[Godfrey Muganda]

Hey, I am new to this and I need some help. Apologies if this has been
answered before.

What is the best way to wire a 2 channel amp that is 2 ohm stable to a 4 ohm
DVC sub?

Should I

1) bridge the amp and use only of the 2 voice coils? Seems that I am
"wasting" the unused voice coil.

2) bridge the amp and wire the 2 coils in series? My understanding is this
will present an 8 ohm load to the amp, I am worried
that this will cut the power output from the amp due to higher resistance

3) wire one channel of each amp to a separate voice coil? I am worried
about the effect of two different signals on the same cone.
Besides I get less power from each channel because the amp is not
bridged. (My head unit has subwoofer preamp outputs: are
the left and right signals on sub preouts usually the same, or are they
different)

I know I cant bridge the amp and wire the voice coils in parallel, because I
understand that presents a 1 ohm load to the amp,
which is only 2 ohm stable.

So which of 1, 2, and 3 will give deepest and clearest bass?

Thanks all.

[D.Kreft]

On Mar 24, 7:50 am, "Godfrey Muganda" wrote:

What is the best way to wire a 2 channel amp that is 2 ohm stable to a 4 ohm
DVC sub?

See the "Wiring Your Subwoofers" tutorial on the JL Audio website:

http://mobile.jlaudio.com/support_pages.php?page_id=161

-dan

[Matt Ion]

Godfrey Muganda wrote:
Hey, I am new to this and I need some help. Apologies if this has been
answered before.

What is the best way to wire a 2 channel amp that is 2 ohm stable to a 4 ohm
DVC sub?

Should I

1) bridge the amp and use only of the 2 voice coils? Seems that I am
"wasting" the unused voice coil.

"Wasting"? Not really...

2) bridge the amp and wire the 2 coils in series? My understanding is this
will present an 8 ohm load to the amp, I am worried
that this will cut the power output from the amp due to higher resistance

Correct there.

3) wire one channel of each amp to a separate voice coil? I am worried
about the effect of two different signals on the same cone.

The amp probably has a "mono" mode - switch that on, and both channels will get
identical signals.

Besides I get less power from each channel because the amp is not
bridged.

Since most amps' RATED output is "at 4 ohms" you'll get approximately the rated
output. Just because the amp CAN run safely at 2 ohms, doesn't mean it HAS to.

I know I cant bridge the amp and wire the voice coils in parallel, because I
understand that presents a 1 ohm load to the amp,
which is only 2 ohm stable.

Two flaws he main one is, two 4-ohm loads wired in parallel gives you two ohms.

However, when two-channel amps are listed as "X ohm stable" they're usually
talking "X ohms on each channel". Unless the amp specs state otherwise,
bridged, the amp is PROBABLY not stable below four ohms.

So which of 1, 2, and 3 will give deepest and clearest bass?

I'd just go with option 3, each voice coil on its own channel, and set the amp
to mono mode (whether the deck outputs a mono signal on the sub pre-outs, nobody
can tell you without knowing the make and model of the deck).

[D.Kreft]

On Mar 24, 8:24 am, Matt Ion wrote:

2) bridge the amp and wire the 2 coils in series? My understanding is this
will present an 8 ohm load to the amp, I am worried
that this will cut the power output from the amp due to higher resistance

Correct there.

This is not correct--I think you may have misread his post.

Given a single dual-4 Ohm sub, wiring the coils in series and
presenting an 8 Ohm load to a bridged amp will give the exact same
power output as wiring each channel ("stereo") direct to each of the
two voicecoils.

Unless the amp is stable into a 2 Ohm load *when bridged*, this is
really best option for you. It's not going to get the most power
possible from the amp, but given what you've got, it's as good as you
can get.

3) wire one channel of each amp to a separate voice coil? I am worried
about the effect of two different signals on the same cone.

The amp probably has a "mono" mode - switch that on, and both channels will get
identical signals.

Simply wiring the VC's in series will avoid this potential problem. It
also means you'll have to run one less pair of wires from your sub amp
to your box.

I know I cant bridge the amp and wire the voice coils in parallel, because I
understand that presents a 1 ohm load to the amp,
which is only 2 ohm stable.

Two flaws he main one is, two 4-ohm loads wired in parallel gives you two ohms.

