Has anyone built the Seas 'Mimir' design?

[Tony D.]

Looks interesting and not very expensive for what seems a good design...if anyone has built and/or has an opinion feel free to post.


http://www.seas.no/index.php?option=com_content&task=view&id=210&Itemid=202


J.B.

 

[PeteMcK]

here's something similar to compare it to, using newer drivers:
http://www.zaphaudio.com/SR71.html

...or how about this one?
http://www.troelsgravesen.dk/SEAS_CA18RLY-COMPACT.htm

 

[MisterTwister]

I'd use larger capacitor in woofers part of crossover, to drop high frequency response some more. those woofers sound nasty above 1k.
and by looking at curves, I would not even consider Troels' design, it probably plays too loud too soon, due to cone breakup.

 

[DcibeL]

I'd use larger capacitor in woofers part of crossover, to drop high frequency response some more. those woofers sound nasty above 1k.

Really? Distortion measurements of the CA18RLY lead one to believe it will sound just fine at any frequency. The coated paper cone has nearly no cone breakup mode at all.

 

[MisterTwister]

do distortion measurements show cone breakup?
rising FR above 1k is one huge breakup. at least I think what it is.

seas paper cones (ones that I saw) are thin and breakup easily. I wouldn't cross them much above 1k, if used in two way design.
they may be fine in a 3 way as midrange, less xmax is used and less cone flexing. have not tried it yet.

 

[DcibeL]

do distortion measurements show cone breakup?
rising FR above 1k is one huge breakup. at least I think what it is.

Well, all cones breakup, but in this one there is no harmonic distortion associated with it, only linear distortion (amplitude change). A rising response due to breakup that doesn't have non-linear distortion products associated with it can be easily corrected in the crossover.

The breakup of this driver is very smooth and subtle like a good paper cone should be, easy to use above 1kHz. Crossing over at 1kHz will severely limit your tweeter options.

Back to the topic, the Mimir has a good driver selection, but the crossover could use some work. Response is not very smooth, and looks to be lacking in BSC. I would choose a Zaph, Troels, or Jay_WJ design over the Mirmir.