Per my "Stupid HK Breaking . . . AGAIN!" thread, I took my car to an audio place this afternoon, in search of relief. The guy there listened and suggested that it was most likely an issue with my amp that is causing all the distortion and volume issues. He recommended that I make an appointment to let them have the car for the day so that they can "spray out" (clean?) the amp and check the solder connections and other wiring, as well as check the volume controls to make sure nothing there is sticking. If none of these measures work, he suggested bypassing the amp.

I . . . don't understand. He explained it to me several times -- and I feel I may be on the verge of understanding, but I'm just not quite there yet. It sounded as though he intended, if it came to it, to replace the h/u, which would then function as a receiver, and route out the amp altogether . . . ? I suppose I could understand how that works with a h/u that functions as a receiver, but I didn't know they could do that. And I'm sorry, but it just seems weird that you can completely bypass a piece of equipment that, presumably, has a purpose.

Will this affect the sound quality? Am I way off base in my comprehension? Help me, NAMmers, Please!

 

Most modern head units come with a built-in amplifier. Some of them are powerful enough to satisfy "most people". If the audio place does this, they would basically run wires from the speakers directly to the new head unit, and therefore bypass the H/K amp.

What they are proposing (if cleaning the amp and checking the wires doesn't fix it) would effectively be a complete replacement of your H/K system, although they may have offered to re-use the speakers... but that's it.

Sound quality of the resultant setup would be dependent on many factors, most especially the quality of the new head unit (and its' amplifier), how well they match to your H/K speakers (or the new ones you put in), and how well they "tune" the configuration for your car. Results can vary widely depending on the components used, their expertise, and the amount of time they spend paying attention to detail. Keep in mind that sound quality and volume are two COMPLETELY different things, although many people confuse the two when they're sitting there getting excited about their new setup.

As for what they mean by "spraying out" the amp, it's mostly likely using compressed air, to remove excess dust, etc.

 

Yeah, I know it's a total replacement, but considering this is the second full HK setup to break on me, I'd just as soon replace it. The guy seemed to be under the assumption that leaving my speakers would be fine, but I would make sure that, if it comes to the replacement of the h/u, any resultant system would sound good . . . to me. I'll replace the speakers as well, if it means being happy with the end result.

I'm fully aware of the differences between sound quality and volume.

Thanks Edge

 

OK.
First - the HU is standard whether HK is present or not. You could "bypass the H/K amp" with no need to change the HU.
Second - the H/K speakers are NOT suitable without the H/K amp. There's no crossover for the doors, and all coils are 2 ohm which is too low for most HUs.

(third - please use a different stereo guy, my opinion!)


Losing the H/K amp will drop your max volume, and lose the H/K features (spatial, etc). If you're OK with that ...
Get some aftermarket speakers, or search for someone selling stock speakers at a low price.
Bypass the amp, and drive the speakers from the HU.
If you're not happy with sound quality, a good aftermarket HU might give you better sound, maybe a little more volume ...

As for the bypassing itself:
The front speaker outputs from HU run to the H/K amp and of course the speakers run to there too. It's easy enough to splice those together.
Unfortunately the rear speakers don't run from HU. Your choice is to not drive the rear speakers at all, or run extra wires from HU to H/K amp position (stripping out the cars interior to do this).

You're welcome to ask more questions. Meanwhile here's the H/K amp pinouts on my website:
http://www.gbmini.net/HKconnections.pdf

 

PS:
Blowing out the amp is pointless.

 

I do not particularly wish to lose volume. Honestly, I didn't find the stereo all that loud in its functional days, so to think that potential volume would be decreased significantly gives me pause. And makes me sad. At no point do I wish to use my stereo to sonically clean rust from bolts (or the door sill), but I drive quite alot on the highway with the windows down. Plus, um, I just like some music to rattle my brain a bit.

So I will lose potential volume if I replace the h/u and the speakers? And replacing the h/u basically requires replacing the speakers? Should I replace the amp, as well? And should I do this before or after I slam my head repeatedly in the car door? :impatient

(I'm not concerned about the DSP features.)

 

Think of the H/K amp and speakers as a "matched set". If you're going to replace one, then you replace both.

This is what I tried on GBMINI#2 - it didn't work because the installers were crap, but it can work ...
Install new amp and speakers. Spend good money on the speakers if you want crisp clear sound (which hopefully you have heard on the H/K system when it's not failing on you); otherwise if you just want volume, spend the money on power ... either way, be sure the amp and speakers are well matched.
If you want sub-bass (the stuff you more feel than hear), consider subwoofers. You don't need to have them thump down the road for everyone else, but it's nice to have a bit of a deep kick on tracks which justify it (shame you can't meet/hear GPMINI, which sounds amazing inside, but basically silent outside).

You have two choices to drive the new amp/speakers. Speaker levels from the stock HU, or replace the HU then drive from speaker levels or from RCAs. In theory the RCAs give better sound, especially if you use the amps to drive subwoofers - in practise you risk engine whine which ruins the sound, unless you have an installer who can prove good installs in previous MINIs.

On GPMINI, I drive the subwoofers through an amp from RCAs, but the other speakers are driven through (DPSM) amp from speaker levels - gives amazing bass AND zero engine noise


Finally, consider spending $500+ for new front/rear speakers, and the same again for a 4 channel amp to drive them. Plus install, and of course a new HU is extra. Subwoofers add more cost, take up more space, and probably need another amp.
You could save money by ignoring the rear speakers and just doing front speakers, with an amp. Or you could try still driving the H/K rear speakers with the new amp - it might be able to push some semi-bass out of them.

All my opinion, having now been through similar with three MINIs ...

 

(Savannah - sad we didn't meet during TGICR)

 

I don't think anyone in this thread suggested that the HU was different, did they?

Good info though.

 

Oh sure -- that'd be great, but I decided to go to Europe next month rather than spend every shred of cash on car audio!

Seriously -- thank you for the explanations/advice. I don't think I understand, though, why the rear speakers couldn't be driven directly from the h/u if the fronts can be . . . ?

I really don't want anything esoteric -- or even immediately impressive. I'd like something that sounded as good as the HK before it crapped out. Twice. I really was happy with that system; it sounded perfectly . . . fine. And given the amount of road noise I get in the cabin anyway, anything much in excess of "fine" is wasted.


In typical Toastian fashion, I was in Pittsburgh for the duration of TGICR -- I was sad to have missed it!

 

Edge - the first message looked like the installer suggested pulling the stock HU; I just wanted to emphasise that's not necessarily needed.


No. I said drive the H/K rears from an amp - unlike most HUs, the amp can generally handle 2 ohm load and have enough power to make those H/K rears work for bass, even successfully driving into the dual voice coils with appropriate wiring.