Huge volume loss w/ new HU (BOSE)
 

I had my very cool, (and very Chinese) new head unit installed professionally after hearing about the complications with bose audio.

The volume now is 1/3 what it was before.

This quite reputable shop (that probably wanted nothing to do with this 10 inch android HU) is blaming the amp in the new HU and say I need a new external amp. I really don't want one at all.

Could it be:

Bad wiring with the bose?

The unit came with 2 fuses for the amp one 2A one maybe 10A. They gave one back. Could it be the wrong one?

If I need an amp, can I get a small one that will fit in the dash?

Thanks for your help in advance, car audio is above my pay grade.


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Trust your shop, if it is reputable, like you say.
Ask them if they bypassed the bose amp, or used a harness to feed into it. Its not likely they bypassed it, but it is possible, and would explain your loss of volume.
Im curious about the 2 fuses for the HU, probably the 2 amp on the switched 12v side, and the 10 amp on the 12v constant side. ask them why they only used one. This would not affect your volume issue, however.
Many companies do offer Micro amps, Some are as small as a pack of cigarettes, and have decent power ratings. NVX is one that comes to mind.
Good luck

Guessing your new headunit (Android-based?) has low-voltage pre-outs which have trouble driving your Bose amp to its power limits. You could try having a line-driver put in, if you go with an aftermarket amplifier, you might need new speakers, too. I don't know anything about the factory Bose setup in the 370, but in previous vehicles I had seen with Bose setups (including my Tahoe) the Bose speakers were odd impedance and didn't play well with most aftermarket amps, either.

So... a line driver would boost your preout voltage to the Bose factory amp.

OR

An aftermarket amp (and possibly speakers, too) would possibly be more able to utilize a relatively low preout voltage we often see on some of these Android-based headunits.

Like stated above if it's a android head unit their voltage output for pre out is terrible. You'll have to boost it but IMO this introduces distortion and I would instead look to upgrading your speakers and an aftermarket amp.

They shouldn't have bypassed the bose amp for two reasons, 1 the tweeters and woofers don't have a crossover in between them so they couldn't have run all the speakers off 4 channels. and 2 the ohms is different then normal aftermarket car speakers.

Thanks, this was helpful. I have no idea about any of this.

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This whole thing was almost $1,000 and I just bought the car no financing 2 months ago. I'm not an audiophile, I can't justify what might be $6-800 at this place. I definitely don't meant to come at the shop like this but I mentioned the Bose audio and they acted like it was no problem, so I let the pros go.

Now they say I need an amp. You guys tell me I need an amp and speakers.

I really don't want to sound entitled here but I was an only child and if I spent another 3-400 on an amp install, and THEN they told me I need speakers? I would post the angriest Yelp review ever posted.

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Welcome to the world of audio upgrades... like owning a BOAT - Bust Out Another Thousand.

IF it is a problem of not driving the Bose amp to full output, you can get a line driver relatively inexpensively, but I don't know how this is all connected. You'd have to have a conversation with the installer and see if this is from low-level (RCA) output voltage, if they used a line-out converter or something, etc. I don't know the specifics on the Bose amp and what it needs as fars as inputs or input voltage. Maybe someone else can chime in here if they know about the Bose systems in these cars, I don't.

My installer 1st connected the speaker to new HU through normal wiring. I got a buzzing noise. So I had them switch to the composite line and no buzzing. If that makes sense. Buzzing is gone and the level was lower but I just had to up the volume. No biggie and no buzzing.

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Many wise replies here to give you a general idea what "could be" the issue, and at the end of the day, noone knows what the installer did, or what his reasonings were for doing it except himself. Take it back, ask a few questions, and explanations of WHY he did what he did, and then discuss a suitable solution. Discuss any restraints you may have budget wise, and see if he can offer a resolution that will keep you happy.

Reason I do my own work.

I Plug and played (all harness connectors, zero hard wiring) a Pioneer touchscreen HU to my all OE Bose system by using the search function on this forum. Even rearranged my steering wheel control functions how I wanted and did it all for under $350. Pioneer HU was 2nd hand re-manned but never used until I broke the seal.