Failed amp, new HU, but not sure best solution
 

I got a JVC KD-R880BT for Christmas and I'm trying to figure out if I can bypass the toasted H/K amp using just the head unit. Money is tight and I can't afford an amp or replacement speakers right now, so I've been trying to figure out a solution. I've been reading posts, watching videos, and doing everything I can to educate myself but I feel like my head is spinning... so I thought I'd just ask. I've got the 2005 Mini Cooper-S with the Harman Kardon system complete with toasted amp.

The maximum output of the JVC is: 50W x 4 / 50W x 2 +Subwoofer (4 ohms) 50W x 1 ...so If the H/K speakers are 2Ω there any way to drive them using the new JVC head unit?
I'm also wondering if I run them in series would that raise the resistance from 2Ω to 4Ω? Would that be a solution, or is my grasp of resistance/impedance incorrect?
The JVC seems to have some sort of internal crossover and/or frequency control, would that be able to do the job of protecting the tweeters etc?
This is the exact head unit I'm working with: http://www.us.jvc.com/car/indashreceivers/kd_r880bt/
I'm continuing to read, absorb, and learn as much as possible; thanks again to everyone who's posted so much helpful info on here. I'm going to keep on shoving things into my brain but thought I'd go ahead and ask for help. Thanks!

I also just discovered that the R52 (convertible) seems to have 6 inch rear speakers, not the 6x9 that I thought. I'm going to attempt to run the stock speakers from the HU without an amp, hopefully nothing blows up.

The HK system has 4 rear speakers (mid and woofer on each side). The rear speakers are coaxial so it is a single physical unit on each side, but electrically the mid and woofer drivers are independent and connect to different HK amp channels.

Setting aside speaker compatibility for a moment, rewiring to bypass the HK amp is a fairly involved job. The HK amp receives only one set of left and right audio input from the headunit, which it processes and feeds to 8 channels to drive the separate speakers. So there is wiring from the rear of the car to each speaker, but between the headunit and HK amp there are not enough wires for both the front and rear outputs of your new headunit. One possibility is to run an additional set of 4 wires to the rear of the car. Alternatively, you can ignore the existing wiring and install all new wiring from the headunit to each speaker. You could start with connecting just the door speakers.

You can find an overall wiring diagram for the HK system here:
https://www.newtis.info/tisv2/a/en/r.../radio/pekkz5S
On that website, the HK system is called "dsp_r50" if you want to look up specific components.
Here's the wiring diagram for the HK amp: https://www.newtis.info/tisv2/a/en/r...-s-cab/suyW2tt
and its connector pinouts: https://www.newtis.info/tisv2/a/en/r...-s-cab/ZI5ZLyl

Regarding connecting to the existing HK speakers, I don't think anything will blow up as long as you don't try to play it loud, but they just won't sound good. Unlike "regular" speakers, the HK speakers have no crossovers because they are in the HK amp (e.g. high pass filter for the tweeter so that it won't try play low frequencies). There will be a lot of distortion in the sound with your new headunit driving the HK speakers. After you get it working, the remedy is to replace the HK speakers with aftermarket.

Edit: I forgot that in the R52 convertible, the HK amp is under the passenger seat, not in the rear compartment as with hardtops.

I've done timing belts that weren't this complicated. I'm thinking I should just gut everything and try to acquire some "good enough" speakers. If I'm replacing the 2Ω H/K speakers with 4Ω speakers, do I really need an amp? Would I be able to wire the aftermarket speakers straight to the HU?

Yes, if you gut everything, you will be able to connect most aftermarket speakers directly to the headunit. It will be a pain to take the car apart to add speaker wiring, but not too bad. The website I linked earlier has instructions for removing interior trim panels: https://www.newtis.info/tisv2/a/en/

It has been a frequent complaint about the HK system that everything is proprietary and it isn't possible to mix and match with individual aftermarket components. People who have an HK system and want to upgrade it to something better usually do gut everything and start from scratch.

Yeah, I seem to recall a few people swapping in a JL amp that allowed frequency and crossover control at the amp, wondering if that might be a solution too. I'd assume it would have to be at least a 6 channel amp, but I'm still in the learning curve. I've watched a ton of Youtube videos trying to "get my learn on" but it's still all a bit confusing.

I’ve seen a few threads on using a JL Audio XD600/6 as a replacement. Recently there was another on a JBL MS-8 replacing a blown HK amp.

That's the one I was thinking of; I think it had frequency adjustment at the amp so it acted like the HK internal crossover. I'll look into the JBL MS-8 and see what that's all about. I really wish I had a better grasp of some of this stuff.

Does anyone know if all the speakers are 2Ω?

speaker impedance
 

Speaker impedance should be taken with a grain of salt. I have no idea where the 2 ohm number for the HK system comes from, and I don't have HK system. The impedance is complex and is a function of frequency, and is only resistive at DC.

https://cimg3.ibsrv.net/gimg/www.nor...97e33aa4aa.jpg

Most car audio HUs or amps are designed to be idiot-proof so I would be very surprised that your HU or aftermarket amp not able to cope with the HK speakers. There are bound to be a lot of people piling many speakers in parallel on a amp that spec for 4 ohm, and these HUs and amps work just fine unless you go overboard.

