CARA definately works. It just takes a lot of input. But it did give a position for my speakers and room treatment that gave a flat frequency response. I still fine tune by ear, but it gives the best general placement. I'd like to help you out, but it takes too much work.
We sell the optimizer and sizer from RPG and the CARA. The sizer is really only for new construction to get optimum dimensions. Not really applicable for you--and I figure you already knew that, but for others reading this post I wanted it to be clear. The optimizer works well for rectangular rooms. It's pretty easy to use and straightforward. The CARA is far more flexible, but as mentioned above, it takes a lot more time and a lot more input. The learning curve is pretty steep, but the payoff it pretty big in terms of flexibility.
If you like working on the computer, doing drawings, and learning new programs--get the CARA. If you have an unusal shaped room, then you have no choice--you have to use the CARA. If on the other hand you don't want to spend a lot of time and just get some basic assistance for a rectangular room, then the RPG is probably better suited for you.Rives Audio Software Page
I use and like CARA. As mentioned above it takes some effort, and frankly you really need to have an extra PC around as model runs can take hours. It is German software and does not violate German software laws that state: All programs should offer as many features as possible regardless of the impact on usability. Once you get the swing of things the flexibility it offers is really impressive. Beyond helping with placement, Cara teaches you what is going on with the acoustics of your room and speakers. I have enjoyed that on a nerdy level quite a bit. I would say that if you have mid-level or higher computer skills and are willing to put a little time in CARA is one of the best bang for the buck tweeks for your system. For casual use it is probably too much, there are free programs around that can really help with basic speaker placement in rectangle rooms. Also, CARA will not just tell you where to put acoustic treatments though it has a very nice feature that tells you the tonal balance of your room (ie is it your speakers that are bright or the room?) CARA works by using a model of your room, speakers, and furnishings in the room (including acoustic treatments if you put them in) and then does acoustical calculations while changing the position of the speakers and / or the listening location. Then it gives you the location that produced the best frequency response. After you get a location you can change the furnishing or add absorbers and see if you get a better score. The biggest strength of CARA is exploring speaker placement options in unusual shaped rooms. It really can help by giving you some ideas you would not have thought of. For me, even my first simple runs suggested moving both speakers and listening position 2ft to the right. I had not considered this in the past as I had a table there but in the past I had moved the speakers all over the open area of the room. Anyway, huge improvement by just doing that. Also, helped with bass adjustment by giving the best distance for the speakers from the front wall. This distance +/- 6in was constant no matter what I changed in the model and helped narrow things down.
Look here for something simple:
bottom of page 'Visual Ears'
The RPG Optimizer is pretty much useless in all but a rectangular room. Don't waste your money.
The CARA program is capable of very good results, but as mentioned above, can be very demanding of your time and quantity / quality of data that it requires. Having said that, it can provide an extremely close "starting point" in terms of speaker placement.
If you want to take that a step further, you can use the data garnered from CARA and then optimize the installation by utilizing a digital room correction device to take temporary measurements. Using this approach, CARA gets you into the ballpark and fine tuning the placement using the digital room correction device gets you the best results possible. Once you've obtained the best results possible, you can then pull the digital correction device and listen to your system as you normally would.
Without CARA and using a digital room correction device by itself and taking measurements, you may end up trying a million different placements without obtaining as good of results as is ultimately possible. Without the digital room correction device and relying strictly on CARA, CARA will only tell you how your room / speakers should work theoretically, based on the data that you entered. Given that there are variables to individual building construction and the data that you entered may not be 100% accurate, the fine tuning using digital room correction tests makes up the difference between theory and reality and leaves little room for error.
The only problem with this approach? It can be VERY time consuming and the speakers may end up in a place where you don't want them or they aren't conducive to room lay-out. If you have a dedicated listening room, this isnt' really a problem. For those with their system in a room that is "community property", don't count on keeping the speakers in a convenient location. It just ain't gonna happen.
Other than that, it should be noted that CARA comes in both a metric and "Imperial" measurement platform. Make sure that you buy the one that you need or get ready to invest in a tape measure that has both meters and feet : ) Sean
You need ETF now, not a room simulator package. ETF will capture the current performance of your system and then you can consult/employ a Rives Dealer for interpretation and advice on what treatments you will need to treat your system as it now functions.
The CARA package is powerful and the more info you feed it the better information you will get, but buying ETF will give you actual information to work with.
Using people without experience in how to apply acoustic treatments can lead to extra expense, and an ineffective application of treatments. So maybe think about a "budget" as you would if you were buying a CD player and see if professional help falls within those numbers. Consulting a professional like a Rives/dealer will be worth it in the end.
I agree with Cinematic Systems IF you are planning on staying in the same place for awhile. I rent and CARA makes more sense for me. But, if you can get an acoustic expert to come in (assuming it isn't unreasonably expensive) it can make a huge improvement and you won't have to go through the sometimes frustrating job of trying to figure it out on your own.
Cinematic: What is "ETF" ? Sean
goto www.etfacoustic.com, it is a software/ measurement program.
Just to add to cinematic--the ETF software is fantastic. All of our dealers use it for acoustical measurements (they are required to in order to be a Rives dealer). We find it to be the most cost effective product out there. It's not the easiest to use and does have a few quirks (just visual things--not operational)--but it is incredible what it does for $150. We also sell this software and highly recommend it for in room acoustical response.
Back to the original question of CARA. I can tell you that it is remarkable how close the model and actual measurements are until the room gets very complex and then the deviation probably has as much to do with designing the room in CARA as anything else. The comparison is what has made me a very firm believer in just how powerful CARA is.
I'll have to check out the ETF stuff, thanks for the info and comments guys. As to Rives comments about CARA, i agree that it is a very good program. Problem is, most simulations aren't perfect due to a lack of very specific input data, hence my comments about "filling in the gaps" with digital room analysis and further tweaking. Sean
I have ordered the CARA software package, hopefully i have the patience to input enough info for good results. thanks for teh responses
I am moving into a new place and will finally have the room to build my listening space. I'm going to be building my system (home theater 70%, 2 ch 30% in this room) from scratch. Should I employ the services of Rives or this type of software prior to buying the equipment, or will I receive more of a benefit from thist type of room analysis after equipment is in for tweaking & placement purposes?