[DeTomaso] Pantera Stereo/Speaker install question

Doug Braun doug at silicondesigns.com
Mon Dec 15 11:25:59 EST 2008


One correction Chris.  The non-polar capacitors you're speaking of aren't
rated in Watts, they're rated in Volts.  The types typically used in speaker
crossovers are metallized polypropylene, polyester film and oil filled.
Polypropylene provides higher audio quality at higher cost vs polyester.
Oil filled provide high audio quality but they're bulky.  For a low-cost,
low quality option, two 8 uF (MicroFarad) Aluminum Electrolytics can be
wired in series (minus to minus).  This series combination provides 4 uF
equivalent capacitance.

Doug Braun


-----Original Message-----
From: detomaso-bounces at realbig.com
[mailto:detomaso-bounces at realbig.com]On Behalf Of Christopher Kimball
Sent: Monday, December 15, 2008 7:55 AM
To: claywillmott at hotmail.com; Pantera List Serve
Subject: Re: [DeTomaso] Pantera Stereo/Speaker install question



NOW you're talking!

Although I don't know if your head unit will have right and left front and
rear outputs, and utilize a fader to balance between the two, I'm almost
positive it will.  These would be four RCA, low-level connectors coming from
the back of the unit.  Leave the speaker wires unhooked and taped off.

If that's the case, here are two options for you:

Option #1:

For best sound and most power:  Plug the front outputs of the head unit into
the existing amp.  Hook the tweeters to its outputs, but, and this is really
important:  ON THE POSITIVE LEAD ON EACH TWEETER, PUT A 50-WATT. 4
MICROFARAD, NON-POLAR ELECTROLYTIC CAPACITOR IN SERIES (a 25-watt would
probably suffice, too).  That sounds complicated, but you can go to Radio
Shack and buy a couple for about three bucks (assuming they have two in
stock and the salesperson has a clue, which most of them don't).  If you
strike out, let me know--I may have a couple I can mail you.  Basically, you
solder the end of the positive wire to one end of the capacitor and then
solder the other end of the capacitor to the positive terminal of the
tweeter.  The negative wire hooks up as usual.  Failure to do this will blow
up the tweeter, which is probably what happened to your old ones, resulting
in the static you mentioned.

Next, hook the rear outputs from your head unit to the inputs of the new
amp.  Hopefully, you'll be able to bridge your new amp to a two-channel
configuration, if not, you might want to go to option two, below.  Anyway,
assuming you can bridge it, adjust the crossover to a low-pass
configuration, so the highs are eliminated.  Most amps have an adjustable
crossover which you can fiddle with once everything's all hooked up.  Just
adjust it until you like the sound; there's no chance of doing any harm to
the woofer.  Hook your woofer wires to the amp's left and right channel
outputs (the ones used when bridged to a two-channel configuration) and your
ready to go, with maximum power and clarity (assuming both amps are working
correctly.  I ordered one recently and so far have gotten two bad ones in a
row.  I'm STILL waiting for a good one to arrive!)

To avoid phase problems and the associated lack of bass or oddities in the
high-frequencies, it's important you use wire that has one side coded
somehow so you can connect the plus and minus of each speaker to the correct
plus or minus of the amps, and that the tweeters are also hooked up with the
positive and negatives the same, too.  Usually if the speaker doesn't have a
plus and minus sign next to the corresponding terminal, the positive one
will have a red insulator or mark next to it.  This phasing part of hooking
up speakers is true no matter if you use option one or option two I'm
describing.

Option #2:

Use the new, four channel amp and run the head unit's four outputs into the
amp's inputs, again taping off any speaker wires from the head unit.  On the
amp's front channels, adjust the crossover to high-pass and hook the
tweeters up to those channels, but to be safe I would still use capacitors
on the tweeters (come to think of it, they may already have them attached,
although if you say you have a big crossover unit for each set of
woofer/tweeter, the caps could be located in that).  You can adjust the
high-frequency cut-off adjustment on the amp for the tweeters the same way
you did for the woofers to get the best sound.

Anyway, once your tweeters are good to go, hook up the amp's rear channels
just as described in #1.

Then you're done!

As long as you use the capacitors and amp crossovers as I've described,
there is no need to use the big, passive crossover unit you mentioned.  In
fact, those things suck power from the system, so if you can use electronic
crossovers instead, it's always better.

