Rockford Fosgate TM400X4ad Power Marine 400 Watt Class-ad 4-Channel Amplifier

Rockford Fosgate TM400X4ad Power Marine 400 Watt Class-ad 4-Channel Amplifier

(48 customer reviews)


Out of stock

The TM400X4ad is a 400 Watt 4-channel amplifier with high efficiency Class-ad technology and a conformal coated pc board designed for motorsport and marine applications.

(48 customer reviews)


Out of stock

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The Power TM400X4ad 400 Watt 4-channel ultra-compact, amplifier is built on Rockford Fosgate’s proprietary Class-AD technology, featuring Constant Power to produce the same output at both 4-Ohm and 2-Ohm impedances. Flexible vehicle integration enabled through low-level and high-level inputs with auto turn-on. Top mounted controls allow easy access to built-in crossover and C.L.E.A.N. input/output clip detection circuits. The 3-stage thermal lock extrusion with dual fan forced induction keeps everything cool while real-time thermal/protection schemes safeguard the amplifier.

  • Rockford Fosgate proprietary Class AD technology
  • 4/2 Ohm muti-impedance Constant Power
  • Differential inputs with high level auto turn-on feature
  • 8 AWG power/ground connector w/ upgraded RCA connectors
  • Remote-Out feature when using high level inputs
  • 2/4 channel input switch
  • 4 Ohm bridged capable
  • C.L.E.A.N. input/output clip detection and indicator LEDs
  • Top mounted controls
  • Dual fan cooled
  • Real time thermal sensing
  • Dual extruded heat sinks
  • Discrete surface mount technology
  • Marine grade two part epoxy coating on circuit boards
  • 2-Year Warranty

48 reviews for TM400X4ad Power Marine 400 Watt Class-ad 4-Channel Amplifier

  1. Jeff

    Awesome Sound

    Sounds Awesome! Better than I had expected

    2 people found this helpful

  2. Lance

    easy to install could use a little more power but highly recommend

    easy to install could use a little more power

  3. michael leonard

    Customer service is great

    This amp rocks. 9813 head unit and 4 t1650. Clear and loud. My amp is adjusted under half way, but it still drounds out all road noise. Like sitting in a sound studio

  4. Zachary m Franz


    Great sound glad I broke down and got it.

  5. Donald wilson

    It doesn’t need to be flashed to work!

    It’s a great deal, easy install(just watch the Rockford fosgate you-tube video) & works right away! Seriously! Any questions you can call them! They will help! Im really satisfied! And it doesn’t need to be flashed to work!

    3 people found this helpful

  6. A. Lopez

    Short lived

    So I got this amp back in October and only used it a hand full of time around 10. Last night when I was riding all of a sudden no music took my bike apart and found the amp to be non serviceable. Only had it for 5 months and used a no more then 10 times.

  7. Kevin

    Awesome compact amp

    Awesome amp period! It is very easy to tune with built in clip light. Install on an 08 Harley street glide.

    One person found this helpful

  8. Debbie Anderson

    Great Purchase

    Bought this got my husband. He loves it. Had it installed in a 1971 CJ 7. Recommends it

  9. Florida1


    Great sound quality. Have this amp pushing 4 full range Kicker 8s and it’s plenty of power for them.

    One person found this helpful

  10. Jessica Eidahl

    Amp didn’t work

    Got this for the wiring kit I ordered for my motorcycle. Shipping was fast and the price was pretty on par with everyone else. Amp was faulty and would blow the main line fuse every time. I don’t feel it was the sellers fault more like Fed Ex. Return was easy and quick, but getting my money refunded is taking forever it seems like

    2 people found this helpful

  11. llawen

    Over priced

    Cooling fans? Where? Gets very very hot. Sounds good. Can’t hear or feel any fans. I actually think my Duel from Walmart is better.

  12. Reagan D. Dent


    Perfect amp for the money!

  13. Brian


    Excellent experience

  14. mark broesder

    Five Stars


  15. Emmett Graham

    Sounds great

    Easily installed, notified the seller about optimum speaker setting. Sounds great

    One person found this helpful

  16. Enigma

    Can you hear me now?

    I replaced my Boom amp, in my 2015 Streetglide, with this, and couldn’t be happier. This is a tunable amp, and when paired with Biketronics line levelers, the sound is crystal clear. The only downfall is, is that it comes with a tuning cd. Rushmore bikes, do not have CD players in them. I would suggest that RF included an HDMI type of tuner. No biggie, I just tuned it by sound. Set the frequency to 80htz, set the gain to HP, the equalizer and the input levels, to 2 O’clock. I put Hertz HCX 165’s in the batwing, and infinity Kappa 682.11’s in the saddlebag lids. (These did not fit without serious modifications.) But, they do sound incredible. And both sets of speakers easily handle 100 watts RMS. The amp, by the way, is rated at 4×100 watts RMS, but, test over 500 watts RMS. (Mine is 532) This is verified by the included test sheet, that shows the born on date. This is not a plug and play amp. You have to purchase separate wires. It requires RCA inputs, which Harley does not come with. This is where the line levelers also come into play. The LL’s have the harnesses that plug into the Harley radio, and have RCA’s out. You simply get a shielded male-male RCA wire to connect the amp to the LL’s. Then, you can either buy the wire harnesses for your amp to speakers, from V Twin. Or splice speaker wire’s into the supplied harness. Either way you choose, you will be thoroughly impressed and satisfied.Follow up: This amp is still awesome! I’ve since upgrade the lid speakers twice. I’m now rocking Polk MM692’s, with the aid of adapters and a whole lot of work. This is a solid buy, and I got a heck of a deal.

