ADA Depot - A Forum To Support Users of ADA Amplification Gear

Miscellaneous => Discussions => Topic started by: rickeb1 on April 04, 2018, 08:47:05 AM

Title: General EQ Question
Post by: rickeb1 on April 04, 2018, 08:47:05 AM
Let's say I have an amp that I like the tone of, but I feel it could use a slight boost in the mids (i.e. it sounds a little too "scooped").  Let's also say that the amp does not have a mid tone control knob, only bass and treble.  But. let's say I have a parametric eq that I could insert into the amp's loop.

My question is, around what frequency would I start working the parametric eq to add "mids" to the sound?  I know I can try setting a boost and then start sweeping through frequencies, but it would be nice to have a starting point, and to better understand what frequencies equate to "more mids", as I am sadly kind of ignorant in that regard.

Thanks!
Title: Re: General EQ Question
Post by: vansinn on April 04, 2018, 12:22:36 PM
In general:
180-250 Hz will add thumpf, you know, the pump-in-the-chest drive.
400-600 Hz will add a fuller body.
800-850 Hz adds a harder, Tom Scholz / Boston sound.
1120 or so Hz can create the ESP Active EMG old-school snarl tone.
Around 2000 Hz adds a harder, more edgy tone.

All of this is adding something, also known as additive filtering.
The other direction, removing something, is called subtractive filtering, which is often overlooked, because many tends to naturally want to add to their sound.

Lets say, as you've stated, that your amp sound a Bit too scooped in the mids.
Maybe you hear it this way because it really is scooped, but if in reality it's only a small touch scooped, how you perceive it could be because the ranges above and below are really a Bit pumped up.
If so, instead of adding more mids, you might have success with gently scooping-out some of those ranges.

Sometimes, removing something else than the immediate felt problem can result in greater clarity, where adding what immediately seems to be missing can lead to a more swollen tone.

I'm not saying this is what you should do; it's just a suggestion.
But hey, you got a graphics EQ, so go experimental, dude ;)

As a comparison, the ADA MP-2 has a fou-band stack and a 9-band graphics EQ.
I used to add all kinds of small little EQ'ing with the EQ, and could fiddle forever, until I learned to keep it fully flat, setup the 4-band first, and then, using the 9-band, lift a few spots just a touch - and cut away what was intruding into the soundscape, i.e. using subtractive filtering.

This is actually the same approach photographers use.
Rather than trying to flood the studio with lights, use a black panel on the other side of the model to remove some light there, in order to create a more felt contrast.

And now to the fun department..
Of course the ultimate solution to your problems would be to have the amp modded with different power transformer and power tubes, and replace those pesky scooping 12" speakers with some harder sounding ones.
Yup, I'm in that mood tonite; it's just meant as a joke - well, not that there isn't some truth in such mods, but it can be a rather expensive solution.
Title: Re: General EQ Question
Post by: Soloist on April 04, 2018, 01:56:11 PM
I would say for adding mids between 400hz (low mids) and 1k ( high mids). Sweep the mids with a narrow Q to find the sweet spot!  :thumb-up:
Title: Re: General EQ Question
Post by: Dante on April 04, 2018, 10:36:43 PM
^^ gotta agree with both of them ^^

I generally use 80-160 Hz for a bass/low-mid adjustment (width of 0.7-1.0), somewhere around 400-800 Hz for mids (width of 0.0), and 220 Mhz for highs (width of 0.5 to 1.5). I spike each one very narrow at first, until I find the freq I like. Then, if one sounds like it needs more in the mix, I widen that spike until it sounds full. I usually go a bit beyond where it sounds good, and then roll it back to the sweet spot. Just my technique, YMMV.

The spike isolates the freq you are looking for - good or bad - then, you boost/cut as you like. Widening the freq makes it stronger in the mix...for lack of a better description. It's tricky at first, but you'll get it with enough practice. Some gear is 'tuned' a bit different, so the freqs could vary a bit from these actual numbers, TRUST YOUR EARS.

Title: Re: General EQ Question
Post by: Dante on April 04, 2018, 10:45:06 PM
To add: This is a rough description of my 3 main tones I use...

I boost the mids for clean tones, and for those Classic Rock tones that use very little gain. Just a bit of overdrive (a la Malcolm Young)

I boost the lows, lightly scoop the mids, and keep the highs flat for a more 'modern' Rock tone (a la Foo Fighters)

I turn the lows to 11, scoop the mids to the Earth's core, and boost the highs a bit for that \m/ METAL tone (a la anything in the devil's tuning - drop D - which includes a LOT of those 'new country' songs played by Hollywood musicians who moved to Nashville to make a buck - but I digress)
Title: Re: General EQ Question
Post by: rnolan on April 05, 2018, 04:49:52 AM
Hey rickeb1, well some good tips here already, and short answer as to where to start for mids, I think Soloist nailed (400 through to 1kHz).
However, there are a bunch of variables (speakers, cab(s), PUs etc) that you need to balance to get "your" tone.  The main one though is probably volume.  Our ears hear frequencies very differently at various volumes (please read - https://en.wikipedia.org/wiki/Fletcher%E2%80%93Munson_curves).  So the sound is "flat" (i.e. your ear perceives all the frequencies equally) at around 98db, now that's quite loud but it's the minimum level you should use to set your eq and tone.  98db is a little (allot for me  >:D ) less than stage volume which is really where you really want to set your tone and patch volumes.
Title: Re: General EQ Question
Post by: rickeb1 on April 05, 2018, 08:39:24 AM
Wow, thank you all so much for all of the great info!  This was far more than I was even hoping for, and I really appreciate it!  Ya know, this is a really great little community here!
Title: Re: General EQ Question
Post by: vansinn on April 06, 2018, 01:13:53 AM
Yeah, we're a tight bunch of old farts in here - plus of course some new blood comin' in ;)
Title: Re: General EQ Question
Post by: Chucky on April 12, 2018, 06:24:55 AM
As added info, Fender amps mid control is centered at 700hz.
But it is a sweeping mid control, so as you turn it up, it doesn't only boost that frequency range, it also sweeps up slowly from 700 to 800hz.
So this is another way to think about it.
Trusting your ears and going for YOUR sound is always the idea.
Title: Re: General EQ Question
Post by: MarshallJMP on April 12, 2018, 07:21:29 AM
Well the mid center freq of a fender tone stack varies with the treble control, with everything in the 12 o'clock position the mid freq is around 500Hz.
Title: Re: General EQ Question
Post by: Chucky on April 12, 2018, 08:45:08 AM
Well the mid center freq of a fender tone stack varies with the treble control, with everything in the 12 o'clock position the mid freq is around 500Hz.
I stand corrected.
I reminisce vaguely the info from a tech friend of mine...
I might not recall the EQ freq correctly....I was actually struggling and wondering if it was from 600 to 700hz instead of 7 to 8--...
Title: Re: General EQ Question
Post by: GuitarBuilder on April 12, 2018, 02:42:20 PM
If you want the ultimate EQ control for guitar, you should look at the Tom Scholz designed the Rockman Instrument Equalizer.  Tom realized early on that the typical parametric EQs available for studio or live work did not have the ideal frequency bands for guitar.  He came up with a much better combination:

62, 125, 250, 500, 700, 1000, 1400, 2000, 2800, 4000, 8000, 15000 Hz, all +/- 12 dB.  I've tried duplicating the results on typical studio EQs and this is superior every time.

You can pick one of these up on eBay.

(https://www.snapagogo.com/images/2018/04/12/1Ds_20120116_0121.jpg)