Audiotek At804S 4 Channels Class Ab 2 Ohm Stable 1000W Stereo Power Car Amplifier, Gray

This is a great nice amp. It is a small and powerful device thats simple to install. It is worth the money. I give it 5 stars because there is no background hiss and it is very powerful Add the small size and its a winner.The hiss I am referring to is actually on every amp I tried in this price point. It is subtle and for many people not a big deal. I am not referring to a large loud hiss from wiring etc, just the general background noise an amp of this quality generally has. The PDX F4 does not have any hiss or background noise that I an hear at all, it's amazing!I returned the MRX-F65 fior this PDX F4 and though the PDX F4 is is sightly lower rated in power it sounds noticeably better and even louder than the MRX-F65.If you are deciding whether the 35.00 to 55.00 more is worth it for the PDX F4 over teh MRX F65 it definitely is. The slight background noise that I heard with this MRX-F65 amp is inaudible using the PDX F4. So anyone that says the SNR difference is meaningless is wrong, at least in this case. The higher SNR of the PDX F4 over the MRX-F65 that is on paper actually translates to a huge difference for any type of music that has a quiet or silent background in my car.I tested several amp, anoung them the Alpine MRX-F65 that cost about 35.00 less today. Getting into an PDX F4 for me amounted to a large gain in sound quality(background sound dead silent now) for a small amount of money in the scheme of a 2000.00+ car stereo system.MRX-F65 - Good - 269.00 today - solid amp and great as long as the gain is set correctly - can clip(did for me) for extended usage at higher volumes.PDX-F4 - Great - 304.00 today - silent background more useable power and the gain can be set a bit higher than the MRX F65 - no clipping for extended loud volume sessionsI am a verified buyer of both the MRX-F65 and PDX-F4 and hooked both into my car and listened to the same CD and songs virtually side by side. I used the IASCA Official Sound Quality Reference CD. I suggest anyone that really wants to test and tune their system to get the CD. Although the CD is for testing and setting up a car audio system it also demonstrates differences in amps speakers etc if you have the luxury of having different things to test side by side(or buy a few items and return what does not sound best). Playing the first track instantly showed me the Alpine PDX F4 was better than the Alpine MRX-F65 by a fair margin. The IASCA test CD is a nice complement to some of the competition Bass test CD's easily found on Amazon.I wholeheartedly recommend the Alpine PDX F4.

I have three audiotek amps in my truck now. .The 400 watt 4ch. is not very good. It does not put out near what it should. But the 2000w/2ch is perfect on 10" subs, and the 1000w\4ch is great on the highs and mids.had a lot of trouble with motor and alternator noise, but once I finally got rid of it, the two bigger amps sound great.

Pros: Extremely high quality sound output from an impressively small package, connectorized power and speaker connections, sounds just as good if not better than any quality Class AB amp I've ever listened to. There is so much usable power here, that I have the gains turned only 1/4 to 1/3 above the min - I am able to turn it up slightly above 1/2 before clipping (fed w/ 4-volt pre-amps, and measured as per my o-scope). Even without any distortion, its way too loud for my ears when I run it from my o-scope setting, so its just set lower. This amp definitely wants to be running a nice set of components up front and some midbass or 8" speakers for the rear. Probably could run 4 pairs of speakers off this amp at 2 ohms per channel with plenty of power supplied to each speaker set. My amp is rated at 120 rms watts per channel @ 14.4 V, but I'd guess I'm only running it at 65% of its capability at full head unit volume. I'm judging its sound quality from my old school Infinity Kappa 60.2cs components which are still in pristine condition.The speaker wires need to remain properly polarized when screwing into the connectors, but then the connectors can be plugged into the amp either way - the amp figures out the speaker polarity! Extremely high quality build as well - top clamshell portion of enclosure is machined aluminum and the bottom chassis I believe is steel. I've also checked some of the board components and layout on ampguts.com before purchase and this thing definitely has a nice modern layout with very little to no wires running wildly across the circuit board. Even though the seller isn't an authorized dealer, the amp was 100% brand new in box, unopened - box wasn't rough handled either. Wonder how this would rate against a more expensive JL Audio amp...Cons: The amp doesn't get old school HOT to fry an egg, but it still gets warm enough to the touch where it could become uncomfortable - I was expecting it to operate a little cooler, but I do have it in a closed space behind the back seat in a Tacoma double cab. The Alpine badge does not rotate, and you may end up with a very nice looking amp with an upside down badge like me - I still prefer this type of badge though over the PDR line and its sticker badge. The PDX line might be overkill over the PDR line (PDR line is supposed to borrow its electronics heavily from the PDX's)...if you can test listen to both, you might be able to save some money if the PDR doesn't sound too much different from the PDX line.Price is the price, but you get what you pay for in the car audio market, and Alpine isn't one of the old schooler's who sold out or who is 'letting themselves go' ! If your an adult with a flexible stereo budget who appreciates smart engineering details, get the PDX line. If your a kid with a very limited budget, go with the MRV or PDR line.

The PDX has to be one of the best amps on the market, I am consistently impressed by how much power, quality and efficiency they packed into these little things. I installed the first generation of PDX amp in my truck a few years ago, a teeny tiny amp pushing close to 600 w/rms and never giving me any problems. I purchased 2 of these new pdx-f4 amps for my boat and I absolutely love them, they take a beating in the engine compartment all day long churning out incredible output and not a single issue. They're also very efficient and can run for hours and hours on a single battery charge. They do get pretty hot which I found out is normal so give them some airflow.Compare the size and price to the new JL audio stuff and you will see that the PDX line is also a great value.Update 7/2015- still running strong and taking incredible abuse, after running these for a few years now I am very impressed by the ability of these amps to consistently push great sound as the battery voltage drops