    16 people found this helpful

  17. Chris Miller

    Works well


  18. Amazon Customer

    Amplifier plus!!

    Very good amplifier!! Sounds great!!

  19. Bryan Castle

    Great amp!

    I installed this in my 2013 Harley Ultra! Works great!! Sounds great!!! Easy to set up!!

    2 people found this helpful

  20. W & T

    Great Amp. Last one failed after 1 1/2 years …

    Great Amp. Last one failed after 1 1/2 years but still bought another one. These little Amps kick it !!!

  21. munis.subra

    Value for money

    Sound quality met my expectations

  22. Dan Cortright

    Great product

    Great amp, easy to mount and makes the radio sound fantastic

  23. supercan

    Top notch

    Works as describe

  24. daniel pici

    Awesome amp

    Awesome amp very easy to tune with built in clip light

  25. Mark Frese

    Five Stars

    Great system

  26. Jeremiah

    It pounds my wetsound speakers

    Boom boom

  27. Amazon Customer

    Excellent produit

    Installer dans un FLHTK 2016, ça blast à mon goût !!! 💯👍😉😎

  28. DJTULO


    Putts out great power and sound.

  29. Steve F

    Excellent addition to the Harley

    I added the speakers a year ago, and they were definitely better than the stock Harley speakers, but still not the sound quality I was looking for at higher volumes and highway speeds. Added this amp to the system, and WOW night and day, this thing really drives the speakers and puts out awesome sound! Highly recommend.

    One person found this helpful

  30. Amazon Customer

    Great Buy. Sounds Great

    Installed on 2017 Harley RoadGlide with Sony deck. Sound is awesome.

    One person found this helpful

  31. Amazon Customer



    One person found this helpful

  32. ar1271

    Great amp

    Great amp… impressed with the power and the sound. Happy with decision.

    4 people found this helpful

  33. jerry fiscaletti jr.

    Save your money..

    It’s definitely loud enough. Sound quality is terrible. Had to take the fairing off four times for adjustments..I called the factory for some further help, and the guy I talked to must have been a tractor mechanic..No helpful information at all..Overpriced junk, with a box of parts that go to different motorcycles that I dont need..1000.00 dollars, see ya..

  34. LoRay Cox


    Best Amp money can buy, the sound is awesome.

    One person found this helpful

  35. Amazon Customer

    Terrible refund process when item is defective

    Front Chanel had static

  36. Randall S Blackwell

    5” sounds amazing

    Installed this on my brothers 2018 roadglide with 4 Polk Mm1 6.5” sounds amazing

    4 people found this helpful

  37. Edwinssiv

    2016 Road Glide Ultra

    I was a little skeptical about the 400watts when you can do 700 watt with J&M but this amp rocks! I would have given it 5 stars but with the flash you lose your fade from front to rear. No big deal but it would be nice to have…With the Rockford Fosgate Harley-Davidson Amplifier Installation Kit 1998 install was super easy!I am running it with Polk Audio MM1 Series 6.5 Inch 300W Coaxial Marine Boat ATV Car Audio Speakers and I love the set up! My whole set up was just a little over $800.00 compared to $1200-$1400. I ordered a refurbished unit so I am hoping it holds up….

    4 people found this helpful

  38. Amazon Customer

    Brokerage Fee

    Happy with the price and shipping. Just wish I was told of the brokerage fee coming into Canada.

  39. Curtis



  40. Amazon Customer

    It Just Rocks!!!

    Added TM400X4AD 400 Watt 4 Channel Power Marine Amplifier, Rockford Fosgate TMS65 6.5 speakers up front, and Rockford Fosgate TMS69BL14 speakers in back….BOOM!!! Now when I listen to Metallica… So do the neighbors!

    7 people found this helpful

  41. yves duguay

    Easy to install… excellent product

    Excellent product, the sound is totaly perfect

  42. James Andrews

    Just buy it you will be glad you did

    Paired this with Sony head unit on my 2017 street glide and the fosgate TMS65 speakers and wow no more turning the volume all the up to hear it on the highway.

  43. jonathon

    Clean sound and plenty of power

    Clean sound and easy install. I have this on 4 Kicker 8” coaxial speakers on my wake tower. Plenty of power.

    One person found this helpful

  44. Amazon Customer

    Great Amp but wont last long

    Bought the amp Dec 30th. Instalation was easy, Amp sounds amazing but gets very hot. The amp lasted only 5 months. Sent back to Rockford fosgate for repaire. Repair was fast and said the piwer connector burned up. great amp but does not last. hopefully repairs are good and last more then 5 months. Update. Rocford Fasgate warrantied the amp. Sent it to them (Had to pay), they sent the amp back saying it need the power block changed out and sent me a new power block. I reinstalled the amp and nothing. After checking everything with an amp meeter it was determined the amp was still an issue. Emailed them back and Customer service rep Chris said that they had fixed the amp and reset it to factory settings. After another email to them they have decided to send me a refurbished amp after I once again pay to send them the non working amp. So after spending over $500 on the amp I get one that has been repaired. Not sure I trust it will work. Will update once I recive my $500+ dollar used amp.

    One person found this helpful

  45. Amazon Customer

    Five Stars

    Awesome is all I can say!!!!!

  46. Maynords76

    Five Stars

    Awesome snow and great price, love the set up cd and clipping lights, soo small and compact.

    One person found this helpful

  47. MrPikola

    Compact and Punchy!

    Great performing product. Works as advertised. A nice pocket rocket with big puch!

  48. Christy Kimbell

    Great product. It’s been over a month with no …

    Great product. It’s been over a month with no complaints. Installation went well. Performance is 5 stars. We received it very quickly and with very minimal freight charge too. Happy customer here.

    One person found this helpful

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