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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 => LAB Lounge => Topic started by: Sameer Muzamil on July 23, 2014, 11:27:32 AM

Title: faulty 1/4" cable
Post by: Sameer Muzamil on July 23, 2014, 11:27:32 AM
Hi

Yesterday, I found out that whenever I connect this particular 1/4" cable to the mixer makes the speakers produce buzzing noise. I am not using this cable to connect the speakers to the mixing board. Just connecting one side to the input of the mixer itself is enough. Rest of the 1/4" cables I have doesnt give me this problem.

What could be the reason for this? I opened up the both ends of the cable and its seems to be fine. No lose connection or anything. These cables are quite expensive. is this a fixable problem?

Thanks.

sameer
Title: Re: faulty 1/4" cable
Post by: Craig Leerman on July 23, 2014, 01:19:40 PM

Sameer

Please go to your profile and change the "Name" field to your real first and last name as required by the posting rules displayed in the header at the top of the section, and in the Site Rules and Suggestions (http://forums.prosoundweb.com/index.php/board,36.0.html) in the Forum Announcements section, and on the registration page when you registered.

Thanks
Craig



Title: Re: faulty 1/4" cable
Post by: Mark Cadwallader on July 23, 2014, 11:32:04 PM
Sameer, at the risk of suggesting the obvious first, did you confirm that you have a TRS (tip, ring, sleeve) connector on both ends of the cable in question?  I have grabbed a TS cable when I needed a TRS cable, or the other way around.  (I personally try to avoid 1/4" cables for that reason.). Likewise, I have seen somebody trying to figure out what is wrong with the signal, when using a heavy guage 1/4" TS speaker cable instead of a light guage 1/4" TS instrument cable on a guitar.  Mark C.
Title: Re: faulty 1/4" cable
Post by: Scott Holtzman on July 23, 2014, 11:40:36 PM
Sameer, at the risk of suggesting the obvious first, did you confirm that you have a TRS (tip, ring, sleeve) connector on both ends of the cable in question?  I have grabbed a TS cable when I needed a TRS cable, or the other way around.  (I personally try to avoid 1/4" cables for that reason.). Likewise, I have seen somebody trying to figure out what is wrong with the signal, when using a heavy guage 1/4" TS speaker cable instead of a light guage 1/4" TS instrument cable on a guitar.  Mark C.

Do you have a cable tester or an ohm meter?  If ohm meter check t-t r-r t-r (should read open at both ends)

Title: Re: faulty 1/4" cable
Post by: Doug Johnson on July 24, 2014, 08:56:14 AM
If the cable is a T/S cable, check to make sure the cable is a shielded (instrument) not an unshielded speaker cable.
Title: Re: faulty 1/4" cable
Post by: Sameer Muzamil on July 24, 2014, 09:58:59 AM
Hi

it is T/S cable thats connecting my speaker and the mixer. Do you think i should go and buy some TRS?

Thanks
Title: Re: faulty 1/4" cable
Post by: Jeff Carter on July 24, 2014, 10:22:55 AM
Hi

it is T/S cable thats connecting my speaker and the mixer. Do you think i should go and buy some TRS?

Thanks

That depends.

I'm assuming from your description that there's no separate amplifier and we are dealing with either a powered mixer (amplifier inside the mixer) or powered speakers (amplifier inside the speaker cabinet).

If it's a powered mixer, you need a TS speaker cable (heavy, unshielded conductors that as Mark C has already mentioned, will absolutely cause you noise problems if you try to use them as instrument cables...)

If it's a powered speaker, *and* the mixer output and speaker input are both balanced (check the manuals) then a TRS cable is what you should have ideally but for a short run it's entirely possible a TS cable would be fine. For this configuration you would want a shielded cable (instrument cable, not speaker cable).

Incidentally, this is why I don't like 1/4" TS speaker cables... they can look almost exactly like 1/4" instrument cables  but are definitely not interchangeable.
Title: Re: faulty 1/4" cable
Post by: duane massey on July 25, 2014, 01:45:04 AM
More info needed. Brand name, model #'s of the gear for starters........
Title: Re: faulty 1/4" cable
Post by: Mark McFarlane on July 26, 2014, 07:05:25 PM
Hi

Yesterday, I found out that whenever I connect this particular 1/4" cable to the mixer makes the speakers produce buzzing noise. I am not using this cable to connect the speakers to the mixing board. Just connecting one side to the input of the mixer itself is enough.

Quote
it is T/S cable thats connecting my speaker and the mixer. [/size]



It seems like you are contradicting yourself. 


Shielded TS cables are typically used to connect something like a guitar to the input of a mixer.  These have very light-gauge wires (skinny copper).  The shielded help prevent noise from entering this low-voltage signal/wire.


Unshielded TS cables with thick copper wires are used to carry the high voltages between the amp and the speakers.


It is not unusual for an unshielded cable connected to an input off a mixer to pick up noise.


Exactly where are you putting the cable?
Is the mixer self powered (i.e. there is an internal amp that directly drives the speakers)?
Is the TS cable shielded or not shielded?  What is the manufacturer and model # of the cable?