my profile | my password | search | faq & rules | forum home

» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » Using Ivie Analyzer with Mic Multiplexer (Page 1)

This topic comprises 2 pages: 1  2

Author Topic: Using Ivie Analyzer with Mic Multiplexer Manny Knowles "What are these things and WHY are they BLUE???" Posts: 4247 From: Bloomington, IN, USA Registered: Feb 2002 posted 09-25-2003 09:59 PM                     One of the things I really like about the Ivie IE-30A Analyzer (apart from its small size) is that it displays the frequency response and the SPL at the same time. Evidently, this is why the microphone connects to a 6-Pin XLR connector because one day the SPL readout stopped making sense and we discovered a bad solder connection. Fixed it; back in business. But now I have a few questions. 1. Why does the Ivie microphone need 6 pins? 2. What if I wanted to use my Ultra-Stereo microphone multiplexer? 3. I know that an adapter cable won't be a problem but does this mean that I won't get SPL readouts?  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 09-26-2003 08:27 AM                     The Ivie mic connector supplies low voltage DC voltage for the high voltage invertor thats inside the mic. Thats why the extra pins. I had an Ultra multiplexer for a while with my PC-40 and didn't like it much. Even though the PC-40 can average out the 4 mics the hassles of having to match the levels between mics was a big hassle when doing alot of B chains. Eventually I biought the R-2 and never regretted it. Among other things it does that automatically!! I only use the PC-40 for A chains or just performing system B chain balance....not any critical EQ'ing. I believe the US multiplexer feeds the line input of the Ivie. Mark @ CLACO  |  IP: Logged Manny Knowles "What are these things and WHY are they BLUE???" Posts: 4247 From: Bloomington, IN, USA Registered: Feb 2002 posted 09-26-2003 08:38 AM                     Thanks Mark. If I used the USL mic mux through the line input do you think I'd get a reading on the Ivie's SPL meter? What about going via an 6 pin to 3 pin adapter cable? ...and what's a PC-40?  |  IP: Logged Matt Zeiner Expert Film Handler Posts: 146 From: Windsor, CT USA Registered: Sep 2003 posted 09-26-2003 08:56 AM                     Hey y'awl. New member here. This is a great community here and I'm glad to be a part of it.. The Ivie only has an unbalanced 100k input and relies on a DC bias put to pin 2 to set its input gain. As such, I don't think you will be able to get precise SPL results from anything but a properly calibrated IE-2p. You could use a relay to switch between the multiplexer and an IE-2 (put 2 .1mfd caps - 1 across pin 2 and pin 6 and 1 across pin 4 and pin 6 to avoid damage to preamp in mic and power source in the Ivie)... though that would be one more thing to set up in the course of your B-chain... Of course, your relative measurements between channels would remain accurate, and the USL has adjustments for each microphone and for overall levels - you could just set up your microphones and calibrate the USL to your IE-2p... Should keep you in the ballpark. Though I have a multiplexer, I only use it if I am required to (gasp!) as I have gotten quite used to doing B-chains predomenantly by ear and the IE-2 w/B&K capsule is very accurate for single point near-field measurements - which is the method I prefer to use.  |  IP: Logged Manny Knowles "What are these things and WHY are they BLUE???" Posts: 4247 From: Bloomington, IN, USA Registered: Feb 2002 posted 09-26-2003 09:19 AM                     More controversy! Matt -- doing B-chains by ear is pure unadulterated scandal! And near-field measurements!? You're toying with emotions here. I swear I can hear arteries tensing. Okay, enough of my kidding. I actually have worked in the near-field measurement at the start of the B-chain because that has helped me determine whether I've got a problem with the room, the speaker or something else. But I have to say that -- like a lot of the other folks around these parts -- I try to stick to the prescribed method as much as possible. Thanks for the input -- and Welcome!  |  IP: Logged Matt Zeiner Expert Film Handler Posts: 146 From: Windsor, CT USA Registered: Sep 2003 posted 09-26-2003 09:28 AM                     Hey - we all have our own methods of doing things - thats part of the beauty of life. What does it matter how we get where we are going if we both end up in the same place? My B-chains do end up very close to the X-curve - the way I go about it has nothing to do with the end result. If (as some have stated) the X-curve is a symptom of flat response pink noise being played in a room and picked up by a microphone (or array of microphones), then is stands to reason that if you are outputting near flat pink noise at the source (i.e. nearfield) you will have an approximation of the x-curve in the far-field. Then tweak by ear with known program material. I have just removed some of the arbitrary facets of the process. Like I said - if the customer demands that I use a multiplexer and go by the book, I do. No problem. I just find that I personally get more consistent results (and more CP faders sitting at 7) when I do it my way. We can agree to disagree, you know....  |  IP: Logged Daryl C. W. O'Shea Film God Posts: 3977 From: Midland Ontario Canada (where Panavision & IMAX lenses come from) Registered: Jun 2002 posted 09-26-2003 09:52 AM                        quote: We can agree to disagree, you know.... Where's the entertainment in that for me?  |  IP: Logged Manny Knowles "What are these things and WHY are they BLUE???" Posts: 4247 From: Bloomington, IN, USA Registered: Feb 2002 posted 09-26-2003 04:18 PM                     Anyone with an Ivie Analyzer want to bring this thread back on topic?  |  IP: Logged Matt Zeiner Expert Film Handler Posts: 146 From: Windsor, CT USA Registered: Sep 2003 posted 09-26-2003 04:25 PM                     sure. I have used the IE-30 with the USL mux many times. like I said earlier - you will get an SPL readout, but it will not be precise. I use the 6 to 3 pin adapter available from Ivie. seems to do the trick. The PC-40 is another Ivie analyzer - check web page you can find all sorts of info there about all of their products. I highly reccomend getting the 1036 probe if you don't have one. there's nothing like the Ivie with that accessory for troubleshooting crossovers behind the screen or signal tracing in general. using the probe and the dbmv conversion charts, you can quickly calculate gain, power output, dbvu...whatever you need to know. I absolutely love mine.