Thinking of buying a microphone multiplexer. Change my mind!

[Mark Gulbrandsen]

"And when tuning a non-ovation room? You swap the sound processor"

Why would I? They set up fine and sound great.

[Marco Giustini]

You mean "why wouldn't I"?

In that case, it sounds like a good approach.

"Can you tune my sound system?"
"Yes, you'll need a new sound processor" (also a new NEC projector and a new GDC server for eternal reliability I hear)

[Stefan Scholz]

In the Atmos tuning school, I was taught that calibrating the mics using a barrel-type cablibrator that emits a 94dB beep and SMAART is an essential preparation step in the process.

Compared to some of the gear we use for digital installation and service, Octacaptures aren't that pricey - around $600 on Amazon. But once you add 5 to 8 reference mics with stands and cables, a calibrator, and a SMAART license to that, the total kit cost is around $2-3K.

Not only for Atmos, youz need a standard to work against. You need to know the actual SPL. Beside calibrator a thermometer and barometer is important, as the generated SPL and coupling into the microphone is specified for a certain temperature and barometric pressure only, correction to be applied for deviation.
The expensive parts are Measurement mikes, calibrated calibrator (and recal fees), and eventually the Smaart licence, which I do not remember to be excessively costly.

Another approach that just works with the single (preferebly class 1) mike is the handheld analyzer, where you walk around the room during the integration time. We figured out, it works equally well like the multiplexer system.
For me, multiplexing is more convenience, I do not like to walk all the time.

[Mark Gulbrandsen]

Back in the 1980's into the 90's I installed lots of HPS John Allen systems. He always tuned them by ear. Then I bought my R2 and re-tuned many of them with that, and what an incredible difference! One customer even called me because he thought I had installed new speakers, that it sounds so much better than it did. I can say that at least at the sites I did that taking the room into account made a huge difference.

[Sean McKinnon]

I am in the octa-capture/SMAART camp.

[Stefan Scholz]

Back in the 1980's into the 90's I installed lots of HPS John Allen systems. He always tuned them by ear. Then I bought my R2 and re-tuned many of them with that, and what an incredible difference! One customer even called me because he thought I had installed new speakers, that it sounds so much better than it did. I can say that at least at the sites I did that taking the room into account made a huge difference.

So I'm not the only one to have done the same. ...
Listening is an important task, but none has magic ears, you are dependent on so many factors every day.
We always re eqd afterwards.
I'm still using one of the large systems in my house, with modified drivers (BMS instead of police sirens midrange, new 10" and new tweeters) as well as full active 4 way drive. And added extra Infra woofers wi for more low end power. Tuned with R2/ D2, I always got very good results.
The R2/ D2 made me get very similar results in any house, that had a good enough speaker system installed.
I also use the Smaart toolkit on a mobile device, it's absolutely great, but not my main system to tune auditoriums.Still prefer the method they taught us at the ranch.

[Steve Guttag]

I've found, over the years, for what they do, the R2 and D2 had the best method and, BY FAR, the most consistent results. They have the advantage that all of their microphones are all calibrated against a common reference mic (Tim Holmes has it and calibrates all of the microphones). What I've found that if I tune a room and my system looks like it is already tuned, the person before me had an R2 or D2. It is incredibly consistent with the results. I've supported THX rooms (particularly screening rooms) over the years. I've seen how a system degrades, year by year over a long span of time and what the effects, typically are. The R2/D2 makes that easy as well.

The R2/D2 does not let one see impulse response type stuff as it wasn't designed for it. Since it was developed for THX rooms, it can presume that the room is, at least, somewhat close to right and the RT60 as well as NC tests will verify (or show issues). They also make RT60 and NC measurements easy to perform/document.

If I can only carry one RTA, it will be the D2. I have complete faith in it.

I do own a SMAART and Octacapture (with MM1 mics...8 of them). Smaart opens the world up to analyzing the audio from different perspectives and also being able to compare one channel to another. Getting time alignment is possible with Smaart, in a precise manner whereas one has to know what they are seeing with a typical RTA (like seeing how the speakers "add" while adjusting the delay of one). With Smaart, you can precisely measure it.

As to "golden ears"...well there are different types of those people. I was talking with a person that is really highly regarded for their ability to hear what is going on with a sound system. RTAs are but one tool and they give one a picture of the frequency response where the microphone is or a spacial average for multi-mics. But that isn't going to tell the whole picture (or sound). This guy can hear what the problem is and know what changes to make (be it EQ, time alignment, room treatment...etc.) to make it sound better. As he told me, the key is to understand what you are hearing to know what the problem is. He brought his own test material (a variety of traditional test material as well as male/female spoken voice) and would walk the room with/without meters and by the time it was done, it was pretty clean sounding everywhere. I was merely his hands in the booth doing as he said. I'd say, he got out of that room, that equipment, what they had to offer and using what tools were at our disposal.

