My Polk Lsi 705's needs an economy subwoofer

Not a lot of money, and I have to order them because I live in a place with no audio stores. What's a good sub in the $150--250 range? I am particularly looking for something that performs well at relatively low volume. It will be in a large rectangular room with 11 foot ceilings and lots reflections -- a glass door and bouncy concrete walls.
Comments
Big room, sub to hit lower than the 705's, for under 250 ? Maybe Dayton subs, but I won't commit to the quality of the sound as compared to others.
Subs don't usually do well for low volumes.
My guess is your problem is elsewhere in your system, those 705's can belt out some decent low end. What are you driving the 705's with ?
Sony 850c 4k
Pioneer elite vhx 21
Sony 4k BRP
SVS SB-2000
Polk Sig. 20's
Polk FX500 surrounds
Cables-
Acoustic zen Satori speaker cables
Acoustic zen Matrix 2 IC's
Wireworld eclipse 7 ic's
Audio metallurgy ga-o digital cable
Kitchen
Sonos zp90
Grant Fidelity tube dac
B&k 1420
lsi 9's
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk
There will be compromises in a budget subwoofer, but they can be minimized for $249. At $150 there isn't much worth looking at. Check out Amazon for other offerings like the Polk PSW505, Elac S10, Klipsch R-10SWi.
A subwoofer and low volume tends to not make much sense. Why have a subwoofer at all if you're not going to crank it up and use it? The LSiM705s will not benefit from an added subwoofer at low listening levels.
If you decide to upgrade to better gear later to better suit the large room, move the bargain subwoofer to an office or bedroom system.
2. JM Labs Electra 920.1; Parasound JC2 and JC5; Sony HAP-Z1ES; Marantz SA8004 SACD; Music Hall MMF7 and Acoustech phono pre; PS Audio P1000; MIT S1 Cables
3. Polk LSiM703; Anthem Pre-2L SE; Parasound A21; Sony 48" 4K TV; Wyred4Sound DAC 2; Oppo 203; Squeezebox Touch; PS Audio Power Director 4.7; MIT S3 cables
Or, shameless plug, my yamaha that I am selling is much heavier and much better sounding than that onkyo. http://forum.polkaudio.com/discussion/179720/yamaha-rx-a1010-and-parasound-hca-1000a#latest
Game Room HT: Denon AVR-X4200w; Sony UBP-x700; Definitive Technology SM450; Definitive Technology LCR2000; Definitive Technology StudioMonitor350; Mirage Nanasats; Sub - HSU VTF-2 MK5
Master Bedroom
Cambridge Azur 551r; Definitive Technology promonitor 800; ACI Titan Subwoofer
Obviously your losing bass response at lower volume levels, which for the most part, is somewhat normal. A sub isn't going to help with that. More power will help some, and that receiver is pretty weak when it comes to power.
Your choices as I see it, is....
A- buy a better more powerful receiver. Make sure it has preouts to be able to add an amplifier down the road. Yours doesn't, which limits your abilities.
B- if your system is just for music listening, move away from receivers and get a pre-amp/amplifier combo when the 'ol wallet allows.
you can add a subwoofer if you want, but in your price range finding one that will dig deeper than your speakers is going to be tough. Especially if you have a large room. Bigger the room, bigger the sub needs to be to pressurize that room.
As for what you have right now, some things you can check is....
Are your speakers set to full range ?
Are speaker levels set to 0 or slightly in the + side ?
Is your receiver set to "no subwoofer" or none, if you don't have one now.
Hope that helps ya out some, let us know how it goes.
Sony 850c 4k
Pioneer elite vhx 21
Sony 4k BRP
SVS SB-2000
Polk Sig. 20's
Polk FX500 surrounds
Cables-
Acoustic zen Satori speaker cables
Acoustic zen Matrix 2 IC's
Wireworld eclipse 7 ic's
Audio metallurgy ga-o digital cable
Kitchen
Sonos zp90
Grant Fidelity tube dac
B&k 1420
lsi 9's
Parts Express kind of runs the gamut vis-a-vis subwoofer options: from the ridiculous to the (relatively speaking) sublime, FWIW.
https://www.parts-express.com/cat/powered-subwoofers/95
FWIW, I have (had) a cheap powered subwoofer for a long time -- a 10" ported powered "Atlantic Technologies" brand buyout from Parts Express. It did its job, but was kind of one-note and not particularly 'musical' (for lack of a better term).
Recently upgraded to something in another league entirely, though.
2. JM Labs Electra 920.1; Parasound JC2 and JC5; Sony HAP-Z1ES; Marantz SA8004 SACD; Music Hall MMF7 and Acoustech phono pre; PS Audio P1000; MIT S1 Cables
3. Polk LSiM703; Anthem Pre-2L SE; Parasound A21; Sony 48" 4K TV; Wyred4Sound DAC 2; Oppo 203; Squeezebox Touch; PS Audio Power Director 4.7; MIT S3 cables
Still, imho....a big room, lower volumes, and a cheap sub = you just wasted your money.
Sony 850c 4k
Pioneer elite vhx 21
Sony 4k BRP
SVS SB-2000
Polk Sig. 20's
Polk FX500 surrounds
Cables-
Acoustic zen Satori speaker cables
Acoustic zen Matrix 2 IC's
Wireworld eclipse 7 ic's
Audio metallurgy ga-o digital cable
Kitchen
Sonos zp90
Grant Fidelity tube dac
B&k 1420
lsi 9's
"No, that's silly talk. Dude, you can't possibly be this audio dumb so quit the act." - Doro