Elk keypad wiring question

[apostolakisl]

In these large commercial settings, wouldn't 70V speakers be used anyways? Unless you're talking concert halls; but 70V is the preferred method for most larger commercial installs. That has to change things.

Something isn't adding up... Maybe I'll disconnect my speakers and crank my amp and leave it all day (I already ordered a replacement) - I doubt any harm will come.

70v is great for commercial installs because of the length of wiring. Higher voltage is used to generate power instead of higher amperage. So lower amperage means smaller gauge wires which means a lot less money. If you needed to run several hundred feet of speaker wire around a building it becomes impossible to use standard audio equipment becuase the wire gauge would be astronomical. Bascially all PA systems run on 70v. I am sure someone out there knows more about the fidelity aspects of this, but you don't get the hifi sound out of 70v systems. I am not sure why.

 

[Spanky]

The reason Elk does not recommend using the 4 pin slide on J connectors on the M1 board is strickly for realibility. I have used them for years with no problems, but keep in mind that the wire is not crimped down the same as under the terminal strips. Short runs in the control box work good with the 4 pin J cables. If you are making connections inside the control box, you can ignore the RS-485 wiring rules and star out the connections.

 

[Del91574]

In these large commercial settings, wouldn't 70V speakers be used anyways? Unless you're talking concert halls; but 70V is the preferred method for most larger commercial installs. That has to change things.
Something isn't adding up... Maybe I'll disconnect my speakers and crank my amp and leave it all day (I already ordered a replacement) - I doubt any harm will come.

When you're dealing with existing infrastructure and modifications to the infrastructure, you're left with what's existing to make work and keep up and running until the site is ready for a complete cut-over. The case I was referring to would be a large hospital and medical campus that has multiple buildings and offsite properties that are connected only via steam tunnels or skywalks. Factor in multiple panels and many different manufacturers that were installed over the years, it is what it is. In the case of sites like this and fire systems/mass notification, downtime is not an option, otherwise the site needs to be placed on fire watch, which adds up quickly in man-hours.

Would I like for these to be 70V or even 25/50 to cut down on AWG as well as address a lot of concerns, sure, but in the case of a legacy system like what I'm dealing with, it's not an option unless the site/floor/area can be brought down and then back up the same day with 0 to minimal downtime during the transition. We're dealing with the cards we're left with.

Running an amp with 0 load is different than running with too high a load, which is what was alluded to, connecting a bunch of speakers in series in error vs. properly impedance loading an amp or audio output section. Too high a load, you're likely to blow out the output transistors. If you're lucky, you won't damage the amp or those transistors, or better, the amp has a protection circuit. Lots of amps do have protection circuits, many don't.

I'm only speaking from what I've dealt with in real world experience and not armchair quarterbacking. I'm looking at a nice rack of 5 masters and 5 backup amps that were blown up by too high an impedance load being attempted to be driven by a digital voice system going to an analog output board feeding them. Luckily in my case, the entire site's amps didn't give up the ghost.

 

[Del91574]

70v is great for commercial installs because of the length of wiring. Higher voltage is used to generate power instead of higher amperage. So lower amperage means smaller gauge wires which means a lot less money. If you needed to run several hundred feet of speaker wire around a building it becomes impossible to use standard audio equipment becuase the wire gauge would be astronomical. Bascially all PA systems run on 70v. I am sure someone out there knows more about the fidelity aspects of this, but you don't get the hifi sound out of 70v systems. I am not sure why.

I deal with these daily, and the wire AWG is typically very large for a normal install, with #14 to #10 being run for these sorts of systems. While it's true that it does allow a somewhat smaller conductor be run, the main reason why it's used is to simplify the impedance loading on an amp and allow the adjustment of sound level at the speaker by using different taps. In actuality, it's installation more resembles how mains electricity gets run from a power plant to your neighborhood then to your house.

You can get fidelity out of these sorts of systems, but the hardware becomes more expensive at that point to where other means are more cost effective or at the same price point.

 

[apostolakisl]

I deal with these daily, and the wire AWG is typically very large for a normal install, with #14 to #10 being run for these sorts of systems. While it's true that it does allow a somewhat smaller conductor be run, the main reason why it's used is to simplify the impedance loading on an amp and allow the adjustment of sound level at the speaker by using different taps. In actuality, it's installation more resembles how mains electricity gets run from a power plant to your neighborhood then to your house.

You can get fidelity out of these sorts of systems, but the hardware becomes more expensive at that point to where other means are more cost effective or at the same price point.

Yeah, I think "somewhat smaller" guage is not at all giving justice to the facts. You can run 1000ft of 70 v speaker wire on 22 guage wire depending on how many speakers you are using. 22g is cheap stuff and easy to pull. Even if you used 18g, still cheap. 1000ft into a standard 8 ohm load would be "not-recommended" by any amplifier manufacturer. For all intents and purposes, you simply can't run 1000ft of speaker wire off a standard amplifier. And if you were to do the math and try to do it, probably you would come up with something like 2 gauge wire or even bigger. So aside from being "impossible" it would cost a fortune and being a demanding install trying to yank through 100's of pounds of big fat wire.

On the other hand, there are ways to run multiple speakers off a single amplifier with individual volume control not using 70v provided it is a smaller building.

Simply put, long speaker wire runs are only possible because of 70v and it is all about the wire guage (or in other words, the amps). All of the other stuff is possible and regularly done on BOTH 70v and regular voltage systems. Home audio distribution is the perfect example of systems running multiple individual controlled speakers without 70v.

I still don't know why hifi isn't done on 70v. The physics behind 70v systems not carrying (or only cost prohibitively carrying) hifi signals is completely unknown to me. Perhaps it is the transformers at the speakers.

 

[tmbrown97]

I've only installed a few 70-volt systems - it was for building-wide audio or large training/conference rooms. You tend to lose the stereo imaging (which is fine) in favor of very balanced audio throughout the space. It does make it a whole lot easier to connect a large number of speakers up. But, we've gone WAY off topic ;-)

 

[Del91574]

You can do HIFI on 70V, but generally the cost involved in doing such prohibits such an install and other routes are generally taken.

 

[reko19]

follow up question for you guys. how do you usually connect Cat5 cable to the wires provided with the keypad. there are small crimp connectors that are provided with the package, never had goof luck with them. was thinking small wire-nuts or solder / heat shrink tubing?

thanks.

 

[wuench]

I use the provided crimp connectors, twist wires together insert and I crimp in 3 places, test by trying to pull them out, and then usually wrap them in electrical tape or heatshrink. But solder/wirenuts/heat shrink are fine too. It's really whatever you are most comfortable with.

 

[reko19]

I use the provided crimp connectors, twist wires together insert and I crimp in 3 places, test by trying to pull them out, and then usually wrap them in electrical tape or heatshrink. But solder/wirenuts/heat shrink are fine too. It's really whatever you are most comfortable with.

thank you

 

[pmb1010]

there are small crimp connectors that are provided with the package,

heh... when I worked at NY Telephone one summer in 1972, subbing for the guys on vacation.. they would call them "rat rubbers".
But i've not heard that term since then.