The only context I'm really familiar with using these things is in Mastering to add some "depth" by adding artificial harmonics. But I don't really understand when you should know when a good time for using a harmonic exciter would be. Nor, do I understand how to use I.e. How can you tell if you've used too much? And which frequency ranges does it generally work best for?

Anyone have some good insight?

 

A good exciter can add artificial treble/high frequencies where a conventional EQ would fail or add too much noise (although an exciter can add just as much noise if you're unlucky, depending on the signal...)
There is a substantial difference between an exciter and a high frequency EQ: While an EQ boosts the frequency range covered by the EQ curve, an exciter will use lower frequencies to generate artificial harmonics in the higher frequency range.
Simpler said: If your signal is 100% low pass filtered at, let's say 8 kHz, an EQ boosting at 12 kHz will have no or minimal effect, while an exciter will "fill" the 12 kHz range with harmonics that are usually generated by overdriving lower frequency bands and filtering out the "good" harmonics that are part of the distorted signal.
Exciters vary greatly in their effect and character, so I do recommend to try out a few and make sure they really add something good to your signal.
An exciter can add to all kinds of sounds with a distinctive attack, like picked guitar/bass, percussion, drums (make the snare bite) for example, and make such signals subjectively louder because of the enhanced attack phase, although the overall volume can remain almost unchanged.
Of course it's not limited to attacks, exciters can also brighten up your sounds and let them "shine".

I would use an exciter whenever I try to boost the treble of a signal but a conventional EQ just can't do it.
This is rare, however, because in most cases a good parametric EQ will do the job.
If your signal is too noisy already, there's another option: Mix it with a different, high-pass filtered signal that adds the treble you want.

This was for treble exciters. There are also various "bass exciters", usually they create synthetic low frequency tones with volume, pitch and envelope matching the source signal. Again, these vary greatly and you have to check them out for yourself.

 

Wow, that was incredibly insightful and exactly the kind of explanation I was looking for!! Thanks

 

So, just to clarify, a treble exciter will take lower frequency content and add high harmonics. Is this effectively true for multiband exciters as well? Only, a higher frequency bandpass would add low frequency harmonics (like the bass exciter you mentioned?)

 

No technical numbers to cite – just from my own ears, according to my experience and taste.

I use the Waves Aphex plug-in, sidechained, to add (via buss-knob level) more presence in a mix to vocals (esp. background vocals), acoustic instruments, and percussion, when EQ doesn't address their need for more presence and raising their channel levels isn't an option. I do not use this effect on electric guitars, which usually results in a "scratchy" sound or feel, especially on distorted/overdriven guitars. I find it good to apply the effect gently and sparingly: as I said, when adjusting levels and/or EQ is either insufficient or too consequential.

A harmonic exciter also affects the "feel" of the sound, which I can't really explain, but one might really like how it maken acoustic instrument feel, as well as sound, in the mix.

 

Tech explanation aside, which fiction has definitely tackled well, care must be taken with exciters. Just like too much compression will sound awesome when you're turning the clock but horrible the next morning, too much harmonic exciter may sound harsh. A little of it will go a long way. Exciters like Waves' Aphex emulation or BBE Sonic Maximizer can go to extremes with your audio. In that sense, I prefer Slate Digital's Reviver (free but ilok dependent). The harmonic content it adds to the signal is very subtle, and since it is actually a plugin to add to an audio track more than to a mix buss, adding it to various sources will almost always provide pleasing results all combined. On low frequency content, an amazing plug-in is Bark of Dog (free and clever putdown on the revered Voice of God exciter). It tightens the low end in a way that is hard to explain.

 

exciter is usually an high passed saturator (tape or whatever)

Bark of god is not an exciter, just a resonant hipass filter

 

Vocals, bass, drums, Synths, basically.... whatever you want.

 

I use exciters on LQ material or vintage audio to synthesize some high end, from 3khz to whatever. Tonebooster's evoke does good on the high end. if you want low & high end exciting, try Izotope Ozone 5. For low end exciting, try LF VOxengo Maxpunch (but that also does a few other things as well).

Sometimes I use exciters on acoustic guitars to make them stand out in the mix. Although EQs will do, they don't make them stand out as much as exciters.

 

Yes, only that with multiband exciters you can fine-tune the processed frequency ranges in both coverage and effect depth separately which is a good idea.

No, distorting a signal won't give you lower harmonics (except with some analog gear, likely a highly overdriven valve plus transformer stage ;-). That's why "Low-end exciters" are often actually "Subsonic Synthesizers".
The dbx "Boom Box" was one of the first products that incorporated this principle.
They add synthesized lower frequencies, and imho this is where the problem starts: It's no problem to synthesize low frequency "harmonics", but it's critical to control its envelope and its pitch(es) precisely, and that's where many products fail.
They usually fail so badly that I'd rather use a simple Synth VSTi and "play" the low sine waves and adjust the envelopes to perfectly match the beat. Or add a sample with nice low-end, e.g. to enhance a bass drum. It's much *tighter* and you have full control.

Stevitch said:

That's what counts in the end, isn't it?

 

BTW, another option from the sound kitchen:
Use a good parametric EQ and try setting very high Q and high gain to emulate a low (or high, why not) frequency resonator.
(Thanx M3RCURYsoto: Bark of Dog uses this principle).
The high Q will only boost one specific frequency, and if you need more, you can use more bands.

Make sure the bands of your PEQ all cover the full frequency range or you won't be able to add multiple "resonators" in the bass range.

 

its all about the Bass,about the Bass ! No treble

 

A thing that exciters do, and no eq do that, is a physical effect that pleasure me in the lower frequencies: while the bass sounds tends to be uniderectional (thats why in live shows they need a "tuned" speaker box), the exciters makes them omnidirectional and more balanced. Thats why I mix far and closer from my monitors, and loud and quiet...
Also the emulations are far from the hardware, and I advise by at least one

 

Yeah this is the only reason I've ever used them. Got a sample with a lot of noise and no high end? May as well try an exciter. I know a lot of EDM people use them all the time, but for hip hop I don't need everything to be all bright and sparkly