Adjustable speakers

[M29]

I ran across this on the 18 watt forum and thought it might interest those here. This is the first time I heard of these, very interesting.

http://eminence.com/fdm.asp


Not sure how this works but It appears to me that you adjust the amount of magnet within the voice coil. If this is so wouldn't it just change the efficiency of the speaker, which would introduce a certain amount of attenuation?

[M29]

[hubberjub***]

That's pretty freakin' cool. I can't wait to hear some clips of that.

[M29]

Some of us are always trying attenuate an amph so we can play in a nice distortion zone at home at a lower volume. By the looks of the frequency chart this design does not affect the overall tone much. Usually the tone is degraded quite a bit with traditional attenuation.

If they are adjusting the magnet in and out of the voice coil it can be a very touchy thing to do. The clearance is so close that you run the risk of the voice coil rubbing on the magnet. I wonder how they are doing it.

This is interesting to me.

M

[mrmudcat]

Very interesting to me. In an iso cab this would be *****ing me thinks

[gatorbrit]

These look really cool. There was an article about them in the current issue of guitar player.

They claim that they'll attenuate 9dB. I'm having a hard time picturing what that means. For example, if you have a 50w amp cranked what would 9 db attenuation sound like? 25 W? 15 W?

[Ch0jin]

-9dB should give you approximately half the perceived volume.

Where it gets funky is that -9dB is equal to 0.125893 x the original power, so technically, it'd sound like a cranked 6W amp


Looks like quite a cool idea though. Would be a bit of a pain to tweak if you run a closed back 4x12 though. Make sure to pack the cordless screwdriver

[gatorbrit]

-9dB should give you approximately half the perceived volume.

Where it gets funky is that -9dB is equal to 0.125893 x the original power, so technically, it'd sound like a cranked 6W amp

A 6W amp - that would be fantastic. I have this monster 50w which I can never play past "1" at home. Being able to crank the amp a lot and not deafen people would be really nice.

The speakers have just been released and are on sale, I'll be on the look out for some more reviews

[jim p]

It would be nice if they would show a chart of the impedance just to know it won’t be a problem for a tube amp. The one down side is the dip in the high frequencies at approx 1.5 kHz. You would lose the highs using a resistive attenuator also but not a dip like that. While some hot plates add an inductor to not have the high frequency loss. Weber uses a voice coil with no cone for an attenuator so it has the same impedance rise with frequency as a speaker. The other interesting thing is the bass boost when you dial the output down. To get an idea of the high frequency loss look at the response curve for one of their standard speakers. http://eminence.com/pdf/legend-1058.pdf