Room acoustics

[jeffc[_2_]]

I'm searching for a new house to live in, and one of the criteria is a nice
room to be used as a dedicated stereo room (2 channel). I'm looking at one
house that doesn't have a room yet, but has the space for it. It's a
prewired for power and prevented for HVAC. Basically an unfinished bonus
room over the garage.

The problem is, it's not exactly a rectangle shape. Although it is
symmetrical. But I just don't know how the shape of the room might affect
the acoustics. Basically it has 2 rafters that would jut below the ceiling
at one end of the room (this could be either the listening end or speaker
end). I don't have photos, which I could get next time I look at the house,
but in the meantime is there a starting point for me to learn more about the
negative (or positive) affects of these sorts of room idiosynchrasies?

[MiNe 109]

In article >,
"jeffc" > wrote:

> I'm searching for a new house to live in, and one of the criteria is a nice
> room to be used as a dedicated stereo room (2 channel). I'm looking at one
> house that doesn't have a room yet, but has the space for it. It's a
> prewired for power and prevented for HVAC. Basically an unfinished bonus
> room over the garage.
>
> The problem is, it's not exactly a rectangle shape. Although it is
> symmetrical. But I just don't know how the shape of the room might affect
> the acoustics. Basically it has 2 rafters that would jut below the ceiling
> at one end of the room (this could be either the listening end or speaker
> end). I don't have photos, which I could get next time I look at the house,
> but in the meantime is there a starting point for me to learn more about the
> negative (or positive) affects of these sorts of room idiosynchrasies?

Try the FAQ at Cardas.

Stephen

[Kalman Rubinson]

On Sun, 29 Apr 2007 20:57:50 -0400, "jeffc" > wrote:

>I'm searching for a new house to live in, and one of the criteria is a nice
>room to be used as a dedicated stereo room (2 channel). I'm looking at one
>house that doesn't have a room yet, but has the space for it. It's a
>prewired for power and prevented for HVAC. Basically an unfinished bonus
>room over the garage.
>
>The problem is, it's not exactly a rectangle shape. Although it is
>symmetrical. But I just don't know how the shape of the room might affect
>the acoustics. Basically it has 2 rafters that would jut below the ceiling
>at one end of the room (this could be either the listening end or speaker
>end). I don't have photos, which I could get next time I look at the house,
>but in the meantime is there a starting point for me to learn more about the
>negative (or positive) affects of these sorts of room idiosynchrasies?

Nothing you have mentioned so far suggests any acoustical problems.
Dimensions and construction/materials are more important.

Kal

[jeffc[_2_]]

"Kalman Rubinson" > wrote in message
...
>> Basically it has 2 rafters that would jut below the ceiling
>>at one end of the room (this could be either the listening end or speaker
>>end). I don't have photos, which I could get next time I look at the
>>house,
>>but in the meantime is there a starting point for me to learn more about
>>the
>>negative (or positive) affects of these sorts of room idiosynchrasies?
>
> Nothing you have mentioned so far suggests any acoustical problems.
> Dimensions and construction/materials are more important.

Well, I wasn't very clear about the "rafters". Since they angle down, that
means the ceiling would slope downward to follow them. The rafters are
about 12" wide, so either they would jut below the ceiling, or the ceiling
would have to be installed a foot lower, to follow them rather than the
regular ceiling joists.

[Arny Krueger]

"jeffc" > wrote in message

> I'm searching for a new house to live in, and one of the
> criteria is a nice room to be used as a dedicated stereo
> room (2 channel). I'm looking at one house that doesn't
> have a room yet, but has the space for it. It's a
> prewired for power and prevented for HVAC. Basically an
> unfinished bonus room over the garage.
> The problem is, it's not exactly a rectangle shape.

If its not a square, this may be good news.

> Although it is symmetrical. But I just don't know how
> the shape of the room might affect the acoustics.

Non-parallel walls are generally considered to be a good thing, within
reason.

