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Title: Alternative to Gentner phone interface
Post by: (Brian) Frost on July 14, 2015, 04:50:55 pm
I do a lot of conference calls using a Gentner connected to a sound system for big corporate meetings that take place around the world.  With the limited bandwidth of the phone system I wonder whether anyone has tried using an interface and their laptop to make a higher resolution phone call via skype or google voice instead of the gentner.  I feel like the phone system is the weak link and everywhere we can remove it from the chain would help.
Title: Re: Alternative to Gentner phone interface
Post by: g'bye, Dick Rees on July 14, 2015, 04:57:49 pm
Relying on internet bandwidth/connectivity is a slippery slope, I think.  There's still something to be said for point-to-point copper...cell phones notwithstanding.
Title: Re: Alternative to Gentner phone interface
Post by: Tim McCulloch on July 14, 2015, 04:59:45 pm
I do a lot of conference calls using a Gentner connected to a sound system for big corporate meetings that take place around the world.  With the limited bandwidth of the phone system I wonder whether anyone has tried using an interface and their laptop to make a higher resolution phone call via skype or google voice instead of the gentner.  I feel like the phone system is the weak link and everywhere we can remove it from the chain would help.

Most 3rd world phone lines sound better than anything I've gotten off of Skype.  Some of it is downright horrible.
Title: Re: Alternative to Gentner phone interface
Post by: (Brian) Frost on July 14, 2015, 05:39:52 pm
Most 3rd world phone lines sound better than anything I've gotten off of Skype.  Some of it is downright horrible.

Agree skype is often bad, but my google voice calls sound far better than the 3000hz bandwidth limited phone calls i get from ma bell.  I do see the point in their reliability, and thats why I brought up the topic to discuss. 

keep em comin.
Title: Re: Alternative to Gentner phone interface
Post by: David Buckley on July 14, 2015, 05:52:31 pm
I feel like the phone system is the weak link and everywhere we can remove it from the chain would help.
You are correct, it is, but you wont get better results by switching to Skype or other consumer grade solutions.  Or, at least, not today.  With VoIP one can have "HD Voice" or "Wideband voice" and these system do deliver much better audio quality.

If you have the money to spend, if if you've got a Gentner then you probably do :) then a VoIP solution like this (http://www.comrex.com/products/stacvip.html) will enable you to have high quality audio.  There are other products, a google for hd voice should get you started.
Title: Re: Alternative to Gentner phone interface
Post by: (Brian) Frost on July 14, 2015, 05:56:44 pm
You are correct, it is, but you wont get better results by switching to Skype or other consumer grade solutions.  Or, at least, not today.  With VoIP one can have "HD Voice" or "Wideband voice" and these system do deliver much better audio quality.

If you have the money to spend, if if you've got a Gentner then you probably do :) then a VoIP solution like this (http://www.comrex.com/products/stacvip.html) will enable you to have high quality audio.  There are other products, a google for hd voice should get you started.


Thank you, thats the kind of information Im looking for.  I'd note that facetime audio for iphone is HD voice tho i find it unreliable. 

My gentner is paid for but when the time comes to upgrade Ill look into the comrex voip solution.

Title: Re: Alternative to Gentner phone interface
Post by: Luke Geis on July 15, 2015, 01:26:54 am
As far as I'm concerned the Gentner phone systems are dead.......... So many other ways to do the same thing for less $ and just as good as performance. The difference is that the " other ways " are not always in a box with a name on it.
Title: Re: Alternative to Gentner phone interface
Post by: (Brian) Frost on July 15, 2015, 01:42:36 am
As far as I'm concerned the Gentner phone systems are dead.......... So many other ways to do the same thing for less $ and just as good as performance. The difference is that the " other ways " are not always in a box with a name on it.

Can you be specific, thats what interested in tho would like to hear whats worked and what hasnt so Im not starting this from scratch.
Title: Re: Alternative to Gentner phone interface
Post by: Mac Kerr on July 15, 2015, 11:46:57 am
Can you be specific, thats what interested in tho would like to hear whats worked and what hasnt so Im not starting this from scratch.

The JK stuff is pretty good, but as far as I am concerned the only telephone interface I want to see is a Telos One (http://www.telosalliance.com/images/Telos%20Products/Discontinued%20Products/Telos%20ONE%20Family/one-hybrid-manual.pdf). I have never like the Gentners due to their lack of easy to use level controls and level monitoring. There are more modern interfaces, but I really like the UI of the Telos. I have 4 of them on the job I'm headed out to this afternoon.

Mac
Title: Re: Alternative to Gentner phone interface
Post by: David Buckley on July 15, 2015, 04:48:19 pm
Telos and Genter and JK, although their kit ostensibly does the same thing, and they all make good kit, their products are all aimed at different marketplaces, and thus have different strengths and weaknesses.

It is my current opinion that for VoIP, Comrex have the edge on Telos: better kit, better interface, and better value for money, though I would certainly not turn down a Telos!  Its not for no reason that Telos haven't had the radio studio market to themselves for yonks.

