I am in the process of planning a speaker build. I am making sure my current wiring is up to the demands of a new system. The amplifier is a CV 1800, which can put out 9.5 amps at 4 ohms in stereo (600 watts) or 19.5 amps at 4 ohms in a bridged mono setting (1800 watts). I am wondering what it would put out at 3 ohms. I am lost as how to calculate this, as I don't think it follows any basic V=IR, P=VA equations that I could use in an ideal situation. The wire I'm using is rated at 300 volts and 12 amps. Would this be adequate for use at 3 ohms? (I'd also guess the wire is about 50 ft)

The wire: http://www.farnell.com/datasheets/2335141.pdf

The amplifier data sheet (The Cerwin Vega website isn't responding to me): https://mans.io/item/cerwin-vega/cv-1800 or, just search cv 1800 data sheet

  • 1
    \$\begingroup\$ 12 gauge wire will not have any problem with 9.5A as far as heating goes. Even 19.5A would be OK as long as it is not continuous (which it won't be, for audio). I am not sure about the sound quality implications. How long is the wire run? \$\endgroup\$ – mkeith Oct 27 '17 at 2:57
  • 1
    \$\begingroup\$ If you are worried about wire INSIDE the speaker, just use much larger wire, or run several strands of the 12 gauge wire. If you are worried about the wire run between amp and speaker, you need to state how long the wire run is. \$\endgroup\$ – mkeith Oct 27 '17 at 3:47
  • \$\begingroup\$ The wire would be somewhere around 50 feet if I had to guess because it's in the wall already O.o What would be the max distance? (and yes between the amp and speaker) \$\endgroup\$ – user167026 Oct 27 '17 at 6:54
  • \$\begingroup\$ If it is in the wall already, then just try it out to see how it goes. I don't think there is any hazard. So it is only a matter of sound quality. There is a table on the wikipedia page for speaker wire. For 12AWG wire, they list 60 feet as the max. They are not considering current limits, but sound quality. Not sure how reliable it is, but I think it at least suggests you might be OK. en.wikipedia.org/wiki/Speaker_wire \$\endgroup\$ – mkeith Oct 27 '17 at 7:00
  • \$\begingroup\$ I was under the impression that running speaker wire at too high power will make the casing melt due to heat and could cause a fire? \$\endgroup\$ – user167026 Oct 27 '17 at 7:20

I am by no means an audiophile/speaker designer, but with the numbers that you gave, I would say no. 9.5 amps @ 600 Watts through 4 ohms resistive equals 2.65 Ohms reactive. and 19.5 Amps @ 1800 watts through 4 Ohms resistive equals 0.73 Ohms reactive. The amp numbers at 3 Ohms instead of 4 would be 10.3 Amps @ 600 watts stereo and 21.97 Amps @ 1800 watts mono. If I am wrong on that, someone please let me know. I am not too familiar with speaker design, and it has been a year and a half since I took an AC course. In general, less resistance equals higher Amperage. In my opinion, the 12 Amp rating would be cutting it a little close for the 9.5 Amp stereo design. This might be common practice and generally accepted amongst speaker system designers, but I wouldn't know.

  • \$\begingroup\$ Your answer is gibberish and you say several times that you don't know what you're talking about, so do the decent thing and delete your answer please. \$\endgroup\$ – Neil_UK Oct 27 '17 at 6:39

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.