Will I damage my amp?

[Richard Veal]

I want to run a test.

I will need to run a sound or signal from my amp with a speaker lead attached but no load/speaker, the reason is to put a meter on the other end to see what voltage drop occurs at distance, compared to a short cable.

The reason being I have an arena event coming up where the configuration will be as shown below.

Just want to know if anyone knows if i am safe to perform such a test

Thanks

[rob1963]

I want to run a test.

I will need to run a sound or signal from my amp with a speaker lead attached but no load/speaker, the reason is to put a meter on the other end to see what voltage drop occurs at distance, compared to a short cable.

The reason being I have an arena event coming up where the configuration will be as shown below.

Just want to know if anyone knows if i am safe to perform such a test

Thanks

In a word, No.

The quickest way to blow an amp is to run it with no load (speaker).

[Richard Veal]

Fair enough Guv, is there away of doing this then?

[rob1963]

Unfortunately I'm not an expert, so I am not sure. All I know is that you can't run an amp with no load.

Hopefully someone else will be able to give you some advice on how to achieve what you want.

[Jaggiebunnett]

The set up will work but you will lose power with such long leads so use 2.5 mil/12 gauge or thicker speaker cables and of course speakers on the end:p
cranked amp/no load = smoke.:eek: :eek: :eek:
Voltage drop is best measured with a load in the line:rolleyes:
good luck:) :) :)

[Jiggles]

Ok here goes this is from my soundlab amp manual :o

Maximum length for a 4 Ohm load using 2.5mm cable is 11.4M
Maximum length for a 8 Ohm load using 2.5mm cable is 22.8M
Maximum length for a 16 Ohm load using 2.5mm cable is 45.6M

See if that helps

[Dimension Videotheque]

I want to run a test.

I will need to run a sound or signal from my amp with a speaker lead attached but no load/speaker, the reason is to put a meter on the other end to see what voltage drop occurs at distance, compared to a short cable.

The reason being I have an arena event coming up where the configuration will be as shown below.

Just want to know if anyone knows if i am safe to perform such a test

Thanks

If you just want to find out the voltage drop, just put a known voltage down one end of the cable an measure it the other end with a multi meter. Measure the output from say a 12v supply, hook it up to the cable and then measure the other end, at least you can work out the losses on the cable. You won't have to use your amp for this at all so you don't risk smoking it.

Just a thought.

Mike

[CRAZY K]

The set up will work but you will lose power with such long leads so use 2.5 mil/12 gauge or thicker speaker cables and of course speakers on the end:p
cranked amp/no load = smoke.:eek: :eek: :eek:
Voltage drop is best measured with a load in the line:rolleyes:
good luck:) :) :)

Im sure thats good advice--only thing is when I used to cover outdoor PA for schools etc we only used standard thickness speaker cable( and even thinner) for lengths of around 30 metres with absolutely NO drop in speaker signal power at all.

Admittedly thats outdoor all weather speakers which are a different animal.

Could be an expensive exercise for one gig:eek:

CRAZY K

[Richard Veal]

I've done these outdoor events for several years (charitys both of em) but in the past have just set up at one end and blasted it, thought this would be more user friendly I guess a field test is in order.

Thanks for the advice though - why i didnt think of the battery i'll never know

[CRAZY K]

I've done these outdoor events for several years (charitys both of em) but in the past have just set up at one end and blasted it, thought this would be more user friendly I guess a field test is in order.

Thanks for the advice though - why i didnt think of the battery i'll never know

So if you suffer a voltage drop---how does that relate to loss of music power?

In music watts power for example---can you calculate a figure needed to give the necessary output?

Just wondered--like I said--for high frequency pa speakers I had no drop at all.

CRAZY K

[Dimension Videotheque]

So if you suffer a voltage drop---how does that relate to loss of music power?

In music watts power for example---can you calculate a figure needed to give the necessary output?

Just wondered--like I said--for high frequency pa speakers I had no drop at all.

CRAZY K

It depends on the impedance of both the speakers and the amplifier used. Voltage drop could indicate poorly matched speakers which could result in alot of 'music power' being lossed i.e.

Wattage is the theoretical electric power that would be transferred from amplifier to speaker if the loudspeaker was actually exhibiting its nominal impedance. The actual electric power may vary from about twice the nominal power down to less than one tenth.

High frequencies tend to travel less than lower frequencies, this is also true in electrical terms. The key is to match amplifier / speakers / Connectors and cable as best you can, in terms of cable, the thickest the better. Buying 4 ohm speakers on an 8 ohm amplifier can have dramatic effect, especially on long speaker cable runs. Distortions can also be introduced.

another 2p's worth :D

Mike

[TonyB]

You get less loss at line level so it if it was logistically possible, it would be better to have two amps, one placed between each pair of speakers with a long XLR cable to the amp (daisy chained from one channel to the other) and then a 15ft speaker cable to each speaker.