Beatles REDD.44 and RS128
Beatles REDD.44 and RS128
Agustin Saraviaagusaravia@hotmail.com
When using recording software we may find that track level meters don't make sense for mixing. Slow attack or sustaining instruments, e.g., pads, organs, vocals, end sounding very loud in the mix while fast attack and percussive instruments, e.g., snare drum, bass drum, end sounding faint and low in the mix. Often the advice we get is to avoid monitoring levels with the meters at all and just rely on our ears. While reasonable it's also true that meters are tools that help make some tasks easier provided we know how to use them. Besides, level meters allow our ears to focus on other sound parametres, like frequency content, microtuning, etc. In EMI Studios in the early 1960s, these advantages of level meters were of concern and that's why in late 1962 the EMI REDD.37 mixers were modified by changing the EMI REDD.44 Peak Level Indicators with EMI RS128 VU Meters, as it can be read in the following quote from the REDD.37 mixing desk manual.
"VU Meters.
Slower reading VU Meters are due to be fitted on the REDD.37 in place of the Peak Level Indicators. The latter had a scale range of 55dB, whereas that of the VU Meter proper is only 23dB." (REDD.M37, EMI, Hayes, UK, 1964, p.21). [3]
But what is the difference between a peak programme meter (PPM) and a VU meter? Mainly their integration time and, therefore, their different sensitivity. A Type I peak programme meter, or DIN PPM, features an integration time of 5 ms, measuring short loudness fluctuations and peaks. Therefore, it is useful at the recording stage since it helps to avoid even the fastest peak going over 0 dBFS (i.e., 0 dB full scale in the digital domain) and create digital distortion. That's the reason that recording software developers include them as default meters.
In the early half of the 20th century, in the analogue domain, a PPM was useful in situations when going over a certain loudness threshold was not desirable, like in disc cutting, recording directly to disc, or radio broadcasting modulation. That is, when the focus was on the sensitivity of the transfer medium.
Human ears aren't sensitive to such short peaks and, therefore, a PPM does no conform with human loudness perception. That's the reason that the snare drum ends sounding faint while sustaining instruments, like pads, end sounding louder.
However, the integration time of a VU meter is nearly 300 ms which is closer to human loudness perception. It follows that a complete recording software suite should include a VU meter in the mixer view or in plug-in form. This is not always the case, and only in recent years has this begun to change.
A VU meter scale measures Volume Units (VU). Each VU equals 1 dB. However, 0 VU is not aligned with 0 dBFS. Rather it is aligned with the deprecated EBU standard of -18 dBFS. This is because the slow integration time of the VU meter will let fast peaks pass unnoticed, which in turn could lead to digital distortion. Therefore, 0 dBFS is located way higher so as to have some headroom before digital distortion begins.
If our DAW doesn't include a VU meter we can always use a third party plug-in.
1 EMI REDD.44
The EMI REDD.44 was built around a Siemens und Halske B-J47b DIN PPM. EMI REDD.17 and REDD.37 mixers had a REDD.44 in the top center panel until December 1962. The REDD.37 mixer in EMI Studios Room 2 had the REDD.44 removed because its red light wouldn't turn off after a peak overload. EMI Studios balance technicians in London couldn't find its usefulness whereas EMI Pathé Marconi balance technicians in Paris went on employing it into the 1970s, even with the solid state EMI TG12345 mixers.
2 EMI REDD.48
The EMI REDD.48 was built around an Ernest Turner 703 Nordic PPM. EMI REDD.43 table top mixer had two built in REDD.48.
3 EMI RS128
The EMI RS128 was built around an Ernest Turner 702 VU meter. In December 1962, REDD.37 mixers were retro-fitted with four RS128 in place of the original REDD.44, and the four REDD.48 were removed. The newer EMI REDD.51 mixer had built in RS128 from its very beginning.
References
[1] B. Kehew and K. Ryan, Recording the Beatles, 2nd ed., Houston, TX, US: Curvebender Publishing, 2010.[2] A. Nisbett, The Sound Studio, 7th ed., Waltham, MA, US: Focal Press, 2003.
[3] "Stereosonic"/4-Track Mixer Assembly REDD.37, EMI, Hayes, UK, REDD.M37, 1964.
[4] "Stereosonic" Mixer 4/8 Way, Table Model, Types REDD.43 & REDD.43X, EMI, Hayes, UK, REDD.M43, 1960.
