Aural Exciter

Special Interest Groups Audio Processing
1

Hello to all.

I did a search on “aural exciter” and there seems to be no thread started on this topic. I have also been looking for a plugin for this effect. I have to say, that with all the really insightful and complicated plugins created by so many talented programmers, I am surpirsed this effect has not yet been created.

If anyone knows of a plugin for this effect, please let me know.

I did a search on how an “aural exciter” works, and it seems that when affex first offered it in 1974, it was shrowded in mystery.

It is really simple as it turrns out.

The way an arual exciterr works is to add a distortion to a seperate feed of only the high end of the program so as to add harmonics. Then this effected portion is sent out ahead of the orignal track (original track is delayed) a tad to account for the sluggish velocity of the tweeters ability to reproduce high frequencies at the same rate that the woofer is doing what it does.

You can create your own aural exciter “manually” in Audacity by following these steps.

1.) select and duplicate the track(s) you want to apply the effect to.
2.) select the duplicate track. Using the “equalization” function in the effects list, reduce all frequencies to the left of 5k hz down as far as they will go. This essentially leaves nothing but program frequencies above 5k hz
3.) Select the duplicate track. Using the “amplifiy” function in the effects list, bump up the pre-selected, defauult value by about 3 or 4. be sure to un-check the check-box for “allow clipping” (you DO want to allow clipping). The duplicate track now is a high pitched, rather distorted version of the original.
4.) select the duplicate track and using control-1, zoom in so you can see individule wave bumps (I usually hit it about 19 times). Using the shift tool, shift the duplicat track forward a “hair”, maybe 8 jumps (I dont know what fraction of a second this is, but it is not much).

Play bak the duplicate at a level just loud enough to hear a little enhancement. You can use the mute button on the duplicate track to switch between regualr and enhanced mode. Adjust the level of the duplicate track to your liking…too much of an “aural exciter” can be a bad thing, so use it sparingly.

I would love to know how to program a plugin to do this or even a macro of some kind.

For now I will have to keep doing it manually.

Try it, you’ll like it…

Ciao

2

I joined simply to post this reply to your explanation, betta.

You sir, are a bloody genius!

3

Since this is about a specific effect, I have split it from the more general discussion that it was originally posted in.

For anyone interested, the Aural Exciter was originally developed by Aphex systems. More information about it here: http://en.wikipedia.org/wiki/Aphex_Systems

From hat article:

The Aural Exciter is said to enhance clarity and intelligibility by adding phase shift and musically related synthesized harmonics to audio signals.


While this will add harmonics, clipping tends to produce rather non-musical harmonics (odd harmonics). The effect may sound better by introducing even harmonics instead.

4

OK, so here’s my attempt at making an Aural Exciter type effect.

This is not attempting to emulate the Aphex Systems effect. It is just a simple effect that adds musically related high frequency harmonics to the processed audio. There is no “reverse dynamic tracking” or “Big Bottom” effect, however I think it may still be useful for some.

It will, for example, brighten up vocals, which may be useful for anyone that is recording vocals with a dynamic microphone (which typically have limited high frequency response).

Another possible use could be for increasing the frequency band width of music that has been recorded at a relatively low sample rate. If you have a recording that has been recorded at say 22kHz, then it will probably sound a little dull. However, mixing that track at a sample rate of 44.1 or 48kHz and then applying a little of the “Exciter” (a setting of around 0.1 should be sufficient) will brighten it up.

Limitations:
This plug-in has been tested on Audacity 1.3 only so there are no guarantees that it will work on Audacity 1.2
It has so far only been briefly tested, so it may still need some tweaking.
As with other Nyquist plug-ins, it is most suitable for use with fairly short selections of audio. I have used it successfully on a 3min 30s track, but I would not advise trying to run it on an entire album.

To install - download the zip file and unzip it into your Audacity plug-ins folder. When you restart Audacity it will appear in the Effects menu. It will be called “Vocal Exciter”.

Please let me know what you think of this effect, and feel free to modify it in any way you like.
vocal-exciter.ny.zip (679 Bytes)

5

for your aphex model 104 aural exiter plugin go to digidesign.com.

i found this plugin while searching the process of aural exciting. maybe you can answer my questions. this unit is in a rack with a couple of other units. i purchased this rack used and a new to live sound generating and am a home studio owner that has only used plugins for recording. how useful is an aural exciter in the studio. second in the rack there is an alesis 3630 compressor/limitor, zoom rfx1100 effects processor, alesis meq230, crate ls1 eq and ofcourse the aphex 104. i will be using a peavey 32fx mixing console. what is the order in which i should chain them. third what is the best application for each unit ( vocals, guitar, bass etc.)

thanks, hope to hear from you soon.
stephen siders

6

This was the effect that brought the name Aphex Systems to prominence. Their Aural Exciter was something of a cult thing back in the 1970’s.

I’ve never used one, and in fact never even seen a real one. I guess they are useful if you want that particular sound. There are many other “enhancer” effects, but the Aphex one has a distinctive colouration that may or may not be to your taste. There is some information about their current model here: http://www.aphex.com/204.htm

I don’t know this particular model, but compressor/limiters can be used pre or post recording. It can be useful to set the limiter for recording, just above the peak level of the signal that you are recording. This will do nothing! unless there is some random peak during the recording session that attempts to go above 0dB and ruin your otherwise perfect take, in which case it will limit that peak and save the day.

Note that if you use compression during the recording, if you apply too much it is near impossible to correct. Use very sparingly during recording (or not at all). You can add more compression after recording if you want.

The same goes with other effects.
I like to record “dry” (no effects, or at least very little effects) and then apply effects later. There are some exceptions to this, for example if a particular effect is intrinsic to a musicians “sound”. For example, if a guitarist achieves a unique sound using his/her amp and effects, then I will let them set up their equipment to produce that “sound”, then record it as accurately as possible. In this case, there are effects being used prior to the recording, but not as part of the recording process - I am still essentially recording dry. In this type of situation I may ask the guitarist to modify their sound slightly, but only if I know from experience that their sound is not going to translate well onto the recording (To make a recording sound like it is played in an auditorium when it is played in the studio is not necessarily just a matter of adding auditorium reverb. Many instrument will respond to the environment in which they are being played, so a guitar amp cranked up to 11 in a concert hall will not sound the same as the guitar amp set the same in the studio. Most commonly it is necessary to use less effects when recording.

There are no rules here. It depends on the sound that you want to achieve.

Lets say you have chorus effect and a reverb effect.
If you chain them “instrument > Chorus > Reverb >” then the reverb will be applied to both the instrument and to the chorus effect.
If you chain them “instrument > Reverb > Chorus >” then the reverb will be applied to the instrument, but not to the chorus effect (the chorus effect will be added to the instrument and the reverb).
These two chains will sound different - it is up to you which you want.

I tend to take an experimental approach to recording. Just because a particular effect is used on one instrument and not another does not mean that you must not use it on the other. Using effects in unusual ways can sometimes produce very interesting results. However if an effect is not used in a particular situation, it may be because using it like that sounds rubbish, but then again that is also a matter of taste. Personally I dislike the sound of “Fuzz Boxes”, but sometime that is just the effect that is wanted/required.

8

For an “un-exciter”, just use the Graphic EQ and reduce the high frequencies.