Customer Ratings & Reviews

Solved that static alternator whine issue

My brand new car's factory sound system sounded terrible so I decided to upgrade it. I had to keep my factory radio because the car's functions depend on the screen/radio of the car. I installed a JL audio 300/4v2 along with Focal components and after I was done installing everything, there was a tremendously loud static noise coming from the speakers, even with the volume all the way down. When I would rev up the engine, it would make a whistling, whining noise from the alternator. I spent 2 days trouble shooting the problem. Separating wires, re-grounding, running new wires, adjusting gains, etc. and none of that worked. I saw this LOC from NVX and decided to give it a try since it claimed to have a digital noise filter feature. Man, as soon as I installed I was blown away. That annoying noise was GONE! The music sounds crystal clear now. I purchased that particular set up because I wanted an SQ sound system and now it delivers that very clean music with absolutely NO distorting noise. I was stressed out for 2 days wondering how to fix it. If you are in the same situation, buy this LOC. It will end your problems with all that unwanted noise. Forget those "solutions" people talk about all over the internet about re-grounding, ground isolation, and all that junk. This LOC solved it for me. It was so easy to install, it has adjustable gains, and feels very sturdy. Even if you turn the gains all the way up on the LOC, you will still hear no unwanted noise.

Excellent product

Easy to install in factory stereo. Great product. No noise at all. High fidelity sound.

perfect!

No unwanted noise, soft turn on and off, cant even tell its there. It does its job seemlessly in my 09 Jeep Grand cherokee with boston acoustics system. I wanted full range sound out of the door speakers so I pulled off the output from the factory amp of the dash speakers and rear speakers. All speakers are now full range and amplified with a kicker ZX350.4. I can keep the gain super low on the amp and cross over the speakers to keep the bass out with the amp controls. This LOC made all that possible to use the kicker amp with NO NOISE.

Good Converter

I bought this to replace another one that I bought that had terrible noise and poor quality. This one however is great and works as you would expect. Spend the extra couple of bucks and get this one

bueno

Me gusto lo fácil que es instalar lo y los resultados son bienos

NVX Output converter

This converter was easy to install plus it added power and more clarity to my speakers. It has a remote wire for my amp.

Perfection! NVX is the best!

Durable, small, easy to use, fun, quality build and sound! Great LOC! No unwanted noise! Love the gain controls and remote turn on for an amplifier! Works wonderfully with my NVX JAD900.5 and my NVX 4 channel rcas! NVX is the only way to go! I just can't get enough of NVX! Thanks NVX and Sonic Electronix for all of your support!

Seems legit

My first time using CCA wire. I was pleased to see the amount of copper in the power and ground wi hires. Quality fuse block. The RCA patch cords are awesome being bundled together. Made installation that much easier.

By Anonymous on November 14, 2018 Verified purchase

Worked great!

I installed this unit on my boat due to my radio had to pre amps.. Easy to wire although theres a bunch of wires. Works great for triggering your amp though! My radio put out 160W so I left all my channels on the unit turned down. Would highly recommend!

Great value

No complaints nice price, work's extremely well. Glad I purchased it from Sonic Electronic..

By Frederick on August 28, 2018 Verified purchase

Digital Converter

I used this to convert wired to RCA. This device worked great. I eventually replaced the factory head unit with a Pioneer that had RCA outputs.

Great value

Used this kit in my 88 Corvette C4. Wired into my 1600watt 4 channel Cervin Vdga amp. High quality and looks great. Excellent value and good quality

Not the best, but Good.

This is an ok kit. Came with everything that Is described. The RCA plugs ARE NOT gold plated.
The remote wire is very thin. Speaker wire is decent but not the best. You get what you pay for.
Overall a good kit ... not the best quality ... alright for the price paid.

By PapaFinnDaddy on August 29, 2020 Verified purchase

Great kit!

This has everything you need to install a 4 channel amp. Good quality materials.

Belva BAK44BL

Heavy duty, rugged, works very well. Would recommend to anyone looking for budget friendly wiring. However be advised if you run a stock head unit you'll need a line out converter.