> Basically it has 2 rafters that would jut below the
> ceiling at one end of the room (this could be either the
> listening end or speaker end). I don't have photos,
> which I could get next time I look at the house, but in
> the meantime is there a starting point for me to learn
> more about the negative (or positive) affects of these
> sorts of room idiosynchrasies?

What ideosyncracy? Normal rafters in a room have negligable acoustical
properties. If anything they are diffusers, and generally speaking diffusion
outside the direct path for sound is a good thing. Worry about walls,
floors, and large flat expanses of ceiling.

[Arny Krueger]

"jeffc" > wrote in message

> "Kalman Rubinson" > wrote in message
> ...
>>> Basically it has 2 rafters that would jut below the
>>> ceiling at one end of the room (this could be either the
>>> listening end or speaker end). I don't have photos,
>>> which I could get next time I look at the house,
>>> but in the meantime is there a starting point for me to
>>> learn more about the
>>> negative (or positive) affects of these sorts of room
>>> idiosynchrasies?
>>
>> Nothing you have mentioned so far suggests any
>> acoustical problems. Dimensions and
>> construction/materials are more important.
>
> Well, I wasn't very clear about the "rafters". Since
> they angle down, that means the ceiling would slope
> downward to follow them. The rafters are about 12" wide,
> so either they would jut below the ceiling, or the
> ceiling would have to be installed a foot lower, to
> follow them rather than the regular ceiling joists.

Sloped segments of ceiling are generally good. Cathedral ceilings generally
sound better than low, flat ceilings.

[dizzy]

jeffc wrote:

>The problem is, it's not exactly a rectangle shape. Although it is
>symmetrical.

That's a problem? The less cubic the room is, the better.

If the room is a conventional "rectangular" room, ideally the
dimensions vary by the golden ratio, i.e. with 8' height, a good width
would be 13' and the length 21". This reduces resonances, which are
an unfortunate fact of indoor audio, but are worst when
room-dimensions are the same or multiples of each other.

*The above pretty-much describes my listening room, and if anyone
thinks that I didn't notice and appreciate this before I bought the
house, they would be sadly mistaken. 8)

[ScottW]

On Apr 29, 5:57 pm, "jeffc" > wrote:
> I'm searching for a new house to live in, and one of the criteria is a nice
> room to be used as a dedicated stereo room (2 channel). I'm looking at one
> house that doesn't have a room yet, but has the space for it. It's a
> prewired for power and prevented for HVAC. Basically an unfinished bonus
> room over the garage.

I'd say your biggest issue is being over the garage unless you live
alone.
My room is over my garage and I'm very glad I thoroughly insulated the
floor
to limit sound from the garage.

ScottW

[Kalman Rubinson]

On Sun, 29 Apr 2007 23:19:57 -0400, "jeffc" > wrote:

>
>"Kalman Rubinson" > wrote in message
...
>>> Basically it has 2 rafters that would jut below the ceiling
>>>at one end of the room (this could be either the listening end or speaker
>>>end). I don't have photos, which I could get next time I look at the
>>>house,
>>>but in the meantime is there a starting point for me to learn more about
>>>the
>>>negative (or positive) affects of these sorts of room idiosynchrasies?
>>
>> Nothing you have mentioned so far suggests any acoustical problems.
>> Dimensions and construction/materials are more important.
>
>Well, I wasn't very clear about the "rafters". Since they angle down, that
>means the ceiling would slope downward to follow them. The rafters are
>about 12" wide, so either they would jut below the ceiling, or the ceiling
>would have to be installed a foot lower, to follow them rather than the
>regular ceiling joists.

OK. Same comment.

Kal

[jeffc[_2_]]

"dizzy" > wrote in message
...
> jeffc wrote:
>
>>The problem is, it's not exactly a rectangle shape. Although it is
>>symmetrical.
>
> That's a problem? The less cubic the room is, the better.

Yes, basically I was saying I think a rectangle is better than a cube, but
it's not a rectangle - it's an odd shape, which makes it less predictable, I
guess.