Twenty years ago, my HT consisted of a Yamaha RX-V480, a pair of Polk Large Monitors, a Radio Shack 12" passive subwoofer, and a Klipsch KV-2 CC spkr. Soon, another pair of Polks and two more RS subs followed. My son gave me a Sony 10" powered sub (SA W2500) some years later, and I retired the RS passive subs. Wanting more, a few years back found me getting a Polk PSW-505 - a 12" powered sub - which proceeded to vibrate things off of a wall mounted shelf in my last home, a frame cracker box. 7/13 found us moving into a brick garden home - with carpet & pads over concrete. Skip ahead to Christmas - my office stereo got a pair of NHT SuperOne 2.1's - nice - light on the acoustic suspension style bass, however. Love the abrupt thump - wanted NHT's similar designed 8" sub, so I started planning it's purchase... until I heard the Polk HT sub 'buzz' - gasp, the speaker's surround is tearing! I looked for a sealed replacement - found the JBL 550 in Black on Amazon - $600.. and the cherry version for $290. A call to JBL and I learned that they had dropped the cherry finish, otherwise it was identical. I ordered on Monday - I had it in my office and on by lunchtime Wednesday. What of the 12" Polk in the lr HT? Well, it's buzz was an empty DVD jewel case sitting on the subwoofer. I put the case up and the buzz went away.
To those who suggested this sub - thank you! I am quite happy with the bass extension it affords me - great aid for those NHT's. I haven't decided where I like it - mainly for music - 100Hz... 80Hz... or lower? James Taylor's 'Fire and Rain'; Paul Simon's 'Graceland' and 'You Can Call Me Al'; Bonnie Raitt 'A Longing in their Heart'; Marc Cohn 'Walking in Memphis'; and my fifty year old favorite - as the others, on a CD - Getz/Byrd "Jazz Samba" - all sounded better than even over my Koss Pro-4AA or Sony MDR-V6 headphones. I heard some bass notes for the first time on a loudspeaker, thanks to that sub. Wednesday after lunch saw the arrival of 'Longmire' Season 3 on BR disc - I played that, all ten episodes, over the office 25" LCD HDMI-equipped monitor and an old Sony BR disc player. A modern western, there isn't much bass - but the theme music sounded great. I'll have to watch some kind of disaster movie to give it a workout, although I am elated with it's music use. Yeah, it was a good deal... to me!
John