Film-Tech Forum ARCHIVE: Stage Accompany Speakers

This is topic Stage Accompany Speakers in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Tim Asten (Member # 4051) on 11-10-2006, 05:11 PM:

Does anybody have any experience on speakers from Dutch firm Stage Accompany.They use very low distortion ribbon treble units,which they claim are far better than horn loaded compression drivers.I must admit from a hi-fi point of view,what they say does seem to make sense.However i have yet to find a cinema that uses them.Maybe they are a well kept secret. [Wink]

Posted by Ron Curran (Member # 3631) on 11-10-2006, 11:32 PM:

Hi Tim,
We once had an issue with our centre speaker and, till I could get it fixed, I wired in my ESS Heil AMT1s from home.
They have a ribbon top end and they sounded fine. No power handling problem either.
I am not sure how similar the Stage Accompany speakers would be.

Posted by Mark Gulbrandsen (Member # 72) on 11-11-2006, 02:29 AM:

Ribbon Speaker:

The ribbon speaker consists of a thin metal-film ribbon suspended in a magnetic field. The electrical signal is applied to the ribbon which vibrates creating the sound. The advantage of the ribbon loudspeaker is that the ribbon has very little mass; as such, it can accelerate very quickly, yielding good high-frequency response. Ribbon loudspeakers can be very fragile, thin ones can be torn by a strong puff of air. Ribbon tweeters emit sound that exits the speaker in a roughly cylinder-shaped pattern. Above and below the ends of the ribbon there is often less treble sound, but the precise amount of directivity depends on the length of the ribbon. Ribbon designs generally require powerful magnets which make them costly to manufacture. Ribbons have a very low resistance that most amplifiers cannot drive directly. A step down transformer is therefore used to increase the current through the ribbon. The amplifier "sees" a load that is the ribbon resistance times the transformer turns ratio squared. The transformer must be carefully designed so that its frequency response and parasitic losses do not degrade the sound, further increasing cost relative to conventional designs.

Air Motion Transformer:

The Air Motion Transformer - or short AMT - works by squeezing the sound out through an accordion like flexible diaphragm. The AMT is often described as a Ribbon - but that is only a half truth. Looking at the AMT from above you see that it looks like many small ribbons turned 90 degrees so the sides faces the listener. These ribbons forms one long voicecoil which when placed on the flexible mylar in a strong magnetic field make the diaphragm flex.

Posted by Richard Fowler (Member # 893) on 11-11-2006, 07:32 AM:

I have used the SA tweeters in several locations in "problem" space situations with excellent results. In small 140 seat rooms, 42 feet in depth ( 12.8 meters ) and a 350 seat room, 70 feet in depth ( 21.34 meter ) with the optional wave guide horn.
Bass cabinet response is very important since the ribbon tweeter has to have a crossover point over 1KHZ. 1/3 octave EQ is recommended since there is a "spitty" spike ( ribbon resonance?? ) that has to be notched. They handle subtantial power and the only failure we have had was a maintinance guy and a loose screwdriver due to the very high magnetic flux of the driver.

Posted by Tim Asten (Member # 4051) on 11-11-2006, 08:04 AM:

Thanks for all your comments.Also interesting are the Stage Accompany amplifiers which have a special dampening module or so it seems,which controls the speaker driver movement from return sense wires from each speaker.All very thought provoking.

Posted by Gordon McLeod (Member # 33) on 11-11-2006, 01:35 PM:

I beleive Big Sky distributes an American made Ribbon driver stage speaker as also there is a second dutch firm similar technology