jkleban
There are many other ways to record a good acoustic guitar rhythm track without slamming the fundamental frequencies.  Craig, this tip isn't one of your best but it does show how you continue to think outside the box.

This isn't done while recording, it's done during mixdown. In other words, it's for situations where you have to deal with something that already exists, or something like a situation where someone decides they really need to add an overdub that wasn't anticipated in the original arrangement...or the arrangement might have changed.
 
Also remember you don't have to "slam" the fundamental. I've gotten the best results by reducing about 2dB or so. It's about subtlety, not slamming.
 
I would be interested to hear from people who've actually tried this in the manner intended to see what they think. It's probably best to decide whether or not it's a useful tip after trying it in a problematic mix.

I realized no one's going to understand why I find this useful unless I post an audio example. It seems the only person who's tried it is Mike, and he's relying on auditory memory from almost 30 years ago so I don't know if he had the same tools we have now.
 
The clip is in the key of D. The first half is without the "tightener," the second half with. I tried to adjust it for somewhere between subtle enough not to sound weird but different enough so people could hear the difference. The link is good for 7 days.
 
https://www.hightail.com/download/ZUcyb2VPYSt3TGk5TE5Vag
 

It is true that all I had was a couple of analog Ashley parametric EQs to brain storm with. We can set today's EQs much more precisely. Maybe that makes difference.
 
I was wondering if you were going to post an example.
 
I've been curious if people can repeatedly identify the result of 2dB cuts in a blind ABX test.
 
 

Jeff Evans
I like the second half a little better. I also hear the change as slightly broad in nature. To me the sound is a little less cluggy in the low mids and the upper mids/highs are slightly pushed forward. Sounds like a tiny bit less of the notes and a touch more of the distortion etc..

 
Thanks for listening!!! What you describe hearing are the precise results this effect is supposed to produce.
 

But maybe you don't need a complex comb filter to achieve a similar result. I feel I might be able to get it just the same with something like the Pultec EQ.

Well, you know how much I like Pultecs  but I don't think that will do the job here. Although the change sounds broad in nature, the four notches are very sharp - IIRC the Q is around 20-24. This effect is somewhat guitar-centric so let me fill in the details, and while I'm at it, explain why arranging is not well-suited to fix what this technique fixes.
 
The open strings on guitars produce more level and sustain longer than fretted notes. I don't think it's a coincidence that the most popular chords for pop guitar (E, A, D, G) include at least one open string for the root and at least one additional fretted note for the root. As not all chords have voicings that encompass all six strings, the root is often represented by more notes than any other chord note. Interestingly a standard four-note D major chord (i.e., the root, not the 5th, is the lowest note) has only one open string and two root notes total, but that's perhaps why dropping the low E to open D is one of the most popular alternate tunings, if not the most popular. 
 
Barre chords are also popular; although they don't have open strings, a typical major chord in the most common barre fingering has three fretted root notes - half of the total voicing. Furthermore, even solid body guitars resonate. When you have multiple root notes, not only do they tend to reinforce each other, but will excite open strings in that key if they aren't muted. (And of course, pianos are off the hook in terms of resonances.) 
 
This is why arranging isn't the issue. There are only so many ways you can voice chords on a guitar, and music notation doesn't have instructions like "play the D a few dB more quietly if the voicing uses an open string and a piano is playing at the same time." So, the sharp filter prevents interference with nearby notes that tend not to resonate and aren't being played on open strings, which allows "taming" open strings and resonances if they become excessive.
 
If you line up the second half of the audio example and throw it out of phase with the first, you might be surprised at how little difference there is given the results. But what's left has a sharp, whistling sound, not the broader bump you'd hear with a standard EQ.
 
Thanks again for the comments, it's helpful to have an objective set of ears confirm what I'm hearing. I only post about experiments with results that I find useful (no need to embarrass myself posting info on experiments that fail), but my hope is that others will find them useful as well.
 