As to the crossover on the door speakers, most 2 way speaker systems has no real crossover - just have a single capacitor (high pass/dc blocking) for the tweeter. Only one speaker wire pair to the door.

The most challenging part about the audio install is getting the new wire into the doors through the factory location. It was a real PITA. However the sound quality I have now was worth it. I installed 6.5 inch Hertz speakers in the front and 6x9 Hertz in the rear. I haven't decided weather or not to add a sub yet but I ran the wires sans the RCA while I was doing everything.

I have my amp (smallish 5 channel) under the driver seat. I cut out the foam and it fits nicely.

I'm not even trying to do anything that elaborate, I mainly listen to podcasts and boring stuff. I don't want to announce my arrival in the zipcode with dish rattling bass; I just want a stereo that works. The HK amp is toast though, and from all that I've read it seems that I've got to gut half the system just to listen to "Car Talk" on NPR. I've already got a JVC head unit, so that's why keeping the stock HK head unit isn't a priority, and I'd rather not replace the speakers if I can make the system work by replacing the defunct HK amp.

I did a sound quality based setup although I guess it can get plenty loud but I haven't tried it. It sounds to me like you should just get a replacement amp and install that head unit. The adapter kit from Crutchfield saved me a lot of time on my install. I didn't reconnect the steering wheels controls because I don't use them but there are kits for that as well.

I may have a line on an amp that my friend isn't using, it's a JL 300/4. It looks like it can handle 2Ω (if I read the specs correctly) but I'm not an expert on this stuff clearly. I'm wondering if this would work paired with the JVC KD-R880BT head unit I have. Maybe run the rear speakers and door mid's on one channel, and the tweeters on the other channel; then I could set the filter/crossovers accordingly? Thoughts?

You would run the following

2 channels for rear 6x9's
2 channels to front mid - they are crossed over internally for the tweeters

What I don't know is how easy it would be to amplify the stock system without running all new wires (the rear are simple to rewire but the front is not).

I've got the H/K system in an R52 (convertible) so the rear speakers aren't the 6x9 speakers, they're the round ones (6.5 I think?). I don't know if that makes a difference in impedance or not.

I thought the front speakers didn't have any crossover as it's done in the HK amp (which is dead), am I wrong on that? I

I was going to mount the replacement amp under the passenger seat (which is where the dead HK amp is now) and just use the existing wires that run from there to all the speakers; unless there's a reason the preexisting wouldn't work.

If I'm understanding the HK system correctly, there's 6 channels total and 12 wires leaving the HK amp, driving each speaker separately. I'm trying to figure out if I can use the JL 300/4 amp to drive all the speakers somehow. I don't know if my question makes sense...

Your questions make absolute sense, even for one that doesn't have a HK system. Audio is audio and not hi-tech rocker science. Your easiest path is to avoid the difficult job of running the speaker wires from your new HU to the speakers. To this it is easier to substitute the failed HK amp with your JL. The only thing you need to figure out is the input feed to your new amp from the HU can utilize the existing one for the HK HU and amp. Since you only have 4 channels you will need to add DC blocking capacitor to the tweeters in the doors.

Wait, when you say the front speakers are crossed over internally... I'm not sure I know what you mean. In the door? In the speakers? I thought they were crossed over in the HK amp, am I missing something? I also thought there were 4 wires running to each door; 2 for the mid and 2 for the tweeter. Wouldn't that constitute a channel for each, i.e. 2 channels per door, making a total of 4 channels for the front?

There are 2 pairs of wire per door with the HK amp so no crossover at the speaker - consistent with crossover being done by the amp. This is per MINI wiring diagram.

I'm going to follow this thread very closely...... I have an '06 R52 JCW with a bad amp under the passenger seat...and I'm not going to spend close to $300 for a used HK amp not knowing if it's even a working unit or not........I really don't give a crap about the HK system.....and I still have the stock CD head unit installed along with the AUX port in the glove box.......I too don't need window rattling sound that can be heard from 2 blocks away.....

So, my options are as follows:

(1) Purchase a used HK amp and take a chance...(probably not gonna happen)
(2)Try and bypass the amp under the seat and run the speaker wires from the OE head unit to the rear and door speakers....(I have most of the interior out right now anyway from chasing electrical issues)
(3) Purchase a new CD-USB head unit and 4 speakers and install those in place of the OE head unit and OE speakers

One question that was asked above was if the "voice" for the factory NAV system (which I have) comes through one or more of the stock speakers?? I never saw a reply to that question

Sorry for the thread hijack, but I figured it might be better than staring a whole new thread about the same thing

Bryan

There are a few threads about installing a JL Audio 6 channel amp in place of the HK with minor wiring changes. Also, there's a thread with the HK being replaced by a JBL MS-8 amp. Both amps are small and capable of handling 2 ohm load of the HK speakers.

With a new head unit, you'll lose the voice guidance of the factory NAV and other system sounds which come through the radio.

PM that you sent is replied to, thanks

Well crap, nothing is ever simple on these little cars, is there, thanks

Bryan