speaker with transformer

[rotylee]

has anyone used these in a low power amp?
is there any benefit to the 24v transformer attached to full range ceiling speakers.?
http://www.parts-express.com/pe/pshowdetl.cfm?&DID=7&Partnumber=300-020
w/o transformer
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-010



this thing flipped?
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=242-860

[tempus]

What do you want to use one for? That speaker/transformer setup is designed for the type of system where 1 power amp has a lot (like dozens) of speakers connected to it, like you get in a grocery store or WalMart. I think the idea is to be able to connect a zillion speakers to the same output but have the amp still see an 8 ohm load. Check this out:

http://www.alectrosystems.com/audio/Distribution/70volt.htm

[ClinchFX]

this thing flipped?
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=242-860

If you mean upside down, no, it's meant to hang high on a wall facing slightly down at people in the room.  These are intended for use in lo-fi announcement/background music systems.

Those small 70V line transformers can sometimes be used as output transformers in low power tube amps if they have the right combination of primary tappings.

[Earthscum]

I'm guessing they are used in a distributive speaker system. In these systems, there is a pretty decent voltage running through the system, kinda like phantom power from a board.

http://svconline.com/mag/avinstall_distributed_speaker_systems/

In a typical paging, background music or noise-masking system, several loudspeakers are placed across a single amplifier in parallel. They must often be powered at different levels, and the calculations involved in determining the actual load impedance at the amplifier's output are quite tedious.

A solution for this problem comes in the form of the 70-volt distribution system, which was developed to make all calculations simple and straightforward. In this method of distribution, amplifiers are designed so their full power output exists at 70 volts RMS. The load impedance that corresponds to several output power ratings is shown below

[rotylee]

found someone here using a line transformer similar to the one attached to the speaker i mentioned.
http://www.diystompboxes.com/smfforum/index.php?topic=70802.0

[slacker]

Yeah line transformers make nice cheap output transformers. I've never seen one attached to the speaker before.

You can supposedly use them with real amps as well not just low voltage ones have a look here. http://ozvalveamps.elands.com/optrans.htm

this thing flipped?
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=242-860

If you want a cheap speaker cab, try looking on Ebay for car sub woofer boxes. I got one that takes a 10" speaker for £20, nice solid MDF construction. I Put a Jensen C10Q in it and it sounds surprisingly good.

[drewl]

You kidding?
You never worked in a factory or warehouse?
Since my bosses know I'm a musician/gear nut, guess who got to set up the PA/phone/speakers etc. in our new building?

The line trannies are for no loss when running hundreds of feet of speaker wire as well as running multiple speakers from an amp.
We have a bunch with the tranny mounted to the speaker, I've used them in homemade monitors for our studio also.

[Andi]

Aye - as has been said, for non-music applications 70v line (or 100v line in Europe) is used where you want to have lots of speakers over a wide area or long distance.