Spectrum analyzer?

Kr4...Thanks for your answers. Is there any device that can equalize delay at all frequencies? Anyway, I question your statement that delay should be uniform across frequency. In a highly reverberent hall, where delay is easy to hear, the tonal quality varies greatly as the sound dies away. In fact this variation is an essential characteristic of such sound. It wouldn't be realistic if it didn't happen that way.

There are many devices that attempt this with varying degrees of success. These include the usual suspects such as Audyssey, TacT, ARC and a slew of PEQs when coupled with RoomEQ Wizard. The one I like best is the Meridian MRC which measures the broadband decay above the Schroder frequency (~200-300Hz in most domestic rooms) and then calculates filters for band below that frequency. What is nice is the ability to adjust the decay target, to modify/delete/create filters and the ability to graph the results.

You are right about concert halls since there are effects there which are different from those in small rooms (short latency reflections, distance effects on frequency, etc.). Nonetheless, there is a definable RT-60 across most of the audible frequencies well into the bass in concert halls but small listening rooms have their low frequencies dominated by room modes below the Schroder frequency.

In addition, if you want to reproduce the concert hall acoustics when you play a recording of them, you do not want to superimpose the acoustical characteristics of the small room on them.

BTW, there's a great new book on all this from Floyd Toole.

Kal

I use and recommend SmaartLive (software on a PC) which is the industry standard for pro live sound work. In addition to RTA functions, it has real-time transfer function measurement . . . which is a much faster, more stable, and more accurate display mode than an RTA. Its FFT parameters include a FPPO (fixed-point-per-octave) setting, which greatly reduces the need to change FFT parameters to properly resolve the frequency domain of interest.

Phase and time-domain (impulse response) data are additional functions, and it can do so both with test signals or program material (music). It even has a good speaker-impedance testing function.

Hi, I think you are asking good questions and and you are headed in a good direction. There are probably a number of considerations but I think you can save some money and take a first pass with some PC-based software and a microphone. I've spent many years with hifi and several years ago after building my system to the max I got serious about figuring out room acoustics; the process convinced me that no matter how good your equipment is the room will be a huge part of the equation. If you start with some software and a microphone - and if you happen to get some equalizers so you can make the process interactive - you will get a very valuable sense for the challenge and importantance of room acoustics. After this first highly informative and relatively inexpensive pass at analyzing and correcting acoustics you might then decide to go on to room treatments or even a full room design - but I think you can learn a bunch with the PC software and a microphone; and while equalizers might not be the best or right long term solution, the ability to treat the signal (to perhaps a 1/3 octave level) and then see the results graphically on your computer and hear the results with your ears will add significantly to your knowledge and skill - which will help you make further decisions on how to best invest your time and money.

Check out these two older threads on audioasylum:

http://db.audioasylum.com/cgi/m.mpl?forum=speakers&n=177308&highlight=trueaudio&r=&session=

http://db.audioasylum.com/cgi/m.mpl?forum=speakers&n=178395&highlight=Yada&r=&session=

the spectrum analyzer is useless is you cannot alter the anomalies of your room.
In other words, the analyzer will show you the peaks, nulls in your room but thats it.
I bought a Goldline RTA few years back and while it showed me the peaks and nulls in my room, that all it did.
It tried using traps and panels, while it did improve it did not really cure my peak in my room which was around 60-80 hz.
I was about to sell the analyzer since it stayed most of the time in the box.
It was not until I bought a Accuphase digital voicing equalizer that i was able to exploit the use of the RTA.
Given that I had a peak of 63 hz in my room at +8 db, which the RTA showed, I then use the Accuphase bring up the 63 hz frequency and with a stroke of a pen, pull it down to about -7 db. Problem solved and everything begin to make sense.
In short, RTA is useless unless you have some sort of equalizer to alter your frequencies or room acoustics. But room acoustics is a bit tricky as in my experience, it did something else but not really cure the peaks in my room. If it did, just a small bit compared to the Digital room correction.

Another option as many guys said here is to use the Tact or Lyndorf room correction. THese works very well.