clamping speaker mount. how it effects sound?

[kikonenko]

Hi, this is my first post heh. I've been reading AH for quite awhile and it helped me a lot.

I'm no audio expert but i'd like to wall-mount my rear bookshelf speakers above ear level for a better delocalization of the surround channels. My speakers aren't threaded, so i thought i might use these (google image: clamping speaker mount). I'm concerned though that this might have some ill-effect(s) on the sound. My reasoning(plz forgive my ignorance):

if you pinch a guitar string with two fingers, and while pinched you pick it, it will sound very very different (and much quieter, almost silent) then picking it normally. That must happen because you couple your body mass to the string, so it can't resonate/vibrate. Something similar woud happen when you fasten the speaker to the mount with a strap or clamp the sides of it like in those clamp mounts, like you don't let the cabinet resonate in its natural frequencies and attenuate a wide frequency range (esp. trebles, which i love) from the sound output because it's coupled to the wall which absorbs them, right? (quoted from wiki "Sometimes considered part of the enclosure, the base may include specially designed "feet" to decouple the speaker from the floor.")

I couldn't find any info and would really appreciate acoustic experts words on this.

A more generic question/worst case possible would be: if i fit a speaker cabinet in a wall cavity and fill it all around with concrete, leaving just the front of the speaker flush with the wall, would this immobilized speaker not sound at all, or sound very different than resting on a footstand?


Thank you very much for your help.

[lsiberian]

Hi, this is my first post heh. I've been reading AH for quite awhile and it helped me a lot.

I'm no audio expert but i'd like to wall-mount my rear bookshelf speakers above ear level for a better delocalization of the surround channels. My speakers aren't threaded, so i thought i might use these (google image: clamping speaker mount). I'm concerned though that this might have some ill-effect(s) on the sound. My reasoning(plz forgive my ignorance):

Wall-mounting a speaker is normally a bad idea unless it's designed to be wall mounted. Also you want the tweeter to always be aimed toward the ears for accurate response.

1. You might have a bad seating placement(couch against the wall)

2. You might have bad speaker placement in 5.1 surrounds are side(not rears)

3. You might be too close to the speakers.(1 meter from the speaker to your ear is a bad thing)

4. You might be crazy.(Sometimes we can manufacture issues in our head and need to grab a favorite beverage and just enjoy the movie.)

I think 4 is definitely true for all of us here. Moving the speakers up can help with 2 and 3, but it won't fix issues with number 1. Make sure you aim the tweeter at your ears wherever you put the speakers.

I've found in some situations adding additional surrounds really helps.(This should be a last resort though)

Don't get too carried away with resonance science these are surrounds.

[kikonenko]

Hey thanks . I've done a lot of reading about setup, and got it almost perfect. listening position is same distance for center and fronts (an arc) with fronts in an equilateral triangle. and rears are about 120 degrees (i like them a little behind, not firing oposite to each other at my ears). Now the surrounds are on top of a pile of boxes (poor man's footstands ^^), but since everyone recommends them to be at standing ear height, and i can't find footstands that high, i decided to use wall mounts. i also don't like them being 8" close to the wall, but i have some acoustic treatment plans in mind for the summer

You can definitely count me in the crazy club heh.

Just for the peace of mind though, could you point out the flaws in my reasoning? i really think it is flawed because otherwise who's buying those clamp mounts?

edited (excuse my use of rears and surrounds interchangeably, i do understand that rears are not meant for 5.1, but i sometimes call them rears because they really are a little behind of me, although closer to my sides).

[lsiberian]

Hey thanks . I've done a lot of reading about setup, and got it almost perfect. listening position is same distance for center and fronts (an arc) with fronts in an equilateral triangle. and rears are about 120 degrees (i like them a little behind, not firing oposite to each other at my ears). Now the surrounds are on top of a pile of boxes (poor man's footstands ^^).

You can get speaker stands for nearly any height. Or you can make them assuming you have access to a home depot. A couple plates of wood with a couple pieces of 2 x4s would work.

[kikonenko]

I thought about building them myself but i've never used a welder before and really $30+shipping for a pair of speaker mounts is dirt cheap, but i'll ask a hardware shop tomorrow anyway, maybe they could get it done for me. I haven't seen any set of solid steel stands, and that would be perfect because sand filled ones seem a bit wobbly, specially with as little as 6"x6" which seems to be the standard for retail.

Thanks for the advice lsiberian. I'll post back when i find something, hopefully soon.

[kikonenko]

Hey . I asked in the hardware store but they're asking me big money for what i want, and didn't look very professional either so i'll skip on that one. Why do you think wall mounting isn't a good alternative? Is it because of reflections? I mean i'm going to put acoustic absorbent panels behind them and at 1st reflection points so being close to the wall shouldn't be a problem right?.

[lsiberian]

A pair of Sanus speaker stands would work.

Bookshelves are specifically designed to operate off the wall. Acoustic treatment can help, but you still have issues with baffle step. Hanging from the ceiling is also a good option.

FYI treating first order reflections is a bad practice. You lose a lot of your acoustic energy from a reflection that actually enhances sound.

[j_garcia]

Something similar woud happen when you fasten the speaker to the mount with a strap or clamp the sides of it like in those clamp mounts, like you don't let the cabinet resonate in its natural frequencies and attenuate a wide frequency range (esp. trebles, which i love)

The cabinet should ideally be as inert as possible. If a clamping mount, which uses foam to isolate the speaker from the clamp, should have ZERO effect on any given speaker. It sounds like you are talking about a lot of theoretical stuff and haven't actually TRIED anything yet. Get the speakers, listen to them, go from there.

[kikonenko]

Will do . And thanks for the foam tip