Keep stock Bose audio? Or aftermarket but no amp?

[EricCR]

I have 4 coaxial Polk Audios (DB651) that I removed from another car where I upgraded everything. The Polks still work just fine and sound good for what they are. They have surprisingly good bass for being 6.5".

 

I also installed a Sony head unit in the Pathy a few months ago, but I'm still using the factory amps and speakers. It sounds ok-ish, as these Bose systems did, nothing to write home about but serviceable.

 

Now, instead of throwing the Polks in the trash, I thought that perhaps they could find a new home in the Pathfinder, but I have no inclination to add a dedicated amp or anything else, so they would be powered by the Sony's head unit. The car is not used often enough and I have 3 other rust buckets where I would rather invest in audio.

 

Would you leave the Bose system alone, 200W amp (allegedly), 22 year old paper cone speakers or would it be sightly better to drive the Polks from the HU's amp (about 20 RMS x 4) and bypass all the Bose stuff? I'm sure the new speakers would sound better, but I'm not so sure how much the Bose amp levels the play field with the stock 1 Ohm speakers.

 

If anyone has bypassed the factory amps and can share their experiences, I'm all ears.

 

 

Edited August 7 by EricCR

[Slartibartfast]

How did you connect the aftermarket radio to the Bose amp? I don't know the R50 sound system, but when I put a head unit in my '95, it didn't have a line-level output, so I wired the outputs of the HU's amp to the inputs for the factory amps. This did work, but it was not ideal, not least because it amplified the stupid beeps that Sony programmed into that head unit to an uncomfortable volume. I remember picking up some bass and mids when I got around to bypassing the amps.

 

If you've got the amps connected to a line-level output, or a converter, then you're probably in better shape than I was.

[hawairish]

I've considered changing out the speakers in mine a couple times, but bypassing the amp is just not something I've wanted to bother with, let alone bypassing it with another amp (and I've been sitting on a nice 5-channel for a while).  I don't think it'd be difficult at all, and the HU amp is probably sufficient, but I've also never minded the Bose setup.  Knock-on-wood it still sounds decent enough after 20 years.  Finding other speakers to fit the low impedance of the Bose amps has also not yielded anything worthwhile.

 

I have replaced my HU with a couple Pioneer units over time, each time having some sort of "amplifier interface adapter" to put some gain into the signal to suit the Bose amps.  I tried it once without it and the audio level is too lower (I even tried putting the Bose HU in my Frontier for fun...volume level was also questionable).  I first used a Scosche unit (OEA4) and now a PAC unit (ROEM-NIS2).  Sound quality isn't mind blowing, but isn't terrible either, so I stuck with the Bose amps and speakers.

[EricCR]

On 8/8/2025 at 2:27 AM, Slartibartfast said:

How did you connect the aftermarket radio to the Bose amp? I don't know the R50 sound system, but when I put a head unit in my '95, it didn't have a line-level output, so I wired the outputs of the HU's amp to the inputs for the factory amps. This did work, but it was not ideal, not least because it amplified the stupid beeps that Sony programmed into that head unit to an uncomfortable volume. I remember picking up some bass and mids when I got around to bypassing the amps.

 

If you've got the amps connected to a line-level output, or a converter, then you're probably in better shape than I was.

 

I used the head unit's pre-amp outputs and a harness adapter with RCAs so it's mimicking what the factory Bose head unit did: sending low level signals to the amp. The only issue is that the Sony I chose (AX4000) has rather weak 2V outputs so volume is a tad low, but it's still louder than my ears can take it at max. I also have a LOC that I purchased from Crutchfield (PAC-ROEM-NIS2) just in case my plan A (using the pre-amps) wasn't loud enough, but I haven't felt the need to install it. The stereo beeps are relatively quiet. The whole thing sounds exactly like it did with the Bose head unit, just with more flexibility thanks to the EQ, time alignment and crossover settings. I hated the Bose's very limited bass and treble options.

 

On 8/8/2025 at 5:03 PM, hawairish said:

I've considered changing out the speakers in mine a couple times, but bypassing the amp is just not something I've wanted to bother with, let alone bypassing it with another amp (and I've been sitting on a nice 5-channel for a while).  I don't think it'd be difficult at all, and the HU amp is probably sufficient, but I've also never minded the Bose setup.  Knock-on-wood it still sounds decent enough after 20 years.  Finding other speakers to fit the low impedance of the Bose amps has also not yielded anything worthwhile.

 

I have replaced my HU with a couple Pioneer units over time, each time having some sort of "amplifier interface adapter" to put some gain into the signal to suit the Bose amps.  I tried it once without it and the audio level is too lower (I even tried putting the Bose HU in my Frontier for fun...volume level was also questionable).  I first used a Scosche unit (OEA4) and now a PAC unit (ROEM-NIS2).  Sound quality isn't mind blowing, but isn't terrible either, so I stuck with the Bose amps and speakers.

 

I'm in the same boat. I don't mind the Bose amp+speakers one way or another. I know it can be much worse or much better. My speakers seem to be intact, not blown or distorting, but the front set, for being components, are definitely not great. The tweeters have no definition and mid-frequencies could be clearer.

 

I'd also prefer not replace the amp. Bypassing it is easy enough. I found these instructions and I like that you don't need to take apart half of the interior to lay new wiring, just crimp some existing wires together.

 

I guess if I were to commit, the best option would be a 50/50 approach. Keep the rear speakers driven by the factory amp and bypass the front amps and put a good set of components, driven by either a small amp or the head unit. For now I think I'll keep the Polks in a drawer since I don't think it makes sense to replace Bose components with aftermarket coaxials.