Speed and pitch changer - software?

[dave2010]

Looking at specs of old Minidisc kit recently I wondered about some of the speed change features that some devices have. Pitch control is obviously useful for musicians, but speed? Apparently slowing sounds down without changing pitch is useful for language learners, and I guess that hearing complex music slowly could also be uaeful. Conversely, I suppose that some slow music might benefit from being speeded up.

I looked to see if there's any software that can do this and found http://www.ronimusic.com/amsldox.htm

Is there other software or are there other audio players that do this? Does anyone find them useful?

[Mr Nad]

As far as I am aware, pretty much all audio editors will allow time stretching without changing pitch, and many allow the pitch to be changed without altering the time.

HOWEVER, artefacts begin to invade when time stretching reaches a certain point. Nasty chirrups and a kind of 'digital echo' become apparent. This, of course, ruins the audio.

There is a solution though...

I'm a keen amateur film maker, and one thing that stops me editing with Adobe Premiere Pro is that fact that it is seriously cr@p at working with audio. Poor audio will ruin even the greatest film, but great audio can make a bad film bearable.

Instead of Premiere, I stick with Sony Vegas Pro for one reason alone. It's the best mutli-track sound editor around. It comes with Zplane Elastique Pro which employs a time stretching algorithm that AVOIDS the digital artefacts.

I'll try to post some samples for you in a while.

So, if you want to time stretch your audio with the highest quality, give Vegas a shot. Even the humble home version include Elastique, which at £55 is an absolute bargain.

Have a look here (http://www.sonycreativesoftware.com/buy/moviestudiope) for more information.

I also use Audacity (too complex for the casual user), Goldwave (good, but can be a little tricky at times), and Adobe Audition (complex, but a supreme noise reduction algorithm). None of them comes close to Vegas for time stretching or pitch shifting.

[dave2010]

Do any hardware units do pitch shifting in real time? Speed shifting is a little harder, and obviously can't be done with a live source - at least regarding speeding up, but should be possible with a recording. Do any of the software systems allow real time operation, or are they really batch processing systems only? There's no obvious reason why a software system shouldn't be at least as versatile if running on a fast processor, but I'm guessing that they're not all equally flexible.

Real time pitch and speed shifting could be useful for musicians. Having to edit and then play back could be a bit of a dampener.

[YNWaN]

You can do this in Audacity.

[Mr Nad]

Do any hardware units do pitch shifting in real time? Speed shifting is a little harder, and obviously can't be done with a live source - at least regarding speeding up, but should be possible with a recording. Do any of the software systems allow real time operation, or are they really batch processing systems only? There's no obvious reason why a software system shouldn't be at least as versatile if running on a fast processor, but I'm guessing that they're not all equally flexible.

Real time pitch and speed shifting could be useful for musicians. Having to edit and then play back could be a bit of a dampener.

Yes, there must be systems that shift pitch in real time. There are toy 'voice changers' that will do just this - making the voice higher or lower as the sound is played.

As for speed changes, Vegas will do this as you stretch the timeline. So you can be replaying a recording, and as you play it, stretch it, and hears the change immediately. No need to click 'apply'.

For ultimate control, and to give that 'turntable slowing' effect, something like Adobe After Effects will do the trick. There is also a free plug-in for Audacity to do this, but it's not nearly as flexible. But free vs £800...

[YNWaN]

You can change speed, pitch and tempo already in Audacity, no plug-in is needed to do that (not in real time though) - it also has something called 'sliding time scale/pitch shift', all of these features are in the 'Effect' menu.

However, to adjust the speed/tempo of music is to seriously undermine the intention of the musicians making said music!

[Mr Nad]

For free, Audacity is a seriously good sound editor - and multi-track, too. However, as with many of the open source software offerings, it suffers from being too technical for beginners to use. To do simple things takes too many steps and previewing exactly what you want isn't always possible.

The current beta are better and offer improved preview facilities, but it is still lacking compared with paid-for offering.

For simple editing - normalising, trimming, and noise reduction - it excels. For mastering, and advanced noise reduction I use Adobe Audition. For most other audio work I use Vegas.

[dave2010]

You can change speed, pitch and tempo already in Audacity, no plug-in is needed to do that .....

However, to adjust the speed/tempo of music is to seriously undermine the intention of the musicians making said music!Not necessarily. There have been recordings which were possibly made at the wrong pitch. In any case, once a recording has been put on a CD it's pretty much up to the listener what happens to it. If someone wants to play it back at twice or half speed, then why not let them?

There are respected musicians who have adapted other music - e.g Shostakovich, who "ripped off" Rossini and Wagner to name two in his 15th Symphony, and there are many composers who have adapted music by changing the speed and pitch etc.

Where there are musicians who want to practice or even perform they may want to take a track, and adjust the speed or pitch. Admittedly most people don't want this, and simply want the music at the speed and pitch at which it was recorded, but I'm just pointing out that not everyone wants to do this.

There are some devices which will do pitch and speed change almost in hardware - for example some Sony Minidisc devices, but apparently they don't work well enough and there's a hiccup of around 1 to 2 seconds while they do the switch. There are certainly some musicians who might appreciate a device which could do speed and pitch changes smoothly in real time. What about the people at IRCAM in Paris? I bet some of them do this sort of thing.

I don't know of any good consumer electronics devices which will do speed and pitch changes smoothly in real time.

[YNWaN]

Modifying a recording because you want to use it to make something new is one thing - adjusting it because you want it to play a bit faster/slower is another.

I don't know of any software/hardware that will adjust tempo in real time (though some samplers may) - I can't see any purpose for one either mind you.

[dave2010]

Modifying a recording because you want to use it to make something new is one thing - adjusting it because you want it to play a bit faster/slower is another.

I don't know of any software/hardware that will adjust tempo in real time (though some samplers may) - I can't see any purpose for one either mind you.I've already stated some of the reasons why people might want to do this. Sometimes musicologists want to test out ideas of tempi - did Beethoven really mean the tempi he wrote? One way would be to take a recording, and adjust the speed. This way the effects can be assessed. In the past that would also have raised (or lowered) the pitch, but I believe modern equipment may make this possible in real time.

Similarly musicians might want to check out pieces in slightly different pitches.

It seems to be fairly well known that some recordings have been made at the incorrect pitch, so correcting that would make sense.

Singers may find it difficult to sing "at pitch", and may want to try singing along with a recording at a slightly different pitch for practice purposes - assuming they don't have an accompanist on hand. In any case, it might take a really good accompanist to be able to transpose every piece into a performable key. Similarly they might find it hard to sing "at full speed", so might want to stretch out the music. This could also apply to instrumentalists.

Lastly, I've read that amongst other techniques, such as needle scratching (outch I hear/see the people on the analogue threads say/write) that DJs like sometimes to use speed and pitch bending. I may not approve myself, but that doesn't mean they shouldn't be allow to do it.

You seem to want to deny others the right to try or to do things simply because you don't see the point for yourself, or you think they shouldn't.

[nat8808]

You can often pick up an Akai S1000 (late 80's, early 90's sampler) for just £40 these days... Cool factor, make some music with it, time stretch, pitch shift...

time stretching is great for learning guitar solos and understanding foreign language, perhaps spoken too fast.

[dave2010]

Very interesting - didn't know about this. Thanks.

Though nothing on the bay today - http://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p3693.m570.l1313&_nkw=Akai+S1000&_sacat=See-All-Categories - only manuals and other accessories.