As far as tweeter location; if the tweeters are aimed upward, their present
location will probably work OK.  What I did was use some tweeters that were
round and not very deep.  I put them in the existing door holes that were
used for the manual window cranks.  The little, round metal covers popped
out, I had to grind 14" or so off the plastic manual-crank receptacles, but
the tweeters are flush with the door panels, look great and, for sound
purposes, the location is very good, too.

Feel free to call me if you have any more questions or need help as you're
hooking it all up. 253-232-2321.

Sincerely,

Chris




From: claywillmott at hotmail.com
To: chrisvkimball at msn.com; detomaso at realbig.com
Subject: RE: [DeTomaso] Pantera Stereo/Speaker install question
Date: Mon, 15 Dec 2008 10:20:12 -0500








Thanks for all the responses.


Q:When you say "front" and "rear" so you mean the system has a four
channel amp, and you use the fader in the stereo head unit to control
the back to front balance?  If so, and if the amp has no electronic
crossovers in use, then the
tweeters must have capacitors in line to eliminate low frequencies.  If
that is the case, then the woofers are probably getting full-range
frequencies, which is OK.  That being the case, it wouldn't matter
which were front and which were rear.

A:The amp is a four channel Panasonic and it is set on two channel.  The
right and left front speakers exit the amp to the door woofers.  The right
and left rear speakers as labeled on the amp go to the two tweeters mounted
by my knees.   It previously has no cross overs, all speakers seem to have
full range.  By this I mean the woofers had high frequency and the tweeters
seemed to attempt to deliver bass/static.  The older amp does not have
crossovers internally. I have the new speakers and head unit installed
already the same way the previous owner had it.  My newer Amp has not
arrived yet  as I ordered it later trying to avoid the two box styled
crossovers.  Thus I have full range through all my new four components.
Thus can I just wait on the new amp or will I need to get started installing
the two crossovers also.

The specific components are Alpine iDA-X100 head unit with the ipod
features, Alpine SPX 17-REF component speakers (6.5 inch) and tweeters
that came with two large crossovers (One for right and one for left ).
The amp is a Alpine PDX 4 x 100 with built in crossover.



I was told you need to use the large crossovers and mount in the door
but I would rather not put those in my door and shouldn't an amp with a
built in cross over work just as well?  If it will sound just as good I
would like to Not use the two crossovers.



Also, the last guy put the two tweeters mounted in the panel by the
fuse box on the right and the hood release on the left.  These are
aimed at you knees roughly.  Any place you can stick tweeters that is
relatively hidden and aimed more towards the head?  Trim pieces around
the headliner?

I hope that makes sense, this is the first time I have done amps, stereo etc
work.

Clay
1343



From: chrisvkimball at msn.com
To: claywillmott at hotmail.com; detomaso at realbig.com
Subject: RE: [DeTomaso] Pantera Stereo/Speaker install question
Date: Sun, 14 Dec 2008 18:31:21 -0800








When you say "front" and "rear" so you mean the system has a four channel
amp, and you use the fader in the stereo head unit to control the back to
front balance?  If so, and if the amp has no electronic  crossovers in use,
then the tweeters must have capacitors in line to eliminate low frequencies.
If that is the case, then the woofers are probably getting full-range
frequencies, which is OK.  That being the case, it wouldn't matter which
were front and which were rear.

If, on the other hand, the amp has electronic crossovers built in, then you
should use the high pass channels for the tweeters and the low pass for the
woofers.

If the amp has the same crossover options for both front and rear channels,
then all you have to do is switch the crossover frequencies from front to
back, change the wires for the woofers and tweeters the same, and that's
that.

Of course, it would probably be easier just to switch the line inputs from
the head unit.  Switch the front to back and visa-versa and that should do
the same thing.

If you can give me more detail I can help you more effectively.

Thanks!

Chris
#3846



> From: claywillmott at hotmail.com
> To: detomaso at realbig.com
> Date: Sun, 14 Dec 2008 20:50:50 -0500
> Subject: [DeTomaso] Pantera Stereo/Speaker install question
>
>
> I just put in a new stereo and speakers but kept my amp that came with the
car for now.  The speakers are component as were the previous (two 6.5 inch
woofers and two 1.25 inch tweeters).
> The last guy had the woofers as front speakers and the tweeters as rear.
The tweeters are in the front of the car and the woofers are in the door.
> Shouldn't the tweeters be front and the woofers be rear??
> Also, if my battery is a gel mat is it safe to mount the cross overs
behind the battery?
>
>
> Thanks in advance.
>
> CW
>
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