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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => SR Forum Archives => LAB Subwoofer FUD Forum Archive => Topic started by: Rick Jones on February 26, 2007, 06:57:13 pm

Title: MTL2 Wiring
Post by: Rick Jones on February 26, 2007, 06:57:13 pm
Hey guys,

How are the speakers in an MTL2 wired? Do both speakers move in to the cabinet at the same time or does one move out while the other moves in? I'm trying to figure out how the polarity of the speakers is wired. Sorry for the dumb question. <G>


Rick Jones

Title: Re: MTL2 Wiring
Post by: Phil LaDue on February 26, 2007, 08:02:34 pm
Rick Jones wrote on Mon, 26 February 2007 18:57

How are the speakers in an MTL2 wired? Do both speakers move in to the cabinet at the same time or does one move out while the other moves in? I'm trying to figure out how the polarity of the speakers is wired. Sorry for the dumb question.


The EDS is available here:
http://archives.telex.com/archives/EV/Speakers/EDS/

Title: Re: MTL2 Wiring
Post by: Mike Butler (media) on February 27, 2007, 11:20:22 am
The spec sheet says it is two separate 8-ohm loads (using all 4 pins of a Speakon). Since it doesn't say anything about needing to wire one in reverse polarity to the other, I would go with the default mode (but you can try experimentally flipping one to see what happens--probably a good amount of cancellation).
Title: Re: MTL2 Wiring
Post by: Mac Kerr on February 27, 2007, 12:03:51 pm
Since it is 2 identically mounted drivers, they need to operate identically. A positive voltage on the +pin of each pair in the NL4 should make the speaker cone move out from the box.

Mac
Title: Re: MTL2 Wiring
Post by: sheldon harris on March 03, 2007, 11:10:39 am
use speakon 4 pin connectors.

connect pin 1 positive to the top woofer negative and pin 1 negative to the top speaker positive.

then, follow that same order for woofer two and pins 1 and 2.

to make sure that you have done it correctly, do a phase check with a 9 volt battery.  positive end of battery on on any one of the positive pins will result in the woofer travelling toward the magnet or negative pressure. which for the mtl2 is really positive since the drivers are reversed.

same rule applies to deltamax,mtl4 and other ev manifold type boxes.       i met a few that was reversed from the speakon connector, so that is also an option, in case someone other that yourself is servicing the boxes. (people tend to do the old red in positive/negative in black number when servicing boxes without actually checking the phase sometimes)

good luck

sheldon
Title: Re: MTL2 Wiring
Post by: Hal Mahan on March 06, 2007, 03:42:45 pm
I must respectfully disagree, both pin 1 & 2 positives go to the positives on the woofers, at least on the ones I have.

http://archives.telex.com/archives/EV/Speakers/EDS/MTL-2B%20 EDS.pdf

Hal
Title: Re: MTL2 Wiring
Post by: Phil LaDue on March 06, 2007, 06:01:08 pm
Hal Mahan wrote on Tue, 06 March 2007 15:42

I must respectfully disagree, both pin 1 & 2 positives go to the positives on the woofers, at least on the ones I have.

  http://archives.telex.com/archives/EV/Speakers/EDS/MTL-2B%20 EDS.pdf

Hal


There are eight models with the MTL prefix.

Edit: actually eight models
Title: Re: MTL2 Wiring
Post by: Hal Mahan on March 06, 2007, 06:36:26 pm
I will repectfully disagree with you, as well. There are 8 models with the MTL prefix, 4 of which refer to the MTL2, & all show pin 1 & 2 positive to positive on the woofer.

I gotta wonder what the MTL2BT sounded like, never had the chance to experience one for myself,,,,,

Hal
Title: Re: MTL2 Wiring
Post by: sheldon harris on March 12, 2007, 10:14:31 pm
Hal Mahan wrote on Tue, 06 March 2007 19:36

I will repectfully disagree with you, as well. There are 8 models with the MTL prefix, 4 of which refer to the MTL2, & all show pin 1 & 2 positive to positive on the woofer.

