I've not done step up speakers before, so if someone wants to help me, that would be much appreciated.

I found this really nice 60W speaker on the side of the road ready to be thrown out so I picked it up and wired it up for my computer. Of course though, my computer doesn't put out 60W. So, how would you recommend step upping the voltage for the speaker. I was thinking op-amp, anything else more practical? also, how much power would you say a macbook (not pro) outputs through the headphone jack? Thanks?

 

Hello,

The output of a headphone will be a couple of 100's mWatts.
When you want to use your 60 Watt speaker you must use a power amplifier.
On elliot's site there are several power amplifuers descibed.
http://sound.westhost.com/projects-1.htm

Greetings,
Bertus

 

Are there any I should avoid due to too much ground being returned back into my compy? Also, I am not good at nomenclature, 60W means you are stepping up to 60W, right, and since my computer is just under 1 Volt of out, that first one would be perfect, right? Where do I get a 35V battery, Don't they make transformers that take voltage for the wall and transform it lower? I think I have one but it's at least 50 years old, should I try it or not?

Thanks

 

The only thing to be really concerned about is the impedance of the speaker. They come in all flavors, most internal speakers on computers is 8Ω. High power speakers tend to be less, 4 or 2Ω. This isn't a big deal, but it affects how the amp works.

 

A speaker needs to have an enclosure that is designed for its specs. The enclosure allows the speaker to make good bass if it matches the speaker's specs. If it doesn't match then the speaker might sound boomy at an upper bass frequency without any deep bass, or it simply will not have any upper and lower bass.

60W might be the "Whats" rating of the speaker. They exaggerate the power ratings of speakers and amplifiers. 20 real Watts is pretty loud and a 20 Watts amplifier into 8 ohms needs to have a supply of about 40VDC.

The first amplifier on Rod Elliot's site is a 60W amplifier that uses a plus and minus 35V supply that is 70V! Its output is 60 Watts or 2000 Whats. It might even be 20,000 Whats!
It would probably blow up your 60 Whats speaker. Your speaker might be only 10 or 15 Watts max.