However, when two-channel amps are listed as "X ohm stable" they're usually
talking "X ohms on each channel". Unless the amp specs state otherwise,
bridged, the amp is PROBABLY not stable below four ohms.

Essentially, he got it right...even if worded a bit imprecisely.

-dan

[Matt Ion]

D.Kreft wrote:
On Mar 24, 8:24 am, Matt Ion wrote:


2) bridge the amp and wire the 2 coils in series? My understanding is this
will present an 8 ohm load to the amp, I am worried
that this will cut the power output from the amp due to higher resistance

Correct there.


This is not correct--I think you may have misread his post.

I think I did too.

Given a single dual-4 Ohm sub, wiring the coils in series and
presenting an 8 Ohm load to a bridged amp will give the exact same
power output as wiring each channel ("stereo") direct to each of the
two voicecoils.

Right.

Unless the amp is stable into a 2 Ohm load *when bridged*, this is
really best option for you. It's not going to get the most power
possible from the amp, but given what you've got, it's as good as you
can get.

Well, mathematically, it's no different from running the two voice coils each on
its own channel... real-world there will be some variations depending on
frequency and the exact designd of the amp, but they're functionally negligible.

3) wire one channel of each amp to a separate voice coil? I am worried
about the effect of two different signals on the same cone.

The amp probably has a "mono" mode - switch that on, and both channels will get
identical signals.


Simply wiring the VC's in series will avoid this potential problem. It
also means you'll have to run one less pair of wires from your sub amp
to your box.

Unless you're blowing money on $200/ft. Monster cables or some such ****, it's
really not a big issue to pull two pair instead of one

[cdd]

On Mar 25, 11:40 am, Matt Ion wrote:
D.Kreft wrote:
On Mar 24, 8:24 am, Matt Ion wrote:

2) bridge the amp and wire the 2 coils in series? My understanding is this
will present an 8 ohm load to the amp, I am worried
that this will cut the power output from the amp due to higher resistance

Correct there.

This is not correct--I think you may have misread his post.

I think I did too.

Given a single dual-4 Ohm sub, wiring the coils in series and
presenting an 8 Ohm load to a bridged amp will give the exact same
power output as wiring each channel ("stereo") direct to each of the
two voicecoils.

Right.

Unless the amp is stable into a 2 Ohm load *when bridged*, this is
really best option for you. It's not going to get the most power
possible from the amp, but given what you've got, it's as good as you
can get.

Well, mathematically, it's no different from running the two voice coils each on
its own channel... real-world there will be some variations depending on
frequency and the exact designd of the amp, but they're functionally negligible.

3) wire one channel of each amp to a separate voice coil? I am worried
about the effect of two different signals on the same cone.

The amp probably has a "mono" mode - switch that on, and both channels will get
identical signals.

Simply wiring the VC's in series will avoid this potential problem. It
also means you'll have to run one less pair of wires from your sub amp
to your box.

Unless you're blowing money on $200/ft. Monster cables or some such ****, it's
really not a big issue to pull two pair instead of one

The differences of each of these setups will be hard to hear-go with
what you've been told but
there is one way that I got around all these impedance probs and that
is to get 1 amp for each speaker.
run it in bridge mode(2ohm load subs-4ohm load for bass/mid/treble/
super treble. I have used a separate
amp for all these frequencies via a active crossover network-The point
is that 2 amps will drive 4 coils
in bridge mode safely and without overheating or changing the most
efficient way of wiring it there is no other way.
Also a 4 channel amp will give more wiring config's as well-

good luck

just something to think about in the future.

[D.Kreft]

On Mar 26, 10:04 pm, "cdd" wrote:

there is one way that I got around all these impedance probs and that
is to get 1 amp for each speaker.

I think you may have missed this, but he's already got one amp for his
one subwoofer. Your suggestion doesn't really seem applicable here.

run it in bridge mode(2ohm load subs-4ohm load for bass/mid/treble/
super treble. I have used a separate
amp for all these frequencies via a active crossover network-The point
is that 2 amps will drive 4 coils
in bridge mode safely and without overheating or changing the most
efficient way of wiring it there is no other way.

