[ANDREY MAXIMOV]

EMIMENS ALPHA-15,  BEYMA, HEIL AMT

[ANDREY MAXIMOV]

To receive a normal bass, two Alfy15 are necessary. Then we will receive 93db on 40gts!

[versus rider]

What is your cut off frequency for alpha 15. I found bracing across the back of the magnet to brace the frame gave a cleaner sound up to 350hz, without, it didn't sound so good and only useable to 200hz.

[FullRangeMan]

What is your cut off frequency for alpha 15. I found bracing across the back of the magnet to brace the frame gave a cleaner sound up to 350hz, without, it didn't sound so good and only useable to 200hz.

Great tips, thanks for inform

[ANDREY MAXIMOV]

What is your cut off frequency for alpha 15. I found bracing across the back of the magnet to brace the frame gave a cleaner sound up to 350hz, without, it didn't sound so good and only useable to 200hz.

Frequencies of the section of filters 400gts and 6000gts

[versus rider]

Frequencies of the section of filters 400gts and 6000gts

you may be ok with 400hz, but as I said you will need to brace the magnet to get good sound quality from the alpha 15 at that frequency.

[ANDREY MAXIMOV]

you may be ok with 400hz, but as I said you will need to brace the magnet to get good sound quality from the alpha 15 at that frequency.

To fix a loudspeaker magnet?

[FullRangeMan]

To fix a loudspeaker magnet?

Seems it was used to change the moving mass cone/suspension resonance freq, I see it first used in the Yamamoto OB:
http://www.6moons.com/audioreviews/yamamoto9/speaker.html

[versus rider]

I think it stiffens the frame and so improves the sound quality. It was someone on here that suggested it some time ago. I don't know the science behind it but it works.

[ANDREY MAXIMOV]

I think it stiffens the frame and so improves the sound quality. It was someone on here that suggested it some time ago. I don't know the science behind it but it works.

And it is possible to look at the picture or a photo as it is made.

[opnly bafld]

I have never used any support/brace.

Here is another example:

[MJK]

I am not a fan of the magnet bracing (or magnet mounting) schemes shown above. Basically you are trying to achieve some degree of pre compression between two very stiff members. If there is any relative vibratory motion you will get a rattle as the pieces go in and out of contact. It can be clearly seen in near field SPL measurements of the woofer with and without the brace, my measured results produced a saw toothed ragged SPL response over a frequency band when the brace was engaged in a friends speaker system. The metal woofer frame should be stiff enough on its own to not vibrate/resonate over the range of bass frequencies being reproduced in an OB system. Securing the driver to a stiff baffle using the mounting holes and decent screws or bolts securely tightened should be all that is required.

[FullRangeMan]

I think it stiffens the frame and so improves the sound quality. It was someone on here that suggested it some time ago. I don't know the science behind it but it works.

I read it change the Fs. I suppose it would be better implemented a device it real wood not steel.