I gotta wonder what the MTL2BT sounded like, never had the chance to experience one for myself,,,,,

Hal


hello Hal,
i am going to respectfully challenge you.
if you notice i posted after the pdf was given by Phil.

information that i could have directed him to also.

obviously, i still answered for a very valid reason:one that has caught many sound-guys. being, the correct wiring for these boxes. (some of yorkville systems has the same issues as well you have to use the entire system and the procesor or its going to be out of phase)

the wiring is correct on the pdf file,but only for the "MT SYSTEM"
if the gentleman is using MTL2s along with other subs,top boxes and processor other than what comprise the "MT SYSTEM" it would be incorrect to wire the boxes how the factory indicated on the pdf file

i have to admit, that i was a little presumptuous when i gave my answer to the "MTL mystery wiring."

no one ever uses the entire mtl system, subs,top cabs and processors.
i should have asked him a few questions first. i assumned he did not have the entire system and had MTL2 boxes that he wanted to use with other tops and processor.(like most people are doing recently)

i gave him the wiring that would make his subs compatible with all other cabinets, positive voltage applied to positive speaker terminal results in speaker moving out or away from the box:

as quoted by mac "Since it is 2 identically mounted drivers, they need to operate identically. A positive voltage on the +pin of each pair in the NL4 should make the speaker cone move out from the box.
Mac

the only problem with that, the MTL has the drivers reverse-mounted in a bandpass manifold, so the woofers move into the box.in other words the phase will be reversed.


in order for his boxes to be compatible with the existing convention of wiring for sub-woofers in terms of phase,he would have to wire his boxes exactly like i said. if he wants them to be compatible to the "MT SYSTEM" or other existing MTL boxes used with the MTH tops and processor, then he would wire it exactly like the pdf file says.

you mention the MTL2BT, they sound similar to the MTL2B but better than the MTL2A.

to shed some light on all what i just said about the wiring, i am going to use the speaker you mentioned as an example: find the pdf file and check the wiring:
its going to be exactly opposite to what the MTL2A/B is! which is essential how i told the gentleman to wire his boxes.


the reason why its opposite, because EV had to bring it back in phase with the other "MT LINE", which have their magnets out. this MTL2BT as you will see from the pdf file has its magnet in the box like a conventionally mounted speaker. thats why its wired the way it is "OUT of phase".("IN" if referenced to other "MT SYSTEMS"

i hope this explanation shed some light on the misconception of wiring an ELECTROVOICE MT SYSTEM SUBWOOFER.

if I'm wrong, then i have been wrong for years and only doing what worked for me, sounded good to me and got the job done.
sheldon.

"i am hoping that we we all strive to give credible information around here: i would never knowingly tell someone to:"wire a jbl driver black as negative knowing that the positive voltage on the black produces a positive pressure. i would have to give all the facts. sometimes its not all about knowing, but knowing the reason why"

sheldon.
Title: Re: MTL2 Wiring
Post by: Al Limberg on March 13, 2007, 10:00:56 am
Hi Sheldon -  I'm not here to argue your MT wiring points - never used them, don't expect I ever will. However,  I had to respond to your JBL/black positive comment. While it holds true for older models (2226, etc.) their newer designs do follow the AES standard of "positive to red causes forward cone motion".  Rather than change the wiring on older models, only those models 'created' after the cutoff date meet the standard. I guess they figured it was better than having to look for a particular serial number or production date to see how a driver was wired.  The newer models have a tag affixed under the terminals pointing out the wiring protocol.

?;o)
Al
Title: Re: MTL2 Wiring
Post by: Hal Mahan on March 13, 2007, 03:46:50 pm
Sheldon, I can now understand your earlier post, you make a point of which I did not see where you were coming from. I have 4 stacks of MT2`s which get used on a regular basis, & are processed with either an EV DX34a or KT DN800 with the MT2 cards installed (I think the KT sounds better,,,), and will admit to not using just the MTL2`s without either processor, usually from an aux. Interesting, I may have to try it your way to see what happens. I just may have learned something today!!

May I retract my disagreement (respectfully, of course)??

