How To Install Aftermarket Stereo With Bose System

Installing a car stereo in a vehicle with a manufactory amp

Should you bypass the stock amplifier or use it?

Factory amplifier — bypass it or proceed it? That's the question we'll explore in this article. Hint: if you lot want the all-time sound from your new stereo or speakers, the extra work it takes to bypass the manufactory amp is totally worthwhile.

The factory stereo systems in many of today'due south vehicles include an external amplifier. This manufactory amp is designed to make cheap factory speakers audio amend. Just it doesn't do yous any favors when you supplant the stereo or those stock speakers.

Retaining the mill amp usually makes information technology easier to install a new stereo, and in some vehicles that's your simply choice. Merely your new stereo's sound is limited to what that amp can practice.
Bypassing the factory amp takes a fiddling more work because you have to run the featherbed harness to the factory amp, which is oft located in some other part of the car. Information technology's usually worth the extra effort because you lot'll get better sound from your new stereo, even if you're keeping those factory speakers.

While planning an commodity about a automobile audio installation, we came across an unexpected opportunity to showcase a question that our Advisors answer regularly here at Crutchfield:

Should I bypass the factory amp or should I keep information technology?

In many cases, nosotros'll have wiring solutions for a vehicle that either work with the factory amp or let you bypass the amp. Which mode is improve? We decided to compare both options and hear for ourselves.

JVC KW-R925BTS CD receiver in car

We chose the JVC KW-R925BTS CD receiver for the features Dave wanted, including preamp outputs that worked with the amp integration harness.

A willing car sound test subject

Dave, one of Crutchfield's editors, wanted to supervene upon the factory sound system in his family unit'south 2002 Toyota Highlander. A couple of us on the car writing team got together, researched Dave's vehicle, and recommended the JVC KW-R925BTS CD receiver and JVC speakers to meet his requirements for the new setup.

We noticed that the stock arrangement in Dave's Highlander included a manufactory amplifier, and Crutchfield offers ways to either integrate or bypass the manufactory amp in this Toyota. We decided to use this opportunity to test our theory that information technology's always improve to bypass the factory amp. We continued Dave's new stereo both means to meet what really sounded the best.

Setting the stage with new speakers

Dave inverse out the speakers before installing the new stereo so they'd be ready for the test. The right pry tools and comprehensive Crutchfield MasterSheet™ instructions led him through the procedure, and once he had the first door speaker done, the others went smoothly.

Dave replaced the front speakers with JVC CS-DR1700C half-dozen-3/four" component speakers upward front, using a universal backstrap to brand a bracket for each tweeter. JVC CD-SR1720 6-3/4" 2-fashion speakers mounted straight into the factory brackets in the rear doors.

Wiring on back of receiver

To use the amp integration adapter, Dave plugged the adapter'south RCA plugs into the JVC receiver's preamp outputs.

Getting the new radio ready for the test

To install the JVC radio, Dave began by securing the Toyota-specific kit that Crutchfield offers to the radio chassis. He as well ran his Bluetooth® microphone cable from the cavity to the dashboard. One time the radio was secured with a few screws, information technology was time to motion on to the wiring.

Dave thought that wiring to the existing factory amp in his Highlander would exist fine, since information technology still worked. The installation would've been a footling easier, since he wouldn't have to run whatsoever cables to the amp location. Retaining the factory amp meant he could connect the new stereo to the plug in the dash cavity, where the old radio had been plugged in.

Here's where we chimed in, explaining that Dave could await improve audio past bypassing that manufacturing plant amp and direct feeding the JVC receiver'southward ability to his new speakers. Keeping the factory amp in play would negate many sound attributes his new stereo offers.

plugging in the amp

Easy access to the factory amp's plug enabled united states of america to test both methods.

Switching between the bypass harness and the integration adapter

Nosotros had easy access to the wiring harness that continued to the manufacturing plant amp in Dave'due south Highlander. And then we helped him wire the radio in a way that safely let us switch between the amp integration and bypass setups to compare the audio.

How to bypass the factory amp

To bypass manufacturing plant amp, Dave simply unplugged the cable from the amp and plugged information technology into the featherbed harness's plug.

How did information technology sound?

To put things in perspective, Dave works primarily on the dwelling house audio side of our business, so he's been exposed to some of the best sounding home audio systems out there. Here are his thoughts on the two methods of connecting his new car stereo:

"At first, I idea I wanted to use the manufacturing plant amp for more ability and ameliorate sound. It likewise looked like an easier installation, since I didn't have to get to the amp. With the amp integration harness, the audio was meliorate than what I was used to. It had a lot more item than the factory radio and speakers did."

So, he heard some improvement in the sound when he kept the factory amplifier in the arrangement. Even going with the easier installation, his music would benefit. Only then we moved on to the second function of the experiment:

"There'due south that missing bass... Bypass it is!"

"However, when the bypass was connected, I exclaimed 'Ah, there's the missing bass!' Bypassing the mill amp returned the low end that had been missing on the commencement go-circular. The middle and high frequencies were also much more natural without losing the particular. Information technology was a huge difference. Bypass information technology is!"

Factory amps can also include factory frequency settings

It's non just nearly the power. The mill amp tin can too include a filter or crossover network for specific frequencies that may non sound optimal with a new system. By bypassing the factory amplifier and feeding the JVC receiver's power directly to the speakers, Dave also bypassed any filters in the factory amp, sending a pure, full-range signal to the speakers.

Occasionally, we may not accept a specific bypass harness available for a vehicle. Just if you lot don't mind splicing some wires, you tin utilize a speaker-wire parcel, like the Crutchfield CSW9W-20 9-wire speaker cable, to achieve the output section of your factory amp.

Running wire

At that place it is! The Toyota's factory JBL amp is mounted under the rear seats. Information technology doesn't have to be removed to be bypassed, which saves some time.

Installing the featherbed harness in the vehicle

One time Dave decided to stick with the improved sound from the featherbed adapter, he had to route the adapter's wiring to the factory amp, which is located under the rear seat in the Highlander. He constitute this wasn't every bit hard as he initially thought.

He fished this wiring bundle from the radio crenel, under the glovebox, and behind the kick panel trim on the passenger's side of his vehicle. Dave removed some of the door threshold trim, which revealed very handy channels that accommodated his wiring nicely. He neatly hid all the wires under the trim and plugged this bundle into the connector that plugged into the factory amp.

running wire

Dave ran the bypass harness from the nuance cavity to the factory amp location, using the vehicle's trim to conceal the wiring bundle.

Concluding thoughts

Dave did a final sound check, making sure everything was working properly before replacing all the trim pieces. The new stereo system makes his family driving duties much more fun. By bypassing the factory amplifier, the music sounds more detailed and clear than information technology did when he used the amplifier integration harness. Whenever at that place'south one available, we recommend bypassing the factory amp to get better sound.

If yous're considering a new stereo for your vehicle, keep this option in listen. Our OutfitMyCar™ tool volition show you the connectedness options for your vehicle. And if you have any questions, nosotros're available to aid via phone or chat.

Dave in his car