Post your questions, opinions and reviews of the MPC1000. This forum is for discussion of the OFFICIAL Akai OS (2.1). If you wish to discuss the JJ OS, please use the dedicated JJ OS forum
By Darm Wed Mar 14, 2007 9:21 pm
Does anyone here know what do numbers on filters(in program menu) mean?
I usually cut an 808 sample using lowpass at 10, and I was wondering how many Hz is that?

By Darm Sun Mar 18, 2007 3:25 pm
It can't be. You can't hear what is under 20Hz. And when I am cutting with a lowpass at 10- I still hear the sound!
The hi pass would be also useless if it was only able to cut up to 100Hz. So the numbers are not Hz's. So what the heck are they?

By SicksentZ Sun Mar 18, 2007 3:47 pm
Darm wrote:It can't be. You can't hear what is under 20Hz. And when I am cutting with a lowpass at 10- I still hear the sound!
The hi pass would be also useless if it was only able to cut up to 100Hz. So the numbers are not Hz's. So what the heck are they?


I always assumed they were a scaled percentage.
User avatar

By rinseout Sun Mar 18, 2007 5:38 pm
That made me curious, of course you should tweak the cutoff by ears, but i wanted to know. So i loaded a noise sample, pulled up the resonance of lp2 and recorded with cutoff 100, 90, 80 ... and heres the result:
Image

Cutoff settings are 100, 90, 80 ... from left to right, obviously, the frequency in hertz is shown at the scale to the left in logarithmical graduation.

By Darm Sun Mar 18, 2007 6:23 pm
rinseout? how can it be?
I really can hear the bass sample, when I cut it at 10. And it can't be 10 Hz.
Speakers just can't produce a sound that low!

By elmarielito Sun Mar 18, 2007 6:45 pm
Looking at rinseout's pic, if you have your cutoff at 10, it seems the cutoff frequency would be around 500hz or 300hz (not sure from the pic).
User avatar

By rinseout Sun Mar 18, 2007 10:29 pm
The stripes didnt fit the screen so the one for 10 is missing.
I made another one with better (whiter? ok not funny :wink: ) noise, 100, 90 .... 10 from left to right.
Image
So freq for a cutoff 10 would be around 70, if you take the middle of the resonance´s freq range. Hope that helps
User avatar

By M02 Sun Mar 18, 2007 11:08 pm
There is a conversion table floating around for this somewhere. I've seen it, but can't fin it now. Anyone have it handy?

By Darm Tue Mar 20, 2007 1:11 am
Conversation table? Yep! That's exactly what I need!
I couldn't find it thought(
User avatar

By Murahachibu Fri Apr 27, 2007 4:07 am
Does anyone have the conversion table. I'm trying to understand the filters a bit better.

Thanks.

By anstill79 Fri Apr 27, 2007 5:38 am
Rinseout, what program are you using in those screenshots?
User avatar

By rinseout Fri Apr 27, 2007 1:57 pm
Those are screenshots of spectrapro.

I´m not so into the numbers thing, trust your ears not the numbers, but you guys got me curious so i made a formula to convert the value into the cutoff freq:

0.74*(cutoff value in the mpc)² = cutoff frequency in hertz

The 0.74 is estimated roughly from the picture.