By Anonymous on May 15, 2018 Verified purchase

Junk

Upon receiving product, I carefully read instructions. Installed unit as directed in instructions. Product did not work, so I cut the unit out and threw it in the trash.

Great Deal on a great product

I could not be happier with this amp. True quality from top to bottom. The sound is fantastic. I used this as a full range four channel amp to drive four kicker speakers. It gets its signal from the factory Nissan HU which is a very low quality HU in my opinion. I decided to try to keep the factory HU due to the factory steering wheel controls, bluetooth and stock look for theft deterrent appearance. I found the front channels on the HU clipped out way early compared to the rear when setting up the amp. So i switched the amp to 2 channel input / four channel output the set it up with the clip lights ....and perfection! What a great feature. I am very happy.

By Gerry on March 16, 2017 Verified purchase

Great Product

Pros: Easy to install, all the needed features, underrated.

Cons:None.

By Dustin on February 8, 2018 Verified purchase

Amp

Very pleased so far.. sounds just as my amp that I replaced.. easily installed, with a very small space required for installation... don't know about durability yet.. but we will see.. for the $$ and power/size ratio I would recommend this amp to anybody.. JL makes some of the best

Nice

Very good sound quality amp and small enough to put under the seats

By Anonymous on March 30, 2019 Verified purchase

JL Audio Class-D 4-Channel RD400/4

Great prices on great equipment and Fast delivery thanx sonic

By Anonymous on March 6, 2019 Verified purchase

Excellent app at a great price. Fast delivery also!

I needed the amp I bought quickly and Sonic Electronix was the only company that had it in stock and at the right price.

Great amp, shipped fast. 100% satisfied.

By David on August 7, 2020 Verified purchase

JL Audio Class-D 4-Channel RD400/4

I would recommend this amp it sounds so clean!!!! I have it running 4 6.5 Phoenix gold coaxal speakers I have had this amp for 6 months and works perfectly.

Excellent price Great power

This amp was a great price and I love the convenience in size. I replaced my factory amp and the Boston acoustic speakers now sound like high-end audio. Very easy to install and with the new clipping feature I have no issues. Will be buying another soon.

By Christopher on March 19, 2020 Verified purchase

Bad quality

The wiring harness was bad out of the package. I could move the harness around to make it work, but I didn't want to install it. Had to run to a local big box store to buy another off brand one.

Good product

I have not installed it yet. But it feels well, the quality of the materials is good, I will install it soon

Ex-Flock-4

Good unit, Good price. I have a 4 channel Amp, this is a 4 channel unit.
All 4 channels work. For $14.99 I did not expect it was going to do the dishes for me too.

Open box saved me $70

JL lives up to their reputation again. Replaced my kicker 4 channel with this amp. A smaller footprint operates at a cooler temperature, and all of the wirings is on one side for cleaner wire installation.

By Christopher on January 24, 2021 Verified purchase

Great product and cheaper than the other ones I have seen

This product is easy to install and is made simple due to the wires match the colors of the speed wire that I bought to get the correct sound out of my system would suggest this product for anyone that is looking to add an amp and sub to their factory stereo

By randy on October 18, 2017 Verified purchase

Nvx Line out converter

I had the Pac lp7 4 installed in my stock car stereo, wich worked great for connecting a Rockford mono amp for subwoofer and a 4 channel amp for speakers, only problem is I was having alternator noise even tho I installed everything correctly, I tried everything and nothing took the noise out, until I read some reviews here wich said this didn't had noise, so I installed this and to my surprise only one channel ( one pair of rca) worked. Instruction said if that happened, then use the ground supplied, but that didn't worked, I checked the rca with a multimeter and there was no voltage,, then I squeezed the cables and there was some voltage, but too low compared to the pac lp7, so this didn't worked out of the package, I put the pac lp7 4 back, at least I have sound with that one, problem is I can't ship it back, cause I'm at another country. I wasted 20 bucks with shipping for this Useless converter.

By Morris on March 18, 2016 Verified purchase

Sounds good for the money

Using this in conjunction with an RD1500 in a regular cab Silverado. Not yet installed but it is running on my test bench on a set of Kicker's bookshelf demo speakers. Good, clean sound and plenty of power while running in 2 channel mode.

