SpiderBy

Guys,

I posted my question to the Car audio forum (https://forums.audiworld.com/audio/msgs/63178.phtml) but has not received any feedback yet so please let me ask here.

In short, I replaced my Symphony I with Alpine iDA-x200 (my car is '01 A4 1.8T non-Bose), connected all the wires and realized that my rear speakers are too silent (they play but very silently and the head unit fader can't help me to get the right balance between rear and front).

It looks like when my Alpine head unit delivers a too low signal when connected via rear RCA outputs.
When I tried to connect rear speakers right to the head unit rear speaker outputs then the signal is too high and as a result the speakers start a harsh sound at mid-volume.

I even tried to measure the voltage on one of the rear speaker outputs for the same volume level set, and it was about a few mV when it comes from RCA and it was about 4-5 V when it comes from the head unit.

I am sure that Symphony output power is somewhere in between and it allows a stock amplifier to make rear speakers playing more or less OK.

Please let me list my questions then:
1. Has anybody encountered the same problem?

2. Does it mean that I need to buy a new amplifier and rear speakers now?
I was going to replace them a bit later anyway, but looks like I am forced to do that.

3. If that's the case, what would you recommend to for the amp + two 6.5" speakers to squeeze into $200 in total?

4. If I buy a new amp, will I have to run the power from battery or I can reuse it from 8-pin connector to the stock amp on driver's side rear speaker?

Sorry for such a long post.

I would really appreciate if you help me with that.

Pelican Pete

I was going to respond to your post instructing you to make sure that you're using the line level outputs from your HU to the line inputs of the rear speakers (IIRC the amplifier is mounted on the left rear speaker.) But it looks like you already know all that, and have gotten even more technical by breaking out your voltmeter.

You can use an external amplifier, powered off the battery. Or if your Alpine has 4 speaker outputs, you can use that to power the rears, and just run speaker wires to the back of the car. Either way you're running wires to the back of the car -- whether line level or speaker level. An external amplifier will give you more power and potentially better sound. But if you're considering using the factory speakers, I'm going to assume that that is not a priority for you.

You *might* be able to utilize the 8-pin connector. But I don't think anybody on here has ever done that. For the amount of time it would take to retrofit something to work, it would actually be easier to just run new wires.

Sorry I can't be of more help. But it looks like you're already on the right path. You just have to finish the job.

Good luck,
P.

SpiderBy

Hi Peter, thanks for your response.

Indeed, I wanted to get the better sound right off the newer head unit and later replace stock rear and then front speakers. Was not sure about adding a sub though...

But looks like I need to do that right now.
Pete, any recommendations on the 2-channel amp + 6.5" speakers with limit to $200-300? I know rear speakers are mostly for fill but not sure if I will be adding a subwoofer later...
So it would be great to get some bass from them.
Or I'd better to run with amp+rear+sub anyway?

You see, it is so easy to run out of the budget

Thank you in advance,
Oleg aka Spider from BY

Pelican Pete

Oleg -- I am by no means an expert in car audio. But I did do some tinkering with my '98 A4.
Throughout all my stereo mods, I always kept my factory Concert head unit, and used the line outs to an external amplifier. An external amplifier will always give you more power (hence better sound) than a powered headunit. In fact some of the better headunits don't even have amplifiers built in, because the manufacturers know that you're going to use a separate amp.
My first amp was a 40w x4 ADS. I bridged the rear channel to drive a JL Stealthbox.
The Stealthbox wanted more power, so I upgraded to a Phoenix Gold 75x4. The PG had plenty of punch and sounded nice. But it had a very limited input stage, and I never got good results with the factory headunit.
Eventually I settled on an Alpine 50x4 + 75x1. And I sold the Stealthbox and got a sealed box sub.
For years I ran without rear speakers altogether, and my sub would usually sit on a shelf in my garage. Eventually I put rear speakers back in the car -- I had Focal speakers all around. Bass was adequate without a sub.

With a 4-channel amp you can run with fronts + sub, and no rears. Or you can run with fronts + rears, and no sub. Alternatively you can get a 5/6 channel amp and get fronts, rears, and a sub.
I really liked my Alpine amplifier, and would recommend it again to anyone.

If you want a 4-channel setup (or 3 channel setup with the rears bridged for a sub), I still have my old Phoenix Gold amplifier. If you're interested in it, make me an offer. It didn't work too well with the factory HU, but it would be awesome with an aftermarket HU such as your Alpine. (I had planned on advertising it in the AW classifieds for $100-150 or so, it just hasn't been a priority right now.)

The most cost effective option would be to get some good speakers all around the car, and just use your Alpine HU to power them. The factory speakers are quite awful. Your Alpine should have enough power to give you a decent sound from some good, effecient speakers. Either way, you're going to get new speakers. A separate amp would add to the cost of equipment and also installation. But it is the next step in the upgrade process.

Good luck!
-- P.

SpiderBy

Hi Pete!

First of all I am really sorry for not getting back in time - was totally torn apart last week.

And I really appreciate sharing your story and thoughts - those are really helpful for me. And surprisingly inline with what I am heading towards

So after getting weak sound at rear from stock speakers I bought 6-1/2" Alpine SPS-600 and installed them at rear desk. The sound became really more solid and clear, but still a bit "flat" and I feel a lack of bass. I suspect my HU simply can't "feed" them. So apparently my next purchase is an amplifier. And I guess I need to follow one of your suggestions and go with 4-channel amp for rears and fronts (no sub).

And to get a better balance (new HU, new rear speakers) I am quite persuaded I need new fronts (components 5-1/4" + 1" tweeters).

Thank you for offering your Phoenix Gold amp, just curious what is the model? Is it V754 Ryval?
Looks like it costs about $100 on ebay.
Though I am getting to think I should stick to Alpine brand (and you also recommend Alpine amp ).
So considering 4ch amp MRP-F600 or PDX-4.100. Perhaps I would even buy a used one cause I guess an amp is either working or not.

Anyway, I have to wait for April or so to settle my budget
But I gonna end up with something I would really enjoy

Pete, really appreciate your help!

Thanks a lot,
Oleg