[[email protected]]

Hello everyone,

Im just finishing collecting all the pieces for my new car stereo,
going in my '84 BMW 528e (finally replacing the one that was stolen
several years ago), and have a few questions regarding a 7-channel
setup.

Im planning on running the front 2-ways, rear 3-ways and a 15" sub off
of a 5-channel amp (see specific component information below), and run
a set of tweeters off of the head unit itself.
1) Will this work? If I use the front, rear and subwoofer RCA outputs
from the head unit, can I still use the head unit to drive the
tweeters?
2) If so, would I need an equalizer / filter just for the tweeters?
3) Would I need a resistor to control the relative volume of the
tweeters to the rest of the system?
4) Should I disable the tweeters on the multi-element speakers (and
use a bandpass filter), so they only provide mid-range frequencies?
5) I have not bought the tweeters yet, any recommendations?
6) The JL Audio 500/5 gives 25W RMS to the rears, 100W RMS to the
fronts, and 250W RMS to the sub, can I swap the front/rear channels to
give 100W RMS to my rears?

I currently have the following components:
- Alpine CDA-9825, with Front, Rear and Subwoofer RCA outputs
- JL Audio 500/5 5-Channel Amplifier
- Fronts: Infinity KAPPA 462.3cfp 4" x 6" two-way (60W RMS)
- Rears: Infinity KAPPA 693.3i 6" x 9" three-way (110W RMS)

Thanks for any help you can give,

Michael

[brianlanning]

wrote:
Im planning on running the front 2-ways, rear 3-ways and a 15" sub off
of a 5-channel amp (see specific component information below), and run
a set of tweeters off of the head unit itself.
1) Will this work? If I use the front, rear and subwoofer RCA outputs
from the head unit, can I still use the head unit to drive the
tweeters?

A long time ago, I had a sony head unit where the amplifier was
outboard and ran through the RCAs. It was weird then and is probably
not done at all now. Unless you have something like this, you won't be
able to control the amp in the head unit and the RCAs separately.
Maybe some head units can do it. But I really doubt it.

2) If so, would I need an equalizer / filter just for the tweeters?

You'd need some sort of passive crossover. Many tweeters come with
them. An equalizer is a different animal.

3) Would I need a resistor to control the relative volume of the
tweeters to the rest of the system?

Good luck with that. Remember also that impedence will change with
frequency. I'm no math expert in this regard, but without a low
frequency driver on the head unit amp wired up with the tweeter, the
amp may not be seeing a 4 ohm load all the time. This is bad. Your
tweeters may clip and/or fry if the amp freaks out.

4) Should I disable the tweeters on the multi-element speakers (and
use a bandpass filter), so they only provide mid-range frequencies?

You could, but I'd just leave them hooked up. What's wrong with the
tweeters on the coaxial speakers? Why do you need an extra set of
tweeters?

5) I have not bought the tweeters yet, any recommendations?

Listen before you buy, if you can.

6) The JL Audio 500/5 gives 25W RMS to the rears, 100W RMS to the
fronts, and 250W RMS to the sub, can I swap the front/rear channels to
give 100W RMS to my rears?

Yes. Just run the front channel RCAs through the back channel on the
amp and hook the front channel speakers up to the back channel speakers
on the amp. Just pay attention to any internal crossovers that may be
in the amp. They may behave differently wrt the front and rear
channels. But it shouldn't matter.


I currently have the following components:
- Alpine CDA-9825, with Front, Rear and Subwoofer RCA outputs
- JL Audio 500/5 5-Channel Amplifier
- Fronts: Infinity KAPPA 462.3cfp 4" x 6" two-way (60W RMS)
- Rears: Infinity KAPPA 693.3i 6" x 9" three-way (110W RMS)

If you really want an extra set of tweeters, why not pick up a separate
amp? IIRC, sounddomain has a pioneer 60watt rms 2 channel amp for $90
or so. You really should avoid the amp in the deck. They tend to be
on the cheap and noisy side.

brian

[MOSFET]

wrote in message
ups.com...
Hello everyone,

Im just finishing collecting all the pieces for my new car stereo,
going in my '84 BMW 528e (finally replacing the one that was stolen
several years ago), and have a few questions regarding a 7-channel
setup.

Im planning on running the front 2-ways, rear 3-ways and a 15" sub off
of a 5-channel amp (see specific component information below), and run
a set of tweeters off of the head unit itself.
1) Will this work? If I use the front, rear and subwoofer RCA outputs
from the head unit, can I still use the head unit to drive the
tweeters?

With most HU (head units), the answer is yes.

2) If so, would I need an equalizer / filter just for the tweeters?

You WILL need some type of high-pass crossover to control what frequencies
get to your tweeter (otherwise you will likely blow them). A simple
capacitor in-line with the tweeter lead will give a 6 dB per octive cutoff
and should do the job fine. A few posts back, someone posted a link that
contains a chart with all the capacitor values and their respective
frequencies. See that when selecting a high-pass filter capactitor.