I'm not sure if you're advocating the use of a multi-way (i.e. more
than just a simple 2-way) electronic crossover and forgoing the use of
passives entirely, but if you are, this approach has a few "issues":

1. First and foremost is expense...more amps == more money and a
good 3-, or 4-way electronic crossover is going to be more
expensive
than a 2-way of equivalent quality;

2. Increased risk of noise problems...the more electronics you have
in
your system, the greater your chances are for picking up
radiated
noise (engine noise);

3. Difficulty in tuning...simple 2-way active systems are a lot
easier
to get right than a complicated multi-way setup.

Also a 4 channel amp will give more wiring config's as well-

Well, sort of. In this case I don't see how a 4-channel amp is going
to help the poor guy. If you're recommending a 4-channel amp to run
the whole system, then he's still going to have the same problem with
impedance from his dual 4-Ohm VC subwoofer (assuming a 4-Ohm stable
amp is purchased). And recommending a 4-channel amp to act solely as a
subwoofer amp (the presumption being that the amp would be fully
bridged and each side of the amp run into one VC) is a bit silly too--
it'd be easier to simply "trade" in the current subwoofer for a dual 8-
Ohm variety, which would allow him to present a perfectly safe 4-Ohm
load to his amp.

-dan

[cdd]

On Mar 28, 6:47 am, "D.Kreft" wrote:
On Mar 26, 10:04 pm, "cdd" wrote:

there is one way that I got around all these impedance probs and that
is to get 1 amp for each speaker.

I think you may have missed this, but he's already got one amp for his
one subwoofer. Your suggestion doesn't really seem applicable here.

run it in bridge mode(2ohm load subs-4ohm load for bass/mid/treble/
super treble. I have used a separate
amp for all these frequencies via a active crossover network-The point
is that 2 amps will drive 4 coils
in bridge mode safely and without overheating or changing the most
efficient way of wiring it there is no other way.

I'm not sure if you're advocating the use of a multi-way (i.e. more
than just a simple 2-way) electronic crossover and forgoing the use of
passives entirely, but if you are, this approach has a few "issues":

1. First and foremost is expense...more amps == more money and a
good 3-, or 4-way electronic crossover is going to be more
expensive
than a 2-way of equivalent quality;

2. Increased risk of noise problems...the more electronics you have
in
your system, the greater your chances are for picking up
radiated
noise (engine noise);

3. Difficulty in tuning...simple 2-way active systems are a lot
easier
to get right than a complicated multi-way setup.

Also a 4 channel amp will give more wiring config's as well-

Well, sort of. In this case I don't see how a 4-channel amp is going
to help the poor guy. If you're recommending a 4-channel amp to run
the whole system, then he's still going to have the same problem with
impedance from his dual 4-Ohm VC subwoofer (assuming a 4-Ohm stable
amp is purchased). And recommending a 4-channel amp to act solely as a
subwoofer amp (the presumption being that the amp would be fully
bridged and each side of the amp run into one VC) is a bit silly too--
it'd be easier to simply "trade" in the current subwoofer for a dual 8-
Ohm variety, which would allow him to present a perfectly safe 4-Ohm
load to his amp.

-dan

Sorry didn't see he only had one speaker-amp-obviously he has limited
wiring
Configurations and the advice you have offered this person is sound
advice!!
However, I use an active crossover network-MX-7 Multi-function
electronic crossover/parametric
-It does take
7-8 amps to get the full frequency range
Although I have removed the super tweeter one and retuned the
crossover to cover those frequencies
This means only 7 amps-as for tunning-I have never had so much control
over each part of my system.
It's easy to stuff the input sensitivity up on the amps and have
different volume increase rates-but each
Speaker is getting only the frequency's it's designed to run-I can
drive 6/9 speakers at very high spl levels
Without distortion and have clean tight bass to go with it -all amps
are velocity and fusion-I am happy with
My system and have no noise prob's-(alpine alternator)-seems to work
just hard on belts. I don't just run 6/9's
Which are directly wired ( speaker to own amp) but have piezo tweeters
(own amp) 8'' mid/bass speakers(own amp) Got 15'' MTX 1000w
thundercast subs as well etc etc

As I say I am quite pleased with my system-although far from what I
consider really loud-it sounds real nice-
-What do you think the bad points of a system like this is compared
with the passive crossover and 2 way sub/mid-top split of most
installations-you mentioned noise but this hasn't been a prob
Nevertheless, set up is not easy I must say and I have a few
electronic toys to help with this-but any suggestions would help
As I am always looking for more sound pressure or quality.

