This is topic What is a good RTA? in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by John Westlund (Member # 913) on 08-25-2002, 01:29 AM:
I was wondering what RTA's are out there that are good but dont cost thousands of dollars.
Thanks, John
Posted by Pete Naples (Member # 761) on 08-25-2002, 05:42 AM:
You can do a lot worse than the Abacus Electrics ARTA80.I use one of these, absolutely love the thing.
http://www.abacuselectrics.com/arta80.htm
Don't know what it would cost in US$ though.
Posted by Barry Hans (Member # 477) on 08-25-2002, 09:11 AM:
Gold- Line makes an affordable one that does a fair job. I have a Audio Control that is priced in the same area but I have'nt been that impressed by it. I really check into TerraSonde Audio tool box. Ouside of the display size I have heard really good things about it. I know when I was looking the price was always the stumbling point.
Posted by Dave Williams (Member # 299) on 08-25-2002, 10:04 AM:
I happened upon this one. It is a software based RTA. I do not know how well it works, but it's cheap. Like ten bucks, with a two week free trial. Worth a shot anyway.It is from allen & heath, a very reputable audio company. We use thier boards over at the Hale Theater (stage productions) where I do some work from time to time.
http://www.allen-heath.co.uk/rta.asp
Dave
Posted by Steve Kraus (Member # 476) on 08-25-2002, 10:30 AM:
I'm curious how they would calibrate for an unpredictable microphone.
Posted by Barry Hans (Member # 477) on 08-25-2002, 11:37 AM:
Forgot to mention Ivie. http://www.ivie.com/ Here's links to some other I mentioned also: http://www.terrasonde.com/ http://www.audiocontrolindustrial.com/ http://www.gold-line.com/
Posted by Dave Williams (Member # 299) on 08-25-2002, 11:59 AM:
Unpredictable microphone?Dave
Posted by Ken Layton (Member # 133) on 08-25-2002, 12:35 PM:
The Ivie unit is excellent, but hoo boy get out the wallet! 
Posted by Frank Angel (Member # 248) on 08-25-2002, 03:09 PM:
At one theatre they had a White, which was very expensive but a beauty to use. Now I have a Tenma which does the job, as they say and they have a model in the poor man's price range. They also make reasonably priced oscilloscopes.My assistant has gotten one of those software RTAs for his laptop. It sure has all the bells and whistles -- does print-outs with graphs and fancy stuff, but I asked the same question....how does it compensate for the microphone? Every RTA I've ever seen had its own lab mic that had to be used with it. How do the software RTAs know what they are listening through or the specs of the audio card for that matter? Doesn't compute for me.
Posted by Steve Kraus (Member # 476) on 08-25-2002, 05:18 PM:
They don't specify what mic to use do they? Therefore the mic response is unpredictable. The computer's sound card might be as well. It says something about doing a calibration first. I may have to download this just to see how they do this because short of setting up in a "known" pink noise soundfield and adjusting the RTA readings so that it matches the known curve I don't know how they do it. Thus I'm curious.I once did a rudimentary B chain alignment with an RTA that lacked the correct mic by tracing the pink noise curve I got in a known properly aligned room (I think I used the output from the SPL meter) and then setting the EQ so it matched the weird curve from the non-cal mic. Crude but it ended up sounding fine.
Posted by Manny Knowles (Member # 1171) on 08-25-2002, 05:21 PM:
Maybe they are anticipating a muxer. That doesn't need to be calibrated to the RTA like a single mic, does it? I was told that they just need to be adjusted for SPL matching.I just did a room (with a CP-45 processor) yesterday with an IVIE IE-30 and I'm very happy with it. I used to like the CP-45 until I realized how IMPOSSIBLE it is to do a proper EQ with the minimal amount of EQ controls they give you. The IVIE is a cute little thing, too.
I have also used one that was made by AudioControl. I think the model number was 3051 or something like that.
Posted by Mark Gulbrandsen (Member # 72) on 08-25-2002, 07:39 PM:
I have an Ivie PC40 that I have had for years now. With occasional tightning up all the screws, and calibration of the unit, its sort of like the Ever ready bunny, just keeps on going. The Ivie filters are ultra high quality as is the mic that comes with it. No complaints, it does what its supposed to. About a year after I had bought the Ivie I installed my first THX system and got to see first hand what the R-2 is really capable of. I was sold on it and immediately ordered one that I am still using as my primary analyzer today. Its never been any problem except for the one time a carpet installer sliced through one of the mic cables.