The point I forgot to make in my original posting was:  The nice thing about VoIP is that it is natively "four wire", so it will always work better than hybrid based boxes, which have to undertake black magic  to convert a two wire POTS line to a four wire audio interface.
Title: Re: Alternative to Gentner phone interface
Post by: Luke Geis on July 15, 2015, 11:52:57 pm
Many phone systems these days that are used in conferences have 1/8' outs, not to mention many programs and or converter boxes that will VoIP signal into the analog world. The Telos boxes are definitely one of the best these days as it does simplify the engagement, but I have had a several low budget conferences where the attendee's are spread across the globe and didn't have to use a single box to make it work. Citrix has a couple of programs aimed at this type of setup as well as a couple other companies. You can get temporary licenses too. Skype is an alternative and quality is less than desirable, but it does work. I think it should be more on what your client is willing to pay and the level of quality they wish to acquire. I would look more into renting the units than buying though.

Imagine a VoIP to analog converter which can be obtained cheaply for under $100 a basic telephone set and a universal telephony adapter ( UTA ) that can also be had cheaply. For about $200 you can have a perfectly fine VoIP converter.
Title: Re: Alternative to Gentner phone interface
Post by: David Buckley on July 17, 2015, 09:09:55 am
Imagine a VoIP to analog converter which can be obtained cheaply for under $100 a basic telephone set and a universal telephony adapter ( UTA ) that can also be had cheaply. For about $200 you can have a perfectly fine VoIP converter.
Interesting approach.

What I fail to understand is why there isn't a reasonably priced PC (or Mac!) solution for this.  Or maybe there is and it has passed me by.  Anyway, as I noted above VoIP is natively four wire, so all that is needed is bit of client VoIP software that connects to a soundcard and manages the call setup and has decent codecs for HD voice.  Of course, that soundcard could be a Dante virtual soundcard, and thus one has a complete software VoIP to Dante audio with just one ethernet cable.

That would be quite handy as one could have a bunch of VoIP connections on one PC with a truckload of mix-minus mixes without needing the heap of cables...
Title: Re: Alternative to Gentner phone interface
Post by: Hayden J. Nebus on July 17, 2015, 09:54:42 am
A few months ago I had to do this in a pinch on a site with no POTS. We bought a magic jack at the corner drugstore and used it with a USB interface. We needed send only, which worked well.
Title: Re: Alternative to Gentner phone interface
Post by: Scott Holtzman on July 17, 2015, 06:42:00 pm
Interesting approach.

What I fail to understand is why there isn't a reasonably priced PC (or Mac!) solution for this.  Or maybe there is and it has passed me by.  Anyway, as I noted above VoIP is natively four wire, so all that is needed is bit of client VoIP software that connects to a soundcard and manages the call setup and has decent codecs for HD voice.  Of course, that soundcard could be a Dante virtual soundcard, and thus one has a complete software VoIP to Dante audio with just one ethernet cable.

That would be quite handy as one could have a bunch of VoIP connections on one PC with a truckload of mix-minus mixes without needing the heap of cables...

The VoIP idea is genius.  All you have to do is get a softphone such as 3CX and en external device to interface the phone line to a SIP connection (these are called ATA's  Analog Terminal Adapter).  With a little programming the softphone would ring,you would be bridged to the POTS line.  The phone network only uses 8Khz PCM so you don't need an HD CODEC Then use your favorite USB audio device as the ear and mouth outputs from the softphone.

Brilliant, simply brilliant.

Title: Re: Alternative to Gentner phone interface
Post by: David Buckley on July 18, 2015, 08:22:57 pm
The VoIP idea is genius.  All you have to do is get a softphone such as 3CX and en external device to interface the phone line to a SIP connection (these are called ATA's  Analog Terminal Adapter).  With a little programming the softphone would ring,you would be bridged to the POTS line.  The phone network only uses 8Khz PCM

Fx: Sound effect of me slapping my head

But............ the whole point of this thread is using VoIP is deliver better audio than the bandwidth limited POTS line delivers :)  There are ways of getting quality audio over the interwebs, but they generally suffer from terrible latency, as they use buffering to ensure an interruption-free audio path.  Getting decent audio bandwidth with low latency without chewing up huge amounts of internet bandwidth is much harder, it's the classic case of pick any two.  HD voice using G.722 codecs appears to allow one to have all three...
Title: Re: Alternative to Gentner phone interface
Post by: Keith Broughton on July 19, 2015, 08:57:32 am
The JK stuff is pretty good, but as far as I am concerned the only telephone interface I want to see is a Telos One (http://www.telosalliance.com/images/Telos%20Products/Discontinued%20Products/Telos%20ONE%20Family/one-hybrid-manual.pdf). I have never like the Gentners due to their lack of easy to use level controls and level monitoring. There are more modern interfaces, but I really like the UI of the Telos. I have 4 of them on the job I'm headed out to this afternoon.