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 09-26-2003 08:55 PM                     If there is a way to calibrate the USL multiplexer to the SPL of any of the IVIES I don't know about it. I would e-mail Clint at USL and ask him if it can be done. There are many of us that had them and then switched to the R-2 after finding out the many limitations of the USL unit. I always felt it was only half way engineered. It is however a good back up system if the R-2 fails. The USL should have incorporated automatic level matching between mics and some sort of way to calibrate it to your analyzers SPL meter....no matter what make analyzer you have. Its still something that USL could easily pull off and it would be helpful to the industry since the R-2 is now long out of production, but USL are too busy wasting their engineering time building stupid digitally based products that no one will buy. Like getting good Pink Noise test film these days both a good analyzer and reliable test film simply don't exist any longer. Mark @ CLACO  |  IP: Logged Matt Zeiner Expert Film Handler Posts: 146 From: Windsor, CT USA Registered: Sep 2003 posted 09-27-2003 01:41 AM                     Hey Mark. The USL has individual microphone gain controls, a master level control, and a scan rate control (MMP-10 manual p.6). If its set up properly, its a pretty good unit. Perhaps not an R2, but...  |  IP: Logged Manny Knowles "What are these things and WHY are they BLUE???" Posts: 4247 From: Bloomington, IN, USA Registered: Feb 2002 posted 09-27-2003 02:13 AM                     ...and, lookee here! USL makes an optional cable for connecting to the Ivie IE-30A. It's on one of the last pages of the manual. Hmmm...maybe I'll get one.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 09-27-2003 08:40 AM                     "Hey Mark. The USL has individual microphone gain controls, a master level control, and a scan rate control (MMP-10 manual p.6). If its set up properly, its a pretty good unit. Perhaps not an R2, but... " _________________________________________________________________ The individual gain controls are exactly what I don't like about it. What scan rate should you use? Sure it works ok when its all set up and tweeked, but that is time consumming and moving all that stuff between theatres in a large plex is also time consumming. It all needs to be readjusted each time unless the rooms are EXACTLY the same. Of course that is not the case in real world plex's. Going to the R-2 saved me alot of time as I've always had alot of "add on to" theatres to maintain and no one os the same as the next. I'd love for USL to come out with an upgraded version of it that would at least do the gains automatically. Mark @ CLACO  |  IP: Logged Manny Knowles "What are these things and WHY are they BLUE???" Posts: 4247 From: Bloomington, IN, USA Registered: Feb 2002 posted 09-27-2003 09:58 AM                     Now wait just one cotton-pickin' minute here... The individual mic gains have to be re-set from room to room!? I never knew that!!! Why is this so? I'd also like a quick explanation of how the R-2 deals with all of this. With photos, if possible. I use both sets of microphones -- the one that came with my RTA and the multiplexer mics. Actually, I only use the multiplexer on the premiere houses. The little rooms get the single mic treatment. My RTA has a knob that can boost or cut the level of the incoming signal so I don't suppose it would be too much of a hassle to if I ever noticed a discrepancy between the levels. If USL ever upgraded the multiplexer I hope they offer some kind of a trade-in or at least offered the "box" separately for those of us who already have mics.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 09-27-2003 10:25 AM                     Manny, Assuming the houses are all identical and you place the mics in exactly the same position in each house the levels from each mic should be almost identical to the last and its not a problem. In my case however with many differing size/shape houses the levels were almost always different causing the display to bob up and down several DB as you alternate between mics. So long as you tweek mics 2,3, and 4 to mic 1 when you move to the next room its fine, but if you don't the bobbing effect comes in making it hard to judge what is going on. Now with the PC-40 you can take readings fomr the USL over a time period and average them out as the R-2 does and end up with a meaningful response of a room, but with the PC-30 you can't do that as there is no averaging mode. The PC-40 was in fact the forst THX approved analyzer till the advent of the R-2. With the PC-40 I've averaged a room with the single IVIE mic by walking the room with the average mode running. It workes quite well and is the back up method I use today if the R-2 heads south for a short vacation during an install. With the R-2 when you hit F8, same as the GO button, the analyzer automatically adjusts the gain of mics 2, 3, and 4 to mic 1's level in a split second before the actual readings are started. This makes for a display that is exactly the same level from each mic(assuming the R-2 is calibrated by THX once a year or so) and also makes for very accurate averaging. Averaging can also be done over several differeing time periods with 20 seconds being the shortest and 60 seconds being the longest. The longest averaging periods can be used for somewhat more meaningful information when eq'ing subwoofers or looking at other LF information. There are other analyzers that can also average and perhaps Gord could step in and tell more about those as I know he has owned at least one Gold Line that is capable of doing an averaging mode routine. There are also others that are capable as well. Hope some of this helps. Mark  |  IP: Logged

All times are Central (GMT -6:00)

This topic comprises 2 pages: 1  2

Printer-friendly view of this topic

Hop To: Select a Forum: Category: Operations -------------------- Digital Cinema Forum Film Handlers' Forum Large Format Forum Ground Level Feature Info, Trailer Attachments & REAL Credit Offsets Category: Community -------------------- Film-Yak Film Handlers' Movie Reviews The Afterlife Bob Maar's Joke-A-Thon Category: Classified -------------------- Equipment and Supplies Wanted/For Sale Help Wanted/Seeking Employment Category: System -------------------- Software Beta Testing Forum

The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion and agrees to release the authors from any and all liability.