I recently purchased an AT Pro-88w (830) wireless:

http://www.audio-technica.com/cms/wls_systems/f706c310ed826ec4/index.html


I am just a hobbyist, but I am very, very pleased with the unit. The "bang for the buck" is unbeatable ($155 without shipping). While playing around with it outside (with female voice), I got what I consider to be very high quality sound (very natural sound, little to no noise, no static) out to about 50' or so, and usable sound out to about 100'. I got understandable speech, but with increasing static, out to 300'.

I would like to buy another, and use the two together with the stereo mic input on my camcorder (via 1/8" stereo miniplug to 2 mono minijacks) to record two audio channels.

The Pro 88w comes in five different models, each with two switch-selectable channels. Before ordering another unit (actually, I'd like to get 4 and use two for the camera, and two to feed a Zoom H4 field recorder), I emailed AT to confirm that the units had sufficient selectivity so that multiple units could function in the same vicinity, without mutual interference. (Assuming that there is no other external interfering source.)

To my strong surprise, I received an email from AT saying that the PRo-88w models are not designed to work in the vicinity of any other Pro-88w's. I am especially doubtful because of the availability of models quite separated in frequency.

Who am I to doubt the technical (dis)claims of the manufacturer? Yet, I really do question it.

I wonder if anyone here has used more than a single AT Pro-88w simultaneously?

Thank you.

Regards,

DG

I have several PRO88w's. I have never used more than two at a time yet - though will be soon when I shoot an improv group (Will be using 4 to a mixer).

I regularly piggyback two receivers on my camera and feed them into the XLR inputs with AT adapters. I have never had a problem using 2 at a time. In fact they work extremely well.

I agree, they are a huge bang for the buck... and can be found on E-bay for about half of what you paid. Good little units.... best used within 50 feet of the receiver in my experience.

The newer ones have a poorer quality mic in my opinion.... but I have 2 I got with the 830 Omni which is a great mic, IMHO.

Thank you for your informative comments.

Guess I'll start with two.

Just judging from the "A" and "B" channel separation on each unit (.8MHz), and the frequencies favailable or each model, it is possible to select three models, and guarantee that, regardless of channel choices on each unit, there is > .9MHz of separation for every possiboe combination.

So, I would expect that it must be possible to use at least 3 units simultaneously.

Possibly more.

DG


P.S. Might you please say what two models you use together? For instance, T13 and T57?

P.P.S. The less expensive Pro 88w's that I have found didn't have the MT830mw lav, which I like. But, perhaps, I just didn't search enough.

I have units operating at T13, T24 and TVHF, that I have used together in 2's at one time or another. I velcro the receivers together and mount them on the hot shoe on my Z-1.

I have purchased all of mine on E-bay.... I see that you CAN buy them with 830's new (about $165)... but my luck on E-bay hasn't been 100% ... I have saved a bunch though... even have one set with a handheld mic as well. (The 288)

"I have units operating at T13, T24 and TVHF, that I have used together in 2's at one time or another."

Thank you for that information. Those frequency differences are as close as any of the Pro-88w's get. So, if T!# and T24 work simulaneously, then any Pro-88w pair should also. (Despite what AT tech support says.)

I figure they are great for my purposes, and present less of a ri$k if spectrum issues in the U.S. go the wrong way, and obsolete these devices.

Regards,

DG

So, if T!# and T24 work simulaneously, then any Pro-88w pair should also. (Despite what AT tech support says.)
Regards,

DG

Hello David,

The support people at Audio-Technica US are extremely capable and really do care that their gear works properly. There are more issues than direct frequency conflicts that do have an effect on the quality of the audio.

Regards,

Ty Ford

"There are more issues than direct frequency conflicts that do have an effect on the quality of the audio."



Thank you, Mr. Ford, for your comment.

Can you expand at all?

I'm thinking that, based upon reported experience, that I have a reasonable shot at using multiple Pro-99ws (on different frequencies) at the same time. In other words that it is a reasonable risk to try it.

What issues, in addition to frequency selectivity of the devices, might I be concerned about when trying to use two of these wireless units at the same time?

Thank you.

DG

P.S. Perhaps, another issue could be that the transmitter of one of the units emits spurious RF that would be in-band for the channels of another pair of units? It would appear that Mr. Swanberg has operated two or three units simultaneously without experiencing this. But, I guess that doesn't mean that all units would be so well behaved.

Hey David,

"Ty" please.

There are intermediate frequencies that are part of the transmission. Audio Technica and other wireless mic makers normally do all of this math for you and indicate how many wireless units can be transmitting on different frequencies at the same time without causing problems.

Call AT's wireless shop at the Stow, OH HQ and ask their advice.

Regards,

Ty Ford

I can only add that my successful usage has all been within about 30 feet of the receiver in multi setup usage. Not sure the issues AT has with using multiple Pro88's, and certainly acknowledge Ty's expertise, but at the cost I think it is worth a try based on my experience.

I'm betting the mfgr. is understandably conservative.

It's not just the AT Pro 88w. All wireless have the same (or similar) problems.

You have to choose your frequencies with some care.

Regards,

Ty Ford

Per Ty's suggestion, I just phoned AT. The person with whom I spoke said the same thing as the email I received a few days ago, and that is that the lack of shielding on the Pro 88w makes it unlikely that multiple units can work simultaneously. He especially cautioned against stacking two receivers together on top of a single camcorder.

I would rather they under promise than over promise.

So, I conclude that it could work, but if it doesn't, the responsibility is mine.

DG