Hal
Title: Re: MTL2 Wiring
Post by: sheldon harris on March 13, 2007, 05:03:17 pm
Al Limberg wrote on Tue, 13 March 2007 10:00

Hi Sheldon -  I'm not here to argue your MT wiring points - never used them, don't expect I ever will. However,  I had to respond to your JBL/black positive comment. While it holds true for older models (2226, etc.) their newer designs do follow the AES standard of "positive to red causes forward cone motion".  Rather than change the wiring on older models, only those models 'created' after the cutoff date meet the standard. I guess they figured it was better than having to look for a particular serial number or production date to see how a driver was wired.  The newer models have a tag affixed under the terminals pointing out the wiring protocol.

?;o)
Al


al,
very well said.
i am aware of a change with the jbl drivers,i did not know it was all of them from a specific point in time.(are you sure the change was made on newer compression drivers like the 2450/51?.
if thats the case, i know someone who has some work coming,he has to change all his wiring(2450s)!
but, on a side note,experienced has taught me to phase check all drivers. i have seen brand new factory boxes with wiring issues(i would not say which ones, it might start a riot here:lol: )even mid level consoles i bought came with banks of 8 channels not working because someone forgot to plug the interface clips in!

feels good when we can sit down like gentlemen and "discuss" and share resources Smile

sheldon.
Title: Re: MTL2 Wiring
Post by: Al Limberg on March 13, 2007, 05:27:29 pm
Hi Sheldon,
JBL has published a tech note covering the subject (link included hopefully) and both the compression drivers you mention evidently predate the change and are thus black/forward. Perhaps I didn't state the change properly.  As a for instance, let's pick the 2226 cone driver.  At the time the model was introduced, black/positive was the JBL method and thusly the 2226 will remain until it is no longer produced.  On the other hand, the 2035HPL 15" driver was introduced after the change  so it is made with red/positive.  It appears as though the wiring of complete speaker cabinets using red and black connectors like studio monitors and theatre cabinets follow the same rules (in fact a wiser man might go double check the cabling on his 4410a monitors hooked up to his stereo at the moment! (oops!))



ttp://www.jblpro.com/tech-library/JBL_TechNoteN1V12C_v5.pdf

?;o)
Al

edited to prevent Andy from having a grammar stroke

Title: Re: MTL2 Wiring
Post by: Jeff Hatzer on April 25, 2007, 10:15:24 pm
sheldon harris wrote on Mon, 12 March 2007 21:14

Hal Mahan wrote on Tue, 06 March 2007 19:36

I will repectfully disagree with you, as well. There are 8 models with the MTL prefix, 4 of which refer to the MTL2, & all show pin 1 & 2 positive to positive on the woofer.

I gotta wonder what the MTL2BT sounded like, never had the chance to experience one for myself,,,,,

Hal


hello Hal,
i am going to respectfully challenge you.
if you notice i posted after the pdf was given by Phil.

information that i could have directed him to also.

obviously, i still answered for a very valid reason:one that has caught many sound-guys. being, the correct wiring for these boxes. (some of yorkville systems has the same issues as well you have to use the entire system and the procesor or its going to be out of phase)

the wiring is correct on the pdf file,but only for the "MT SYSTEM"
if the gentleman is using MTL2s along with other subs,top boxes and processor other than what comprise the "MT SYSTEM" it would be incorrect to wire the boxes how the factory indicated on the pdf file

i have to admit, that i was a little presumptuous when i gave my answer to the "MTL mystery wiring."

no one ever uses the entire mtl system, subs,top cabs and processors.
i should have asked him a few questions first. i assumned he did not have the entire system and had MTL2 boxes that he wanted to use with other tops and processor.(like most people are doing recently)

i gave him the wiring that would make his subs compatible with all other cabinets, positive voltage applied to positive speaker terminal results in speaker moving out or away from the box:

as quoted by mac "Since it is 2 identically mounted drivers, they need to operate identically. A positive voltage on the +pin of each pair in the NL4 should make the speaker cone move out from the box.
Mac

the only problem with that, the MTL has the drivers reverse-mounted in a bandpass manifold, so the woofers move into the box.in other words the phase will be reversed.


in order for his boxes to be compatible with the existing convention of wiring for sub-woofers in terms of phase,he would have to wire his boxes exactly like i said. if he wants them to be compatible to the "MT SYSTEM" or other existing MTL boxes used with the MTH tops and processor, then he would wire it exactly like the pdf file says.

