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RetroSound Quad4

Compact add-on amplifier for RetroSound radios — 45 watts RMS x 4 channels

Item # 068QUAD4

You've got a classic car with a RetroSound radio installed, but you want more power for your front and rear...

You've got a classic car with a RetroSound radio installed, but you want more power for your front and rear...

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$169.99
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About the RetroSound Quad4

More power, Captain

You've got a classic car with a RetroSound radio installed, but you want more power for your front and rear speakers. Enter the RetroSound Quad4, an ultra-compact 4-channel amplifier rated at 45 watts RMS per channel, which offers plug-and-play hookup to any RetroSound radio. You can connect other aftermarket car stereos via the Quad4's low-level RCA inputs.

More power, Captain

You've got a classic car with a RetroSound radio installed, but you want more power for your front and rear speakers. Enter the RetroSound Quad4, an ultra-compact 4-channel amplifier rated at 45 watts RMS per channel, which offers plug-and-play hookup to any RetroSound radio. You can connect other aftermarket car stereos via the Quad4's low-level RCA inputs.

Big sound, small package

At roughly the size of a large candy bar, the tiny Quad4 delivers a mighty sound, while its dimensions allow mounting almost anywhere, including under seats and behind the dash. If you're using a sub in your classic ride, you can activate the built-in high-pass filters to remove the low bass from your full-range speakers so they play louder and cleaner. The Quad4 also features advanced thermal and short-circuit protection so you'll be able to enjoy your sound for years to come.

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Product highlights:

  • ultra-compact 4-channel amplifier
  • 45 watts RMS x 4 at 4 ohms
  • direct input/output connection to all RetroSound radios
  • RCA inputs available for non-RetroSound receivers
  • switchable high-pass filters (110 Hz, 12 dB/octave)
  • frequency response: 10-40,000 Hz
  • advanced thermal and short-circuit protection
  • fuse: 15A
  • 10-gauge power and ground leads recommended
  • dimensions: 7-3/16"W x 1-13/16"H x 2-15/16"D
  • warranty: 1 year
  • Our 60-day money-back guarantee
  • MFR # Quad4

What's in the box:

  • 4-Channel amplifier
  • 4 Mounting screws
  • User's Manual

Customer reviews

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RetroSound Quad4 reviews

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8 reviews

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RetroSound Quad4

Crutchfield customer from Fairview, NC on 5/8/2018

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I have a 1963 beetle with retro sound stereo plug-and-play just like it said works great

Pros:

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0 of 0 found this helpful

Simple and compact

Marcus from New Bern, NC on 3/9/2018

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Easy install and compact....has made a big difference from basic system

Pros: Easy to install and compact

Cons:

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0 of 0 found this helpful

RetroSound Quad4

Crutchfield customer from Indianapolis, IN on 1/9/2017

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Really like the entire system, agree easy to install. However, after plugging in the amp, right rear speakers would not work, completed trouble shooting of the entire system and from my opinion found that the green wires in the Quad unit were not working at all. I contacted Crutchfield for replacement via on-line chat and within minutes they had ordered a new one for exchange and sent instructions on how to mail this one back.

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2 of 3 found this helpful

Simple Plug & Play

Crutchfield customer from Bettendorf, IA on 7/7/2016

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Was super easy to install. Just plugged in and ran the power wire with fuse which was included in the kit and extremely satisfied with the results

Pros: Simple and easy to install when used with RetroSound Radio

Cons:

Crutchfield response on

5 of 6 found this helpful

Easy install

Daniel from Prosser, WA on 6/17/2016

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Very easy install. System sounds a lot better. Plud and play with my restrosound model 2.

Pros:

Cons:

Crutchfield response on

0 of 0 found this helpful

Quad 4

Phil from Virginia on 11/15/2015

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I has a Retrosound model 2. So this review is only relevant if you own a Retrosound. Pretty much a plug and play. Yellow power wire to + battery terminal. Black ground wire to nearby metal car frame. Other wires use retrosound model 2 wire connectors. The Quad 4 is small and easy to hide under the dash. Restrosound model 2 is not a great stereo when it comes to sound so I feel the addition of the Quad 4 is a must. Sounds is full and richer at all volumes. Also love the retro look this system gives my 59 Porsche 356 replica. Awesome.

Pros: Compact. Plug and play with Retrosound model 2. Full rich sound.

Cons: None.

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5 of 5 found this helpful

RetroSound Quad4

Crutchfield customer from Massachusetts on 10/6/2015

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nice addition to the head unit. Makes all the difference in the sound quality .

