SEAS Thor Speaker / NCMS Rhythm 9500 Unlimited


I've read about these new speakers from SEAS designed by Dr.Joseph D'Appolito and have quite an interest in them. The most recent issue of Audio Express talks about them at length and they look to be a really nice design for those of us who like a well built transmission line speaker. If you haven't seen them yet got to http://www.madisound.com and go to "kits" and they're at the bottom.

My question is,"Has anyone heard these speakers or tried to build them yet?" I'm curious for some input if you have heard them. I don't like the fact that Madisound has opted to delete the base plinth that was part of the original design so I will most likely have to build the cabinets myself. The article has a mini review but I'm looking for more reactions to these speakers.

The other kit that I've been looking at is the North Creek Music Systems / Rhythm 9500 Unlimited. Again, if you have not seen it check out, http://www.northcreekmusic.com/NorthCreekKits.html
Costwise the NCMS Rhythm 9500 Unlimited is qiute a bit more expensive but comes from some great sound guru's. Any thoughts on these would be appreciated.

Thanks,
128x128bryhifi

Showing 1 response by keithvv

Bryhifi,
If you are still debating between the two, here are my thoughts.
I have built both - the NCMS system based on scan-speak drivers a few years ago, and the Seas based Thor last year.
The Rhythm is a well behaved system. Good bass extension, lots of mid-bass, strong detail.
The Thor system is more open/ airy / more detailed with less bass extension, but more "accurate" bass (quicker transients comes to mind) in my opinion.
I believe the reasons for this difference stems from two basic differences between the two systems. First, The Thor is a TL, and the Rhythm is a vented design. The vented design type has more overshoot, and less control of the driver around the resonance frequency. The TL behaves like a closed box around resonance, with better cone control (more damped behavior). Second, the midbass drivers themselves exhibit different behavior. See Siegfried Linkwitz's website (www.linkwitzlabs.com) for his testing and analysis of the underlying driver's stored energy characteristics.
The tweeters used are both excellent. I continue to use both in my "personal" designs.
For the record, both are excellent kits. Both are (IMO) likely the best examples of the use of the drivers in question. I have kept the Thors, and disassembled the Rhythms - I am going to build a Transmission line for them and see how they compare to the Thors one-on-one.
Any questions... please ask. Any different opinions... please comment.
Regards,
Keith Van Vleck