Yahoo Groups archive

MOTM

Index last updated: 2026-04-28 23:35 UTC

Message

RE: [motm] Different ring mod sounds

2000-11-10 by Dan Higdon

AFAIK, no. At least not for signals represented as voltage levels over time (as opposed to frequencies). 4QM is just like "normal" arithmetic multiplication, with neg * neg = pos, and neg * pos = neg. 2Q multiplication forces the modulator to always be positive. Now, I don't know if it does this through full-wave rectification (same as absolute value), or half-wave (same as the function "max (x, 0)"). I suspect half-wave, since that's essentially how a linear vca works.

So for the mathematically inclined, the output voltages are:
4QM (modulator, carrier) = modulator * carrier
2QM (modulator, carrier) = max (modulator,0) * carrier

-hdan

-----Original Message-----
From: jwbarlow@... [mailto:jwbarlow@...]
Sent: Thursday, November 09, 2000 9:17 PM
To: motm@egroups.com
Subject: Re: [motm] Different ring mod sounds


Thanks JH for the detailed thoughts on RM (which I will be digesting for a
while)!

Now another stoopid question, is 4Q multiplication the same as cross product
multiplication and 2Q the same as dot product multiplication?

JB

In a message dated 11/9/2000 7:16:11 AM, synth1@... writes:

>The sidebands
>produced are not
>the same as a 4-quadrant multiplier, because of the "sign" of the signals
>(+
>and - values) are
>"computed" differently.
>

-------------------------- eGroups Sponsor -------------------------~-~>
Create your business web site your way now at Bigstep.com.
It's the fast, easy way to get online, to promote your business,
and to sell your products and services. Try Bigstep.com now.
http://click.egroups.com/1/9183/2/_/529958/_/973826249/
---------------------------------------------------------------------_->


Attachments

Move to quarantaine

This moves the raw source file on disk only. The archive index is not changed automatically, so you still need to run a manual refresh afterward.