AER FS2B and Fostex 200A comments

[InclinedPlane]

I thought I'd share a few thoughts on these 2 drivers. I just received both in the mail. The AERMD2B seems to do everything well. I feel no need for a tweeter. It resolves percussion better than the soft dome tweeters I've used. It's just as fast as Lowther but doesn't have the 20db rise from 300 to 8k that my EX2 did. Neither does it seem to have the awful resonances my EX2s did. It really is fullrange. The midbass seems a bit lean but that might be my room. Overall I suggest to anyone that if you can budget a quality fullrange driver, don't waste your money on the poorly designed (imo) Lowther drivers. Go with the Aer!

The Fostex 200A demonstrates the strengths I've read about. The bass and midbass is fantastic - I feel it beats the AER in the bass. The mids are clean and warm - a real pleasure. There is some minor coloration in the mids but this is a far less expensive driver! Also true is the nasty highs produced by the metal dome. Yep, they're bad. It rings and 'shrings', making more or less of a mess out of the highs. Even if the highs were accurate, they're really still too weak; even on axis.

So This is what I thought I'd do: Run the AER fullrange (16ohm 100db) OB and run it in parallel with the 200A (8ohm 90db) cut at 300hz or something and let the 200a be rear-ported. I assume this combination would make the best use of the 200A and overcome any baffle step loss in the bass.
Any thoughts?

[el`Ol]

There was a plan plus instruction for improving OBs in the bass on German Ebay. I would have given you the link, but currently it is not available. The basic idea was a round baffle that is folded. At the sides the round shape is approximated by rectangular 15cm wide elements with 5cm overlap. The elements are made of very thin (3cm) plywood and after glueing the side walls are treated with hard lacquer several times. The steps and the light material aim at avoiding a boomy sound. Unfortunately the explaination was short and not very clear. Anybody out there who can explain it to us?

[hm]

Hello,
did you any measurements?

look the Raptor measurement AER with 2 x 10" Bass.

I visited AER twice, and want get a resending sample,
to make measurements and listening tests in comparison
to Lowther, AN8", 206E, B200.

Mr. Keller is not interested until today, why not??


your solution would be expensive and "won´t" work.
The AER is a pur horn driver.

[InclinedPlane]

Pure horn driver? Hogwash. It has a Q of over .7

[hm]

look the AER site:

The AER MD 2B is designated for the use in front loaded and back- loaded horns and in an ideal manner as mid & high-range unit. Efficiency, dynamics and resolution are furthermore improved. Also this unit is suitable to serve as a full range drive unit,


It would work in my SAXOPHON excellent.

[el`Ol]

Somebody told me the Bl is more relevant for a horn driver than Qts. So the AER with its huge magnet should be suitable for horn. What I don`t believe: that it is unsuitable for OB, since the IB response is dependent on Qts (or am I wrong here?).

[Scottmoose]

It'll be happy enough, though better with LF support obviously, and slightly off axis.

[youyoung21147]

Very interesting !

Have you made CSD and distorsion measurements of these units ?

[InclinedPlane]

I wish. I don't have any test equipment , but I hope to set up some kind of test area once I move and leave apartment life behind. For now I can only guess at the potential of certain designs.