Exciter - what does it actually do?

[Neil Ogilvie]

I've been using compression and a little widener with a touch of EQ (to bring back the bass down the centre) in my mastering but have considered trying out some Exciter aswell as I've heard this is a common mastering effect.

But what does it actually do? My understanding is it is a form of compression/chorus/reverb/delay on the high frequencies?

 

[Farview]

It adds distortion and a phase shift to fool you into thinking that it sounds better. Don't bother.

 

[Ethan Winer]

Neil,

> what does it actually do? <

These devices typically add distortion, but filtered so its all trebly sounding to add a bit of byte without adding much mud.

Note that these gadgets do not shift phase - or if they do, that has nothing to do with the effect. Since few people really understand what phase shift is, that claim is an easy way to befuddle people into thinking the device is more clever than it really is. In other words, they're trying to snow you with scientific sounding nonsense.

--Ethan

 

[Farview]

I could be wrong on this, but I thought that that was how the 'big bottom' or 'low contour' worked. It adds a slight shift to enhance the lows and dip the lower mids at the same time.
There has been so much mis information about these things, it's hard to keep the real stuff straight.
They aren't a good idea none the less.

 

[masteringhouse]

Neil,

> what does it actually do? <

These devices typically add distortion, but filtered so its all trebly sounding to add a bit of byte without adding much mud.

Note that these gadgets do not shift phase - or if they do, that has nothing to do with the effect. Since few people really understand what phase shift is, that claim is an easy way to befuddle people into thinking the device is more clever than it really is. In other words, they're trying to snow you with scientific sounding nonsense.

--Ethan

If you consider the BBE to be an exciter.

From Electronic Musician:
http://emusician.com/mag/emusic_ten_tips_nailing/

The Sonic Maximizer provides two different processes: linear phase shift and dynamic EQ. I often use a bit of the EQ, but for me it's the phase shifting that makes the difference. The Maximizer is said to restore harmonics to their original time arrangement-a relationship that gets "flattened out," so to speak, by speakers. The Maximizer remedies this flatness by introducing a linear phase shift across the entire frequency spectrum (20 Hz to 20 kHz), effectively slowing down the lower frequencies so that higher harmonics reach the ear before lower ones. The result is a clarification of detail and an improved sense of dimensionality; after engaging the BBE Process, as it's called, I can better hear "around the edges" of the instruments

 

[Farview]

It's the audio version of crack cocain. I like all my frequencies in the phase relationship that I put them in. If the sound of watever you are doing isn't clear enough, fix the sound. Don't put it through a $200 'magic' box.

 

[masteringhouse]

I'm not sure how everyone is defining an "exciter".

Adding harmonic content to a signal is a good thing if the material needs it. That's what tubes, tape, and Crane Song's HEDD unit do. I believe the harmonic content added by the BBEs/Aphex aural exciters and similar units work on slightly different principles. At least they sound different to me.

 

[kylen]

I'm not sure how everyone is defining an "exciter".

Adding harmonic content to a signal is a good thing if the material needs it. That's what tubes, tape, and Crane Song's HEDD unit do. I believe the harmonic content added by the BBEs/Aphex aural exciters and similar units work on slightly different principles. At least they sound different to me.

I've got one of the older 462's and it sits in the PA rack. Maybe the newer one's sound better.

I've also got the plugin and try it out every once in a while but I can never bring myself to print with it. There was some discussion on a website somewhere and the developer explained his modeling technique - it doesn't do it for me though.

The EM article was interesting -it's tru that you have to search for 'flat' on the older models - it's unmarked (I marked mine after scoping it). Also over at SOS Paul White is/was a huge fan of SPL Vitalizer type hardware units. I was thinking about them at one point - I got into Voxengo plugs instead.

 

[Neil Ogilvie]

Thanks for all the replies, although I am still a little confused as to what actually happens! It would appear to be some sort of phase-shifting thing.

I applied a little to the OH's on a drum kit and it did definatly add a nice 'sparkle' to the sound. If used in moderation, I can see it being a useful effect.

