[net.audio] speaker placement

wjm@whuxl.UUCP (MITCHELL) (08/24/84)

<gulp>
The first rule in speaker placement is to READ THE INSTRUCTIONS.
Most speaker manufacturers design their speakers for a specific place in the
room (regarding distance from walls, floor, etc), and these instructions must
be followed if the speakers are to perform up to specifications.
You should check on placement restrictions before buying speakers to make sure
that they can be used properly in your room.
For example, Klipshorns must be placed in corners, while Bose 901's must be
located several feet from the rear wall to obtain the effects the designers
calculated the design for.
The second rule is to make sure that the speakers are far enough apart that
they can provide a proper stereo image (generally at least 6' - preferably 8').
The third rule is to watch out for standing waves in your room.
If a dimension of your room is an integral number of half-wavelengths at some
audible frequency (generally we are interested in a low number - so the bass
frequencies are the ones to be concerned with) you have a standing wave pattern.
The formula for calculating this is  L = v / f
where L is the wavelength of the frequency in question, v is the velocity of
sound (about 1100 feet/sec) and f is the frequency (in Hertz).
This problem is exacerbated if two or all three of the room's dimensions'
cause standing waves at the same frequencies.
Good luck and happy listening,
Bill Mitchell (whuxl!wjm)

sasaki@harvard.ARPA (Marty Sasaki) (12/31/84)

Thanks to all who answered my plea for speaker recommendations. There
are so many companies and after a while they all look and sound alike.
With your suggestions I've managed to narrow down my listening tests to
a task that I can manage.

This brings up my next question, what about speaker placement? It used
to be that you made sure the speaker was not in the corner of a room and
not resting on the floor. Some speaker manufacturers even recommended
that bookshelf speakers be placed in bookshelves. After these
recommendations it was all trial and error.

Bookshelf speakers all seem to be placed on stands now (at least in the
audiophile stores). The height of the stands seems to place the drivers
at the same height as a seated listeners ears. Is there anything more to
this?

I will probably settle on bookshelf speakers and plan on building stands
with tiptoes built into the stands. Do I need to attach the speakers to
the stands, or will their weight be enough to couple the speakers to the
stands?

Thanks in advance.
-- 
			Marty Sasaki
			Havard University Science Center
			sasaki@harvard.{arpa,uucp}
			617-495-1270

tli@uscvax.UUCP (Tony Li) (01/04/85)

> This brings up my next question, what about speaker placement? It used
> to be that you made sure the speaker was not in the corner of a room and
> not resting on the floor. Some speaker manufacturers even recommended
> that bookshelf speakers be placed in bookshelves. After these
> recommendations it was all trial and error.

Unfortunately, speaker placement is a messy subject.  Optimal placement 
depends on the size of the room, the contents, the material in the wall, and
the price of rice in China ;-).  Fortunately there are a couple of good
heuristics.  Speakers should be roughly 6-12 feet apart.  You should have them 
far enough apart that you image well, but close enough so that the sources
aren't distinct.  (That's redundant, isn't it, isn't it?)

> Bookshelf speakers all seem to be placed on stands now (at least in the
> audiophile stores). The height of the stands seems to place the drivers
> at the same height as a seated listeners ears. Is there anything more to
> this?

Nope.  Conventional drivers tend to radiate spherically, so if your ear isn't 
level with the middle of your speaker, you get more of one driver than another.
I had an opportunity to put my speakers (some trashy towers with lots of 
drivers) up on some dressers.  Their sound improved considerably.

> I will probably settle on bookshelf speakers and plan on building stands
> with tiptoes built into the stands. Do I need to attach the speakers to
> the stands, or will their weight be enough to couple the speakers to the
> stands?
> 			sasaki@harvard.{arpa,uucp}

Depends on the weight of the speakers, how much energy you put into them, etc.
Try it and find out.  If you don't get enough coupling, some friction tape on 
the stands should do the trick.

Cheers, 
Tony ;-)

-- 
Tony Li ;-)		Usc Computer Science
Uucp: {sdcrdcf,randvax}!uscvax!tli
Csnet: tli@usc-cse.csnet
Arpa: tli@usc-ecl