[eclein]

I read a post over on AN about raising the subwoofer up off the floor and so I grabbed a box and hoisted the sub up on that baby maybe only 8-9 inches off the floor but it definitely helped put definition in the low end...I would get occasional what I call "boomy" kick drum and low end blooming and boy just raising the sub that small amount really makes a difference..I know there is a formula to follow but right now-"one box up" rule is pretty easy and is just nice sounding...FWIW

[srb]

If you can put the subwoofer on something that won't give, flex or move, like cement, granite, stone or dense wood blocks, I would bet that the bass would firm up even more.
 
Steve

[timind]

Concur. I placed my sub on a 3 inch thick maple block with 1 inch cones under the block. The difference was noticeable. I had to turn the sub level up a bit to get the same volume but it was much cleaner.

[BobM]

I have a down firing REL Strata III sub and it noticeably improved when I turned it upside down, so it was firing upward. I did put a heavy board on top of the now upturned feet with something heavier on top of that.

Prior to that I moved it out of the corner, and that too tightened up and improved the top end. Conventional wisdom often needs to be challenged.

[eclein]

Apparently eliminating a boundry-in this case the floor which I never thought of-helps free up the sound. I will look for a solid base now to perch it on..the height I have now is just right so as not to interfere with TV viewing etc..as I have the sub out in front of my TV but on the same plane as the speakers. I guess room treatments are my next logical step to really tuning in my sound...this is proving to be quite a bit a fun I must say!!

[rollo]

 It is reccomended that the subwoofer driver centerline is off the floor 22% of your floor to clg. hgt. Biggest improvement in bass in my room. Mine now sits approx. 18" off the floor. never going bck.


charles
 

[RUR]

It is reccomended that the subwoofer driver centerline is off the floor 22% of your floor to clg. hgt. Biggest improvement in bass in my room. Mine now sits approx. 18" off the floor. never going bck.

Charles, what's the source for that figure?  Just curious.

[Rob Babcock]

My subs sit on the floor but it would be easy to construct a riser for them (2 x TN1220 Hsu subs- small footprint and not very heavy).  It might be worth a try.

[eclein]

Rob stick'em on a box and check it out...like getting a new sub...very cool stuff.

[pumpkinman]

Ed I have some concrete blocks I used to raise some speaker stands to reach the proper height till I bought taller stands
I could drop them off to you if you like...............Bill

[eclein]

Bill..I kind of like my box...it works fine: concrete + your back = no way brother but I appreciate the thought

[pumpkinman]

Bill..I kind of like my box...it works fine: concrete + your back = no way brother but I appreciate the thought

That's why they make hand carts Ed     

[BrianP]

I got good results putting mine on a stack of concrete pavers (4 x 3" thick), with layers of closed cell foam between the pavers, and between the sub and the top one. Tighter, punchier sound and better pitch definition of the real low notes.

[eclein]

So I finally got around to filling the boxes with heavy books...I'm a bit slow to act sometimes. Immediate difference, much better definition than even before. I'm resting my hand on the sub and thinking if its vibrating then the boxes being empty is like a resonance chamber underneath it...AHA!!! I knew these books would be handy someday!!! 

[nats]

It is reccomended that the subwoofer driver centerline is off the floor 22% of your floor to clg. hgt. Biggest improvement in bass in my room. Mine now sits approx. 18" off the floor. never going bck.


charles
 

would best be raising just at the feet so the down firing sub sees the floor at 22% or a solid riser?

[BobM]

I think a down firing sub is optomozed so the feet are a certain distance from a solid object, the floor, so as to maximize the pressure wave squeezing out through that gap. If you raise it off the floor, or turn it upside down, I would guess it is best to maintain that measured gap space.

I turned mine upside down and put a board on top of those upturned feet with something heavy on top of that. It worked best for me that way rather than just haveing the open sub firing up into the air.