EMG Gramophone Equations/Frequency Responses?

[anchorman]

Don't know if there are filters in YouTube, but recordings of grand organ have pretty low notes which I hear in my pc speakers very well... Check this
https://youtu.be/6sevZ7U0Rus

Much of what we hear in the lower registers is actually the overtones/harmonics, and not the fundamental. Our brains are very good at tricking us into thinking we’re hearing things that are not there. I’m not sure how low the low notes are that you’re talking about, but unless you’ve got some miraculous PC speakers, it’s unlikely they’re reproducing the really low fundamental notes from an organ. Even the subwoofers that often come with such speakers are rarely capable of producing the deepest notes with any sort of loudness/volume. Look at this using a calibrated microphone and a spectrum analyzer and you’ll get a much clearer picture of how deep the speakers can actually reproduce.

[Marco Gilardetti]

Much of what we hear in the lower registers is actually the overtones/harmonics, and not the fundamental. Our brains are very good at tricking us into thinking we’re hearing things that are not there. I’m not sure how low the low notes are that you’re talking about, but unless you’ve got some miraculous PC speakers, it’s unlikely they’re reproducing the really low fundamental notes from an organ.

Agree in full.

[Orchorsol]

Much of what we hear in the lower registers is actually the overtones/harmonics, and not the fundamental. Our brains are very good at tricking us into thinking we’re hearing things that are not there. I’m not sure how low the low notes are that you’re talking about, but unless you’ve got some miraculous PC speakers, it’s unlikely they’re reproducing the really low fundamental notes from an organ.

Agree in full.

Totally. Bottom C of a 32 ft organ stop is around 16 Hz. Yes, psychoacoustics, but also the harmonics of those notes (especially 1st and 2nd) in combination can actually produce the fundamental to some extent. This is used as a feature in some organs where cost or space prevent an actual 32 ft pedal rank: a "resultant" or "acoustic" 32 ft effect is produced by using 16 ft and 10 ⅔ ft pitches in combination.

O/T... That's a *FABULOUS* video you linked to, Inigo. Duruflé is by far my favourite composer (despite the facts that I'm not generally one for favourites of anything, and Duruflé was so self-critical that his output was extremely small) and Thomas Ospital is one of the very best of the younger generation of organists.

[Orchorsol]

Demos of 32 ft organ tones through an EMG Oversize. It physically cannot reproduce the low registers, but...............
https://www.youtube.com/watch?v=4kB3IeTlRcM
https://youtu.be/AkZmr6pbBX8?t=1605

[anchorman]

Very Nice! Indeed, the fundamentals of the lowest notes are not coming through. I just put my hand on the cone of the subwoofer that is attached to my computer speakers, and it barely moves as this video is played.

[Henry]

You will not "hear overtones" unless the fundamental is also present; indeed, that is a requirement.

[anchorman]

You will not "hear overtones" unless the fundamental is also present; indeed, that is a requirement.

true, but the deepest overtones of the organ are recorded, while the fundamental, not so much. the really deep fundamental tones were present originally when the organ was played, but no longer exists in a meaningful way in playback. organs, especially get their characteristic sound from the overtones, so they're present in abundance in the recording.

[Henry]

ALL musical instruments get their characteristic sounds (technical term "timbre") from the distinctive composite wave shapes that they produce.

[anchorman]

ALL musical instruments get their characteristic sounds (technical term "timbre") from the distinctive composite wave shapes that they produce.

Yes, no argument there. All I was trying to say is that there is no requirement for the fundamental to be on the recording, for its recorded overtones to be reproduced. what most of us perceive as deep bass notes are often not actually deep bass notes. that is all.

[Ethan]

There may be a high pass filter in youtube that cuts out the lower frequencies. Or there may just not be much below 150hz on those records.

I haven’t noticed much difference—if any—between my videos before and after uploading them to YouTube, although if the filter cut out frequencies starting below my horn’s actual cut-off, the effect probably wouldn’t be that noticeable. A while ago, though, I played some unprocessed electrical transfers of late-‘20s Victors that I found on YouTube through the Bose, and the bass was still strong at 60 Hz; so I’m guessing most of the lack of bass in large-horn gramophone videos is from the microphones, not YouTube.

Finite horns do let frequencies below the cut-off pass, so they could actually have been the 50 or 70 Hz notes that you heard, rather than the overtones—I think I’ve been able to hear notes around 30 or 40 Hz coming out of my homemade horn, although very quietly; probably much too quietly to be heard if they were present in records, instead of as pure tones. Do you happen to know what range the high pass filter on an iPhone excludes? That’s what I’ve been using for my videos, and it seems to be able to get 90 Hz reasonably well—possibly even lower.

roughly a 100 Hz cut-off for the Mk IX and 80 Hz for the standard Xb—Does that seem accurate to those of you who have heard them in person?

This seems approximately right to me, or a little above those figures - from memory, around 85-90 Hz for the Xb and 75-80 Hz for the Xb Oversize.

Some years ago Bjørn Kolbrek (who co-authored 'THE' vast text book on audio horns in recent years, mentioned by Graham in another thread) visited Graham, Ian Maxted and myself and made numerous measurements on various EMGs and Experts - both from frequency test 78s using various soundboxes, and by injecting frequencies from a tone generator. Fascinating stuff!

That matches what I’ve heard for the Xb Oversize—hadn’t read anything about the Xb, though; thanks! Any idea about the IX? And do the Xb and Xa sound any “peakier” than the Ovesize? I’ve read that a too-small mouth creates resonance and a very uneven response near the cut-off, but I’ve never heard EMGs described that way, regardless of horn size.

It certainly does sound fascinating! I don’t suppose anyone recorded the results…?