Cat 5 Monitors


Anyone have any good/bad, or any experience at all with monitors using cat 5 cable? Stories,comments, recomendations???
Mike M
Never used them, but my first thought would be only to use them at indoor, "easy gig" venues. cat5 cables are really really fragile, if they get run over with a roadcase they're ruined. I'll just stick to my NL4 thanks.
why would you use cat5 cable?
just cos its convenient
or do you have your speakers 'networked' somehow?

that would be quite neat for a permanent installation, if you could somehow send an digital audio signal through a network - say from a pc or mac to a receiver and a set of speakers somewhere else on the network. Much like lighting.
though dont know how much inteference would be an issue - as cat5 aint shielded.

Its great for getting nice monitor mixes that the performers will enjoy, but you still have master control over the unit. Its uses a cat5 interface with analog outputs and inputs. You can buy (or even make) durable Cat5 for much cheaper than the price of an XLR or 1/4" cable. Whats nice about this is many venues (esepecially schools) have cat5 in the wings for computers to connect up to the facility's network. Like for example, in this years musical the directors had a computer connected up to powered and it played all the music for the earlier rehersals. The directors actually would drop the orchestra pitt just low enough to see the stage clearly and controled the music and did their work there. So think about how nice this system would be, you could actually connect the monitors cat5 sends through the cat5 at foh/booth and connect it up at the wings. Thats not patching, the units will find each other see it's IP based I believe. Actually once heard a story about a school running there hazers through there IT department's CAT5 system. It worked fantastic I heard.
Thanks for your input guys even though it sort of got off subject.
Speaking of networking, cat 5 and audio, check out the new Crown I-Tech AMP. I have read about it and I know about it, I was just wondering if anyone has used it, I haven't seen it in real life.
I heard a story about someone wanting to get one, but why would you get one if you are only using one amp????????????
A problem with any kind of digitized audio is latency - the time required to digitize a sample of a waveform, put it in an IP frame, encapsulate the IP frame in an ethernet packet, transmit it, receive it, extract the frame from the packet and the data from the frame, converti it back to analog and get it to the speakers causes a delay. In some cases it's only enough to cause a phase shift and comb-filtering, in others it can be bad enough to be audible as a discrete echo, depending on whether there's other traffic on the network. Digital is good for recording and playback, or broadcast operations where there's no chance of the listener simultaneously hearing the original and reproduced signal. It's terrible for sound reinforcement... and especially for monitors.

I'm with John here. If you're going to go IP based, please don't use the existing switching infrastructure. Get your own switch. Us IT folks like to do heavy maintenance tasks after hours when a concert might be going on. Such things sometimes hog up a lot of bandwidth and will make your hazer control signal potentially latent and groups for packet drops.

Likewise, don't use up all the bandwidth for your concert - you need your own VLAN for that at a minimum
Actually, many theaters actually have direct stage/foh cat5 lines. Sometimes its not even IP based, many of these systems just use cat5 wires because cat5 is just so inexpensive to use. But yes, I completely agree with you Dave. I would never run any cat5 apps without getting them approved/notified by the IT people. But the non-packet transmission ethernet apps do not show any lag. For example, say you need to adapt RS485 to RS232 but you need a long run at RS485 XLR isn't an option. A crossover cat5 cable crimped with the RS485 pins matched up. Although that was slightly off topic since we're discussing audio over IP Cat5, for most apps I've seen non-ip cat5 apps do not show any significant or prominent lag. I have seen monitoring systems that are not using packet transmission (IP), it was basically the same thing as using XLR or TRS.
bdesmond said:
Cable itself isn't the problem. It's the IP backbone that might not be as accomodating.
Even if it's not IP, if it's digitizing signals, serializing them, transmitting them, receiving them, deserializing them and converting them back to analog on a dedicated circuit it's still too much delay.

If it's not digital, but just speaker-level signals using Cat-5 cable, there's other problems. The actual wire inside Cat-5 cable is #24 AWG... pretty skinny for any kind of power. Copper is a good conductor, but it's not perfect - it has resistance. In the case of 24AWG it's about .026 ohms per foot. How many feet between the amplifier and the speaker? Lets assume 50 feet of wire. But you've got to get there and back, so it's actually 100 feet of wire (2.62 ohms) in series with the speaker. Assume a 4-ohm speaker. The amplifier is rated to provide 300 watts into a 4-ohm load, but it's actually seeing a 6.62-ohm load, so it falls back to about 220 watts. Of that 220 watts, 87 is wasted in the resistance of the wire. Your "300 watt" amplifier is maxed out at 220 watts, but only 133 watts are getting to the speaker.

Calculations like that are why my power amps sit directly behind the stacks of main speakers, a separate rack of amplifiers on each side of the stage. Speaker cables are no longer than necessary (4' for 18" each sub, 6' for each 12" mid-bass and each horn) and are all #12 AWG. For monitors the cables are a bit longer - 25' - but they're still #12 AWG and a separate cable runs from the amplifier to each speaker - I don't "daisy-chain" speakers. If anyone wants to do the math, #12 AWG copper wire is .00162 ohms per foot.

Oh I would never use cat5 as a loudspeaker jack, its only meant for a data jack. Cat5 doesn't have the insulation or infastructure to accomadate an amplified signal like that. You don't have to necessary digitize things to use cat5, you can easily just take advantage of it's inexpensive costs and long range. I meant as in matching up the pins, you do not need to process or serialize anything in order to use cat5 is an alternative cable. Not all cat5 apps are using packet/ip transmission. They can be used as an alternative to XLR (not for mics), DMX, and a wide variety of data transmissions.

BTW, I found an artical on the Aviom system being used professionally. Look at all the benefits, this could really save you in situations when IEM mixes are needed and there is no time to personalize each mix.
hey, I'm not expert, but at my church they JUST (one month ago) got a cat5, digital mointor system. Made by HEAR or something like that (I don't run sound for the sanctuary, I run it for the youth gruop...) It uses one main single rack space thingy, that has the inputs (8) and all that, like amini snake. From there, it has cat5 outputs (not sure how many...) and it sends the signals (digital I'm sure) to mini mixer things, where they can mix those 8 signals, and then it has a few headphone out puts. (it doesn't power speakers, just headpones) and it's a neat system...cost atleast $2k I hear....(I was setting up lighting next door, and popped in a couple times to see what they were doing...I've never used the sustem or anything, but it looked VERY neat and nice!)

Users who are viewing this thread