Iow: He use baffle step to manage directivity: last sentence of this message.
https://www.diyaudio.com/community/...ccording-to-john-dunlavy.417486/#post-7787676
If i wasn't clear at 280hz it's middle of 4 octave bsc. From directivity pov, it means circa 90hz= omni= 360*, 1120hz= hemispheric=180* , at 280hz circa 270* directivity.
It seems to be his 'target' of directivity toward the range he talk about ( 100 to 300hz).
Interestingly, this is approximately what ATC target too in their design goal ( +/- 130 or 140*, but over the widest frequency range including toward high freq).
John Dunlavy:
"Most musical instruments are almost omnidirectional at low frequencies, as are most loudspeakers, so it doesn't pose a problem. But as you go higher in frequency, to between 100Hz and 300Hz, if you don't get the beam-width of the speaker correct in this range—and by "correct" I mean that it simulates most live instruments—it will add warmth, unnatural warmth, to the sound of voices and musical instruments. "
I remember you wasn't convinced by Patrick Bateman's approach when he explained it but to me it relates.
https://www.diyaudio.com/community/...ccording-to-john-dunlavy.417486/#post-7787676
If i wasn't clear at 280hz it's middle of 4 octave bsc. From directivity pov, it means circa 90hz= omni= 360*, 1120hz= hemispheric=180* , at 280hz circa 270* directivity.
It seems to be his 'target' of directivity toward the range he talk about ( 100 to 300hz).
Interestingly, this is approximately what ATC target too in their design goal ( +/- 130 or 140*, but over the widest frequency range including toward high freq).
John Dunlavy:
"Most musical instruments are almost omnidirectional at low frequencies, as are most loudspeakers, so it doesn't pose a problem. But as you go higher in frequency, to between 100Hz and 300Hz, if you don't get the beam-width of the speaker correct in this range—and by "correct" I mean that it simulates most live instruments—it will add warmth, unnatural warmth, to the sound of voices and musical instruments. "
I remember you wasn't convinced by Patrick Bateman's approach when he explained it but to me it relates.
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I'm not sure I disagreed with Patrick outright, but let me get this straight.
If you follow what Dunlavy has said then you may get good results but you won't know why.. because emulating an instrument isn't the goal. You won't get there by ignoring the room.. and dealing with the room is what sets the need for directivity (and it varies depending on where you plan to put the speaker).
The key factor is DI, or the relationship between response and power. The goal should be a smooth DI. You also have to know more specifically what's happening to the rearward sound or it won't be smooth, and you have to work out what's happening elsewhere or you won't find a way to do it.
If you follow what Dunlavy has said then you may get good results but you won't know why.. because emulating an instrument isn't the goal. You won't get there by ignoring the room.. and dealing with the room is what sets the need for directivity (and it varies depending on where you plan to put the speaker).
The key factor is DI, or the relationship between response and power. The goal should be a smooth DI. You also have to know more specifically what's happening to the rearward sound or it won't be smooth, and you have to work out what's happening elsewhere or you won't find a way to do it.
"If a loudspeaker's directivity pattern is incapable of emulating the aggregate, the average of the patterns of all of these musical instruments, it will never sound "accurate.""
"if you don't get the beam-width of the speaker correct in this range—and by "correct" I mean that it simulates most live instruments"
I wonder how he even approached this. Once you add stereo to the equation, the beam width of the system is gonna be way off compared to a real acoustic instrument, and is going to vary based on where the instrument is placed in the recording, no?
"if you don't get the beam-width of the speaker correct in this range—and by "correct" I mean that it simulates most live instruments"
I wonder how he even approached this. Once you add stereo to the equation, the beam width of the system is gonna be way off compared to a real acoustic instrument, and is going to vary based on where the instrument is placed in the recording, no?
I don't think Dunlavy ever suggested he was trying to emulate "an instrument or even instruments". How I've read this in the past is that he brought many instruments into his anechoic chamber to get an idea of the average pattern of all these instruments combined. Armed with that information you can design a speaker that has a certain power response as it will react with the room..
Eventually resulting in the smooth power response target he went for. I don't read that as "mimicking instruments". I tend to agree with Krivium here, he did his research to know where to start to deviate from that omni behavior of the lower notes with the power response. Smart thinking if you ask me.
Yeah this is how i understand/interpret it too Wesayso. I had written a long answer but decided not to post it as i don't want to bother people with my OCD and mind reading/interpretation... lol.
Almost took my Ouija board to ask him directly! 🙂
The thing about Dunlavy 'attitude' in loudspeaker design is he is an 'objectivist' (and he makes multiple reference about it in the interview) and he had an understanding of the 'whole picture' ( room+loudspeaker interaction) so having him saying he tryed to mimic instruments seems to be the inverse of his applyed way of thinking.
The initial intent could had been lost in transcription too.
Almost took my Ouija board to ask him directly! 🙂
The thing about Dunlavy 'attitude' in loudspeaker design is he is an 'objectivist' (and he makes multiple reference about it in the interview) and he had an understanding of the 'whole picture' ( room+loudspeaker interaction) so having him saying he tryed to mimic instruments seems to be the inverse of his applyed way of thinking.
The initial intent could had been lost in transcription too.
I agree, I can't imagine Dunlavy ever suggesting a speaker should mimic instruments.
But I can see him trying to figure out what power response is most correct for a speaker.
It isn't touching on this subject specifically but this paper should give some insights to Dunlavy's line of thinking:
Loudspeaker Accuracy by John Dunlavy
But I can see him trying to figure out what power response is most correct for a speaker.
It isn't touching on this subject specifically but this paper should give some insights to Dunlavy's line of thinking:
Loudspeaker Accuracy by John Dunlavy
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Kudos Shaun.......as an engineer i can tell you that there is ABSOLUTELY no reference for what we do or have done. I've had producers come in over my shoulder and tell me how they want a track to sound......or a control room full of drunk artists riding faders.......and i never bite the hand that feeds. lol