Best sub for music,


Not HT, repeat not the boomboomboom of HT  effects.  which does not offer the high fidelity of musical sub bass (20hz-40hz) 
I'd have to go with the seas W26E001. which has a magnesium/aluminum cone. 
What that raitio is, not sure, seems 50/50. 
None of us here like the sound of those old aluminum cones. But my guess is Seas had to incorporate some alumium inorder to gain the 20-30hz and also mabe keep costs down. 
This YT vid says **Aluminum cone** which is confusing YTers.
Its a  composite, and perhaps the best ture woofer on the market.
Been around for ages, still hard to beat for pure natural low mids. .
Magesium is the best material to keep unwanted resonances out in the  60-1k range, very low/hardly measurable distortion. 
The issue here  tops out at 1k, so its really a  sub. 
This woofer may be a  good candidate to pair with a  5 inch wide band. 



https://www.youtube.com/watch?v=RSiuaMWodzI

http://www.seas.no/index.php?option=com_content&view=article&id=362:e0026-08s-w26fx001&c...
mozartfan
This article http://www.soundoctor.com/whitepapers/break-in.htm is a little bombastic but overall there is not much I can argue with. It is a good article for millercarbon to read. He won't like it but, he should read it anyway. He does not start talking about digital signal processing till the end of the article even though he is obviously a fan. It seems he thinks this is above most of us. 

@jheppe815,
Hi, I run the JBL B460's with a Crown studio reference 1 amp which runs on a dedicated 240 volt 30 amp circuit.
IMHO: The Crown  studio reference 1 amp is the best sounding amp Crown makes. All the power you will ever need in a home hi fi rig. Also the B460's have an efficiency of 2.6%, same efficiency as my main speakers. The subs and the mains have a sensitivity of 96 dB @ 1 watt two meters, so they are a good match. I run the main speakers with a pair of Quicksilver silver 60 mono block tube amps. The system sounds effortless.

https://technicalaudio.com/pdf/Crown_International/Crown_Studio_Reference_Series_Manual.pdf
I’ll add another thumbs up for Rythmik subs. I have a pair with my Revel speaker system. The subs integrate flawlessly and are tight, fast and musical. The founder of Rythmik is a huge music fan and designs subs for music. They also happen to sound pretty dang good for HT as well.
JL Audio makes very serious subwoofers. I would take them over REL. A relative has two Gothams. Wow. 
 https://www.jlaudio.com/collections/home-audio-dominion
I believe that it is better to get speakers that go lower than to add a sub. But, that’s just me. 
jheppe815, Your post had me lamenting over my pair of Marantz 8B powered DIY JBL 4530 scoops I used in a back line stage Bass rig in the mid 60's. 
JBL was so approachable and helpful during that period.
My current back packable Upshot rig weighs just 14 lbs. 
  
That 8B was my roundabout introduction to Hi-Fi.