[MGDunagan]

I'm looking for the acoustical prediction speedsheet that Russ Herschelmann talks about all the time. It seems he is updating his web pages and I can't find any links to this tool. Anybody have a copy of it?


I would also be interested in any other software recommendation of predicting the acoustics in rooms of given sizes.


Thanks,


Mark

 

[Savant]

Mark,


I like CARA: www.cara.de, or www.rhintek.com in the US. The loudspeaker and absorber databases leave something to be desired and the interface is not 100% intuitive, but the program is surprisingly inexpensive for what it's capable of in terms of modeling.

 

[jamin]

MGDunagan,


Terry Montlick lists some additional choices here:
http://www.avsforum.com/avs-vb/showt...78#post4535778

 

[Terry Montlick]

Quote:

Originally posted by jamin MGDunagan, Terry Montlick lists some additional choices here: http://www.avsforum.com/avs-vb/showt...78#post4535778

"Odeon, CATT Acoustics, etc. "


These are more accurate, but are ENORMOUSLY expensive because they are sold to professional acoustical consulting firms. We're talking several thousand dollars minimum! Despite its significant limitations as an acoustical ray-tracer, CARA cannot be beat for the price.


- Terry

 

[MGDunagan]

Thanks for your replies. Perhaps I should have called this thread "The RIGHT size HT room" or "Optimizing Room Dimensions". Cara is a good piece of software when you have an existing room and want to optimise speaker location. I'm designing a room from scratch and want to make adjustments to over-all room dimentions. Russ Herchelmann has been providing an excel spread sheet (The Sweet Spot) for this purpose but I cant find a copy. (It seems his websites are under construction.)

 

[Rutgar]

Terry's site also has a great little Room Demension calculator.


And it's free.

 

[HendersonD]

I wrote the spreadsheet that Russ refers to, if you let me know your e-mail address I will send it along


Dave

 

[Fatman513]

 Here's what you're looking for.

 

[MGDunagan]

I was just going to report back that I found the spread sheet and to give credit to Dave Henderson for creating it. "guidetohometheater" is backup and running. Thanks for all the help.

 

[Rutgar]

That's a pretty interesting spreadsheet. One thing though; In the article, he says to avoid all nulls when placing seating. According to the spreadsheet, on the room I'm planning to build, the seating positions both have a single null at 282.3 Hz. It's my basic understanding of acoustics, that I could ignore this null, since it's well above the modal region of the room.


Any thoughts?

 

[MGDunagan]

I ended up using Terry's Room Demension calculator to get me in the ballpark and then Henderson's spreadsheeet to fine tune my demensions.

I could not believe the difference a single inch could make in terms of problem freq. This Brings me to the next few question..........


1.) Anybody get problem freq. below 6?


2.) More importantly...Would the room dimensions that I've come up with using the speadsheet be inside measurements after wall treatment or to hard surface?


P.S. Good question Rutgur, I noticed that the spread sheet (HendersonTool) stops counting problem freq. at 300 hz.

 

[jasplat88]

When I designed my room using this same spreadsheet. It says that I have 4 problem frequencies, but I think Ethan and others can chime in that it is equally important on what those frequencies are and how close they are to each other.


I used the spreadsheet more as a guide as the spreadsheet models based on a perfect and predictable world......unforunately, I can not build that, but I figured it would get me a lot closer than pulling room dimensions out the the air. Just food for thought!


-Jason

 

[MGDunagan]

I will be calling " the spreadsheet " the Henderson Tool for now on unless there's any objection. And as everyone knows "guidetohometheater" that I referred to earlier is now Ultimate AV, old habits, what can I say.

 

[MGDunagan]

Would the room dimensions that I've come up with using the speadsheet be inside measurements after wall treatment or to hard surface?


Anybody?

 

[Ethan Winer]

MGDunagan,


> Would the room dimensions that I've come up with using the speadsheet be inside measurements after wall treatment or to hard surface?