Amplifier question..pick one

JBL GTR-601..600 watts at 2ohm
JBL GTX500..500 watts at 2ohm
Alpine MRV-M500..500 at 2ohm

Will be running a pair of 12" MTX in my single cab..RMS 300 per. I will wire them to be 2ohm load.

GTX500 is $100, $150 for the other 2. They don't seem too much different and I'm not brand loyal per se, my 20 year old Jensen died so I need to upgrade.

 

My vote is for JBL GTR-601. I enjoy keeping up with how modern and legacy amps perform in terms of actual power from amp dynoing. One of the youtubers did either a recent Infinity or JBL (which is Infinity). From what I remember, it did just about its rated or slightly above, so you can't go wrong. The Alpine MRV is due for an upgrade, so I wouldn't buy those new right now - Alpine also produces amps which have protection circuitry that doesn't work, and ends up saturating a DC voltage into your sub - so I can't recommend them.

 

Is that wattage RMS for the amps?

 

I'm using an Alpine MRX-M55 which was sort of a predecessor to the MRV line. It's a rock solid amp - especially at the price point. I wouldn't hesitate to use the MRVs for a second. JBL makes good gear too.

 

Correct

 

I would run this one then.

JBL GTR-601..600 watts at 2ohm

 

Is this the upgrade you were thinking about? The new x-series?

https://alpine-usa.com/product/view/x-a90m

Any chance you can elaborate on this DC spike thing with the Alpines? Never heard this before. That's not something typically seen outside of amp failure.

 

The X-series replaces the PDX series which was 7 years old last summer when the X-series was introduced. I believe the MRV is even older, so they might be ready to replace it soon.

My Alpine PDX M6 600 watt amp has an issue that started after 24 months of use (450 minutes per week actual use) where, only on turn-on, the speaker output will occasionally saturate to +43 VDC. This is essentially a fully clipped signal which will melt and destroy a sub, like mine. When no music or signal is being provided to the amp, the speaker output should just be 0 V AC at idle, but this amp throws 43 VDC. When the 43 VDC is provided to the sub, you hear a loud thump as the sub pushes all the way out, stays there, and rapidly heats up. When the amp is turned off, the sub returns to rest, and you hear another thump. Sometimes the DC offset will clear on its own while playing music, and start playing immediately, other times, it will just remain at 43 VDC. My sub smelled like burning, and the plastic cone actually melted a bit. I thought it was me pushing the sub too hard, but I found it was the amp itself after connecting the repaired sub, watching it push out, and feeling it heat up rapidly. Protection, which is supposed to be monitoring speaker output as well, never kicked in - and the PDX has a microcontroller running software - its ridiculous that its not monitoring for DC existing on the speaker output.

I checked the amp board - nothing visually damaged. I measured all the IC chips including the class-D FET drivers; they were all in spec as per the service manual. The output FETs would measure their shorts and opens inconsistently when checking them via multimeter, so maybe its an intermittently failing output FET. (I never removed the FETs for a better, isolated test). Maybe a bad batch of FETs is the root cause.

I have a complete set of new output FETs and power FETS, as well as driver ICs I had to purchase from China. I never swapped anything though since my workaround is to just turn the radio off and back on again until I don't 'hear' the turn on thump, if the thump occurs.

Go on Amazon, Crutchfield and Youtube, read some of the reviews for the Alpine PDX M6. Same issue which Alpine never addressed.

 

I switched an Alpine PDR amp to a Precision Power Phantom 900.4. More power, clear sound, half the price.

 

Oh I believe you all day with the PDX. I had a couple of them and didn't care for them. Even at idle they got too hot to touch - with no signal! They were both F4s. They sounded great, but a Class D amp should not get that hot - especially doing nothing. My MRX has been a model amp - runs cool, sounds great, plenty of power, small footprint, efficient, small price...wish they still made the MRX - at least sub amps. It's one of the few sub amps you can buy with a variable subsonic filter.

 

I'm starting to see the light as well regarding the alternate manufacture options. Its great to support our American and Japanese car audio brands, but they are making all the electronics in China now anyway.

Some of the watts per dollar prices set by Rockford, and JL and Alpine is just arrogant.

 

It's worth it to go for name brands for head units...but amps...that is a different story.

 

Fair enough but when you support brands like Epsilon owns, the terrorists win

 

Just don't support the Brazilian brand amps. Something isn't right with those - so tiny, not a lot of FETs converting that power, lots and lots of power...and not a lot of material to absorb the heat.

 

Yeah, good advice there. Some of the Brazillian high-efficiency drivers are intriguing in some way but the electronics are generally junk.

Yeah, most electronic stuff is made in China anymore. That's not to say that all manufacturing in China is crap. It certainly isn't. I only know of one amp company that makes amps here in the US - Boland (Bernie Boland was the man behind Orion - and I think PPI). Err, I know a local guy (Victor of VictorySonics) who builds custom amps, but nobody really knows about him. Yet.

 

Always been a fan of Alpine, never had any issues.