Custom Sub

BeginnersLuck · 03-04-2003, 04:16 PM

I've got a questions for you DIY'ers. I have a custom sub with two adire audio tempest drivers mounted in the enclosure. My sub amp is mono output...

What is a better way to wire them, or does it matter?
Each driver has two 8 ohm voice coils...
Should I wire the voice coils in parallel and the drivers in series...
Or the voice coils in series and the drivers in parallel?

Any feed back or suggestions are greatly Appreciated,

Thanks
-Gary

HBombToo · 03-04-2003, 05:36 PM

Is your amp rated @4Ohms?

If so the manufacturer should give you specs for power at both 4 and 8.

HBomb

BeginnersLuck · 03-04-2003, 05:45 PM

Yes, it is rated at both 4 and 8 ohm (540W and 320W respectively)

RuSsMaN · 03-04-2003, 06:04 PM

I would say VC parallel, drivers series.

Either way you look at it, you'll end up at 8ohm, right? I wish there was a good way to get you to 4ohm with all 4 vc's.

Cheers,
Russ

BeginnersLuck · 03-04-2003, 06:10 PM

Thanks for the info!

Dr. Spec · 03-04-2003, 06:18 PM

Straight From The Horses Mouth - Tempest White Paper:

3.2 Why dual voice coils?
After asking about the T/S parameters, the next most common question is ?why dual voice coils?? Most
high-end subwoofers have a single voice coil; so why dual?
Simply put, dual voice coils dramatically increase the flexibility of the driver. Most obviously, the total
impedance of the driver can be changed. As each voice coils is nominally 8W, one can run a single voice
coil and have a nominal 8 ohm woofer. But wiring the voice coils in parallel will yield a nominal 4W
woofer. And wiring the voice coils in series will yield a nominal 16W woofer. All in all, these
configurations allow easy use in low-voltage applications (4W woofer, for use in apps such as car audio), or
multiple driver systems (16W drivers allow one to parallel 2 to 4 drivers in a single system, and still
maintain an acceptable impedance without series connecting any drivers).
Note that the connection flexibility afforded by dual voice coils is equally great. For example, to use a
single channel of an amplifier (or a monoblock amplifier), one can connect the voice coils in parallel or
series (or just hook up a single voice coil) to meet the load requirements of the amplifier.
But, to use a stereo amp, one can connect a single voice coil to each channel. This allows the driver to act
as the ?summing? junction of a stereo signal, mechanically summing the stereo signals into a "mono"
driver. One does not need to electronically sum the channels together. This dramatically eases applications
where passive crossovers are used.
But the most important benefit for dual voice coils is flexibility for the T/S parameters. One can actually
?dial in? a desired Qts of the driver, by resistively loading one voice coil and actively driving the other.
This configuration, which we call Resistively Damped Operation (RDO), uses the second (undriven) voice
coil as an electromagnetic brake. In essence, the resistance across the second coil will determine how
strong the brake is. The smaller the resistance, the stronger the brake.
RDO affects the Qts of the driver by decreasing the Qms of the driver. The RDO brake acts to damp cone
motion, as if the suspension was considerably stiffer. However, as it?s an electromagnetic brake, the Fs is
NOT affected (as it would raise if the suspension components ? the surround and spider ? were stiffened).
This allows one to literally ?dial in? in a desired Qts by varying the Qms of the driver. In fact, a 250 W
5W potentiometer can be used to tune Tempest over a large range. For example, placing Tempest in an 113
liter box, and using the RDO configuration, one can dial in a system Qtc ranging from 0.65 to 1.2. This
allows tailoring the low-end response of the system to meet most musical/home theater reproduction needs.

BeginnersLuck · 03-05-2003, 11:36 AM

Dr. Spec-

Thanks, but that really did not answer my question. I already had that information.

Dr. Spec · 03-05-2003, 01:15 PM

No kidding it didn't answer your question - Russ already did that above and you thanked him for it.

I just thought maybe it would have been a helpful adjunct to your answer if you were considering altering the Qms of the driver for different applications and alignments.

BeginnersLuck · 03-05-2003, 02:50 PM

Actually, I was looking to see if there are any advantages/disavantages to wireing the speakers as I mentioned above: VC parallel Drivers series compared to VC series Drivers parallel...would there be any different sound charateristics?

Both setups offer an 8 ohm load...

Thanks for any help
-Gary

Dr. Spec · 03-05-2003, 04:09 PM

Honestly, I can't answer that question.

Aside from obviously having the same final impedance either way, I have no idea if the sound quality would be different. I would definitely ask Adire this question - they have a good tech department.

03-04-2003, 04:16 PM	#1
BeginnersLuck Polkster Member Sales Rating: (0) Join Date: Mar 2003 Location: Sacramento, CA Posts: 213	Custom Sub I've got a questions for you DIY'ers. I have a custom sub with two adire audio tempest drivers mounted in the enclosure. My sub amp is mono output... What is a better way to wire them, or does it matter? Each driver has two 8 ohm voice coils... Should I wire the voice coils in parallel and the drivers in series... Or the voice coils in series and the drivers in parallel? Any feed back or suggestions are greatly Appreciated, Thanks -Gary __________________ TWFTPQ Receiver: Outlaw 1050 Amps: Outlaw M-200 x 3 (Powering Mains and Center) Mains: RT800i; Center: CS400i; Surrounds: F/X500i Sub1: 214L Vented Tempest Sub2: 122L Sealed Tempest