Pros: EZ plug and play install

Cons: All good

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5 of 5 found this helpful

Retrosound Quad4 amp

ScottM from Massachusetts on 6/18/2014

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Nice little amp that goes well with retrosound stereo already installed in my ride

Pros: Simple add on installation to Retrosound stereo, simply remove speaker and control jacks from stereo and plug amplifier in its place, reconnect the jacks and add a power circuit and enjoy!

Cons: None to date.

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14 of 16 found this helpful

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Product Research

Features

Quadraphonic 4-Channel Amplifier: The RetroSound Quadraphonic (QUAD4) is a full-range Class D (digital) power amplifier featuring 45 watts x 4 RMS power. The Quadraphonic amplifier offers exceptional dynamic range and low distortion for the best possible sound reproduction from your car audio system.

Direct RetroSound Connect & Low-Level RCA Inputs: The Quadraphonic (QUAD4) plugs directly into any RetroSound radio. Low level RCA inputs also allow the Quadraphonic amp to be used with practically any aftermarket car stereo system.

Built-in High-Pass Crossovers: The RestroSound QUAD4 has built-in high-pass crossovers for the front & rear channels. The high-pass crossovers are defeatable if you desire a full-range setup.

Front & Rear Gain: Front & Rear gain control allows you to match the input sensitivity of the amplifier to the output of your RetroSound radio or other aftermarket stereo.

Compact Chassis: The RetroSound Quadraphonic (QUAD4) amplifier's diminutive size means you can install it virtually anywhere, including behind the dash.

Power & Ground: Regardless if you are connecting the QUAD4 amp directly to a RetroSound radio or other aftermarket stereo, you will need to connect the constant +12 volt (yellow) lead to the battery, and the ground lead (black) to the chassis of the vehicle.

Advanced Protection Circuitry: The RetroSound Quadraphonic (QUAD4) offers advanced protection circuitry with thermal and overload protection.

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Customer Q&A

4 questions already asked

Q
Does this amp give true quantaphonic sound to the system?
[ Lenny  Apr 07, 2019 ]
1 answer
A
Since I'm disabled and money is rather tight I haven't been able to install it yet.
[ jack  Apr 15, 2019 ]
Q
Does this really have a sufficient constant power wire? The wiring diagram shows to use the yellow wire for constant 12v, but it looks kinda small to be 10 gauge even. It also says a 15 amp fuse is included, but the yellow wire in the pic doesn't show an inline fuse.
[ David  Aug 16, 2018 ]
2 answers
A
the wire is sufficient. You can cut it shorter and run larger wire to your battery if you choose. I think I used 10 ga all the way. You don't see the fuse because you always mount the fuse as close to the battery as reasonable. like within the first couple feet.
[ Joshua  Aug 22, 2018 ]
A
Yellow wire only runs the clock function,only uses slight amt. Of power
[ roy  Aug 21, 2018 ]
Q
Will this amp work as plug and play with the Custom Autosound USA 230 radio, the way it does Retrosound radios?
[ Scott  Apr 04, 2018 ]
2 answers
A
The RetroSound Quad4 amp only offers plug-and-play hookup to RetroSound radio models. However, you can still connect other aftermarket car stereos via the Quad4's low-level (RCA) inputs. For more details or to discuss further, please contact an Advisor directly by phone (888.955.6000) or online chat. Thanks!
[ Larry  Apr 25, 2018 ]  Staff
A
Scott. Not sure how to answer your question. I have installed the amp into my 1974 MGB but am still unable to get power to my radio through the amp. Still doing wire tracing and troubleshooting.
[ Wayne  Apr 24, 2018 ]
Q
Is there any difference in sound quality between using the RCA inputs and the direct connection with the RetroSound Newport radio? Just wondering if anyone had tried hooking up the amp both ways to hear any difference. Thanks.
[ Jon  Sep 23, 2016 ]
1 answer
A
I'm running a RetroSound Newport radio in my 1987 Buick Turbo Regal and actually using both RCA and speaker level outputs together and there is no detectable difference between the two. I just wanted a nice clear stock looking radio with Bluetooth and auxiliary input connections for cruising. My car has the Factory Concert Sound II 6 speaker system. I rewired the system so the door and dash speakers are not in parallel, then run the 3.5" RetroSound Dash tweeters and rear speakers (JVC 6X9 with adapters replaced the factory 4 X 10 units) on the 20 watt RMS amp in the radio. The 5.25 door speakers and a bazooka dual voice coil subwoofer tube are powered by a Rockford Fosgate 250 X 4 amplifier in the trunk using RCA outputs from the radio. I am not using the Quad 4, so I can't comment there. At my age, 15 on the volume scale is about all I can stand and that's plenty loud. Hope this helps
[ CHRIS J  Sep 23, 2016 ]

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