Less bass on the speaker stands than on the floor?

[SAM992]

Ok, so I have noticed that ever since I put my XR50's up from the 3" stands they were on before (effectively at floor level) to my 2.5' tall stands (they are a solidsteel, high quality stand)... I am getting a bit less bass... not bad bass per se, but not as good as it was when they sat nearly on the floor. The system is set up catty corner so that the speakers are about 6' apart.

Carpeted smallish room (12x14) with lots of furniture and other clutter, speaker distance from the wall hasn't changed, and the new speaker stands are on spikes that are pushed all the way thru the carpet onto the concrete below.

Any ideas on why this counter intuitive situation could be happening?

PS.. oddly, moving them back towards the wall increases the bass

[PHC1]

Originally Posted by SAM992

Ok, so I have noticed that ever since I put my XR50's up from the 3" stands they were on before (effectively at floor level) to my 2.5' tall stands (they are a solidsteel, high quality stand)... I am getting a bit less bass... not bad bass per se, but not as good as it was when they sat nearly on the floor. The system is set up catty corner so that the speakers are about 6' apart.

Carpeted smallish room (12x14) with lots of furniture and other clutter, speaker distance from the wall hasn't changed, and the new speaker stands are on spikes that are pushed all the way thru the carpet onto the concrete below.

Any ideas on why this counter intuitive situation could be happening?

PS.. oddly, moving them back towards the wall increases the bass

Nothing odd about that. Bass is reinforced by the near boundaries such as walls and/or objects like furniture. Floor is also a boundary that reinforces the lower octaves.

Room Modes: The input of acoustic energy to the room at the modal frequencies and multiples thereof causes standing waves. The nodes and antinodes of these standing waves result in the loudness of the particular resonant frequency being different at different locations of the room. These standing waves can be considered a temporary storage of acoustic energy as they take a finite time to build up and a finite time to dissipate once the sound energy source has been removed.

[W9TR]

Yep - the floor is a boundary and you will get bass reinforcement just like you will moving the speakers (or yourself) closer to a wall.

Try it for awhile - while the bass output is lower, the bass fidelity and articulation may be better.

[SAM992]

Originally Posted by W9TR

Try it for awhile - while the bass output is lower, the bass fidelity and articulation may be better.

Yes, it appears to be a very frustrating set of tradeoffs.... one of which is aesthetics .. the stands look much nicer.. The diffidence is less apparent when playing at higher volumes, but I'm going to wait to connect the pre-amp (hopefully tomorrow) and see what if any difference that creates to make a final decision..

[PHC1]

Tune the speaker positioning for maximum midrange coherence and bass bloat and overhang free response. If you can't live with that, start inching them in closer to the walls and/or together a bit. A small, musical, good quality sub will do wonders for your speakers/room/smooth bass integration.

[SAM992]

Originally Posted by PHC1

Tune the speaker positioning for maximum midrange coherence and bass bloat and overhang free response. If you can't live with that, start inching them in closer to the walls and/or together a bit. A small, musical, good quality sub will do wonders for your speakers/room/smooth bass integration.

I just moved them back to about 6" from the rear walls (at an 45 degree angle as they're catty corner), from the original 18" ... and it's made a noticeable difference for the better...

[PHC1]

Originally Posted by SAM992

I just moved them back to about 6" from the rear walls (at an 45 degree angle as they're catty corner), from the original 18" ... and it's made a noticeable difference for the better...

Speakers radiating into the acoustic space without encountering parallel boundaries typically sound quite a bit more coherent but much still depends on room modes and what frequencies are reinforced/excited and which are dulled/nulled.

By the way, sound does not propagate in waves as we were always taught. It really is a bubble.

“Sound in air is the transfer of periodic movements between adjacent colliding atoms or molecules. This sonic energy typically expands away from the site of the collisions as a spherical or bubble-shaped emanation.”