I can say, I too have developed a sense for some sorts of harshness where I can make changes in a tuning to eliminate it just through experience. I always start with S202 though.

[Mark Gulbrandsen]

I just discovered my R-2 and Toshiba laptop and all the software in my storage this morning. It was hiding behind the antique telephones. It's been idle for about 5 years since last used. But it worked last time I fired it up... I gusss I'll list in in the Equipment For Sale thread. But have to make sure it still works first....

[Mark Gulbrandsen]

I've found, over the years, for what they do, the R2 and D2 had the best method and, BY FAR, the most consistent results. They have the advantage that all of their microphones are all calibrated against a common reference mic (Tim Holmes has it and calibrates all of the microphones). What I've found that if I tune a room and my system looks like it is already tuned, the person before me had an R2 or D2. It is incredibly consistent with the results. I've supported THX rooms (particularly screening rooms) over the years. I've seen how a system degrades, year by year over a long span of time and what the effects, typically are. The R2/D2 makes that easy as well.

The R2/D2 does not let one see impulse response type stuff as it wasn't designed for it. Since it was developed for THX rooms, it can presume that the room is, at least, somewhat close to right and the RT60 as well as NC tests will verify (or show issues). They also make RT60 and NC measurements easy to perform/document.

If I can only carry one RTA, it will be the D2. I have complete faith in it.

I do own a SMAART and Octacapture (with MM1 mics...8 of them). Smaart opens the world up to analyzing the audio from different perspectives and also being able to compare one channel to another. Getting time alignment is possible with Smaart, in a precise manner whereas one has to know what they are seeing with a typical RTA (like seeing how the speakers "add" while adjusting the delay of one). With Smaart, you can precisely measure it.

As to "golden ears"...well there are different types of those people. I was talking with a person that is really highly regarded for their ability to hear what is going on with a sound system. RTAs are but one tool and they give one a picture of the frequency response where the microphone is or a spacial average for multi-mics. But that isn't going to tell the whole picture (or sound). This guy can hear what the problem is and know what changes to make (be it EQ, time alignment, room treatment...etc.) to make it sound better. As he told me, the key is to understand what you are hearing to know what the problem is. He brought his own test material (a variety of traditional test material as well as male/female spoken voice) and would walk the room with/without meters and by the time it was done, it was pretty clean sounding everywhere. I was merely his hands in the booth doing as he said. I'd say, he got out of that room, that equipment, what they had to offer and using what tools were at our disposal.

I can say, I too have developed a sense for some sorts of harshness where I can make changes in a tuning to eliminate it just through experience. I always start with S202 though.

With the Klipsch stuff it sounded like the dialog was coming down an 8" pipe into the room. Tuning with the R2 cured that completely and got rid of the boomy bass. There is a large theater chain in Utah that uses a mix of stuff, EV and JBL, and most of the dialog in their theaters also sounds like it's coming out a pipe.

[Carsten Kurz]

How do common processors actually deal with arbitrary switching times of multiplexers? The analyser circuit or software could be very different in their capture/analysis timing/dwell times ? Is it safe to assume that no switching transients occur? Shouldn't the cinema processor know about the mic switchover times so it can actually 'average' in a useful way?

[Marco Giustini]

Most processors don't deal with the multiplexed signal, not sure what the Ovation does but today's hardware allows to input all 4-8 mikes at the same time so no "switching" happens anymore. The D2 Studio still relies on switching but this is done at software level (the sound card inputs all 4 mikes all the time while the older version would actually switch between mikes on an external box).

Smaart not only does it receive the signal from all the mikes all the time but it also averages them in real time - no switching there. In other words, a 16 seconds average on the D2 is made of 4 seconds sound from each mike - the same 16 seconds average on a Smaart system with 4 mikes is made of 16 seconds sound from each microphone.

[Mike Babb]

Marco, the Ov1 and Ov2 are not multiplexing, they are taking simultaneous measurements from between 1 to 8 mics. The data can be combined equally, or weighted towards some mics when calculating the FIR equalization. The reference mic 1 is used to time alignment and levels. Our 3D mic does the same except the precise position of the mics allows for distance, elevation and azimuth of speakers. It's not really used for commercial cinema because of the wider listening area, but the software is much the same.

I'll throw out the offer on here, anyone who wants to see the process, I have a 7.4 bi amp system online in Paris and can show you a real calibration.

[Marco Giustini]

Thanks Mike,

I totally expected that with modern computing power there is no need for "sampling" anymore. In fact, I'm wondering if WinRTA would go that route for the studio version at some point.