Jeroni Paul wrote:

While the hints and arguments provided in these posts are correct I wonder if anyone did read my previous post which I think is relevant to all this.. Mixing the two channels with a Y cord may produce a faint or no sound if wide stereo techniques are applied in the broadcast.


** FM broadcasters are required to produce a mono compatible signal - or at least they were in the past. Studios use a "stereo modulation monitor" that shows when the signal lacks compatibility by metering the difference signal (L-R) and this must not be greater than either L or R.

True story:

A customer had made a commercial (on 1/4 inch tape) for use on FM radio and it was rejected on the grounds that it was "out of phase". I was asked to check it and found the tape seemed OK.

It took some effort to get through to the "engineer" who had made the judgement and he explained how he used such a meter reach his conclusion.

The recording had a bass guitar, piano and drum kit plus vocal, none of which were out of phase. However, the bass guitar had been panned to the left side, almost completely, which made the difference meter reading unusually high. Hence the mad conclusion the whole tape was "out of phase".

I told the customer to do a re-mix and pan the bass to the centre - problem solved.

The correct way is to pan a bass guitar to the left is to split the signal into low and high frequency bands, at say 150Hz, then pan the highs to the left and the lows to the centre.

This suits most broadcasters and would be essential if cutting an LP to avoid excessive vertical modulation.



.... Phil