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[Russell Ault]

{...} Regarding the different spacings - the critical factor is really path loss with the usual physical obstructions {...}

...right up until you start dealing with modern digital switching diversity systems (which, for the record, I'm not a huge fan of), at which point a second critical factor is to make sure that both antennas have basically the same coverage area (because otherwise the RX might "intelligently" jump to an antenna with even less signal).

-Russ

[Paul Johnson]

I've not noticed any diversity switching issues with the ones I've used - it seems to work pretty identically, although I note a few designs don't hard switch, but claim to merge the two creating less noise. I guess some kind of error correction built into these designs.

[Henry Cohen]

...right up until you start dealing with modern digital switching diversity systems (which, for the record, I'm not a huge fan of), at which point a second critical factor is to make sure that both antennas have basically the same coverage area (because otherwise the RX might "intelligently" jump to an antenna with even less signal).

Russ - If you're referring to the [blind] antenna switching in the ULXD, that is not at all representative of higher tier digital systems diversity antenna switching. Some are what we (the marketing guys actually) call 'real diversity" in which each antenna input has a dedicated receiver with a central microprocessor sampling each receiver's RSSI/CNR, BER, FER, and audio SNR for the best audio many times per second. Other systems (e.g. Axient Digital) use maximal ratio combining (MRC) where, again there is a separate receiver for each antenna input port, but the bits or packets from each receiver are added together to produce a single and very robust & coherent data stream for decoding or conversion. The more antennas, the better. (Some of the high tier RF video systems for RF cameras support up to eight RX antennas.)

[Russell Ault]

Russ - If you're referring to the [blind] antenna switching in the ULXD, that is not at all representative of higher tier digital systems diversity antenna switching. {...}

I'm sorry, that wasn't very clear of me. This quote:

...right up until you start dealing with modern digital switching diversity systems (which, for the record, I'm not a huge fan of), at which point a second critical factor is to make sure that both antennas have basically the same coverage area (because otherwise the RX might "intelligently" jump to an antenna with even less signal).

...was meant to be a follow-on to this quote:

{...}...unless your RXs use some kind of "intelligent" switching diversity system (ULX-D, QLX-D, SLX-D, and—now that the patents have expired—EW-D), in which case "very different antenna placement" can actually increase the likelihood of drop-outs. {...}

I do know that top-tier digital offerings don't suffer from these, er, idiosyncrasies (heck, they still even have multiple RF meters!); I'm just feeling salty about this new cost-cutting measure that the rest of us now have to live with.

-Russ

[Bryce Holland]

Wow! Thank you for all of the replies! I am overwhelmed!

[Bryce Holland]

The ASP 2 itself is wideband, but it's also totally passive. To overcome the 7+ dB of splitter loss, Sennheiser recommended (and every installation I've ever seen did this) that a pair of AB 2 line amplifiers be used just upstream of the ASP 2, and to the best of my knowledge all AB 2s are significantly band-limited. I was ASSuming that the OP's setup included a pair of A-band AB 2-As, which are limited to 518-554 MHz.

-Russ

Russ, my apologies for neglecting to mention this in my original post. Yes, I do have a pair of AB3-A boosters between the paddles and the first ASP-2.

So with reading these replies, and with continuing my own research, it seems that the Audio Technica receivers have a wider frequency range then the Sennheiser receivers. So theoretically this could work as long as I keep all receivers within the frequency range of the AB3-A boosters.

And just to re-iterate my initial post, I know that this is not an ideal setup. I just have to use what I have to hopefully make some old equipment last for at least another year. I have been slowly rebuilding this entire sound system over the past several years, so my ultimate goal is to eventually replace all of these old wireless systems with a new setup.

[Russell Ault]

{...} Yes, I do have a pair of AB3-A boosters between the paddles and the first ASP-2. {...}

Ah, okay, those have a slightly wider bandwidth of 516 to 558 MHz. What is the actual frequency range of your A-T wireless?

-Russ

[Bryce Holland]

I sincerely apologize for the long delay in my reply. It's amazing how time gets away from you so quickly at this point in the school year!

Thank you to everyone for your insight, advice, and understanding of this situation. I am pleased to announce that overall it worked very well. I look forward to finally retiring those poor Audio Technica units and building out a proper Sennheiser setup, but for now it worked! In fact, the Audio Technica receivers experienced the best reception they've ever had!

I have included my diagram of the setup in case you are interested. As you can see, it is not ideal, but it worked with minimal issues. There were more issues with interference because of wireless devices from the audience than with this weird setup (this is a cafetorium).

Yes, Russ, this model of Audio Technica has a wider frequency range than the Sennheiser ew100 G2. I just made sure to set all of the frequencies within that range, as well as make sure they were far enough from each other to minimize modulation.

Again, thank you everyone for your support! I hope this follow-up and this diagram helps someone else who may experience a similar situation.

[ProSoundWeb Community]