So the CommPort uses some kind of DSP technology. Does the DSP on the CommPort have the same problems with SCBA that the P25 Vocoder/DSP has?
I have a case open with Motorola, but if anyone has any real world feedback I would appreciate it.
For reference, here's the brochure:
http://www.motorola.com/governmentanden ... ochure.pdf
CommPort and SCBA
Moderator: Queue Moderator
-
motorola_otaku
- Posts: 1854
- Joined: Tue Jan 13, 2004 7:03 am
Re: CommPort and SCBA
Just for kicks, I ran those part numbers through MOL. Holy 
For that, it'd better be so comfortable that I can forget it's there.
For that, it'd better be so comfortable that I can forget it's there.
Re: CommPort and SCBA
Yeah, they are pricey little toys. The customer is getting the version with the big paddle, and the audio accessory costs almost as much as the radio they are buying. I still have not heard back from Motorola so I am still very interested to hear if anyone has these out in fireground service and what the results were.
Re: CommPort and SCBA
Anyone? Anyone? Bueller?
Re: CommPort and SCBA
I have absolutely no experience with the CommPort, so take this for what it's worth.
However, the DSP in the CommPort performs a completely different function than the vocoder in a P25 radio. The DSP in the CommPort is there to process the audio that the mic picks up and do some kind of processing on it to make the audio more understandable, clearer, etc. The vocoder in a P25 radio is there to essentially compress the audio so that it requires less bandwidth to transmit it over the radio channel. A vocoder's purpose in life is to remove information that it considers unnecessary for the reproduction on the other end of the transmission. The DSP, however, isn't restricted in bandwidth because it's operating in the audio domain, not the RF domain. So the processed audio is still full bandwidth all the way through the DSP (information isn't removed, although it may be changed). Analog radios have had DSPs in them to do audio processing for quite some time. Now, it might be possible that the CommPort DSP does something funky with the audio. However, any problems you have with a CommPort will be different and unrelated to the P25 vocoder problem (i.e. it won't cause the audio to turn into a digital garble of nothingness). In fact, using a CommPort with a P25 radio may actually significantly improve your results if it helps reduce background noise before that background noise gets to the vocoder. I can't tell from the literature where exactly the mic is on the CommPort, so I'm not even going to guess how it would work while wearing an SCBA.
Andy
However, the DSP in the CommPort performs a completely different function than the vocoder in a P25 radio. The DSP in the CommPort is there to process the audio that the mic picks up and do some kind of processing on it to make the audio more understandable, clearer, etc. The vocoder in a P25 radio is there to essentially compress the audio so that it requires less bandwidth to transmit it over the radio channel. A vocoder's purpose in life is to remove information that it considers unnecessary for the reproduction on the other end of the transmission. The DSP, however, isn't restricted in bandwidth because it's operating in the audio domain, not the RF domain. So the processed audio is still full bandwidth all the way through the DSP (information isn't removed, although it may be changed). Analog radios have had DSPs in them to do audio processing for quite some time. Now, it might be possible that the CommPort DSP does something funky with the audio. However, any problems you have with a CommPort will be different and unrelated to the P25 vocoder problem (i.e. it won't cause the audio to turn into a digital garble of nothingness). In fact, using a CommPort with a P25 radio may actually significantly improve your results if it helps reduce background noise before that background noise gets to the vocoder. I can't tell from the literature where exactly the mic is on the CommPort, so I'm not even going to guess how it would work while wearing an SCBA.
Andy
Re: CommPort and SCBA
Well, for what it's worth, a clerk from Motorola that called me back (with NO technical knowledge whatsoever, the girl did not even know what DSP was) told me that there WAS a problem with the SCBA + CommPort application. I guess some moron somewhere told her to just call me and say it doesn't work to get the case closed.
I guess they didn't figure I wouldn't let the case close out til someone explained the problem to me.
When I began asking questions as to how similar the DSP in the CommPort was (and things like, who manufactured it) she drew blank after blank, like I was speaking Chinese or something.
I thanked her for her absolutely useless reply, and also let her know I appreciated her wasting me time. Waiting 11 days to hear back was just grand. I fully expect it will take at least another 11 days before someone in the accessories group who actually knows wtf DSP is calls me back.
