909 and other machine tempos and tuning

- ask away
steevio
mnml maxi
mnml maxi
Posts: 3495
Joined: Fri Dec 23, 2005 12:18 pm
Location: wales UK
Contact:

Re: 909 and other machine tempos and tuning

Post by steevio »

Phase Ghost wrote:The tempo is going to be changed by dj's anyways, so why worry about it? I dj at 120 to 121 bpm, so I'd pitch your track down quite a bit (possibly all the way down) to mix it into a set.
yeah but youre missing the point bruv.

most of us record our tracks at specific tempos, personally i usually record at 126, 128 and 130, and we also usually record in a chromatic key with concert pitch of A= 440 Hz, because our sequencers, synths etc. push us in that direction.

its also quite common for specific types of music to stick with regular tempos, dubstep used to be nearly always 140 bpm, much minimal was 126, house 120 etc etc.
also certain keys are much more common than others, E, G, D, etc so as a DJ i often used to find that tracks in a certain genre would mix well, even if the key was different, as long as it wasnt just a semitone or a tritone out,

but if you record at 126.277 bpm, your tune will never be in tune with anything.

take my word for it, because it's a problem for me.
my own stuff mixes together really well though.
twisted-space
mnml newbie
mnml newbie
Posts: 73
Joined: Tue Sep 09, 2008 12:16 am

Re: 909 and other machine tempos and tuning

Post by twisted-space »

try tuning A=438 instead of 440.
steevio
mnml maxi
mnml maxi
Posts: 3495
Joined: Fri Dec 23, 2005 12:18 pm
Location: wales UK
Contact:

Re: 909 and other machine tempos and tuning

Post by steevio »

twisted-space wrote:try tuning A=438 instead of 440.
why ?

the tempos that represent whole number BPMs on the 909 are just coarse digital approximations and are not mathematically proportionate as far as i can tell, if you've got a formula lets have it bro.
twisted-space
mnml newbie
mnml newbie
Posts: 73
Joined: Tue Sep 09, 2008 12:16 am

Re: 909 and other machine tempos and tuning

Post by twisted-space »

Give it a try, I'll tell you why if it works. If it doesn't then my math is worse than I thought it was, which is extremely likely.
User avatar
hydrogen
mnml maxi
mnml maxi
Posts: 2689
Joined: Tue Oct 17, 2006 2:41 am

Re: 909 and other machine tempos and tuning

Post by hydrogen »

steevio wrote: the reason for this is that although the 909 is analogue the tempo control is coarsely digital ( i assume ) and when you dial in say 127 bpm it is actually much slower than that ( on my machine 126.277 ) or example 128 is 127.422 on mine.
twisted-space wrote:Give it a try, I'll tell you why if it works. If it doesn't then my math is worse than I thought it was, which is extremely likely.
your math isn't off but it only works for one of the tempos that steevio posted.

modified_bpm/true_bpm * TUNE_A = tune_a_for_true_bpm

because modified_bpm/true_bpm is a different ratio for every bpm as steevio pointed out
for 127 you would need to tune A at 437.5
for 128 you would need to tune A at 438

if we turned modified_bpm/true_bpm into a non linear equation and only one variable we would have a stronger formula. If steevio checked all the numbers on his 909 we could probably generate a formula for him... but i wonder if this is even consistent between his 909 and another.
------------------------------------------------------
http://soundcloud.com/kirkwoodwest
twisted-space
mnml newbie
mnml newbie
Posts: 73
Joined: Tue Sep 09, 2008 12:16 am

Re: 909 and other machine tempos and tuning

Post by twisted-space »

My math is off, I got it the same for both tempos.

The idea is sound though so as long as you stick to a few tempos, it's easy enough to work out what to tune to.
steevio
mnml maxi
mnml maxi
Posts: 3495
Joined: Fri Dec 23, 2005 12:18 pm
Location: wales UK
Contact:

Re: 909 and other machine tempos and tuning

Post by steevio »

hydrogen wrote:
if we turned modified_bpm/true_bpm into a non linear equation and only one variable we would have a stronger formula. If steevio checked all the numbers on his 909 we could probably generate a formula for him... but i wonder if this is even consistent between his 909 and another.
yeah this is why i asked if someone else would check their 909.

i suppose it could be consistent, they all used the same chips as far as i know, but somehow i doubt they will be.
steevio
mnml maxi
mnml maxi
Posts: 3495
Joined: Fri Dec 23, 2005 12:18 pm
Location: wales UK
Contact:

Re: 909 and other machine tempos and tuning

Post by steevio »

twisted-space wrote:My math is off, I got it the same for both tempos.

The idea is sound though so as long as you stick to a few tempos, it's easy enough to work out what to tune to.

it's a good idea but in practice for me it wont work because i have issues with my Moog tuning. if i want to use my third oscillator free running as a drone osc, and still use my saved patches and change them during a live performance, it can only be tuned to one pitch.
otherwise i would have to tune the third osc on the fly everytime i changed a patch, or retune the whole synth. its not going to happen.

also i quite often use 432 tuning anyway.

i know that the subject of this thread might seem pointless to some DJ's who only ever mix hats and claps in the intros and outros, but i like my DJs to be mixing tonal content, i think its the sign of a true quality DJ, and the magic of DJing for me is the creation of the third tune from the mix. thats when it really trips me out.
Post Reply