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Hi, Charles,

RX8 has some new features including a method of compensating for lost 
high-end--it's an AI/Synthesis thing and I haven't played with it much, 
but for the right program, it might be useful.

If Lou's suggestion about multipath doesn't work (or not enough) I would 
suggest trying the Deconstruct tool after the Spectral De-noise tool. 
This allows separate adjustment of the "tonal" and "noise" components of 
the signal and might improve intelligibility.

Since the stereo FM system has FM sum signal on the main carrier and an 
AM difference signal on the subcarrier, I do think that the summing 
should help get rid of the noise.

The noise is mostly on the AM subcarrier and it was added to the L+R 
carrier in two polarities to generate the stereo signal. So the stereo 
signals that you have recorded on the tape really are:
2L+N=(L+R)+(L-R+N)
2R-N=(L+R)-(L-R+N)

Now, since the N component is of different polarity in L & R derived 
signals (what was recorded on the tape), if you sum the two signals from 
the tape, the N component will cancel:

2L+2R=(2L+N)+(2R-N)

Now, we all know that channel gains and responses never match exactly, 
so you should retain the stereo copy as your preservation master. Then, 
you should create a mono access copy (still a full-resolution WAV) and 
adjust the amount of the signals from each tape channel. There should be 
a point where the noise is minimized as you adjust the gain of the two 
channels in the mixer summing them to mono.

Watch your headroom as you sum things, of course.

Hope that helps!

Cheers,

Richard


On 2020-09-13 2:26 p.m., Charles Reinsch wrote:
> Has anyone here looked at Izotope RX8, and might offer an opinion about 
> upgrading?
> 
> And, lately I have been working with a batch of over the air recordings 
> of FM broadcasts that are full of multipath distortion.  If you have any 
> tips on cleaning up multipath noise, I would be most grateful.
> 
> Thanks,
> 
> Chuck
> 

-- 
Richard L. Hess                   email: [log in to unmask]
Aurora, Ontario, Canada                             647 479 2800
http://www.richardhess.com/tape/contact.htm
Track Format - Speed - Equalization - Azimuth - Noise Reduction
Quality tape transfers -- even from hard-to-play tapes.