 

"The open strings on guitars produce more level and sustain longer than fretted notes. I don't think it's a coincidence that the most popular chords for pop guitar (E, A, D, G) include at least one open string for the root and at least one additional fretted note for the root. As not all chords have voicings that encompass all six strings, the root is often represented by more notes than any other chord note. Interestingly a standard four-note D major chord (i.e., the root, not the 5th, is the lowest note) has only one open string and two root notes total, but that's perhaps why dropping the low E to open D is one of the most popular alternate tunings, if not the most popular."
 
 
The examples you cite, E, A, D, G open chord (first position?) don't repeat the root, rather they include an octave as a harmony.
 
Using 6 dB cuts to illustrate that it is easy to hear a difference is an easy way to make it easy to hear a difference.
 
I think you are stretching facts here to justify your novel idea, Mr. Anderton.
 
best regards,
mike
 
 
edit spelling

 

mike_mccue
The examples you cite, E, A, D, G open chord (first position?) don't repeat the root, rather they include an octave as a harmony.

 
Okay, "same note letter" as the root. I'm sure everyone knew what I meant but if not, they do now. I rushed through that post so I wouldn't miss the beginning of "Edge of Tomorrow" (which FYI I found thoroughly enjoyable).
 

Using 6 dB cuts to illustrate that it is easy to hear a difference is an easy way to make it easy to hear a difference.

 
When posting an audio example, it would be pointless to adjust it so subtly no one could hear a difference, or so heavy-handedly it sounds like crap. The point of posting an audio example is to compare before and after so people can decide for themselves whether the results are beneficial. If they think the results are beneficial, then they will be aware of a new tool for their toolbox and perhaps use it. If they don't feel it's beneficial, they won't. I adjusted the depth to produce what I perceived as a beneficial result with the chosen signal source. Jeff preferred the processed version so to at least one set of ears, I apparently adjusted it correctly
 

I think you are stretching facts here to justify your novel idea, Mr. Anderton.

 
The justification or lack thereof doesn't rest with me, but with the audible results. All I care about is whether clicking on this effect's "enable" button produces something that sounds better. In some cases, it does. In other cases, it doesn't...which means it's no different from any other signal processing technique.
 
Don't worry, no facts were injured in the making of this technique. Guitars exhibit prominent frequencies that relate to particular pitches and notch filters can selectively adjust the levels of frequencies...match up those two sets of frequencies, and it makes an audible difference. Fact-wise there's not much that can go wrong.

mike_mccue
 
I'm hoping someone will comment further about the comparison of phase response in an analog vs a digital filter such as Sonnitus EQ. I always get confused.

 
Here's an interesting paper on the issues involved with phase and stability regarding digital filters, particularly FIR types. I have no idea what architecture the Sonitus or ProChannel EQ filters use, but my next test is to try this with the LP 64 so I can hear if it makes any difference.
 
This is a great text from Analog Devices that's loaded with analog filter theory and includes nifty-looking phase response graphs for analog notch filters. Fantastic for geeking out.
 
 

 

Jeff Evans
Comb filters do sometimes sound different to how they look! It is an interesting idea and there is no reason why it should not work. By choosing those centre frequencies rather carefully it results in something that may sound a little different to broader EQ.
 
I have had some experience with this in terms of synthesiser filters and making synth sounds for example. Using comb filters over a sound but not necessarily modulating the centre frequencies of the notches. ie just using the sound of a comb filter only.
 
I see the same sort of approach here.

Yes, very much so. People often thing of comb filtering as a "moving target" but as you point out, it has static applications as well.
 
The reason why I come up with these things isn't because I sit around wondering what to do with notch filters, but because I have some problem and start looking for a solution. For all I know this simply emulates what happens with mic placement...maybe when we set up stereo mics, what sounds "good" to us is when the comb filtering caused by using two mics attenuates some of the "rogue" signal peaks...anything's possible!