3) Would I need a resistor to control the relative volume of the
tweeters to the rest of the system?

Well, you ALREADY HAVE THAT in the form of your five channel amp. You will
have to set the gains on all five channels to match the output of your
tweeters.

4) Should I disable the tweeters on the multi-element speakers (and
use a bandpass filter), so they only provide mid-range frequencies?

I THINK what you mean is disable the tweeters on your coaxial front
speakers. The answer is yes if you can do this without completely
destroying the coaxials. You don't want the highs coming from two different
sources. This will also likely lead to some unwanted cancellation effects
so, yes, disable the tweets on the coaxials if possible. I don't think you
will need any type of bandpass filter for the midrange speaker, though. I
assume the 5 channel amp has a high-pass filter for the fronts and that
should be sufficent for filtering for those speakers.

5) I have not bought the tweeters yet, any recommendations?

Boy, have you asked the right guy about THIS ONE!!! Coinciendentally, I
have been shopping for tweeters myself lately. I recently blew one of my MB
Quart PTD25's. I wasn't too upset, however, as I really had not been very
happy with the sound of MB Quart (they sound very crisp and bright AT FIRST,
but they begin to wear on you after a while). I bought a pair of JL VR
series tweeters and then promptly blew those (it was my mistake, too much
power). But the JL's sounded SO MUCH BETTER than the Quart's. Overall, I
would recommend textile dome over metal domes, they have a more laid-back
sound which is advantageous in a car. I would DEFINATELY recommend JL VR
series. I am currently using a pair of Advent silk dome tweeters which are
OK, but I am not as happy with these as I was with the JL's so I may try to
pick up another set of JL's. I have heard good things about Seas tweeters
and Dynaudio as well.

6) The JL Audio 500/5 gives 25W RMS to the rears, 100W RMS to the
fronts, and 250W RMS to the sub, can I swap the front/rear channels to
give 100W RMS to my rears?

Sure. No problem.

I currently have the following components:
- Alpine CDA-9825, with Front, Rear and Subwoofer RCA outputs
- JL Audio 500/5 5-Channel Amplifier
- Fronts: Infinity KAPPA 462.3cfp 4" x 6" two-way (60W RMS)
- Rears: Infinity KAPPA 693.3i 6" x 9" three-way (110W RMS)

Good choice on HU's. I think Alpine is the VERY best. I have an Alpine
9853. You can see a picture of my system at:
http://www428.pair.com/mosfet/mtx.html

Good luck,

MOSFET

[[email protected]]

Thank you both for your replies, very helpful.


MOSFET wrote:
wrote in message
ups.com...

2) If so, would I need an equalizer / filter just for the tweeters?

You WILL need some type of high-pass crossover to control what frequencies
get to your tweeter (otherwise you will likely blow them). A simple
capacitor in-line with the tweeter lead will give a 6 dB per octive cutoff
and should do the job fine. A few posts back, someone posted a link that
contains a chart with all the capacitor values and their respective
frequencies. See that when selecting a high-pass filter capactitor.

Awesome, ill go look that up.


5) I have not bought the tweeters yet, any recommendations?

Boy, have you asked the right guy about THIS ONE!!! Coinciendentally, I
have been shopping for tweeters myself lately. I recently blew one of my MB
Quart PTD25's. I wasn't too upset, however, as I really had not been very
happy with the sound of MB Quart (they sound very crisp and bright AT FIRST,
but they begin to wear on you after a while). I bought a pair of JL VR
series tweeters and then promptly blew those (it was my mistake, too much
power). But the JL's sounded SO MUCH BETTER than the Quart's. Overall, I
would recommend textile dome over metal domes, they have a more laid-back
sound which is advantageous in a car. I would DEFINATELY recommend JL VR
series. I am currently using a pair of Advent silk dome tweeters which are
OK, but I am not as happy with these as I was with the JL's so I may try to
pick up another set of JL's. I have heard good things about Seas tweeters
and Dynaudio as well.

I was actually thinking about the JL tweeters. Ive been really
impressed with their equipment, and absolutely love their subwoofers.
Ill probably be looking very seriously at the JL VR.

I currently have the following components:
- Alpine CDA-9825, with Front, Rear and Subwoofer RCA outputs
- JL Audio 500/5 5-Channel Amplifier
- Fronts: Infinity KAPPA 462.3cfp 4" x 6" two-way (60W RMS)
- Rears: Infinity KAPPA 693.3i 6" x 9" three-way (110W RMS)

Good choice on HU's. I think Alpine is the VERY best. I have an Alpine
9853. You can see a picture of my system at:
http://www428.pair.com/mosfet/mtx.html

Yea, I love my Alpine. Ive got the iPod KCA-420i integration unit as
well, and the combo just rocks.

I just checked out your pictures, nice setup!