She also didn't know what to say when I asked why Motorola would market the product to firefighters (indeed, there are guys in turnouts on the marketing brochure) if they knew damn well they weren't compatible.
As you can imagine, this is just one item in a mile long list of how Motorola is falling flat on their face, but that's a topic for another thread
Thank you for the input Andy, I'll post back when I hear from Motorola again
I guess they didn't figure I wouldn't let the case close out til someone explained the problem to me.
When I began asking questions as to how similar the DSP in the CommPort was (and things like, who manufactured it) she drew blank after blank, like I was speaking Chinese or something.
I thanked her for her absolutely useless reply, and also let her know I appreciated her wasting me time. Waiting 11 days to hear back was just grand. I fully expect it will take at least another 11 days before someone in the accessories group who actually knows wtf DSP is calls me back.
She also didn't know what to say when I asked why Motorola would market the product to firefighters (indeed, there are guys in turnouts on the marketing brochure) if they knew damn well they weren't compatible.
As you can imagine, this is just one item in a mile long list of how Motorola is falling flat on their face, but that's a topic for another thread
Thank you for the input Andy, I'll post back when I hear from Motorola again
Re: CommPort and SCBA
I did find it a little amusing that the brochure mentions that the CommPort is perfect for transmitting to firefighters in a burning building, but makes no mention of using it to transmit from a burning building. Subtle marketing trick there. I think they're marketing these toward the IC-types who are often in a noisy environment, but not actually wearing an SCBA. It's a really fancy speaker-mic sorta thingy. For SCBA comms, the best bet is to go with something from the SCBA manufacturer. Scott has a voice amplifier that will plug directly into a radio, bypassing the need for a speaker/mic. MSA might have something similar, but I'm not sure. Beware of sticker shock for those systems though...they'll probably cost more than the radio, but worth it in my opinion...trying to understand someone talking through an SCBA on a radio is tough stuff, even in analog mode.
Andy
Andy
Re: CommPort and SCBA
I havent tried the CommPort, I have used voiceducers with VERY good results while wearing 2 different models of Scott Air-Pak's. The only issue was with transmitting with an active PASS alarm- the audio left a little to be desired but was still intelligible. No issues with the vibrating low-air alert.
I tried the voiceducer with the SCBA with no regulator in place, regulator in place breathing air, with the vibrating alert active, and with an active PASS; both on a P25 and analog frequency. Performed very well in both modes. Also MUCH better than any speaker mic.
Sidenote- radios used were an astro spectra to receive (nice, loud audio), and the voiceducers were on an HT1250 and an XTS2500i.
May be a viable option if price is a big issue with the SCBA voice amp price tags.
-Jamie
I tried the voiceducer with the SCBA with no regulator in place, regulator in place breathing air, with the vibrating alert active, and with an active PASS; both on a P25 and analog frequency. Performed very well in both modes. Also MUCH better than any speaker mic.
Sidenote- radios used were an astro spectra to receive (nice, loud audio), and the voiceducers were on an HT1250 and an XTS2500i.
May be a viable option if price is a big issue with the SCBA voice amp price tags.
-Jamie
James Eslinger
York, Maine
York, Maine
Re: CommPort and SCBA
Finally, I got a call back from a guy on the product team that has actual hands-on technical experience with Motorola products instead of just a clerk whose job is to push paper around.
As some may have expected, there is no incompatibility issue between the CommPort and a two-way radio in analog mode, per Motorola. If you switch into IMBE, then the problems will arise, but those problems are the result of the P25 vocoder and not the DSP in the CommPort itself.
The guy could not (or would not) tell me who makes the DSP in the CommPort.
So I got the answer I wanted (and needed) in the end, and it only took three weeks of waiting and multiple requests that a rep with a technical background work on the case.
That's some world-class service right there
As some may have expected, there is no incompatibility issue between the CommPort and a two-way radio in analog mode, per Motorola. If you switch into IMBE, then the problems will arise, but those problems are the result of the P25 vocoder and not the DSP in the CommPort itself.
The guy could not (or would not) tell me who makes the DSP in the CommPort.
So I got the answer I wanted (and needed) in the end, and it only took three weeks of waiting and multiple requests that a rep with a technical background work on the case.
That's some world-class service right there