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Thinking Outside The Box: SIP Hard Phone + External Speakerphone

I find that I’m simply drawn to novel and innovative approaches to problems. In the VUC post-call ramble this past week Michael White of E4Technologies described something that’s stuck in my mind as being pretty cool.

He was working with a large-company-who-shall-remain-nameless on a very significant installation. It was going along well. They had selected a line of SIP hard phones from a large, well-known  manufacturer, and were generally happy with the results. That is, happy with one exception; they didn’t like the performance of  the speakerphone on their chosen model of desk phone.

Normally, you’d just say, “Bummer” and start looking for a new preferred model of phone. In this case they didn’t. With many phones already deployed, and such a large installation they were compelled to find a different kind of solution.

It was noted that their desk phones featured a 2.5mm analog headset jack. This is in contrast to the RJ-9 type connector found on many desk phones.

The fact of this type of headset connector presented an opportunity. They found that they could simply add an external speakerphone device to the existing phones as required. To be more specific, they found a certain model of ClearOne Chat 50 speakerphone that also features a 3 conductor analog jack.

My ClearOne Chat 50 connected to a Sansa View MP3 player
using an analog audio cable with 3.5mm plugs

This particular model could be powered from a computer via the USB bus or from a freestanding power supply. By adding the Chat 50 to their existing phones there were able to augment the built-in speakerphones where necessary.

This approach is not something that most people would have considered. It’s an uncommon solution…and I find that I just dig that!

Given our situation I might like to try this as a means of augmenting the speakerphone feature in the Gigaset A58H handsets. My wife loves to use it when I call home from afar, but it’s sonic performance has been less than thrilling.

She’s resisted my every attempt to put a fine SIP hard phone on her desk, but she does use a soft phone and a Chat 50. I just need to drop a short adapter cable to the existing Chat 50. It would be a 2.5 mm-to-3.5 mm 3 conductor cable. I am definitely going to try this out!

I had a similar kind of a-ha! moment while working on my presentation for Astricon. I was trying to work out how I could accurately record the audio stream from a G.722.1C encoded call.

I ended up using the analog headset output of the fabulous Polycom VVX-1500 video phone. I used a simple 3 conductor lead to feed it into the line input of a Zoom H2 digital audio recorder.

I think it’s very interesting to face down little problems like these and come up with solutions that are not specifically prescribed by a manufacturer.

This Post Has 5 Comments
  1. I have a chat 50 purchased from E4 Technologies and absolutely love it. First found it this year at Astricon during our “live” VoIP Users Conference and thought it was just a great device. Small and easy to travel with, I keep it in my laptop bag and have found an incredible amount of usage for it. Attaching to a hard phone was something I had not thought of, but simply a perfect use.

  2. The Pingtel Xpressa phones have a jack on the bottom for adding an external 8-ohm speaker. Nice amp can drive a real “thump” from bass sound too. Unfortunately they are an eBay-only item these days.

    I have two different (current) vendor phones with the 2.5mm jack. I’ll have to try this. Thanks!

    1. The Xpressa was such a nice looking phone, but I had a beast of a time getting it to work. I had two, but ended up selling them off. Way too slow a hardware platform to be running Java in a VM. They reminded me of my first Palm Pilot Pro.

  3. Mr. Graves….

    1stly, I love your blog.
    My question: how would you augment the SPhone on the Gigaset A58H with this? (It has no Audio Out!)


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