The advantages of it over everything else is so clear that I'm not sure how, or why anyone would want to use a single point mic system. I even tried the Ultra Stereo Mic system on the Ivie before I bought the R-2, but there are problems with it. I'm going to let others that use the R-2 chime in here about the advantages and disadvantages.
Mark
Posted by Manny Knowles (Member # 1171) on 08-25-2002, 08:24 PM:
Mark...please go on about the problems with using the Ultra-Stereo Multiplexer. I just ordered one but I have not received it yet. My tech from the states uses an Ivie and I think my RTA will probably be one of the AudioControl models.I would like to hear more about the problems you experienced with the USL mic kit. Aren't they Countryman mics?
Posted by Dave Williams (Member # 299) on 08-25-2002, 09:05 PM:
I checked out that allen & heath RTA a bit. It seems like it may lack a few tools needed, but then again, I haven't really tried it. So far as I can tell, you can calibrate your sound card by direct loop, or you can calibrate your microphone, if you have a flat response amp and speaker to put it through. If you don't then you need a calibrated mic to run with it, with the soundcard calibration.I am going to give this sucker a try this week.
Dave
Posted by Gordon McLeod (Member # 33) on 08-25-2002, 09:37 PM:
The USL does an acceptable job I use one with a Goldline DSP30 and at the end of the day it is usually within 1 db compared to my R2 across the board
Posted by Jon Bartow (Member # 241) on 08-25-2002, 10:05 PM:
The R-2 is by far the best for "eq-ing" a theater (or any auditorium) however, the set-up/tear-down time can be a bit prohibitive. (it takes a while to unpack, set up four mic stands, four mics, the 'plexer, the main cable, the main control box, connect and boot up the old laptop, put signs on the doors to keep out nosey ushers and then to pack it up again)
For "A-chains" however it is too bulky (it's a big heavy case) and time consuming (I have an old laptop that takes a while booting up) unless you are doing an entire system (a and b chanins)
Oh, and if price is a concern for anyone looking for a RTA, don't bother with the R-2, it has a big price tag.
Posted by Richard Fowler (Member # 893) on 08-25-2002, 10:29 PM:
On the Ultra Stereo MMP unit the mikes are Countryman omni units specified by USL. The normal Countryman mike is directional and has a rising peak in the mid range frequecy to overcome placement on a person's body....not good for EQ use. The MMP should be recalibrated at least on a yearly basis or if a mike is changed. the mikes are numbered to match the input they are to be plugged in.
Richard Fowler
TVP-Theatre & Video Products Inc. www.tvpmiami.com
Posted by Mark Gulbrandsen (Member # 72) on 08-26-2002, 11:04 AM:
My main complaint was that the gains on the USL unit were not automatically leveled. This makes the display bounce around a bit when switching from mic to mic. For what is is its ok as it does at least utilize 4 mics. I would have like to see USL go a few steps farther though and at least included automatic gain adjust in the thing. As loong as you use it with an analyzer that can attain true averaging(such as the Ivie PC40) of the incomming readings you will get ok results.
Mark
Posted by Aaron Sisemore (Member # 145) on 08-26-2002, 10:26 PM:
Another good software RTA (the one I use) is Spectra Plus:
http://www.spectraplus.com .-Aaron
Posted by Gordon McLeod (Member # 33) on 08-26-2002, 11:04 PM:
The Goldline DSP30 will allow user defined averageing
If one wants take a calibrated SPL meter to each mic position and adjust the gain on the trim pot inside the MUXAlso the PC RTA is very good
Posted by William Hooper (Member # 71) on 09-16-2002, 01:23 AM:
BSW retails the Goldline DSP30 at $1,380 http://www.bswonline.com/public/prod_item.asp?item=DSP30
Does anyone have any experience or knowledge of the DOD rackmount RTA?
Here's a typical retailer's listing for one
http://www.ambientsound.com/dod_sr_rta_series_2_analyzer_and_room_delay.htm
http://www.magdonmusic.com/pa/dod/realtimeanalyzer.htm
31 bands, $319!
That would be great for the theater with the Perspecta unit & really any PAC with per-show setups when running film. Everytime there's a new setup, processor change, or whatever, the RTA could be checked in the booth. The mic could be left in some position in the house that's effective & unnoticed.
Posted by Jean-Michel Grin (Member # 1360) on 09-16-2002, 04:44 AM:
Did someone a tip to make a RS-232 extension cable between the R2 and the PC used for setup.
I've tried very long cables for serial port, but nothin will work if the distance is more than 9 meters (aprox. 27 feets)
I'm searching for a RS-232 line converter / amplifier suitable with those equipements.Any help will welcome.
Sorry for my weak English !