Mac
I use a JK product that was about $150. Cost effective and works just fine.
However, I am interested in VOiP options.
Title: Alternative to Gentner phone interface
Post by: John J Saunders on July 19, 2015, 09:23:56 am
If you are looking for point to point over the Internet and can have hardware at both sides I would look into barix. They have audio encoders and decoders and can encode pcm, MP3, and I think the 711 and 722 codecs. I have tested the latency round trip when I was looking for a comms solution. It has been a year but I think it was 180ms round trip over stable internet connections. One thing about it is that to get low latency 1 device has to have a public IP address. 

Of course none of this helps if you don't or can't have access to the other side of your connection and need something easy that anyone can setup.

If I'm not mistaken getner/clear one and polycom have business ip conferencing solutions.
Title: Re: Alternative to Gentner phone interface
Post by: Scott Holtzman on July 20, 2015, 04:50:17 am
I use a JK product that was about $150. Cost effective and works just fine.
However, I am interested in VOiP options.

What do you want to do with the VoIP connection?

Do you want to terminate PSTN call into a conference bridge the uses a VoIP interface to your provider?

Do you want to put devices at the remote conference locations that utilize a VoIP protocol to backhaul the audio and signalling?

Or something else???

I am not clear on your goal.

Title: Re: Alternative to Gentner phone interface
Post by: Keith Broughton on July 20, 2015, 09:28:48 am
What do you want to do with the VoIP connection?

Do you want to terminate PSTN call into a conference bridge the uses a VoIP interface to your provider?

Do you want to put devices at the remote conference locations that utilize a VoIP protocol to backhaul the audio and signalling?

Or something else???

I am not clear on your goal.
I didn't say I had a goal....just curious.
I don't have a particular need, at this time, but I find the options people are offering are quite interesting.
Mostly, I am able to get a POTS line but sometimes we need to send outbound audio to a conference bridge and only have access to in house "digital" (can't think of the correct word) phone systems.
Title: Re: Alternative to Gentner phone interface
Post by: David Buckley on July 20, 2015, 07:19:19 pm
... but sometimes we need to send outbound audio to a conference bridge and only have access to in house "digital" (can't think of the correct word) phone systems.

JK Audio to the rescue! (http://www.jkaudio.com/that-2.htm)!

Disclaimer: I haven't actually tried this particular box, but have used something functionally similar to connect a modem to a digital phone system for a strange job many years ago.  Of course, with these handset connected interfaces, one is reliant on the hybrid in the phone system, which may or may not be as good as the hybrid in a Telos or whatever.

Title: Re: Alternative to Gentner phone interface
Post by: Tim McCulloch on July 20, 2015, 07:59:09 pm
I use the Gentner Micro-Tel (similar to the JK "THAT-2") for getting audio in/out of a telephone circuit.
Title: Re: Alternative to Gentner phone interface
Post by: Scott Holtzman on July 20, 2015, 08:52:50 pm
I didn't say I had a goal....just curious.
I don't have a particular need, at this time, but I find the options people are offering are quite interesting.
Mostly, I am able to get a POTS line but sometimes we need to send outbound audio to a conference bridge and only have access to in house "digital" (can't think of the correct word) phone systems.

I go back to my statement, a soft phone on a PC with a quality audio interface could make a call via a VoIP provider with a low loss CODEC and if you Internet connection is good quality will be well above any 2 wire hybrid device connected to a POTS line.

Disclaimer: My other vocation is CTO of a VoIP Carrier/Fiber Provider/Cloud Services firm
Title: Re: Alternative to Gentner phone interface
Post by: drew gandy on October 19, 2015, 02:03:38 pm
I go back to my statement, a soft phone on a PC with a quality audio interface could make a call via a VoIP provider with a low loss CODEC and if you Internet connection is good quality will be well above any 2 wire hybrid device connected to a POTS line.

Disclaimer: My other vocation is CTO of a VoIP Carrier/Fiber Provider/Cloud Services firm

Sorry to revive a somewhat old thread but...
I'm curious about the acoustic echo cancellation issue.  As has been said alreayd, with a VOIP system through computer you have the 4 wire (separate in and out) for free but what about the quality (or perhaps suitability is a better term) of the echo cancellation with various VOIP systems?  I have to assume that echo cancellation for a laptop with built-in speakers and mics is a different animal compared to a panel of lav mics and a full PA system.  In particular, aren't the algorithms tuned somewhat based on latency? 
Title: Re: Alternative to Gentner phone interface
Post by: Luke Geis on October 19, 2015, 02:56:53 pm
Going back to the basis of this thread, the original idea was how to get telephony sound without using a Gentner or other expensive interface. While the interfaces do the job very well, some are confusing to set up and others simply too wiz bang for what most are trying to do. If your going to send video with audio Citrix, Skype and a few others are the best way to go. Shoot, if your going to go that route you could even simply run multiple live instances of Ustream.

A way of doing audio only, would be a VoIP converter as I mentioned earlier. For cancellations I think it depends on user setup. You could invert the polarity of one side of the audio conversation and that might do most of the work for you. I think that most converters are going to work the cancellations out for you already though. Not to mention that if you designed and deployed the PA well, there will be minimal issues from loop back anyway.