Long cable run for speakers

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Re: Long cable run for speakers

Post by Wonks »

Yes, it appears to be solid state. When I first looked, the only hit I could find was an eBay picture stating it was a valve amp. That was obviously wrong as I now get a couple more hits showing a solid-state amp with inputs via a 9-pin D connector, two output channels and a big finned heatsink on the rear. The label on the back stating the input voltage also states 140W, which I assume to be the input, rather than the output power, so it's likely to be a class AB amp with maybe 30-40W PC output. All very low-res images though, so difficult to say anything with confidence.
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Re: Long cable run for speakers

Post by Mike Stranks »

Useful updates one and all... :thumbup:

We're now into 'it depends' territory...

It depends on the size of the building, whether this is just for amplifying speech, the accustomed volume that the congregation expects, the efficiency of the speakers etc.

But as a general observation, in my experience if Wonks is right then that output power is on the low-side for the task required. But if the cong is happy with what they already have then changing the speaker cables is not going to materially alter things.

I generally use the 1.5mm 'Speaker Cable' from CPC... good value (https://cpc.farnell.com/pro-power/78-0- ... er%20cable but currently on back-order.) However CPC have loads of other options... just search for 'speaker cable'. But Dave is also right... any decent 2-core mains with conductors of the required thickness is equally good. IME finding it at a sensible price in non-orange or non-white can prove a challenge. Maybe I didn't look hard enough! :)
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Re: Long cable run for speakers

Post by Wonks »

As Rodgers make organs, organ amps and organ speakers, I would guess it's for amplifying an electronic church organ rather than for a PA.
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Re: Long cable run for speakers

Post by Kwackman »

Wonks wrote: Tue Nov 30, 2021 8:57 am As Rodgers make organs, organ amps and organ speakers, I would guess it's for amplifying an electronic church organ rather than for a PA.

Yup, if you google the speaker model the results show it's for an organ.
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Re: Long cable run for speakers

Post by Folderol »

Mike Stranks wrote: Tue Nov 30, 2021 8:33 am It depends on the size of the building, whether this is just for amplifying speech,

This is rather critical information that's missing!
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Re: Long cable run for speakers

Post by twotoedsloth »

Hello,

And thank you for helping me out here.

This is primarily for voice amplification.

Not sure why they purchased organ specific amp/speaker combination.

To summarize your advice, I should use "brown lamp cable"?

Many thanks,

Peter
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Re: Long cable run for speakers

Post by ef37a »

No, I would go for this: https://discountelectrical.com/6242y-tw ... efEALw_wcB

Just tie the earth to Blue and reduce the loop resistance a bit. A 50mtr drum will do your 140feet and while you are in the Lekky store get a couple of ABS boxes to make 'posh' end terminations. Some 6 or 10 amp 'choc-bloc' will serve for connection.

Dave.
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Re: Long cable run for speakers

Post by Mike Stranks »

twotoedsloth wrote: Tue Nov 30, 2021 3:23 pm Hello,

And thank you for helping me out here.

This is primarily for voice amplification.

Not sure why they purchased organ specific amp/speaker combination.

To summarize your advice, I should use "brown lamp cable"?

Many thanks,

Peter

'Brown lamp cable' is almost certainly not what you want.

Dave's put you on the right track. You need cable with a diameter on each connector of a minimum of 1.5mm. Chose colour according to taste.

... and the plot thickens wrt the amp. It has no mic inputs so there must be some form of upstream mixer or preamp(s). But that needn't concern us...

I don't know how the church is placed financially or numbers-wise, but it may be time to start over with something more suitable...

For churches on a budget I've sometimes provided a 'second-user' Inter-M mixer-amplifier... There are some absolute bargains to be had out there at well under £100.
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Re: Long cable run for speakers

Post by AlecSp »

ef37a wrote: Tue Nov 30, 2021 4:05 pm Some 6 or 10 amp 'choc-bloc' will serve for connection.

But not very well. Really, these days, spend a few pennies more and use Wago connectors - quick and easy to terminate, much more reliable, and easily re-usable.
https://cpc.farnell.com/wago/221-412/co ... connectors
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Re: Long cable run for speakers

Post by ef37a »

AlecSp wrote: Tue Nov 30, 2021 7:46 pm
ef37a wrote: Tue Nov 30, 2021 4:05 pm Some 6 or 10 amp 'choc-bloc' will serve for connection.

But not very well. Really, these days, spend a few pennies more and use Wago connectors - quick and easy to terminate, much more reliable, and easily re-usable.
https://cpc.farnell.com/wago/221-412/co ... connectors

I've not come across those Alec but I take issue with your "not very well". Used ' chocs' for 1/2 century and they are still used in junction boxes and used to be used for balanced mic conns!

Not pretty I grant you but I mean OP to use them in the ABS boxes and fit a more presentable connector, jack, Speakon, to the speakers and amplifier.

Dave.
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Re: Long cable run for speakers

Post by Folderol »

ef37a wrote: Tue Nov 30, 2021 7:58 pm
AlecSp wrote: Tue Nov 30, 2021 7:46 pm
ef37a wrote: Tue Nov 30, 2021 4:05 pm Some 6 or 10 amp 'choc-bloc' will serve for connection.

But not very well. Really, these days, spend a few pennies more and use Wago connectors - quick and easy to terminate, much more reliable, and easily re-usable.
https://cpc.farnell.com/wago/221-412/co ... connectors

I've not come across those Alec but I take issue with your "not very well". Used ' chocs' for 1/2 century and they are still used in junction boxes and used to be used for balanced mic conns!

Not pretty I grant you but I mean OP to use them in the ABS boxes and fit a more presentable connector, jack, Speakon, to the speakers and amplifier.

Dave.

Weird. There is no real information as to how they are used, and I would never trust any kind of connector at high voltage (and these are supposedly mains rated) with snap-down locking.
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Re: Long cable run for speakers

Post by Wonks »

Wago are fine. Used them quite a lot on lots of control panels for both sensor wiring and 24v and 230v control signals.

But I really think 1.5mm2 is undersized. 85m (140 feet round-trip) of it will give about 1 ohm resistance, which is significant in comparison to the 8 ohm speakers (which probably drop to 6 ohms orcso in reality). Remember that the existing wiring is 4mm2 and the amp is certainly not overrated for its task. 4mm2 (12 gauge) has about 1/3 the resistance of the 1.5mm2 cable. If the existing cable is undamaged and can be reused, I’d just reuse it.

This in an installation in the USA, so you need to be aware of different codes/regs and any cable needs to comply with both local and national regs. I’ve worked on a few US buildings from afar, and know that cabling in public spaces and atria often need to be ‘plenum’ rated (LSZH). So as I’ve said before, compliance with code really needs to be checked before any cabling is purchased.

I’d agree that the whole PA system could do with reviewing and probably replacing as the existing system seems a bit underpowered and mismatched for its purpose. But that’s impossible to do remotely.
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