Hello,
I would like to start off by saying that I am very new at audio stuff. Therefore, I am ignorant of a lot of the terminology used and am likely to misuse that which I do know. Thanks in advance for your patience.
I recently purchased a '92 Volvo 960 wagon. This particular model's stereo system has 6 speakers, 2 somewhat treble-heavy ones in the dash (tweeters?) and four that put out mids and bass (woofers?). The system comes with an amp that uses a proprietary connection to the head unit. The connection transfers four channels of audio (with a common ground) and a power signal to the amp.
My issue is that I did not receive the head unit with the car. I put in another head unit and wired its outputs to the input of the amp and it sounds amazing, but it's extremely loud even at very low volumes, which is annoying. Through my research I have discovered that this is because the head unit I'm using has an internal amplifier, so the signal is being amplified twice.
I heave now bypassed the amplifier to directly drive the speakers from the head unit's internal amp. However, it sounds nothing like it did with the amp. The output is very treble-heavy (the tweeters are very loud) and there's little-to-no mids audible. I researched this and it would seem that this is because the tweeters have a lower impedance and the amp did impedance matching.
So now, I'm trying to decide what to do next. As far as I can tell with my limited knowledge, I have two options:
1) Buy a head unit with pre-amp outputs, and wire those outputs to the amplifier
2) Do some sort of impedance-matching myself on the tweeters
What would you guys recommend? I have found a very nice head unit with pre-amp outputs that I think would work nicely, but I'm not sure how high-quality the stock amp is, and it's also pretty old. If I decided to do the impedance-matching myself, how would I do this? Would I just put a stepped potentiometer on the tweeters and adjust it until it sounds good, or is there a better way? Or is there another way entirely to fix it?
Thanks in advance for your advice and your help!
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Need help figuring out how to redo my car's audio
The easiest fix, would be to get a Volvo stereo for that car from a junk yard. Just make sure you check the glove box for any security codes, and that you get the right radio. if your car has an upgraded stereo from the base model, you need to get the same model upgraded radio.
If you don't want to do that, you can try a line output converter. I say try, because I have never tried wiring one in with a factory amp. But the theory is still the same, so it should work.
It goes between your radios speaker output and the input of the amp. It basically tones down the radios output, so the amp sees an input it can work with. Make sure you get one with an adjustable output, so you can match it to the input stage of the amp.
The next best bet (if you want to keep the radio you have) is to swap out the speakers for a cheap set of components. Components come with a tweeter and a mid (replacments for the dash and door) and come with a little box that seperates what freqs go to what speaker.
The problem with components is that they really require an amp to be pushed properly. So you might loose some volume.
If you don't want to do that, you can try a line output converter. I say try, because I have never tried wiring one in with a factory amp. But the theory is still the same, so it should work.
It goes between your radios speaker output and the input of the amp. It basically tones down the radios output, so the amp sees an input it can work with. Make sure you get one with an adjustable output, so you can match it to the input stage of the amp.
The next best bet (if you want to keep the radio you have) is to swap out the speakers for a cheap set of components. Components come with a tweeter and a mid (replacments for the dash and door) and come with a little box that seperates what freqs go to what speaker.
The problem with components is that they really require an amp to be pushed properly. So you might loose some volume.
Thanks a lot for the interesting ideas. I'll consider those. Would either of mine work? I'd be really curious to know. Is there a reason you can't connect the amp to the pre-amp output on a stereo?
I'd like to avoid using a stock stereo, as the stock only has a tape deck, and I'd like a full CD changer setup. As for changing the speakers, the stock ones are unfortunately riveted into the frame of the car, and they are bizarre sizes.
Thanks again for all your help!
I'd like to avoid using a stock stereo, as the stock only has a tape deck, and I'd like a full CD changer setup. As for changing the speakers, the stock ones are unfortunately riveted into the frame of the car, and they are bizarre sizes.
Thanks again for all your help!
The problem with using the RCA output from a stereo is you can't adjust the output, and we really don't know if the facctory amp will like it. So your risking a larger amount of money.
A line utput convreter is adjustable, and your only talking 15 to 20 bucks. So if it doesn't work, your only out a little bit of money.
As for impediance matching the tweeters. The are probably a higher restance, or the same resistance as the doors. (probably higher)
That would actually cut their output, not raise it.
Yes you can add an inline resister, but it doesn't fix the mismatch between the output stage of the radio, and the input stage of the factory amp.
http://www.termpro.com/asp/pubs.asp?ID=119
A line utput convreter is adjustable, and your only talking 15 to 20 bucks. So if it doesn't work, your only out a little bit of money.
As for impediance matching the tweeters. The are probably a higher restance, or the same resistance as the doors. (probably higher)
That would actually cut their output, not raise it.
Yes you can add an inline resister, but it doesn't fix the mismatch between the output stage of the radio, and the input stage of the factory amp.
http://www.termpro.com/asp/pubs.asp?ID=119