03-04-2003, 05:36 PM	#2
HBombToo Polk Master Member Sales Rating: (1) Join Date: May 2002 Location: Funny Farm"no doubt there" Posts: 5,321	Is your amp rated @4Ohms? If so the manufacturer should give you specs for power at both 4 and 8. HBomb __________________ *WAREMTAE*

03-04-2003, 06:04 PM	#4
RuSsMaN Hardcore Member Sales Rating: (27) Join Date: Jul 2001 Location: North Texas Posts: 16,022	I would say VC parallel, drivers series. Either way you look at it, you'll end up at 8ohm, right? I wish there was a good way to get you to 4ohm with all 4 vc's. Cheers, Russ __________________ If you're gonna be dumb, you gotta be tough - when you get knocked down, you gotta get back up - Roger Alan Wade

03-04-2003, 06:18 PM	#6
Dr. Spec Polk Expert Member Sales Rating: (1) Join Date: Mar 2002 Location: New York Posts: 3,771	Straight From The Horses Mouth - Tempest White Paper: 3.2 Why dual voice coils? After asking about the T/S parameters, the next most common question is ?why dual voice coils?? Most high-end subwoofers have a single voice coil; so why dual? Simply put, dual voice coils dramatically increase the flexibility of the driver. Most obviously, the total impedance of the driver can be changed. As each voice coils is nominally 8W, one can run a single voice coil and have a nominal 8 ohm woofer. But wiring the voice coils in parallel will yield a nominal 4W woofer. And wiring the voice coils in series will yield a nominal 16W woofer. All in all, these configurations allow easy use in low-voltage applications (4W woofer, for use in apps such as car audio), or multiple driver systems (16W drivers allow one to parallel 2 to 4 drivers in a single system, and still maintain an acceptable impedance without series connecting any drivers). Note that the connection flexibility afforded by dual voice coils is equally great. For example, to use a single channel of an amplifier (or a monoblock amplifier), one can connect the voice coils in parallel or series (or just hook up a single voice coil) to meet the load requirements of the amplifier. But, to use a stereo amp, one can connect a single voice coil to each channel. This allows the driver to act as the ?summing? junction of a stereo signal, mechanically summing the stereo signals into a "mono" driver. One does not need to electronically sum the channels together. This dramatically eases applications where passive crossovers are used. But the most important benefit for dual voice coils is flexibility for the T/S parameters. One can actually ?dial in? a desired Qts of the driver, by resistively loading one voice coil and actively driving the other. This configuration, which we call Resistively Damped Operation (RDO), uses the second (undriven) voice coil as an electromagnetic brake. In essence, the resistance across the second coil will determine how strong the brake is. The smaller the resistance, the stronger the brake. RDO affects the Qts of the driver by decreasing the Qms of the driver. The RDO brake acts to damp cone motion, as if the suspension was considerably stiffer. However, as it?s an electromagnetic brake, the Fs is NOT affected (as it would raise if the suspension components ? the surround and spider ? were stiffened). This allows one to literally ?dial in? in a desired Qts by varying the Qms of the driver. In fact, a 250 W 5W potentiometer can be used to tune Tempest over a large range. For example, placing Tempest in an 113 liter box, and using the RDO configuration, one can dial in a system Qtc ranging from 0.65 to 1.2. This allows tailoring the low-end response of the system to meet most musical/home theater reproduction needs. __________________ "What we do in life echoes in eternity" Ed Mullen Customer Service Director / Product Development Manager SV Sound International www.svsound.com sales@svsound.com techsupport@svsound.com LSi-7 F/X 1000 CS245i

03-05-2003, 11:36 AM	#7
BeginnersLuck Polkster Member Sales Rating: (0) Join Date: Mar 2003 Location: Sacramento, CA Posts: 213	Dr. Spec- Thanks, but that really did not answer my question. I already had that information. Last edited by BeginnersLuck; 03-05-2003 at 02:47 PM..

03-04-2003, 05:45 PM	#3
BeginnersLuck Polkster Member Sales Rating: (0) Join Date: Mar 2003 Location: Sacramento, CA Posts: 213	Yes, it is rated at both 4 and 8 ohm (540W and 320W respectively)

03-04-2003, 06:10 PM	#5
BeginnersLuck Polkster Member Sales Rating: (0) Join Date: Mar 2003 Location: Sacramento, CA Posts: 213	Thanks for the info!

03-05-2003, 01:15 PM	#8
Dr. Spec Polk Expert Member Sales Rating: (1) Join Date: Mar 2002 Location: New York Posts: 3,771	No kidding it didn't answer your question - Russ already did that above and you thanked him for it. I just thought maybe it would have been a helpful adjunct to your answer if you were considering altering the Qms of the driver for different applications and alignments.

03-05-2003, 02:50 PM	#9
BeginnersLuck Polkster Member Sales Rating: (0) Join Date: Mar 2003 Location: Sacramento, CA Posts: 213	Actually, I was looking to see if there are any advantages/disavantages to wireing the speakers as I mentioned above: VC parallel Drivers series compared to VC series Drivers parallel...would there be any different sound charateristics? Both setups offer an 8 ohm load... Thanks for any help -Gary

03-05-2003, 04:09 PM	#10
Dr. Spec Polk Expert Member Sales Rating: (1) Join Date: Mar 2002 Location: New York Posts: 3,771	Honestly, I can't answer that question. Aside from obviously having the same final impedance either way, I have no idea if the sound quality would be different. I would definitely ask Adire this question - they have a good tech department.

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