[AG-TECH] echo-cancellation on the cheap?

[JSalva]

FYI -
We took the initiative to bring in one of these GT1524 devices and prove
whether or not it is a viable alternative. Based on the specs - it should
plug and play - but here is what we found:

Follow this line swapping routine as you swap out the 400 with the 1524 -
AP 400 :	Output1		Output A 	Mic	Input A
    		     |		    |		  |	   |
GT1524 :	Line Out	Aux Out	Mic	Aux In

Initially we were able to receive audio on our node with the default GT1524
settings, but we were not getting anything transmitted to the other standard
node (which is using the AP400)
After a series of test and reset configurations...  on our node with the
GT1524, we adjusted Mic Gain Level to 10 & the Mic line input needed to be
set to 25db

Best Regards,


Jon Salva

 -----Original Message-----
From: 	owner-ag-tech at mcs.anl.gov [mailto:owner-ag-tech at mcs.anl.gov]  On
Behalf Of JSalva
Sent:	Friday, February 01, 2002 12:04 PM
To:	David E. Bernholdt; ag-tech at mcs.anl.gov
Cc:	bernholdtde at ornl.gov
Subject:	RE: [AG-TECH] echo-cancellation on the cheap?

 << File: Gentner GT1524.pdf >> I just received this from our Gentner rep -
Spec sheet on the 1524 - this by definition should work just fine.

I am creating an offer to any non profit agency - if anyone needs one - I'll
pass through our cost of the device  = under $2k - hope this helps.
Best Regards,


Jon Salva

Best Regards,


Jon Salva

 -----Original Message-----
From: 	owner-ag-tech at mcs.anl.gov [mailto:owner-ag-tech at mcs.anl.gov]  On
Behalf Of David E. Bernholdt
Sent:	Friday, February 01, 2002 11:08 AM
To:	ag-tech at mcs.anl.gov
Cc:	bernholdtde at ornl.gov
Subject:	Re: [AG-TECH] echo-cancellation on the cheap?

On Fri, 01 Feb 2002 10:11:27 -0600  JSalva wrote:
> On another note - if you are seeking to use a small node configuration for
a
> personal use within your facility - I know that Gentner has a single port
> cancellation device that supports the same logic as their 400 and 800
> devices - that should cost much less.

I followed this up with Jon & Darryl just now and to satisfy
everyone's curiousity, the unit is the GT1524, which lists for $2500
and includes a telephone interface.

In locating it on the web I also ran across the Gentner VTC AccuMic,
an echo cancelling mic listing for $550.  Undoubtedly one of many
examples which might work in a smaller room.

And finally, I've noted that some of the Polycom speakerphones seem to
have audio line out jacks.  But so far as I can tell, they seem to be
limited to the most expandable models, which are of course also the
most expensive (~$1500 if memory serves).  And I'm not sure it really
provides the capability you want -- I don't think you could play the
computer's sound over the Polycom speakers, and I don't know what
effect that might have on the echo cancellation capabilities.

--
David E. Bernholdt                   |   Email: bernholdtde at ornl.gov
Oak Ridge National Laboratory        |   Phone: +1 (865) 574 3147
http://www.csm.ornl.gov/~bernhold/   |   Fax:   +1 (865) 574 0680