 

[Ethan Winer]

Tom,

> If you consider the BBE to be an exciter. <

Yes, and the author is a victim of the marketing hype I described. This is a big problem with magazine writers and even many pro engineers - they may know how to get sounds, but they're clueless when it comes to how the electronic devices they use actually work. If you'd like to read more about the audibility of phase shift, see the two articles on my web site, 7th in the list:

www.ethanwiner.com/articles.html

--Ethan

 

[Ethan Winer]

Neil,

> it did definatly add a nice 'sparkle' to the sound. If used in moderation, I can see it being a useful effect. <

Yes, a little sparkle can help some tracks. But what you're hearing is either added high frequency distortion, or perhaps some high frequency limiting. Some devices, like the enhancer dbx sells, use HF limiting to get a similar effect.

It's not phase shift. Really.

--Ethan

 

[masteringhouse]

Tom,

> If you consider the BBE to be an exciter. <

Yes, and the author is a victim of the marketing hype I described. This is a big problem with magazine writers and even many pro engineers - they may know how to get sounds, but they're clueless when it comes to how the electronic devices they use actually work. If you'd like to read more about the audibility of phase shift, see the two articles on my web site, 7th in the list:

www.ethanwiner.com/articles.html

--Ethan

Ethan -

I'm sorry but time delay correlated with frequency sure sounds like phase shift to me.

Here is a quote from the BBE site:

"In order to address these problems inherent in basic loudspeaker design, BBE Sound, Inc. has developed a circuit that has two primary functions. The first adjusts the phase relationships of the low, mid and high frequencies. Since a loudspeaker's natural tendency is to add progressively longer delay times to higher frequencies, the BBE sound processing system adds progressively longer delay times to lower frequencies. This creates a kind of "mirror" curve to the time delay curve created by the speaker, neutralizing its phase distortion. "

See:
http://www.bbesound.com/technologies/BBE%5FHDS/

In regards to your articles, I'm well aware of what's on your site since most of your posts seem to be an attempt at driving traffic to your site and end with "see my article at xxx". Why not just answer the question?

If the article is wrong, along with the description on the BBE site, how do exciters work if it's not using phase shift?

 

[kylen]

Thanks for all the replies, although I am still a little confused as to what actually happens! It would appear to be some sort of phase-shifting thing.

I applied a little to the OH's on a drum kit and it did definatly add a nice 'sparkle' to the sound. If used in moderation, I can see it being a useful effect.

I 'watched' mine on a RTA spectrum analyzer as I pumped pink noise thru it (don't listen to that though) as you tweak the lo and hi knobs you can see 2 distinct shelves on the low and high end that are created. I forget where the 'hinge' is on my older 462, let's say about 700Hz or so. As you raise the lo and hi controls past a certain point you'll also notice the mids beginning to 'scoop out'. I have some details about that in an older post somewhere.

I don't know how to look at phase stuff that way (I guess I could run some tests and look at smple timings,argh)...yes it certainly adds sparkle (all the way to broken glass if you turn it up too much, hehe). I think the way to use it in digital mixdowns & masters (if you're gonna) is to do it in parallel and then only on a track or 2, whatever sounds good. I remember using it on some cassette tapes and it worked on a couple of them. Now that I work in a DAW I don't use it anymore.

Here's a BBE article that gives a couple of details about it's hardware operation but is not convinced the magic ingredient is 'phase':
http://www.radio-flier.com/bbe_data.htm

I'm really looking for the one where the software developer discusses his model of the BBE hardware and there are the 'phase' discussions...

 

[Ethan Winer]

Tom,

> I'm sorry but time delay correlated with frequency sure sounds like phase shift to me. <

Sure, and if that's what the BBE box actually did I'd agree with you.

> The first adjusts the phase relationships of the low, mid and high frequencies. <

I won't say they're not adding phase shift because they may be. But if they are it's irrelevant and not what you're hearing. Consider this:

1) Any phase shift they may add has no audible affect other than possibly changing the frequency response due to acoustic interference in the air in front of the speaker drivers. At frequencies near the crossover point(s) some amount of sound is coming from two drivers, and when they combine in the air you get peaks and dips in the response.

