[Asterisk-Users] more cpu intensive echo cancellers ?

[Matthew Fredrickson]

On Feb 10, 2006, at 10:25 PM, Steve Underwood wrote:

> Matthew Fredrickson wrote:
>
>>
>> On Feb 10, 2006, at 1:21 PM, Gerard Saraber wrote:
>>
>>>
>>> Found it, going to go test it right now :) thanks!
>>> So far reports have been positive on the echo, but its a slow day ;)
>>> We're using cisco 7960 phones, they're pricy, but they work great and
>>> sound good, if it wasn't for the echo issue, I would have been able 
>>> to
>>> roll the whole setup out already.
>>> Actually that's not quite true, I still have to make the 7914 addon
>>> module work with the 7960 phone, but that's not a show stopper.
>>>
>>> Either way, so far big thumbs up for the MG2 echo can, and if any
>>> developers read this, feel free to add a compile flag to make it more
>>> cpu intensive ;) and do more canceling.
>>>
>>
>> Does latest MG2 behave better than KB1 on your analog lines?  I heard 
>> in the past that in some cases (primarily with analog lines) that KB1 
>> worked better.  Also, have you tried the echotraining=800  (in 
>> zapata.conf) tweak as well?
>
> A lot of the variability is probably due to thr lack of a DC blocker 
> at the front of the echo canceller. As far as I remember, none of the 
> cancellers in * has a DC blocker.
>

Where can one find out more information on writing a DC blocker?  I 
google'd around a bit, but couldn't find a definitive overview of what 
one was, and how to write one.  Thanks!

---
Matthew Fredrickson