Raising a sub off the floor

[3db]

Please don't shoot the messenger of this post, me!!! I've just read in another forum that raising the sub 25% of ceiling height improves bass SQ to reduce reflections off the ceilings. Is there any truth to this?

 

[ski2xblack]

I think it's the same rationale as using subs at different spots in the room, Geddes style, only including the vertical dimesion too. So there is probably some technical merit to it. The ceiling reflections part is incorrect, it's more to do with modal smoothing.

 

[ryanosaur]

I've seen this mentioned in several places, too. It is absolutely about where the source of the wavefront is located and the interaction with the different room modes.
As to efficacy, I've never experimented with trying to build risers for my 100# Subs.
Based on my intermediate understanding of room acoustics, it passes the sniff test IMO. (Compared to things like replacing power cables and cr@p like that. )

Anyway, one YT video I stumbled on had the guy advocating for three subs at different heights and room locations in a reasonably spaced HT build. *shrugs

Might be fun to try. But consider how much difficulty people have setting up just 2 Subs in 2-dimmensional space! Add that vertical dimmension and watch the Rabbit Hole really deepen!

 

[ski2xblack]

I've never experimented with trying to build risers for my 100# Subs.

I can see the obit now:
"He was a kind person, a generous person, and one who enjoyed high quality music reproduction. Alas, it was his pursuit of smooth modal response that brought about his demise when he was tragically crushed while trying to mount a large subwoofer 4' off the floor..."

 

[lovinthehd]

Well you could always remove the amp/driver to help out a bit....but I've never really wanted to lift mine/stack mine either.

 

[WaynePflughaupt]

It should be considered that most of what you see regarding subs is only “good” for the room used for the report. Unless your room is remarkably similar, it probably will be of little benefit to you.

Regards,
Wayne A. Pflughaupt

 

[VMPS-TIII]

If you can pick up the sub and put it on a higher platform each day, no need to workout.

 

[William Lemmerhirt]

I've seen this mentioned in several places, too. It is absolutely about where the source of the wavefront is located and the interaction with the different room modes.
As to efficacy, I've never experimented with trying to build risers for my 100# Subs.
Based on my intermediate understanding of room acoustics, it passes the sniff test IMO. (Compared to things like replacing power cables and cr@p like that. )

Anyway, one YT video I stumbled on had the guy advocating for three subs at different heights and room locations in a reasonably spaced HT build. *shrugs

Might be fun to try. But consider how much difficulty people have setting up just 2 Subs in 2-dimmensional space! Add that vertical dimmension and watch the Rabbit Hole really deepen!

Brother, it just went from rabbit hole to worm hole!!!!!

But I agree. It seems reasonable and does follow acoustic principles. But for me, I think acceptable behavior can be found in lateral space without going up so long as there’s some room to play with placement and/or EQ. Even if raising a sub does offer some benefits, I think that they’re outweighed by practicality. And waf... And like Wayne said, just because it worked for one room doesn’t mean it will work for another.

 

[ryanosaur]

I found it!
One of the sources I had seen, at least.

Ideal Subwoofer Placement & Pressurization – Acoustic Fields

Today we're going to talk about subwoofer placement and pressurization because a subwoofer is really a pressurization device...

www.acousticfields.com

Some of his stuff is interesting. I like that he won't consult on a room unless it has something like 14' ceilings. Everything else is too low for decent acoustics, according to him. *shrugs

Anyway... I'm intrigued, and believe me when I say I have thought about the logistical feet of getting a 100# sub up into the loft in my room... but no. Now maybe if I switch these out and put DIY subs in my room... *scratches chin thoughtfully
Anyway.... Two subs on the floor. Sloped Clerestory Ceiling helps with some of those modes! That's it.

 

[William Lemmerhirt]

I found it!
One of the sources I had seen, at least.

Ideal Subwoofer Placement & Pressurization – Acoustic Fields

Today we're going to talk about subwoofer placement and pressurization because a subwoofer is really a pressurization device...

www.acousticfields.com

Some of his stuff is interesting. I like that he won't consult on a room unless it has something like 14' ceilings. Everything else is too low for decent acoustics, according to him. *shrugs

Anyway... I'm intrigued, and believe me when I say I have thought about the logistical feet of getting a 100# sub up into the loft in my room... but no. Now maybe if I switch these out and put DIY subs in my room... *scratches chin thoughtfully
Anyway.... Two subs on the floor. Sloped Clerestory Ceiling helps with some of those modes! That's it.

I am seeing IB in your future..... hopefully not ICU lol!!!

 

[mazersteven]

IB Subs are very cool if you do them right.

 

[pcosmic]

Please don't shoot the messenger of this post, me!!! I've just read in another forum that raising the sub 25% of ceiling height improves bass SQ to reduce reflections off the ceilings. Is there any truth to this?

If this were true, you would see folks like Dr Hsu, Rythmik Brian, Danny Richie, etc ask you to suspend their subs in mid air eh? I haven't heard such things from any of those guys

 

[pcosmic]

I can see the obit now:
"He was a kind person, a generous person, and one who enjoyed high quality music reproduction. Alas, it was his pursuit of smooth modal response that brought about his demise when he was tragically crushed while trying to mount a large subwoofer 4' off the floor..."

The best smoothve can only be obtained from a 15 inch sub if you raise it off the floor, seat it kindly on your lap and look directly into it. There is a undescribable smoothve (nirvana) in such a optimized listening scenario....smoothve bass...smoothve bass....smoothvee...it starts to sound even smoothver if you pat that sub gently.

 

[ryanosaur]

I am not here to argue for this implementation.

If this were true, you would see folks like Dr Hsu, Rythmik Brian, Danny Richie, etc ask you to suspend their subs in mid air eh? I haven't heard such things from any of those guys

That they do not, does not make the concept any less valid as a hypothesis for treating In-Room Low Frequency Acoustics.

 

[lovinthehd]

However, you can see what stacked subs have done in the AH setup as well as various setups by Mark Seaton and others....

 

[ryanosaur]

I am seeing IB in your future..... hopefully not ICU lol!!!

I wonder what would happen if you were to design a room with IB subs mounted at a Golden Mean point on each surface, perhaps excluding the floor....
Is it too late to get @gene to include this in his build?

 

[William Lemmerhirt]

However, you can see what stacked subs have done in the AH setup as well as various setups by Mark Seaton and others....

True. But I think the point was
co-location more than raising one off the floor.

 

[pcosmic]

How can i transform from full audioholic to audioholic slumlord? Do i need to suspend subs in mid air?

 

[ryanosaur]

Do i need to suspend subs in mid air?

That may qualify you for Audioholic Jedi. But only if you do it through force of will alone. Bungee cables don't count.

 

[lovinthehd]

True. But I think the point was
co-location more than raising one off the floor.

I was thinking more of vertical room modes vs horizontal room modes from sub positioning....