Thank's cdd

[D.Kreft]

On Mar 28, 3:34 am, "cdd" wrote:

This means only 7 amps-as for tunning-I have never had so much control
over each part of my system.

I bet!

It's easy to stuff the input sensitivity up on the amps and have
different volume increase rates-but each
Speaker is getting only the frequency's it's designed to run-I can
drive 6/9 speakers at very high spl levels
Without distortion and have clean tight bass to go with it

The same may be said of a 2-way (active) system with passive
crossovers on the mids & highs.

And let's not get into highly subjective terms like "tight bass"--
that's a whole other topic.

Which are directly wired ( speaker to own amp) but have piezo tweeters
(own amp) 8'' mid/bass speakers(own amp) Got 15'' MTX 1000w
thundercast subs as well etc etc

You use piezo tweeters? And on their own dedicated amp? Oy vey,
man...that's....odd.

-What do you think the bad points of a system like this is compared
with the passive crossover and 2 way sub/mid-top split of most
installations-you mentioned noise but this hasn't been a prob

Cost, potential for noise, space, and difficulty in setup are the
primary factors against a multi-way active setup. If none of these are
an issue for you, then there is no argument against it.

Speaking to the set-up labor, this might not be a factor for serious
"tweakers." It's kinda like how some people (like me in my youth)
prefer Linux because you can control every aspect of how the operating
system performs because you can hack at the kernel all you want.
However, there are others (like me at present) who prefer to be able
to just hit the ground running, which something like MacOS will give
you--it may not be as flexible, but the gory details are handled for
you, so there's less to worry about.

Nevertheless, set up is not easy I must say and I have a few
electronic toys to help with this-but any suggestions would help
As I am always looking for more sound pressure or quality.

I'd say getting rid of the piezo tweets would be one good way to
improve the quality of your system. :-)

-dan

[Matt Ion]

D.Kreft wrote:

Speaking to the set-up labor, this might not be a factor for serious
"tweakers." It's kinda like how some people (like me in my youth)
prefer Linux because you can control every aspect of how the operating
system performs because you can hack at the kernel all you want.
However, there are others (like me at present) who prefer to be able
to just hit the ground running, which something like MacOS will give
you--it may not be as flexible, but the gory details are handled for
you, so there's less to worry about.

Heheh, ironic you should use that as an example, since MacOSX is built on a
Linux-like platform and can be hacked extensively underneath the friendly shell
To continue the analogy, it would be like having
adjustable-Q/adjustable-rolloff/adjustable-level passive crossovers in your
six-way speakers, set to a happy medium from the factory that will work fine for
most people, but infinitely "tweakable" for the gearheads

Nevertheless, set up is not easy I must say and I have a few
electronic toys to help with this-but any suggestions would help
As I am always looking for more sound pressure or quality.


I'd say getting rid of the piezo tweets would be one good way to
improve the quality of your system. :-)

Seconded.

[cdd]

On Mar 29, 11:20 am, Matt Ion wrote:
D.Kreft wrote:
Speaking to the set-up labor, this might not be a factor for serious
"tweakers." It's kinda like how some people (like me in my youth)
prefer Linux because you can control every aspect of how the operating
system performs because you can hack at the kernel all you want.
However, there are others (like me at present) who prefer to be able
to just hit the ground running, which something like MacOS will give
you--it may not be as flexible, but the gory details are handled for
you, so there's less to worry about.

Heheh, ironic you should use that as an example, since MacOSX is built on a
Linux-like platform and can be hacked extensively underneath the friendly shell
To continue the analogy, it would be like having
adjustable-Q/adjustable-rolloff/adjustable-level passive crossovers in your
six-way speakers, set to a happy medium from the factory that will work fine for
most people, but infinitely "tweakable" for the gearheads

Nevertheless, set up is not easy I must say and I have a few
electronic toys to help with this-but any suggestions would help
As I am always looking for more sound pressure or quality.

