Signal Loss with long cables?

Gord · #1 04-14-2011, 01:03 AM

Hi guys - quick question here. I just bought an Orange amp. It has speakon connectors, but my cabs have 1/4" connectors. I went out looking for speakon to 1/4 cables, and I could only track down one. Problem is, it's 50 feet long! Luckily, it was offered to me for basically the price of a 10 foot cable, so I took it. I have a show in a few days, and was wondering if it's worth it to just play the show with basically 49 feet of it wrapped up, or if it's more worth it to simply cut it off and re-solder the other end. I'm not entirely comfortable with doing it myself, so I would take it to a shop, but I can't remember whether or not I read that signal quality degrades in long cables. Basically, if it will sound better, I'll get it in as soon as possible. If not, I'll sorry about it after the show.

Munjibunga · #2 04-14-2011, 01:11 AM

Don't cut it off and resolder the quarter-inch end. Cut the cable 10 feet from the quarter-inch connector, strip the wires, and re-attach the Speakon plug. It's much simpler.

bassybeenz · #3 04-14-2011, 01:13 AM

IMHO in a live situation it wont make a huge diff, at big shows people often send the D.I. signal much further than 50 ft to the front of house and its not such a big deal. still id say to get a shorter one for convenience. IIRC the signal loss issue is more a problem between the bass and amp/recording console since pickups put out such a low level signal.

play the show with the 50 footer if ya have to and cant find a shorter one is my suggestion.

Gord · #4 04-14-2011, 01:15 AM

I just watched a video - yeesh, that really DOES look much simpler.

bassybeenz - I didn't even think about that, you're right. I think with how easy it looks to get the speakon cable reconnected, I might as well just do this for sake of convenience. Thanks guys!

PhiDeck · #5 04-14-2011, 01:27 AM

Quote:

Originally Posted by bassybeenz

IMHO in a live situation it wont make a huge diff, at big shows people often send the D.I. signal much further than 50 ft to the front of house and its not such a big deal. still id say to get a shorter one for convenience. IIRC the signal loss issue is more a problem between the bass and amp/recording console since pickups put out such a low level signal.

play the show with the 50 footer if ya have to and cant find a shorter one is my suggestion.

The DI output is low voltage, low current, sent to the FoH mixer via a shielded differential pair microphone cable.
How does that pertain to the connection from amplifier to speaker cabinet?

Calaverasgrande · #6 04-14-2011, 06:49 PM

Di signal is not as impedance sensitive. Most DI ouput mic level into an impedance which can vary from 600 ohms on up to 2k ohm or better. Bass amps want to see 2-8 ohms. That is academic. A 50 foot speaker cable might just barely shave the highs a tad. But not more than would be the difference between a live room and room full of people! More salient, what size cable? 12 gauge and you are fine. If it's 18 gauge or smaller you may see some more loss.

testing1two · #7 04-14-2011, 07:03 PM

The big problem with playing a 50' speaker cord is what you do with all the slack. If you coil it neatly behind the amp you potentially create an antenna that sits adjacent to AC power cords which can introduce noise.

You won't lose any signal quality over 50' though. Most PA systems run speaker lines significantly further without audible degradation.

billfitzmaurice · #8 04-14-2011, 08:15 PM

Quote:

Originally Posted by testing1two

Most PA systems run speaker lines significantly further without audible degradation.

Signal degradation due to cable inductance and capacitance can be a problem with runs in excess of 50 feet, so pro-touring PA systems typically place the power amps as close as possible to the speakers. With bass cabs the main problem with a 50 foot cable is that you're lugging around 45 feet of cable that you don't need to.

**IvanMike** · #9 04-14-2011, 09:35 PM

Quote:

Originally Posted by billfitzmaurice

Signal degradation due to cable inductance and capacitance can be a problem with runs in excess of 50 feet, so pro-touring PA systems typically place the power amps as close as possible to the speakers. With bass cabs the main problem with a 50 foot cable is that you're lugging around 45 feet of cable that you don't need to.

I've also seen quite a bit of signal loss. One church I ran sound for a few times had some genius run a short cable to one speaker that was near the poweramp, and a huge cable to the other side. We had to turn the side with the long cable up quite a bit and it still didn't sound right. shorten and reconnect the speakon, save the extra cable and make more short ones!

Calaverasgrande · #10 04-14-2011, 11:50 PM

if it was that much difference it must have been a high gauge (thin) cable!
Though as BFM said, pro PA companies put the amps as close to the speakers as possible.
I got my first pro PA job on that concept alone. The interviewer asked me to draw a diagram of how a pa is hooked up.
I drew a picture of a FOH mixer, Snake, Amp Rack on the side stage, PA cabs, Monitor cabs. He said I was the first person that day to draw the amps in the right place!
OTOH when I was running a PA rental I would often have to run speaker cable in excess of 100ft. Its not ideal, but sometimes the perfect place for the amp rack and the perfect place for the FOH cabs is pretty far apart, Especially at hot outdoor festival type gigs. Put those amps in the shade and pray!

**IvanMike** · #11 04-15-2011, 02:18 AM

Quote:

Originally Posted by Calaverasgrande

if it was that much difference it must have been a high gauge (thin) cable!
Though as BFM said, pro PA companies put the amps as close to the speakers as possible.
I got my first pro PA job on that concept alone. The interviewer asked me to draw a diagram of how a pa is hooked up.
I drew a picture of a FOH mixer, Snake, Amp Rack on the side stage, PA cabs, Monitor cabs. He said I was the first person that day to draw the amps in the right place!
OTOH when I was running a PA rental I would often have to run speaker cable in excess of 100ft. Its not ideal, but sometimes the perfect place for the amp rack and the perfect place for the FOH cabs is pretty far apart, Especially at hot outdoor festival type gigs. Put those amps in the shade and pray!

amen - pretty much at outdoor festivals my favorite place for the poweramps is under the stage if it is a raised one, preferably on top of a few crates or other "open" type structures - often with a box fan blowing on them! Second best is somewhere near the termination of the snake on stage (which usually means near the drums and behind my amp - once again a bit raised, out of the sun if it's a covered stage, and the fan helps them and me!

ps, yes the church in question used some mighty thin cable to save money...