Shipping and customer service experience was not what I expected; both were slower than promised. Product is great.

By Ryan on November 24, 2021 Verified purchase

Great value!!!

its got that boom for ur truck. And just a little adjustment, can tone it down very easily. I very happy and I don't get any distortion at all. A+ in my book...

Works

Was easy to install and did the trick and good price

By Cheng on April 5, 2020 Verified purchase

Works that’s all I care about!

Works Like I wanted too so yea I recommend it

By Ismael on August 17, 2020 Verified purchase

Love it

Better than I expected.Plane to buy a two channel for my subs.

Nice

Outstanding item I used it before and that is why I order more.

Great product

It’s really remove car noise in the wire,good product

By Anonymous on May 6, 2019 Verified purchase

Great value

I would recommend this to anyone who's looking to do it yourself subwoofer

Met Expectations

This item came as described. It was easy to hook up and met all my expectations!

By Anonymous on August 26, 2019 Verified purchase

great product

NVX XFLOC4
works great, sounds great, easy to install and small enough to hide behind factory head unit

Good sound but defective unit

Sound quality was good, no distortion, however I had a intermittent short to the left rear speaker. All connections good, so tried to adjust the RCA output pot screws and the LR fell out. (no i didn't over-turn).
Also, the trigger wiring did not work. The LED trigger indicator worked, but amp didnt power on. So I had to run a 12v wire from radio ignition wire to the amp remote. I think got a junk unit.
Called and spoke to Randy at SonicElectronix customer service, he's sending a replacement unit. Will give more feedback after second LOC installed.

By Dave on July 1, 2016 Verified purchase

Great LOC, great price

This turned out to be a great purchase. Sound quality is great and each line level is adjustable to help tune your system. I am impressed with the quality and will be purchasing more NVX products in the future.

By Steven on July 26, 2020 Verified purchase

Great amp

Works as advertised and put out the power. Looks good too!

By Lou on December 31, 2016 Verified purchase

Awesome!!

By Michael on December 8, 2022 Verified purchase

Great amp

Got this amp to replace old one. This amp is very powerful, clean, and sounds great.

By Anonymous on September 3, 2018 Verified purchase

JL AUDIO Quality absolutely

Clear sound, power and quality on my jl audio c2-650 components

Great Amp

Purchased amp to power focal 6.5 components, and 6.5 coaxial door speakers. Sounds wonderful, works like a charm.

Good for the money

Good budget kit. I like having all 4 channels of RCAs together for a clean install. Would have been nice to have included crimp fittings for the amp side of the power cables, but I had spares lying around from previous installs. Overall, it gets the job done.

By Matt on March 15, 2024 Verified purchase

JL Audio RD 400

Replaced an RD 900/5. Running C2 6.5 mid and tweet. In my opinion the separate amp performs better than the all in one. I updated my entire system, with the exception of the Epicenter, and it just sounds louder and clearer with everything having its own dedicated channel. The RD is easy to set the input gains , has a small form factor and gets more than enough power using 4 gauge power and ground cables.

By TW on May 28, 2024 Verified purchase

Sleek amp!

The weight of it is very nice. Doesn’t feel cheap at all!

By Kolby on August 3, 2024 Verified purchase

Belva 4awg amp kit

This install kit has everything needed to install your 4 channel amp. I definitely recommend this kit if your looking for something that's easy to use and install.

By Jordan on October 26, 2025 Verified purchase

Great price?

This was not only a good price but arrived quickly.Cant go wrong with JL audio amps at a good price!!!.Lower than eBay and Crutchfield .

By Luis on September 19, 2025 Verified purchase

Superior !

From someone who's been into audio for many, many years, JL has the best amplifiers bar none. Crystal clear, clean, powerful, efficient, precise, solid. Dont buy anything else. And Sonic Electronix has a great selection to choose from!

By Danny on January 9, 2025 Verified purchase

Super item!

Very good value! Cable look great!

By Aldis on December 7, 2024 Verified purchase

good kit

perfect amp install kit

By DAVID on December 2, 2024 Verified purchase

Clean and clear sound!!!

By Gerardo on August 8, 2024 Verified purchase