I'd say getting rid of the piezo tweets would be one good way to
improve the quality of your system. :-)

Seconded.

thank's for your input-I have to admit those tweeters are a bit of a
pain in the ass
when it comes to setting up the system-I only ended up using them as
that
was what I had at the time(ex pa gear)-no -they don't sound the
sweetest,
just bloody noisey-will dump them as it's been a while since I have
changed any speakers in the system-


cdd

[Godfrey Muganda]

Thanks everybody for all your input.

The sub is an arc audio KAR 10D. It is a 10 inch sub with dual voice coils
each of which is 4 ohms.
The sub is rated 200 Watts RMS and 400 Watts Max
The amp is an old Alpine 3548 that is rated at 60 Watts/channel. I decided
to bridge the amp
and run it on one of the KAR 10D voice coils. It sounds good, but not as
good as an a/d/s A8 eight inch
sub that I have in my other car. That a/d/s sub is a single voice coil, and
is rated at 20W to150 Watts (If I remember
correctly) The a/d/s is running off of bridged two channels of an Autotex
amp that is rated 75 X 4 RMS.

The a/d/s A8 sounds really good with very tight bass. The ARC 10D sounds
good, but the bass in not as tight
I am thinking of getting an Alpine mono amp, the M350, rated 200 W RMS to
see if it will improve the
sound of the ARC, or maybe just replacing the 10 inch sub with an 8 inch.

Thanks again for all your input.

GM

"D.Kreft" wrote in message
oups.com...
On Mar 24, 7:50 am, "Godfrey Muganda" wrote:

What is the best way to wire a 2 channel amp that is 2 ohm stable to a 4
ohm
DVC sub?

See the "Wiring Your Subwoofers" tutorial on the JL Audio website:

http://mobile.jlaudio.com/support_pages.php?page_id=161

-dan

[D.Kreft]

On Apr 6, 2:29 pm, "Godfrey Muganda" wrote:

I decided to bridge the amp and run it on one of the KAR 10D voice
coils. It sounds good, but not as good as an a/d/s A8 eight inch
sub that I have in my other car.

Well of course not! Would you expect your car to run well if you
unplugged half of your spark plug wires???? You complaining that your
sub doesn't sound very good with only one VC hooked-up is like
complaining that you can't beat your gradma's Oldsmobuick off the line
with half your engine unplugged!

That second set of speaker leads on the back of a DVC speaker is *not*
optional. If you only use one voice coil, you are seriously screwing
with the electric motor that is your speaker and you *can* expect it
to sound like crap (unless you take very definite steps to counteract
this abuse).

Please, for the love of all that which is still good and decent about
car audio, go back to the JL Audio "Wiring Your Subwoofer" tutorial
and *heed its advice*. Trying to be creative is going to either get
you disappointed, or break your equipment.

Sorry if I seem a bit over empassioned about this...offering people
advice when they ask for it and having them ignore it (and then
complain) is a pet peeve of mine.

Now go wire-up that second voice coil and stop trying to be clever.

-dan

[Godfrey Muganda]

D. Kreft,
I did check out the tutorial on JL audio and I do see the error of my
ways.
I will just wait to get my mono amp to rewire the sub's voice coils in
parallel.

Thanks for taking the time.

GM

"D.Kreft" wrote in message
oups.com...
On Apr 6, 2:29 pm, "Godfrey Muganda" wrote:

I decided to bridge the amp and run it on one of the KAR 10D voice
coils. It sounds good, but not as good as an a/d/s A8 eight inch
sub that I have in my other car.

Well of course not! Would you expect your car to run well if you
unplugged half of your spark plug wires???? You complaining that your
sub doesn't sound very good with only one VC hooked-up is like
complaining that you can't beat your gradma's Oldsmobuick off the line
with half your engine unplugged!

That second set of speaker leads on the back of a DVC speaker is *not*
optional. If you only use one voice coil, you are seriously screwing
with the electric motor that is your speaker and you *can* expect it
to sound like crap (unless you take very definite steps to counteract
this abuse).

Please, for the love of all that which is still good and decent about
car audio, go back to the JL Audio "Wiring Your Subwoofer" tutorial
and *heed its advice*. Trying to be creative is going to either get
you disappointed, or break your equipment.

Sorry if I seem a bit over empassioned about this...offering people
advice when they ask for it and having them ignore it (and then
complain) is a pet peeve of mine.

Now go wire-up that second voice coil and stop trying to be clever.

-dan