Reverb Time

what's bpm? bussines process management? or
beat per minute?

no, certainly not. you have to know what is reverberation.

its time that takes signal intensity decay 60db

I was reading when setting your reverb time you have to divide the BPM by 60 is that the correct way?

Hi,

I've only seen that formula used to sync an LFO or delay time to the song tempo, not reverb time.

And not used it for a few years now as all effects softsynths have the ability to automatically sync to
tempo.

wst3

reader1
<snip> its time that takes signal intensity decay 60db

Actually, the time it takes for a sound to decay by 60 dB is the RT60... reverberation is an entirely different thing, though RT60 is associated with reverberation<G>!

erh?
What's difference between them?
 

 

I wrote this easy to read article on Reverb and how it works. You may want to read this, or may not!!
http://audio-mastering-mixing.com/FAQ___Q_A.html#28

Pre-delay is the first knob I touch when tweaking reverbs.

The greater you set your pre-delay will make it seem like there is more space between you and the walls.
Cj

Pre-delay is the time it takes form the induction of the direct signal of the listener and the reverb portion of the effect to be heard
Cj

in acoustic we research the first, second and thid echo sound to affect on hearing.
this pre may occur in midi field? oh, learn a new word.

reader1

wst3

reader1
<snip> its time that takes signal intensity decay 60db

Actually, the time it takes for a sound to decay by 60 dB is the RT60... reverberation is an entirely different thing, though RT60 is associated with reverberation<G>!

erh?
What's difference between them?

The humor didn't make it through I guess... sorry about that!

But, as is sometimes the case, the statement stands true - reverberation time is a somewhat meaningless term that has become popular, and is generally accepted to mean RT60. The reason that's not an accurate use is that reverberation time consists of lots of measurements. For starters, in some spaces you are interested in RT30 (the time it takes for the original signal to decay 30 dB), and in some cases (many really) you really want to know RT30 or RT60 for octave or 1/3 octave bands.

As has already been described, in addition to the overall decay time - to any specific level - we also want to know how long till the first, second, or nth return, and maybe even how many returns.

A graph of energy vs time is almost never smooth, especially at the beginning of time measured.

And on top of it all I just realized there was a typo in my original, and apparently not amusing, post.

Hate it when that happens...

 

erh?
What's difference between them?

The humor didn't make it through I guess... sorry about that!

But, as is sometimes the case, the statement stands true - reverberation time is a somewhat meaningless term that has become popular, and is generally accepted to mean RT60. The reason that's not an accurate use is that reverberation time consists of lots of measurements. For starters, in some spaces you are interested in RT30 (the time it takes for the original signal to decay 30 dB), and in some cases (many really) you really want to know RT30 or RT60 for octave or 1/3 octave bands.

As has already been described, in addition to the overall decay time - to any specific level - we also want to know how long till the first, second, or nth return, and maybe even how many returns.

A graph of energy vs time is almost never smooth, especially at the beginning of time measured.

And on top of it all I just realized there was a typo in my original, and apparently not amusing, post.

Hate it when that happens...

 

this time you are right. do remeber they are the same things.
the early reflect will be very important, it wil define the size of object space.
the decay curve is not ideal at first, that why acousticist endeavor to make it exponient smooth to fit audiences. especially buid a studio, theatre and studium etc. a burst signal used for it.
and a pink noise signal for room frequency response, duo to it can be ananlysized by 1/3 oct band carefully without affected by stand eave of room. and easy find stand waves.
 
 
I believe you type wrong words at your original thread now.
 
just do remember it.
take care.

A better way is to divide 60 by the BPM and you will get the time per crotchet. Then multiply that by the number of crotchets per bar and you will get the time for one bar to pass. So for a tune at 120 BPM it is .5 secs per crotchet and 2 seconds per bar. (of 4/4)

These figures I guess can be useful but the time per crotchet is more useful when setting things like the release time for a compressor. Reverb is more about using your ears and setting the reverb time to be what sounds best in the situation.

The PreDelay parameter is very important and many people dont understand it or use it properly. A shorter reverb on a longer predelay can create the impression of a much longer reverb.

If you are going to do calculations do the one that refers to distance and the speed of sound. Or think about 1ms per foot or approx 3 ms per yard or meter approx. This will give you a clue as to what to set the predelay to. If you are standing in the middle of a room that is say 12 x 12 meters long then the sound might have to travel a total of 12 meters before it comes back to you. (reflection) That is a pre delay of 36 ms before the reverb starts. But if you are standing 2 meters to a wall then it is only 4 meters or 12 ms of pre delay. Start thinking room dimensions and pre delay now. It will help you much more.

The early reflections are also an important paramater and how loud they need to be. Once you get pre delay set right and early reflection levels you will already be into a nice reverb sound and then the actual reverb will be easier to set on top of that. It is amazing just how good predelay and early reflections can sound on their own. Do some experimentation and find out.

Bob Katz points out in his marvelous book on mastering that panning a mono point source sound is actually hard and vague and does not really work. You need to add predelay and early reflections to any mono point source sound before it becomes believable. He says that is why many mixes are two dimensional and lack depth. The predelays and early refs create a much better sense of depth. (not so much the reverbs themselves) Many mono point source sounds can benefit from just predelay and early refs only. (no reverb at all)

Jeff Evans


A better way is to divide 60 by the BPM and you will get the time per crotchet. Then multiply that by the number of crotchets per bar and you will get the time for one bar to pass. So for a tune at 120 BPM it is .5 secs per crotchet and 2 seconds per bar. (of 4/4)

These figures I guess can be useful but the time per crotchet is more useful when setting things like the release time for a compressor. Reverb is more about using your ears and setting the reverb time to be what sounds best in the situation.

The PreDelay parameter is very important and many people dont understand it or use it properly. A shorter reverb on a longer predelay can create the impression of a much longer reverb.

If you are going to do calculations do the one that refers to distance and the speed of sound. Or think about 1ms per foot or approx 3 ms per yard or meter approx. This will give you a clue as to what to set the predelay to. If you are standing in the middle of a room that is say 12 x 12 meters long then the sound might have to travel a total of 12 meters before it comes back to you. (reflection) That is a pre delay of 36 ms before the reverb starts. But if you are standing 2 meters to a wall then it is only 4 meters or 12 ms of pre delay. Start thinking room dimensions and pre delay now. It will help you much more.

The early reflections are also an important paramater and how loud they need to be. Once you get pre delay set right and early reflection levels you will already be into a nice reverb sound and then the actual reverb will be easier to set on top of that. It is amazing just how good predelay and early reflections can sound on their own. Do some experimentation and find out.

Bob Katz points out in his marvelous book on mastering that panning a mono point source sound is actually hard and vague and does not really work. You need to add predelay and early reflections to any mono point source sound before it becomes believable. He says that is why many mixes are two dimensional and lack depth. The predelays and early refs create a much better sense of depth. (not so much the reverbs themselves) Many mono point source sounds can benefit from just predelay and early refs only. (no reverb at all)

Excellent post Jeff! I may have learned something.

Jim

to#21,
it seems you haven't heard of Sabine.

garvolt2002


I was reading when setting your reverb time you have to divide the BPM by 60 is that the correct way?

didn't read the other posts....

I've heard that, or something similar, but I think it would apply to echo so the echo's are in time with the music tempo......

I  have never done this with reverb.... I can't see why you would need to.... a reverb is a decay time... not a repeat time... so no.....

I select the reverb amount and decay by ear..... if it works it stays.... if not I make adjustments so it does work.