musicvid10 wrote on 7/21/2009, 8:03 AM
The Parametric EQ has a phone line preset.

There were a couple of long threads on this subject a while back. Do a search.
Geoff_Wood wrote on 7/21/2009, 4:49 PM
Other than that cut heavily everything below 400Hz and above 4KHz.

Chienworks wrote on 7/21/2009, 8:51 PM
I'd cut that back to 2KHz instead of 4KHz. Then again, i was in the telephone transducer industry for 20 years and got to see a lot of frequency graphs of various telephone mics and earphones over the years. The old standard carbon mics barely had a 2 octave bandwidth. More modern phone systems emulated this narrow bandwidth even when their transducers were capable of a wider range because transmission was more efficient without the wider frequencies hogging the line.
Geoff_Wood wrote on 7/22/2009, 4:01 PM
I loved the rocking-armature receivers !

400-4K is a good starting point, being the channel passband for a FDM or TDM transmission system. Further degrade the bandwidth from there to emulate specific model phones ;-)

musicvid10 wrote on 7/22/2009, 5:56 PM
If I recall, the standard in the 60's and 70's at least in my neck of the woods was 700-2500 Hz.
Geoff_Wood wrote on 7/22/2009, 9:55 PM
Yuk !

Actually that triggers some memory of 300-3400 bandwidth in a 4KHz allocation 'slot' to make a CCITT 12 channel 'group'. It's been a while....

I think different systems (maybe satellite) had tweaked bandwidths to squeeze even more channels in.

L_Town wrote on 7/26/2009, 7:28 PM
WOW! Cool guys. I will have to try out that when I get back to work. I haven't touched that project in a long time and I will need a telephone effect. Thanks so much!
Lavoll wrote on 11/13/2009, 2:51 PM
adding lots of compression after the eq'ing can also enhance the telephone effect :)
musicvid10 wrote on 11/13/2009, 8:55 PM
adding lots of compression after the eq'ing can also enhance the telephone effect :)

Uhh, clipping would be the more appropriate term.