Speakon and Bridging

Drop-the-One · #1 06-08-2010, 07:15 PM

I was told that when I bridged my cabs it's mandatory to use speakon... howcome? Is there a difference between speakon and regular speaker cable?

thanks

quilttopjazz24 · #2 06-08-2010, 07:21 PM

In general you would bridge a power amplifier not a pair of cabinets. Please explain what you are trying to do. What make and model amplifier and speakers are you using?

Drop-the-One · #3 06-08-2010, 07:31 PM

haha sorry, I meant amp

Carvin BX1200 amp 1200w bridged
to
SWR Goliath II 4x10 500w 8ohm cab
to
Markbass 401h 4x10 800w 8ohm cab

The Carvin's fully loaded with speakon and 1/4" outs
the Markbass has speakon + 1/4" in and SWR just has 1/4" in/out

I'm just wondering why people are telling me not to use 1/4" speaker cables when bridging the amp

quilttopjazz24 · #4 06-08-2010, 07:46 PM

The speakon's current capacity is considerably higher than that of even the best 1/4" connector. That's why the speakon is recommended when you're bridging.

With the gear you have, you would likely be fine with a speakon-to-speakon cable from the Carvin to the Markbass and then a 1/4" to 1/4 from the Markbass to the SWR.

A decent 1/4" plug like the Switchcraft 187 will handle current up to 15 amps and will accommodate 14 gauge wire. Keep the 1/4" to 1/4" cable as short as possible.

Hope this helps.

P. Aaron · #5 06-08-2010, 07:47 PM

I use a Hartke LH1000 and I use the speakons in bridge mode. The cabs are 2 LDS 2 x 10's.

I am not sure if this is the only reason, but once I got a much more powerful bass amp, I wanted a more secure connection btw amp & speakers than simple 1/4 jacks. The cab maker & the Hartke manual stated emphatically to use speakons.

Drop-the-One · #6 06-08-2010, 07:57 PM

awesome... thanks so much guys

Growly Lytes · #7 06-08-2010, 08:27 PM

1/4` wont handle anything above 300-400watts of power properly. Thats the max power they can handle without adding noise where a speakon cable can handle alot more than that... up in the thousands of watts easily. Also when bridging `some amps need the speakon cable to be wired in a different way. I think its positive to positive, i dont use bridge on my amp(3400watts @ 4ohm) its too much power.
You should first find out if the speakon & 1/4 cables need to be re-wired so you can use bridge mode.
With my amp i cant just simply connect speakons cables to use bridge mode, i have to have the cables re-wired before.
Good Luck.

Rick Auricchio · #8 06-08-2010, 08:51 PM

There's an electrical reason to use a speakon.

Bridging generally "floats" the ground (negative) connection of each power amplifier in order to connect the two amps in series.

With 1/4" connectors, the ground is the sleeve of the plug, and it's also the entire shell of a metal plug. Having the plug shell floated would create a shock hazard. The contacts of a Speakon are fully insulated and you can't touch them.

BassmanPaul · #9 06-09-2010, 10:13 AM

Quote:

Originally Posted by Rick Auricchio

There's an electrical reason to use a speakon.

Bridging generally "floats" the ground (negative) connection of each power amplifier in order to connect the two amps in series.

With 1/4" connectors, the ground is the sleeve of the plug, and it's also the entire shell of a metal plug. Having the plug shell floated would create a shock hazard. The contacts of a Speakon are fully insulated and you can't touch them.

Not to mention the possibility of shorting that shell against any other grounded object and blowing one channel of your amp!

Paul

Bob Lee (QSC) · #10 06-09-2010, 10:27 AM

The difference is in the connectors, not the cable. The cabling itself needs to be adequate and insulated whether the amp is bridged or not.

In Speakon connectors, the contacts are recessed to be touchproof, and they also won't short out; that's important in bridged mono operation because both sides of the speaker cable are "hot"--that is, they carry live voltage and are not at ground/chassis potential.

mcapote · #11 06-09-2010, 11:40 AM

Quote:

Originally Posted by Bob Lee (QSC)

The difference is in the connectors, not the cable. The cabling itself needs to be adequate and insulated whether the amp is bridged or not.

In Speakon connectors, the contacts are recessed to be touchproof, and they also won't short out; that's important in bridged mono operation because both sides of the speaker cable are "hot"--that is, they carry live voltage and are not at ground/chassis potential.

so does he run a risk running 1/4" from cab to cab since one of his cabs isnt speakon compatible?

I actually run my amp speakon to 1 of my fearfuls then I 1/4" to the other cab from the 1st one(just got lazy and never made the 2nd speakon from the role of wire I have sitting here), im not bridging but now that has me thinking for the future if I decide to bridge my channels.

BassmanPaul · #12 06-09-2010, 12:04 PM

Retrofit the cabinets with speakons. A simple procedure to do.

Paul

Rick Auricchio · #13 06-09-2010, 12:05 PM

Quote:

Originally Posted by mcapote

so does he run a risk running 1/4" from cab to cab since one of his cabs isnt speakon compatible?

Yes, if the plugs have metal shells. If they have plastic shells, then the chance of a short or touching the hot sleeve/shell is minimal.

Depending on the jacks used, however, the entire metal jackplate might come in contact with the sleeve contact. So there would be "hot" metal in easy reach. This is a case where a plastic jackplate and/or plastic jacks are good.