THXtragwag wrote: ↑Mon Jan 01, 2024 4:09 pmsounds awesome, congrats on the success!
curious what level you're cutting at?
I wonder if some of the frequency irregularities between each piece come from the overall volume level?
I can hear the drivers compressing and distorting a little differently on each sample
Hello tragwag,
Thank you for your comment. I thought I wouldn't get any response at all. Your hearing is excellent! Unfortunately, it's true that not all frequency ranges are without problems and I can't check why this is (was) the case at the moment. Because the cutting head and the lathe no longer exist in their original form (08/2023).
What I do know for sure is that I cut the pieces in one cutting operation. Before that, I switched on the EQ on the PC so that I could adjust the characteristic curve when I was still working without a feedback coil. However, as the pieces of music are different, clipping was achieved with Billie Eilish, for example (when snipping). As a result, I cut the songs at different volumes.
Billie Eilish a little quieter and Pink Floid a little louder (because there are so many quiet parts).
In each case, the result is too loud an edit because I wanted to achieve a high signal-to-noise ratio (SNR) and I did.
Unfortunately, I can't calculate my PSNR (peak signal-to-noise ratio) and I don't have the necessary instruments to measure it accurately. But I can say that the signal strength (between noise volume and signal volume) is 30% better than all my previous values.
Example:
The values for Silent Cut for this recording were: [SC]
100 Hz: -57dBv
1 kHz: -95dBv
1.5kHz: -95dBv
10kHz: -100dBv
At low frequencies below 150Hz, the drive motor, mains hum and the like are also things that generate high values.
The values for Music Cut were quite high in this recording. The following table should illustrate this.
When looking at the analysis, it can be determined that the individual songs have different maximum volume levels. Of course, not every song has the same maximum volume in all frequency ranges, but I'll ignore that for now.
Pink Floyd was recorded much louder than Green Day. Billie Eilish was recorded by far the quietest!
So I think some of the frequency inconsistencies between the individual tracks are due to the overall volume.
Additionally, after disassembly work (several days and many signal test cuts later), I noticed that the straight bar on the cone of the right channel had loosened somewhat. I can't say whether this already had an influence on the music cuts.
I hope I have been able to answer the question and have not created any more confusion.
By the way, I did not carry out any further tests with the Cutterhead FP-8.
The reason for this: I already decided in July to build a new cutterhead (new housing) and a new completely revised lathe. And the parts for it have arrived. I will report on this shortly.
Thomas