Speakers RS 249-047

[akis]

Hi

I have 4 of the above speakers which would like to use in a project guitar/keyboard amp. They are 6.5", wide range, twin cone. They are 15 Ohm each. What I do not know is their power rating, it is not mentioned anywhere. Is there a way to determine it somehow? I do not want to burn them by mistake.

[poynton]

http://it.rs-online.com/web/0249047.html




looks like 25w
.

[akis]

Ah great thanks. Therefore I will place 2 pairs of parallel in series getting 7 Ohms total and 100 Watts.

[poynton]

Originally Posted by akis

Ah great thanks. Therefore I will place 2 pairs of parallel in series getting 7 Ohms total and 100 Watts.

That would be 15 ohms

( 2 in // give 7.5 ohms plus another 2 in // = 15 ohms)

So you're building a miniature 4 stack - 4 x 6.5" rather than 4 x 12"

I would rate it at 50w continuous - 100w max peak



Andy


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[akis]

Ah damn yes, they are 15R not 7R each. So I can do either 15R or 3.75R (which I think is too low).

I am thinking of using a 2x25V 80VA transformer I have in the spares box. That should allow for approx. 41 Watts into the 15R load. (trans is rated 230V 11% reg, my mains is 249V, assuming 4 volts drop at the rails).

I am building a small-ish amplifier, something you can carry around easily without major headache (the other amp I made is almost impossible to carry anywhere).

And because the speakers are "wide frrequency range" I will be able to plug in the keyboard or the mp3 player or other instruments, not just the guitar. Normal guitar speakers almost stop working over 4K-5K and cannot really plug in anything except a guitar.