1 new from $179.95

Have one to sell? Sell on Amazon

Kenwood Kac-8405 720-Watt 4/3/2-Channel Amplifier with Variable LPF/HPF

by Kenwood
4.5 out of 5 stars 111 customer reviews
| 20 answered questions

Available from these sellers.
  • Compact 4/3/2-Channel Car Audio Amplifier
  • 720W Max Power
  • Cea Rated: 50W (1.0% Thd+N) @ 4_/4 Ch
  • Cea Rated: 75W (1.0% Thd+N) @ 2_/4 Ch
  • High-Quality Speaker Level Input & Blue Illumination
1 new from $179.95
This item’s packaging will indicate what is inside and cannot be hidden.

Top-Rated Amplifiers
Check out our top-rated amplifiers from great brands like JBL, Rockford, and Boss. Shop now

Product Features

  • Weight: 6.8 pounds
  See more technical details

Product Description

Kenwood KAC-8405 Car Amplifier - 720 W PMPO - 4 Channel KAC-8405 Car Amplifiers

Product Information

Product Dimensions 13.9 x 12.8 x 5.1 inches
Item Weight 6.8 pounds
Shipping Weight 6.8 pounds
Domestic Shipping This item is also available for shipping to select countries outside the U.S.
International Shipping This item is not eligible for international shipping. Learn More
Item model number KAC-8405
Customer Reviews
4.5 out of 5 stars 111 customer reviews

4.5 out of 5 stars
Best Sellers Rank #360 in Electronics > Car Electronics > Car Audio > Amplifiers > Multichannel Amplifiers

Warranty & Support

Product Warranty: For warranty information about this product, please click here


Would you like to give feedback on images?
Would you like to tell us about a lower price?

Customer Questions & Answers

Customer Reviews

Top Customer Reviews

Verified Purchase
I installed this into a 2011 Hyundai Santa Fe directly from the base factory radio. I can't overemphasize how happy I am with this product. It sounds great. Some background. I'm a 40ish male not looking for thumping music nor music loud enough to make my ears bleed. I just want better sound quality from my factory stereo. I upgraded the speakers with Infinity Kappa 60.9CS up front and Infinity Kappa 63.9's in the back. The speakers made a world of difference but I was concerned about blowing the radio out due to the 2ohm speakers so I figured it would be better to put in an amp to avoid that possibility. I had read that an amp really makes speakers sound much better, I was not expecting it to. It did. I can't really explain why. I don't listen to the radio any louder than before but everything sounds much fuller and well rounded. As good as the speakers were, they are now that much better.

The amp was easy to install (I mounted the amp to a 3/8" plywood panel the exact size of the amp feet and then used industrial strength velcro (3 strips) to secure it to the floor under the passenger seat). It fits in perfectly with the terminal connectors facing the middle of the car). I used the speaker level inputs with butt crimp connectors. I did not need to use the amp on wire as it detects input on the speaker level inputs to turn the amp on and off.

There are fans on the amp and they are audible only when the engine is off and the radio is on a volume level < 5. In normal situations the fans are not audible. Only when the radio volume is super low and the car is not moving do you hear it. I'm sure if it became a problem I could put something behind the fans to mute the fan noise, but it is not a concern as you do not hear the fans at all while driving.

So the summary - Great amp. Great sound. Runs cool due to the fans. Works great with OEM factory radio. I'm very pleased with the purchase of this amp.
1 Comment 33 people found this helpful. Was this review helpful to you? Yes No Sending feedback...
Thank you for your feedback.
Sorry, we failed to record your vote. Please try again
Report abuse
Verified Purchase
I installed this amp in a 2 door 2010 Tundra to power Infinity 630's and used the second channel, bridged, to power a 8" Infinity sub woofer. It installed cleanly under the front seat with plenty of clearance. The foot print of this amp is almost equal to a 8x10 sheet of paper.

Instructions and set up was a breeze. I used a 4 awg wiring kit, needed to grind a little off of the sides of the amp wiring kit terminals to get it to fit into the amps screw, no big deal.

At really low volume you can hear the cooling fans running, barely. The cross over filters are nice but could use better markings to accurately set them. You have to "guess" where 100 is, due to the size of the slot for the screw driver. I error on the high side and used the receivers cross over feature to complete the set up.

I started with the gain's set to 4 to match the receivers input, broke in the new speakers and then starting increasing it "1" unit at a time. Currently the gain is set to 1, with the receiver volume set to three quarters the sound is c-l-e-a-n but the loudness will cause you to turn it down.

If you're looking to put together a 2.1 system in your vehicle or need 4 channel or high powered 2 channel bridged amp in a small package i would highly recommend this one.
2 Comments 24 people found this helpful. Was this review helpful to you? Yes No Sending feedback...
Thank you for your feedback.
Sorry, we failed to record your vote. Please try again
Report abuse
By V&A M on August 17, 2011
Verified Purchase
I had been migrating a pretty good audio system from one car to another, during which I installed some Kenwood component speakers (mids & tweets) in the front doors. After installing a head unit I got lazy and put the amp in another car... I figured that the head unit claims 55watts/channel, and the component speakers need a minimum of 50watts, so I'd just get by with the head unit powering the component speakers.

Big Mistake.

LOL, I couldn't turn it up more than half way before the speakers would clip, so at that level the bass doesn't exist. I was getting a headache.

Enter the Kenwood 8405 amp for $120. That price is so low that I thought it must be junk, but the positive reviews were a good sign. When installing I ran into a problem and Kenwood's online support was timely and courteous. It turns out that I wasn't making good contact on one wire... my fault. The amp works... the fans make a certain amount of noise, but hey, it's going to live in the trunk, so what?

So the time came and I turned up the volume, listening to the same whiney speakers that were clipping and giving me a headache... Holy God! This thing makes the speakers sound great! That is: by the specs, the head unit and speakers should have sounded good but they sounded awful. I added this inexpensive amp and the system now hits hard with great sound.
Comment 6 people found this helpful. Was this review helpful to you? Yes No Sending feedback...
Thank you for your feedback.
Sorry, we failed to record your vote. Please try again
Report abuse
Verified Purchase
If you're looking for a basic system, this amp IS the solution. First and foremost, I initially purchased an offbrand amp looking to save a few dollars. Boy, was that a mistake. The sound was hollow, and un-natural sounding. So, I find this KAC-8405, which had a similar power rating to the "cheap" amp (Crutchfield private label Sound Ordnance). All I did was swap the power, ground, remote, and speaker wires over from the cheap amp to this one and turned the stereo on.

In my particular set up, I have the two front channels connected to a set of 6 1/2" component speakers and the rear channels bridged to one 4ohm JL Audio 8W1V2 subwoofer. There are your basic controls that one would expect from most amps. Adjustable High and low pass crossovers for the front and rear channels. There is also a defeatable 18db bass boost switch for the rear channels if you are driving subwoofers, much like in my specific application. One other thing I like a lot about the amp is that there are dual cooling fans when the amp heats up.

Overall, AMAZING is all I can say. The sound quality is there and the bass hits harder compared to the Sound Ordnance amp. I've been doing novice car audio installs for about 10 years now and this amp is up there is sound quality; please believe me in telling you this. You will not be disappointed if you're looking for something with great sound quality, but are not looking to notify the block when you are around with crazy SPL levels of music.
Comment 22 people found this helpful. Was this review helpful to you? Yes No Sending feedback...
Thank you for your feedback.
Sorry, we failed to record your vote. Please try again
Report abuse

Most Recent Customer Reviews