The midi range, not the tweeter, is the most important driver in a speaker.

Here is a Q for the board, 
The SEAS Trym is a 2 way, 87 db, yet rated a  better 8 ohms. 
Here is my Q.
Will a  845 amp work under the load of a  low sensitive speaker ~~rated 87 db~~~ yet 8 ohms...IOW will the tube have issues with the impedance of 87 db?  Maybe not full  orch, but as in  chamber, which i have a  good collection of. 
I may be interested in a  2nd system and want to hear the magic of the 845. 
My guess is the voicing of the 40-250 fq's will be anemic/weak. 

I just cked the specs,,says highly recommended 50 pure class A watts, = 845 is not recommended. ....
I want the Trym, but which tube amp to deliver the goods?


http://www.seas.no/index.php?option=com_content&view=article&id=384:trym-seas-diy-kits&catid=66:seas-diy-kits&Itemid=365

 

I find that the most discerning/challenging speakers have a low impedance point in the 100-150 Hz range.

The Trym's impedance in this range is nice at ~ 8 Ohms or higher throughout the bass. Should be an easy load, with plenty of strength there.

Based on the frequency plot, it will benefit from being 2' or closer to a rear wall.

As for the mention of the Thor, I do have a bit of a soft spot for the Seas Magnesium drivers. They have a unique warmness on the mid and lower mid but very natural, and at the same time, very detail like a hard cone. It took a bit of time to break in and probably may be the longest of any drivers I’ve had. At first they sound a bit cold and clinical, but once fully broken in, it’s all fine. They have a bit of a break up so just be mindful of the xover.

I currently have a pair of speakers that use the Seas Nextel 5.5in driver and the magnesium has the exact the same dimension so it’s a one to one swap. Hm... I have might an itch to get a pair.

But is the mid more important?  Probably but it needs the right tweeter to make a perfect dance partner.  

Hey Andy, I do not see a  listing for the Nextel 5.5 mid,,I do see a  listing fora  SEAS Nextel midtweet, does have the neo magnet of its bigger brother, the Millenium,,the Nextel tweet hasa  higher 92db efficeny,,the Millenium is very low at 89 or 87, can't recall. 
SEAS hasa   new  nano cone W22, which is built on new dewsign materials,,,Its quite expensive , but if you could have Madisound build youa  2 way with the SEAS W22 Graphene + Millenium with Mundorf Silver Oil caps (or whatever cap you can afford, IMHO, that might bea  superior way to go vs the Thors. 
This way, you might not needa  sub, as the W22 will pick up the low fq's very nicely and the Millenium will meet the W22 effectively. 
Basically you are getting the Trym , but witha  superior W22.
Instead of rebuilding my Thor xovers,,I may put that cash in the W22 Graphene+ Millenium. Have to chat with madisound's tech guys, see what their opinion is ,,they havea  great friendly straightup crew ready to assist. 
If you geta  quote on the design, please pass it on.
paul
huge SEAS fan down here in new orleans

Just cking Madisounds web,,no listing for the W22 Graphene,,,so had to google,,now i know why, the W22 Graphene was just released last month, 
Price will be $600+ I am sure, as the W19 Grap is $529. 
She looks a  dandy,,, 


https://audioxpress.com/news/seas-announces-excel-graphene-w22-8-inch-woofer-launch

Andy the W19/Graphene has a super low sensitivty, 85db,,so the W22 will have same,,,= rules out any dream ofa  845 amp. 
Thats the trade off, I miss out on the 845's dreamy liquid mesmerizing mids in chamber/light classical (= 845 can not reproduce complex orchestra),,but the SEAS W22 + Seas T25002 offers its own magical sound world. 
and can handle both complex thick classical and obviously light classical/chamber.
+ The SEAS T25 voices the human voice like no other tweet I've heard, as it isa  true rare Midtweet has that NEO magnet system. 
I see your Nextel 5.5, has HEX magnet, good, but not Neo magnet system, 
The Neo magnet allow the amp superior power, as the super powerful Neo magnet draws the currect of electrons/=The Siemens,  at a  much quicker pace = less resistance to the amp = cleaner sound.