so i have these floor standing speakers - and need an amplifier to power them (to play music off my computer). I have a spare car audio amplifier - can i use it for floor standing speakers? and if i can - how would i go about doing it?
You can only use the car amp if you have a 12Volt supply, and it will likely have to be heavy duty if the amplifier can kick out lots of power.It is possible to use a 12volt car battery and recharge that when it runs down, but there are serious risks if you accidently short out the terminals or the supply lead to your amplifier.
Your next problem is likely to be the impedance, the amplifiers and that of the speakers probably will not match, chances are that the car amp is either 2 ohm or 4 ohm and you speakers are probably 8 ohm.
If the speakers have a higher impedance than the amp then, apart from less sound, the chances are that there will not be much problem.
If the amplifier has a higher impedance than the speakers, fairly unlikely, then you may get more sound but you will run the risk of blowing it.
yeah - the speakers are 8 ohm (doesnt say RMS or not). is that 12 V ac or DC? how safe would it be to use an adapter to power the amp?
It’s 12 volts DC. Look at the Amplifier specs (or even the fuse if it has one) to see how much current it draws. Most likely this will be more than any adapter you can find. Most Radio Shack adapters top out at 1 - 2 amps (1000 - 2000 ma) if you are lucky. A car battery charger would probably be closer to what you need. I’m not sure about the safety of running one of these with no battery attached, or even long term with a battery hooked up.
MC$E
The output stages of car amps operate class AB, meaning they draw current according to the signal amplitude & load demands. During base beats you could see current demands upwards of 10-15 amps, and brief spikes higher than that. If your poswer supply can’t furnish it, you don’t hear it at the speakers (or you hear it clipped). And that sounds just awful. This is why many car audio enthusiasts install super caps to deliver that punch when the main current supply can’t cut the mustard.
You need something like this at a minimum.
MCM has come cheaper ones, but even a 10 amp supply is going to cost you $50-$60.
Don’t waste your time with the car amp. Go to ebay and buy a used Adcom or Parasound or Rotel amp for $200 and do it right. What kind of audio outputs does your computer have?
my sound card has front, rear and sub outputs - but i’m running it in 2 speaker mode at the moment. what kind of wattage should i be looking forin an amplifier? the speakers are Digital Audio DA 2012 - 400 W, 90db, 8 ohm impedance
Are these your speakers? (Warning: PDF) I assume when you say front that you mean typical left & right RCA jacks? If so, I would look for something like this which would allow you to use your speakers with other sources as well. Something like this might be a good value as well.
90db, 8 ohm speakers are, as a rule, pretty easy to drive so I would advise that you go for quality watts over quantity. Quality & quantity = expensive.
If you are serious about good sound, look for a local high end audio store, (NOT Best Buy or similar) and stop in, often times they will have used equipment for sale at great prices. Solid state amps are pretty reliable, so don’t be afraid of buying used. My first amp was a used Rotel RB-981, and I think I paid $350 for it (new was probably $600) when it was a few years old. I still have it, and it works great. Look here to find local dealers. Hope this is helpful.