2) Loudspeakers use all kinds of crossovers - active versus passive, 2-way or 3-way or even 4-way, 6 or 12 or 18 dB per octave, and at any frequencies you could imagine. So how could any device know what to compensate for, and at what slope, and at what frequencies?

3) It's quite a presumption on BBE's part to assume they know better how to manage the crossover behavior better than every speaker manufacturer in the world.

> most of your posts seem to be an attempt at driving traffic to your site and end with "see my article at xxx". Why not just answer the question? <

I did answer the question. Further, my site has no advertising, and I make no money from "driving traffic" there. The reason I send people there is to help them, not for some ulterior motive. Why would you even think that?

> If the article is wrong, along with the description on the BBE site, how do exciters work if it's not using phase shift? <

Again, I already answered that above. The common techniques used by "exciter" boxes are:

* Add distortion at high frequencies only, to add a little bite but without making things muddy.

* Simple high frequency EQ to add a little sheen.

* Compression that affects only high frequencies, again to add some sheen.

Claiming that phase shift is a key ingredient is pure marketing BS. If you read those articles on my site about phase shift you'll understand why it's BS.

--Ethan

 

[masteringhouse]

I won't say they're not adding phase shift because they may be. But if they are it's irrelevant and not what you're hearing. Consider this:

1) Any phase shift they may add has no audible affect other than possibly changing the frequency response due to acoustic interference in the air in front of the speaker drivers. At frequencies near the crossover point(s) some amount of sound is coming from two drivers, and when they combine in the air you get peaks and dips in the response. ...

This may be an interesting read:

http://sound.westhost.com/ptd.htm

3) It's quite a presumption on BBE's part to assume they know better how to manage the crossover behavior better than every speaker manufacturer in the world.

I don't disagree, and I'm not a fan of the BBE either.

Further, my site has no advertising, and I make no money from "driving traffic" there. The reason I send people there is to help them, not for some ulterior motive. Why would you even think that?

You may not be selling advertising, but here is a quote from your site:

"All other acoustics articles are now on the Articles page of my company's site: www.realtraps.com/articles.htm."

Obviously you are trying to drive traffic to your site to help sell real traps and potentially any books. I don't have a problem with anyone doing this, it's just when nearly every post ends with a reference to something on your site that often times doesn't really answer the question. Look back at your previous posts both here and on other sites. Count how many times the post ends with "see my article".

Here's five pages worth from Google (and I'm sure that there many more):

http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&safe=off&q=%22ethan+winer%22+%2B%22my+article%22

We know where your site is, and if we're impressed with your direct response to the question we will come to your site to check out more information. I think that your site has some very useful information on room acoustics, some articles are less impressive IMHO. The one on EQ phase and phase shift was not my favorite e.g. "all EQ shifts phase, unless it uses special trickery". What does that mean? Magic elves?

Again, I already answered that above. The common techniques used by "exciter" boxes are:

* Add distortion at high frequencies only, to add a little bite but without making things muddy.

* Simple high frequency EQ to add a little sheen.

* Compression that affects only high frequencies, again to add some sheen.

Not all exciters act this way, some add content by simulating the harmonic content of tubes, tape, and other techniques.

 

[Ethan Winer]

Tom,

> This may be an interesting read <

Yes, and that just confirms what I was saying, and reinforced by David Clark's phase article on my site. There's no question that phase shift in loudspeaker crossovers affects the frequency response. But it's the frequency response change that's audible, not the phase shift. As I said, there are an infinite number of variables in crossovers, and there's no way for a box like BBE's to improve on all of them, let alone any of them.

> Obviously you are trying to drive traffic to your site to help sell real traps and potentially any books. <

Not so, and I'm sorry you don't believe me. I don't even sell books. If my intent was to pretend to help people just so I could sell acoustic treatment, why would I have spents many months writing and refining my Acoustics FAQ showing people how to build their own treatment? Think about that.

