SPA 3000 Poor Audio

[dean-ny]

Hello,

Wondering if anybody has SPA3000's working well with trix-box. I believe the problem is with the configuration of my SPA3000's. The audio is terrible. There is a lot of ECHO from an entension and the party on the other end hears a lot of missed words. There is also a big delay in the audio.

A brief map of my system. 2 SPA's connected to PSTN lines, 1 Broadvoice Account, 1 Stanaphone Account, 2 FWD Accounts, and 1 TRX Tel account on the Trunks. On the Extensions, I have 6 Local GXP-2000's, 2 ATA 386's (4 Extensions), and 1 Each Extension on the SPA's. I also have one off network extenions with an ATA 286, and one off network extension to a GXP2000. And one Budetone on a off site location via VPN.

Extension to Extenison works fine regardless device or location. All combinations are crystal clear, no echo, no delay, no static and no silence. Broadvoice, Stanaphone, trxtell, also work perfectly from 100% of extenions regardless of device or location. FWD works as well as FWD works which is OK for FWD-FWD, but pretty lousy for 800 calls. But that is not related, I don't believe.

The configuration for both trixbox and the spa's came from suggesions on this site. Functionally they work, but sound is bad.

And one other wierd thing. Faxes are not clear either. Part of the image is missing. This in itself puzzles me because faxes should have error correction causing missed packets to be resent rather than missed from the image. This is using a fax modem on an ATA and an analog telephone line.

Any ideas on improving the audio?

[jhon1980]

already prove with the impedances of the fxs, it is usually a good point to manipulate the quality of the sound

[atheling]

You will have better luck with this question on the Sipura forum at:

http://voxilla.com/forum-viewforum-f-14.html

In my case it took a very methodical bit of level setting to get the voice quality to be acceptable. See

http://voxilla.com/PNphpBB2-viewtopic-t-9320.html

I used two identical telephones one directly on the PSTN line and one on the SPA-3000 to match up gains. For example to get the SPA->handset level set I called a recording (actually a IVR on a PBX) simultaneously from both telephones. You need to let the SPA reboot between each setting so it takes a little while. . .

Once I had all four levels set the echo went away. In my case I found the chopped off bit of words was due to the echo suppression (different from echo cancelation). With the levels set so that echo was within the range the echo canceler could handle I did not need (or want) the echo suppression.