you mention the MTL2BT, they sound similar to the MTL2B but better than the MTL2A.

to shed some light on all what i just said about the wiring, i am going to use the speaker you mentioned as an example: find the pdf file and check the wiring:
its going to be exactly opposite to what the MTL2A/B is! which is essential how i told the gentleman to wire his boxes.


the reason why its opposite, because EV had to bring it back in phase with the other "MT LINE", which have their magnets out. this MTL2BT as you will see from the pdf file has its magnet in the box like a conventionally mounted speaker. thats why its wired the way it is "OUT of phase".("IN" if referenced to other "MT SYSTEMS"

i hope this explanation shed some light on the misconception of wiring an ELECTROVOICE MT SYSTEM SUBWOOFER.

if I'm wrong, then i have been wrong for years and only doing what worked for me, sounded good to me and got the job done.
sheldon.

"i am hoping that we we all strive to give credible information around here: i would never knowingly tell someone to:"wire a jbl driver black as negative knowing that the positive voltage on the black produces a positive pressure. i would have to give all the facts. sometimes its not all about knowing, but knowing the reason why"

sheldon.



Sheldon, thanks for the great information in your post. I run MTL-2's but do not run the Dx34 controller. However, I use an XEQ-3 with, what I'm told, is a "MTL pip module". There is also a phase reverse on each channel.

Would you (or anyone) know off hand what this "pip" does on my XEQ? ie. a phase reverse? eq? Would hitting the phase reverse button be the same thing?
I did a quick search and found nothing. The unit was bought used and I have no docs.

These boxes are wired normally, so I'm pretty interested to find out if I have been taking a performance hit.

thanks.

Title: Re: MTL2 Wiring
Post by: Rudi Gerets on May 31, 2007, 02:06:50 am
Hi All,

We also have some MTL-2 cabinets, wired normally pin1+ to speaker 1+ and pin1- to speaker 1-.
We never use the MTL cabinets with the MTH, but always with Zeck Arena or Zeck 21522 cabinets, all controlled by a Driverack PA or 260 and Crest 8001/7001 amplifiers.
So as i read above, we must change the wiring of the MTL cabinets ?

Sorry for my (bad) English, I'm from Belgium.

GreetZ
Rudi
Title: Re: MTL2 Wiring
Post by: Craig Leerman on May 31, 2007, 03:07:06 pm
Real first and last names are required to participate here.

Please go to your profile and change your alias to include your last name as required by the posting rules clearly displayed at the top of the page.

Craig Leerman
Forum Moderator
Title: Name policy
Post by: Mac Kerr on May 31, 2007, 07:09:10 pm
Rudi, please go to your profile and change your alias to your real full name as required by the posting rules clearly displayed at the top of the page.

Mac
moderator
Title: Re: Name policy
Post by: Rudi Gerets on June 01, 2007, 01:53:46 am
Sorry, about that.
I've changed it.
Title: Re: MTL2 Wiring
Post by: CHRISTOPHER W. LAWLER on November 10, 2010, 12:09:41 am
I own a pair of EV MTL-2B subwoofers, and although the original specifications do call for each woofer to be wired to each corresponding set of pins on the NL-4 speakon connector, I have wired mine as follows & with successful desired results. I'm also sure that you can do the same to satisfy your own customized wiring/cabling schematic...

PINS 1 {+/-} HIGH-PASS-THROUGH

PINS 2 {+/-} L.F. {Both woofers wired in parallel}

Both woofers are connected in parallel & in phase.

My top boxes (EV TX-1152) which are factory configured using pins 1 as pins 2 are pass through, so my wiring configuration makes perfect sense in using the single NL-4 speakon for connecting both systems in a bi-amplified application.

Operation of woofers out of phase or synchronization will end up with phase cancellations & undesirable or unwanted distortion & possible woofer damage or amplifier clipping... (In an attempt to achieve desired acoustical output.)
Title: Re: MTL2 Wiring
Post by: Jason Phair on November 13, 2010, 04:14:03 pm
The regular ole rectangular MTL2's want to be wired with positives to positive.

The trap MTL2's are wired in reverse polarity, as their cones are firing in, and not out.