I followed that Google link and looked at every item on the first three pages. Every single one was a link to an article that either shows how to build bass traps (no sale there), or an article explaining some other aspect of recording. I fail to see what you object to.

> The one on EQ phase and phase shift was not my favorite e.g. "all EQ shifts phase, unless it uses special trickery". What does that mean? Magic elves? <

Okay, let's discuss. By "special trickery" I'm merely referring to the FIR type of digital EQ algorithms that yield less phase shift than usual.

So what else do you object to in that article?

> Not all exciters act this way, some add content by simulating the harmonic content of tubes, tape, and other techniques. <

If they add distortion at all, there's no big difference.

My point all along has been that phase shift per se is inaudible, and when companies like BBE claim otherwise they are being dishonest and intentionally trying to befuddle people. No more, no less.

--Ethan

 

[masteringhouse]

Yes, and that just confirms what I was saying, and reinforced by David Clark's phase article on my site. There's no question that phase shift in loudspeaker crossovers affects the frequency response. But it's the frequency response change that's audible, not the phase shift.

My point with the article was that it was directed at the phase, time alignment, and frequency response issues of speaker systems (the issues that the BBE supposedly "fixes") whereas your article was about EQs and phase relationships. Two different areas where phase is an issue.

As I said, there are an infinite number of variables in crossovers, and there's no way for a box like BBE's to improve on all of them, let alone any of them.

What about speaker systems without crossovers, for example a bass guitar amplifier? Actually I have heard good results from a BBE in this application. It's using a BBE as a "magic bullet" to correct frequency imbalance in mastering that I have issues with.

Not so, and I'm sorry you don't believe me. I don't even sell books. If my intent was to pretend to help people just so I could sell acoustic treatment, why would I have spents many months writing and refining my Acoustics FAQ showing people how to build their own treatment? Think about that.

I followed that Google link and looked at every item on the first three pages. Every single one was a link to an article that either shows how to build bass traps (no sale there), or an article explaining some other aspect of recording. I fail to see what you object to.

Maybe you're right Ethan, see article number 1 on my website:

http://www.masteringhouse.com/tidbits/article1.html

> The one on EQ phase and phase shift was not my favorite e.g. "all EQ shifts phase, unless it uses special trickery". What does that mean? Magic elves? <

Okay, let's discuss. By "special trickery" I'm merely referring to the FIR type of digital EQ algorithms that yield less phase shift than usual.

From the material that I've read, actually no phase shift.

Ethan -

You seem like a very nice gentleman, sorry if I offended but I would personally be less prone to criticism if I saw more direct responses from your posts or at least some references to other great articles on other sites that addressed the question at hand.

- best
Tom

 

[Ethan Winer]

Tom,

> Two different areas where phase is an issue. <

Yes, and both articles come to the same conclusion: Phase shift alone is inaudible in typical amounts. When someone thinks they hear phase shift, what they're really hearing is a change in the frequency response. This has been my point all along. My goal is to educate and explain, and debunk audio myths wherever I see them.

> What about speaker systems without crossovers, for example a bass guitar amplifier? <

Since BBE's claimed "time alignment" is applicable only to speakers that use a crossover, how could it possibly help with a bass amp? More to the point, since phase shift is inaudible the whole concept of a box like BBE's "correcting" anything is moot.

> I have heard good results from a BBE in this application. <

Sure, there's no question that adding a little grit can liven things up a bit, or make a muddy sounding instrument stand out a little in a mix.

> see article number 1 on my website: <

ROF,L.

> I would personally be less prone to criticism if I saw more direct responses from your posts or at least some references to other great articles on other sites that addressed the question at hand. <

I write my articles to address the most common problems. Since almost every one has been published in a major magazine, I'm not the only one who sees their value. I refer people to my articles because I spent a lot of time refining the wording to make things as clear as possible. If you have some articles that serve the same purpose, I'll be glad to recommend them too!

Thanks.

--Ethan

 

[grinder]

Ethan, The articles on your site have helped out alot, in my quest for smoothing out my room. Thanks for all the info, your hard work doesn't go unappreciated.

Thanks, Grinder