[john garnet]

Hi,
I've almost completed building the cabinet for my dual sub. I've got two SW-12-08 drivers and a Rythmik A370XLR servo amp. I've had the amp since last year and it doesn't have the special wiring harness to simplify connections so I need help so that my wiring is correct.

The amp has a pair of thick wires which I think go to the gold driver coil and a pair of thin wires that I think go to the silver servo coil so that's four wires that go to eight terminals on two woofers. Can someone guide me from here so that I get this right? Thanks in advance!

[Danny Richie]

No worries.

The thick wires go to the driver coils (Gold coated binding posts), and you parallel them on there. So the Red wire goes to both positives and the Black wire goes to both negatives.

The thinner wires are for the sensing coil (silver coated binding posts). These must be wires in series. So Red wire to the positive on one woofer and the Black wire to the negative on the other woofer. Then run a jumper from the negative of the first woofer to the positive of the second one.

[john garnet]

Thanks Danny!

In running the thick wires in parallel to the gold driver coils, does that mean that you create a T junction before the drivers and then run an individual wire to each terminal or you run the single wire to the terminal of one woofer and then another length of wire from that terminal to the corresponding terminal of the other woofer? Is the end result the same or does it have to be one method or the other?

Also, in running the jumper from one woofer to the other, I'll need to drill a hole in the centre dividing panel between both woofer enclosures. Does this hole need to be sealed to maintain air tightness between enclosures or is complete air tightness between enclosures not critical? This would also apply to the amp if l mount it in the centre of the back panel because the hole would be half and half over each woofer enclosure. Or better to place the amp over one enclosure only? Thanks in advance!

[Danny Richie]

I run the Red and Black wiring to the first woofer and then run a pair of jumpers from there to the next one.

These woofers are going to be seen by the servo control system as one woofer. So the air space between then does not have to be completely sealed.

[Dynky]

Sorry to kick this old topic up again, but it was the only one I could find on the exact issue I'm having at the moment.

Only difference is that I have the two SW-12-08's in a W frame, with one driver facing me and the other one firing backwards, so the wires from one are inverted on the driver coils, that part I get...but what about the servo coils?
Do I need to invert that second servo coil as well, or simply follow the connection as explained in your first reply?

[HAL]

Since one driver is reversed in direction, both the signal and servo wiring need to be reversed as well to the reversed driver.

Driver wiring in parallel to amp output + and -
Front   + -   
Rear    - +

Servo wiring in series to servo input + and -
Front to rear  + - - + (The plus wires both go to the servo input amp wires)

Hope this helps.

[Dynky]

I couldn't have explained it any better myself 

Perfectly clear now on how to wire up things with that explanation and I'll certainly give it a try tomorrow.

Thanks!

[SteveKi]

John,
I bumped my thread. Jay supplied a picture of the wiring.
Steve


http://www.audiocircle.com/index.php?topic=137720.0

[Dynky]

great, now I can hook everything up just by looking at pics 

[Hank]

SteveKi:  since this question will likely continue to come up, I suggest your linked thread become a 'sticky' and re-titled something like:  "Wiring servo amp and a pair of drivers plus servo amp details".

Admins:  Okay?

[ebag4]

Danny,
Sorry for digging up an old thread.  I just built a pair of Wedge shaped servo sub unit with the 12's but I am having a little issue with the sound as compared to my V1 bass section.  When looking around for the wiring again I found the pic below.  Trying to determine what may be the issue I was looking again and came across two different descritpions for the servo wiring (from different threads).  While both the text and drawing could be considered series wiring the polarities differ (note the positive to positive in the pic).  Does this make any difference?  I "believe"my V1s are wired as noted in your text however I wired the Wedges as indicated in the drawing.  Before I pull all of this out and rewire I thought I would ask if you know whether polarity makes a difference on the servo.

It could be that the "H" frame simply works better in my space.

Thanks,
Ed

No worries.

The thick wires go to the driver coils (Gold coated binding posts), and you parallel them on there. So the Red wire goes to both positives and the Black wire goes to both negatives.

The thinner wires are for the sensing coil (silver coated binding posts). These must be wires in series. So Red wire to the positive on one woofer and the Black wire to the negative on the other woofer. Then run a jumper from the negative of the first woofer to the positive of the second one.

[Danny Richie]

Ed, With the wedge design all wiring is positive with no reverse polarity on anything.

[ebag4]

Ed, With the wedge design all wiring is positive with no reverse polarity on anything.

Danny, I understand that is true on the power coil.  My question is specifically around the servo coil.

Thanks,
Ed

[Captainhemo]

Danny, I understand that is true on the power coil.  My question is specifically around the servo coil.

Thanks,
Ed

In the Wedge cabnet, both are in phase Ed, servo coil and driver coil

jay

[ebag4]

OK Guys, I swapped the SERVO wiring from the way shown on the drawing in the post above to series (negative from amp to negative to first servo, positive from amp to positive of second servo, then jumper between the positive of the first servo to negative of the second servo), huge difference.  After reading Jay's post I rechecked my "H" frames and I do have them wired as shown on the drawing, and they work great.  I didn't realize that the servo coil wiring changed with the power coil wiring when the drivers were in phase. 

This is a bit of a relief, I thought I was going to have to give up on the wedge bass and build another "H" frame.

Best,
Ed

[Danny Richie]

Looks like you found your answer before I could respond. I'm glad to know all is good again.

[ebag4]

Looks like you found your answer before I could respond. I'm glad to know all is good again.

Thanks Danny, yes, much better now.  I was seeing the drivers from the side and couldn't believe how much they were moving, even though I have only seen the drivers from the front in the "H" frames it still didn't seem right.  And then there was the loose bass, I couldn't live with that.  Now to start working with the amp settings, although the "H" frame settings work much better with the servos wired properly!

Best,
Ed

Edit: SO much better .  It is odd how something specific like the bass section can throw everything across the spectrum out of whack