------------------
Jean-Michel Grin - Europlex Cinemas (Switzerland)
Posted by Kris Brunton (Member # 432) on 09-16-2002, 09:10 AM:
I have an R2 that I wouldn't be with out. The only disadvantages that I would complain about are it's size and the set up time. Besides that I am extremly happy with it.We also have a couple of Abacus Arta 80's that are very good as well. I like the fact that it has a battery (which makes a-chaining a complex a breeze) and that it is small. We use the USL multiplexer's with these for B-chaining.
I heard a rumor once that THX was working on another analyser to replace the R2. Anyone else hear anything?
Posted by Chris Markiewicz (Member # 1415) on 09-16-2002, 06:43 PM:
The DOD is OK for the price. I use it for A-chain (ours has a line-level input as well) and for ringing out the auditorium for live stage shows.
Posted by Manny Knowles (Member # 1171) on 09-16-2002, 09:36 PM:
[Edited: Post moved to new topic "Multiplexer -- Ultra Stereo Labs MMP-10"]
Posted by Antonio Marcheselli (Member # 373) on 09-29-2002, 02:34 PM:
Hi,I saw recently a tech equalizing a theater with an ARTA 80 RTA.
Don't you think that the ARTA is a bit... approximative as an RTA? 1dB approximation on the analyzer, the SPL has 1dB approx too...
This tech used the ARTA with just one mike in the auditorium. I saw also the R2 with 4 mikes, I can't believe that the same result can be obtained with an ARTA80 with one mike.
What do you think about?
Bye
Antonio
Posted by Gordon McLeod (Member # 33) on 09-29-2002, 03:38 PM:
The Arta80 is an excellent and accurate RTA but best results are to be obatined with a Multiplexer and 4 mics
Posted by Manny Knowles (Member # 1171) on 09-29-2002, 04:40 PM:
I have a brand-new AudioControl Industrial 3051 RTA and -- now that I've used it -- I have to say that I prefer the Ivie IE-30.First of all, the Ivie unit is tiny and sturdy. It will display SPL and the RTA without having to "toggle" the display. On the Ivie, the A-C weighting is built-in; the AudioControl RTA needs a separate attachment.
The size of the AudioControl unit makes it difficult to set it down (securely) at eye level. It's so big...it wants to be on the floor or on a tabletop. After too much squinting and squatting, I finally resorted to saying a few "Hail Mary's" and just "hoping" that it would stay put atop the rack.
The LED's bounce around too much. I was damn-near thrown into an epileptic seizure by the display. "Fast" is waaay too fast and "Slow" is reeeeallly sloooow. "Medium" is almost okay, but I had to go so far as to switch all the way out to 4dB per step to slow it down a little.
I'm also not getting good results with the SPL meter in the AudioControl unit. After making the necessary adjustment to my Ultra-Stereo multiplexer in one auditorium, I got wildly differing results in the cinema next door. Screen channels were suddenly around 10dB too loud and surrounds were about 10dB too quiet. As a result of these bad experiences, I do not trust the AudioControl product.
Maybe those problems will go away when I get the optional A-C weighting filter but -- at this stage -- I'm ready to get rid of the thing and go for an Ivie. I don't know why they failed to include weighting filters in the 3051. It's really an unforgiveable omission, IMHO.
The Ivie IE-30 is also battery operated (or you can use an AC attachment). AudioControl sells a model 3052 which is battery operated (and also offers printouts). The instruction manual for the 3051 seems to be the same for the 3052, so I'm guessing that they are very similar in all other respects.
~Manny.
Posted by Jamie Sanson (Member # 1161) on 09-30-2002, 08:25 AM:
--------Did someone a tip to make a RS-232 extension cable between the R2 and the PC used for setup.
I've tried very long cables for serial port, but nothin will work if the distance is more than 9 meters (aprox. 27 feets)--------Hi Jean Michel
Flat ribbon cable work well over long distance for
RS232 serial data.
Posted by Pete Naples (Member # 761) on 09-30-2002, 09:43 AM:
In fact, one can achieve stunning results with the ARTA 80 and one microphone. The ARTA 80 has a DIP switch selectable mode, in which it will take 4 snaphots and average them. You move the mic to 4 locations and Robert is you mothers brother! Yes it's time consuming, yes it's a pain in the ass, and yes a multiplexer and multiple mics is a much easier, faster method. However if you've only got the ARTA and it's supplied microphone....... One could argue that this is a more accurate method as you are using one microphone, there is no tolerance between mics to take account of.Re: ARTA accuracy. Whilst the on board LED display only (only??!) resolves to 1dB, if you hook it up to your laptop and run the supplied software you can have much finer scales.