New Install--Questions on crossovers, parallel wiring, etc

[Brentmc]

All,

I am replacing parts of the existing Harman Kardon system in my car with a Pioneer SPH-DA120 head unit and an Alpine MRV-F300 4-channel amp. I will re-use the HK speakers.

The car is a 2006 Mercedes SLK and the stock system is the Harman Kardon 11-speaker system that uses fiber optics from the head unit to the Mercedes amp called (the "audio gateway" or AGW).

The factory amp/AGW uses an active crossover, but now that I am replacing it with the Alpine there will be no crossover for the speakers.

I purchased two AudiopPipe 3-way passive crossovers but am stuck and don't know how to best wire them.

The factory mids and tweeters are wired in parallel. How do I connect these to the 3-way crossovers to separate the frequencies? Do I just rewire them?

I've installed stereos for years, but crossovers, etc were never an issue with the low quality sound I settled for. I want this to be better as it is for my wife and I want her to have great sound.

Thank you,

Brent

Click to read more...

 

[the727kid 10+ year member]

Pretty much no matter what you do... this won't sound right. Either buy the FiberOptical module to retain your factory HK amp, or gut the whole thing.

 

[Brentmc]

Pretty much no matter what you do... this won't sound right. Either buy the FiberOptical module to retain your factory HK amp, or gut the whole thing.

Is that because the speakers being wired in parallel and not being able to separate them? or something else?

FWIW--the fiber optic adapter is near $1K...I can't go there

Thanks again.

 

[the727kid 10+ year member]

I would have to see a diagram of the amp but usually they have outputs for independent channels, so nothing is wired in parallel. I could be wrong about this though. However, your passive crossover has set Xover points which are more than likely very different than the points for HK amp. Further more, 2 3way crossovers only covers 6 of your speakers. You are still left with 5 speakers missing.

These systems are an absolute mess to deal with. I tell customers to either leave it as it is or spend the money and re-do everything.

 

[the727kid 10+ year member]

This piece is $550 https://navtv.com/products/NTV-KIT421/most-hur-mb-opti-1.html

 

[Brentmc]

I would have to see a diagram of the amp but usually they have outputs for independent channels, so nothing is wired in parallel. I could be wrong about this though. However, your passive crossover has set Xover points which are more than likely very different than the points for HK amp. Further more, 2 3way crossovers only covers 6 of your speakers. You are still left with 5 speakers missing.
These systems are an absolute mess to deal with. I tell customers to either leave it as it is or spend the money and re-do everything.

Thanks.

I am only going to re-use the front mids/tweeters and then add a powered sub. Here is the diagram that led me to believe they are wired in parallel--there is only one connection for both out of the AGW/amp (ignore the red arrows)

 

[garychoffmann 10+ year member]

Check the tweeter and mid for a crossover on them. If it only has one set of outputs it may have a passive crossover in that series.

 

[Brentmc]

Check the tweeter and mid for a crossover on them. If it only has one set of outputs it may have a passive crossover in that series.

Will do--thanks for the assist.

That is the only thing that makes sense--otherwise the amp would be sending the full range signal to both speakers with no signal separation...

I will take everything apart tonight and check.

If it does not already have a passive crossover...can I separate the two speakers (they are wired in parallel) and wire them individually using a crossover?

Attached is the wiring diagram with the mids/tweeter circuit circled...H4/34 is the tweeter and H3 is the "mid-range" speaker.

Brent

Thanks.

 

[the727kid 10+ year member]

Looks like mid plays full range and there is a capacitor on the tweeter.

 

[Brentmc]

Looks like mid plays full range and there is a capacitor on the tweeter.

That seems to make the most sense...

I will check...but if not, can I wire the tweeter (H3/34) directly to my crossover? or add a capacitor?

 

[the727kid 10+ year member]

If you remove the cap inline with the tweeter.. then sure. Why would you go through all that extra work though for a passive crossover. You may have the xover point to low and blow the tweeter.

 

[Brentmc]

If you remove the cap inline with the tweeter.. then sure. Why would you go through all that extra work though for a passive crossover. You may have the xover point to low and blow the tweeter.

If it has a cap, I will not remove it. If it does not have a cap, I am thinking I have to add something to limit the freqs ( a cap or crossover).

Would adding a capacitor to the tweeter make more sense?

Here are the crossover frequencies of this specific crossover:

Woofer Frequency: 20Hz-700Hz

Midrange Frequency: 500Hz-3.5kHz

Tweeter Frequency: 4.5kHz-20kHz

12dB per Octave Slope

Thanks again for the assist.