better, but I just wanted to iterate that it's not the fault of the amp.

The one thing I don't like about the amp is that you need to drive all input channels. So you have to drive front, rear, and sub. There is not input switch. So for the OEM hifi system, this meant that I had to split the rear RCAs. It does run a bit hot as well.

The JL does have better specs on paper. The Alpine has a more convenient speaker connection system using plugs. The Alpine being class D on all channels is more efficient. JL using class AB on the front/rear channels should have better sound quality. The JL is big, the Alpine fits where the OEM goes (just barely). Regarding JL amp quality, I have friends that have had to send in their slash amps for repair multiple times. The JL has very strange power ratings, 125x2 for front, 25x2 for rear, 250 on the sub. 25 watts might be a bit low for some on the rear channel though I do agree with what they are implying. The Alpine put out 4x105 and 1x408 on the sub.

If you want a very good 5 channel amp that doesn't put out as much power, go for the Audison SRX-5. I would buy that before the JL.

[Auto]

I just ordered a PDX-5, should have it home in a couple of days.

Badfish

When you installed youre pdx-5, how did you know where to connect each wire from the OEM amp? What I mean is, when you disconnected the OEM amp, how did you know where all the wires came from, exampel how could you know which cable came from the front and which one came from the subs?

[badfish]

Originally Posted by Auto

When you installed youre pdx-5, how did you know where to connect each wire from the OEM amp? What I mean is, when you disconnected the OEM amp, how did you know where all the wires came from, exampel how could you know which cable came from the front and which one came from the subs?

Go here.

[jonywalker]

Originally Posted by badfish

The PDX-5 is a great amp. The sub bass not getting low enough wasn't really a problem with the amp so much as it was with the subwoofers. I used the earthquakes and I discovered recently that the spacer was thick (I started another thread on that). So the foam surround was getting pushed on by the carpet. Plus you can't expect really good low end considering that the subs are in tiny little ported boxes. I will add an EQ to make it better, but I just wanted to iterate that it's not the fault of the amp.

The one thing I don't like about the amp is that you need to drive all input channels. So you have to drive front, rear, and sub. There is not input switch. So for the OEM hifi system, this meant that I had to split the rear RCAs. It does run a bit hot as well.

The JL does have better specs on paper. The Alpine has a more convenient speaker connection system using plugs. The Alpine being class D on all channels is more efficient. JL using class AB on the front/rear channels should have better sound quality. The JL is big, the Alpine fits where the OEM goes (just barely). Regarding JL amp quality, I have friends that have had to send in their slash amps for repair multiple times. The JL has very strange power ratings, 125x2 for front, 25x2 for rear, 250 on the sub. 25 watts might be a bit low for some on the rear channel though I do agree with what they are implying. The Alpine put out 4x105 and 1x408 on the sub.

If you want a very good 5 channel amp that doesn't put out as much power, go for the Audison SRX-5. I would buy that before the JL.

Since I haven't been live experienced with a running alpine pdx I could not make any assessment. Just optically I expected a little more for the pdx-series. Either I am not very trustfull to jl quality because I already detected a very low level failure, the polarity of loutspeaker output, although the sound is very good.
25 watts for the rear channel seems also strange to me, therefore a combined version of 300/x would be a better choice. If 500/5 has the symmetrical front/rear output, that should be the best, an ideal combination of sound quality and power consumption.

[Auto]

Originally Posted by badfish

Go here.

Thank you!

[jonywalker]

Originally Posted by badfish

If you want a very good 5 channel amp that doesn't put out as much power, go for the Audison SRX-5. I would buy that before the JL.

The Audison SRX-series don't seem to have balanced input, only the very expensive VRX-series have the balanced input, which they called ABS - Audison Balanced System.
BTW, the design of Audison products is really great just like all other fashion style products made by Italians. But whether it is worth to pay such high price just for a visual enthusiasm is a very personalized question.

[badfish]

Originally Posted by jonywalker

The Audison SRX-series don't seem to have balanced input, only the very expensive VRX-series have the balanced input, which they called ABS - Audison Balanced System.
BTW, the design of Audison products is really great just like all other fashion style products made by Italians. But whether it is worth to pay such high price just for a visual enthusiasm is a very personalized question.

They are well designed amps. The biggest difference for me is the quality. So many amps are being made in China now and the quality just isn't there. The old school American made amps I still like the best. Lately, car audio equipment has taken a nosedive. There's hardly anymore good high end stuff around.

[VP Electricity]

Originally Posted by jonywalker

The Audison SRX-series don't seem to have balanced input, only the very expensive VRX-series have the balanced input, which they called ABS - Audison Balanced System.
BTW, the design of Audison products is really great just like all other fashion style products made by Italians. But whether it is worth to pay such high price just for a visual enthusiasm is a very personalized question.

I don't think that visual enthusiasm is the only benefit. I love the highs with Audison LRx. I have never run bass so i don't have a good reference, but I did a Eurovan with Morel Integra 4" unbi-q-style pint sources in the dash and a set of Space 6.5 woofers in the doors, and it sounded amazing in the top end.

I am not a huge SRX fan.

[jonywalker]

This is not my comment, it is referenced by
caraudiomag
All in all, I was very impressed by this amplifier. Although lacking a little in low-frequency performance, it had stunning sound quality in the low-mid to high frequencies, which is probably what it was designed for. The fit and finish of the amplifier is very good, and though I shorted, overpowered and overheated it on the bench, it came back to life every time. I'm not sure it will work if I ever figure out how to put it back together, but that's my problem. The only other item I can knock this for is the confusion with the speaker connectors and bridging.

This amplifier is very small and stackable. The "Power Density" name makes perfect sense. At a retail price of $750 and maximum power output of 986 watts, this amp will cost you about 76 cents per watt. I think it's a good value, and perfect to drive a higher-end 4-speaker system.

[dr.roro]

Are you guys just replacing the amps? What's the impedance of the stock Logic7 speakers?

[jonywalker]

Originally Posted by dr.roro

Are you guys just replacing the amps? What's the impedance of the stock Logic7 speakers?

see the attachment.