formula for determing size of speakers per cu.ft.

[Xsound]

Obviously the larger the room, the more presence you need from your speakers, but how do you determine when to move up and how large to go?
Anyone have a formula or rule of thumb to help in determining this?

thnx
X

 

[j_garcia]

There is a formula, but it isn't exactly a simple one. This may help though:

http://www.myhometheater.homestead.com/splcalculator.html#anchor_13193

 

[Sheep]

Thats a cool calculator. It only goes to 120dB on the chart. When I was in a band in highschool, we practiced at 125dB's when we were in the recording studio. It was pretty bad. We were give the title the Threshold of Pain.


SheepStar

 

[Xsound]

that is a really cool calculator, but not quite what I was looking for. What I am wondering is at what size room do you know you need to move from bookshelf to floorstanding? Is there a point where you know the room overpowers the speakers?

 

[j_garcia]

Bookshelf vs floorstanding doesn't really matter; what matters is if you are getting the desired SPL at your listening position and that is determined by how much sound a given speaker can achieve with the available (actual) power rating. Though rather basic, that calculator should actually give you a very good idea of what you will get with a given speaker. There is no rule of thumb for your specific question that I am aware of.

I have a ~4000+ cf room and I am using all bookshelf speakers.

 

[mulester7]

.....guys, would our speakers sound better if the whole room was sound-proofed?....the initial cone-of-dispersion from a front-firing main's regiment passing through one time, and that's it?.....would this be better with nothing reflected for hall or auditorium realism ambience within the chamber?....I say get some halfway normal room conditions and let 'er rip....if you ain't got carpet, get wall drapes....they're much cheaper than two-sided ones that meet....

 

[Xsound]

Bookshelf vs floorstanding doesn't really matter; what matters is if you are getting the desired SPL at your listening position and that is determined by how much sound a given speaker can achieve with the available (actual) power rating. Though rather basic, that calculator should actually give you a very good idea of what you will get with a given speaker. There is no rule of thumb for your specific question that I am aware of.

I have a ~4000+ cf room and I am using all bookshelf speakers.

In theory I understand what you are saying JG, but it is hard for me to fathom that the HSU Ventriliquist system with it's 90db sensitivity

http://www.hsustore.com/vt12.html

will have more of an impact and higher spl than say 5 of these Monitor Audio gold 20's with an 89 db sensitivity

http://www.monitoraudiousa.com/products/gold/series/Gold_Reference_20.htm

assuming that both are powered by the same amp, in the same room.

 

[annunaki]

More drivers or larger drivers yield more surface area. Thus moving more air per watt of input resulting in higher or the potential for higher spl #'s. It will also be driven more efficently.This law cannot be ignored. The in room spl calcultaor is to get one in the ballpark. It was not designed to be exact.

 

[philh]

There is a formula, but it isn't exactly a simple one. This may help though:

http://www.myhometheater.homestead.com/splcalculator.html#anchor_13193

Hmmm

3. The distance from the speaker to the listening position. Expressed in feet. If you know the distance in meters, divide by 3 to get an appoximation in feet

 

[mfabien]

Hmmm

3. The distance from the speaker to the listening position. Expressed in feet. If you know the distance in meters, divide by 3 to get an appoximation in feet

1 meter = 3.28 feet. Therefore a multiplication would be indicated rather than a subtraction.

 

[Shadow_Ferret]

Interesting. According to that I can reach 110.7 db. I was hoping for the threshold of pain.

Something I can't seem to reach until I get a 300 watt amp.

Guess bigger isn't necessarily better.

 

[mulester7]

Interesting. According to that I can reach 110.7 db. I was hoping for the threshold of pain.

Something I can't seem to reach until I get a 300 watt amp.

Guess bigger isn't necessarily better.

.....Shadow, it's all about sound quality at sweet-spot levels....step out in the water, my Son.....

 

[Shadow_Ferret]

I enjoy quality, too. Can't you have loud and quality?

I'm not sure what you mean by sweet-spot level, but I still enjoy listening to rock at reference levels, even at my advanced age.

Still, when I play the 1812 Overture, I want those canons to sound REAL.

 

[mulester7]

I enjoy quality, too. Can't you have loud and quality?

.....absolutely, Shadow....you know the route....sweet-spot levels are YOUR reference-levels....pitch that RatShack spl meter in the trash....it's a huge crutch....and misleading....ears, ears, ears......

 

[Buckle-meister]

Bookshelf vs floorstanding doesn't really matter; what matters is if you are getting the desired SPL at your listening position...

Um, not sure I agree with this. If I use two bookshelves as opposed to my towers, the sound is not the same at all, therefore I would argue that bookshelf vs floorstanding does matter.

Disregarding sensitivity because with a suitably powerful amp, both speakers can be made to sound as loud as each other, my bookshelves have to be placed almost hard up against the wall to reinforce the bass to sound anything close to the towers, and even then they fail.

Maybe I'm missing something though...

Regards

 

[Shadow_Ferret]

.....absolutely, Shadow....you know the route....sweet-spot levels are YOUR reference-levels....pitch that RatShack spl meter in the trash....it's a huge crutch....and misleading....ears, ears, ears......

Oh, I don't own an SPLmeter. I don't have a home theater yet. I have 2 channel stereo. I was using that formula posted on the previous page.

http://www.myhometheater.homestead.com/splcalculator.html#anchor_13193

Buckle-Meister,
I'm in total agreement. I've always maintained that you need floor-standers to get full rich all-encompassing sound. Real floorstanders, with multiple drivers.

Not to say you can't get good QUALITY from bookshelves, just that I don't believe they can fill a room with sound as fully as a floor-stander.

 

[annunaki]

More drivers per speaker results in higher system efficency. Meaning more of each watt is turned into sound. A tower system will sound much less strained at higher spl levels than bookshelves. Sensitivity aside, towers will typically get louder due to having more surface area. This can result in cleaner dynamic capability.

 

[j_garcia]

Not to say you can't get good QUALITY from bookshelves, just that I don't believe they can fill a room with sound as fully as a floor-stander.

Well, if you take the Studio 40 vs 60, you'll see what I'm talking about. The drivers are identical, sensitivity is actually a bit lower on the 60s, thus they will fill the room with roughly the same amount of sound for a given input; the only difference is the 60s have a larger cabinet and lower tune so they definitely have more bass than the 40s, but they won't fill the room any more sound.