Double Bass Mid Range

[Ampig]

I guess that I'm old school or just stupid but I have a hard time with parametric EQ's. Graphic EQ's were just more intuitive to me. I'm using my Genz Benz Shuttle 6.0 on my URB gigs and am having a hard time understanding how to drop out all of the midrange. I'd like to start at zero and then maybe add a little sweetness.
The mid EQ section is similar to what's in the below image

 

[Ric Vice]

I guess that I'm old school or just stupid but I have a hard time with parametric EQ's. Graphic EQ's were just more intuitive to me. I'm using my Genz Benz Shuttle 6.0 on my URB gigs and am having a hard time understanding how to drop out all of the midrange. I'd like to start at zero and then maybe add a little sweetness.
The mid EQ section is similar to what's in the below image

Ampig,
I too am totally confused and befuddled when it come's to parametric EQ, that's why it's just easier for me to use the very simple controls on my older Walter Wood's MI-400-8 Bass, Midrange, Treble. The Genz Benz midrange is actually pretty simple. You just set the midrange center frequency and then cut or boost it. I don't believe that you can totally "drop out all the midrange" because it wouldn't be pleasing or balanced. I once owned a GK MB150E and sold it within 3 months because I didn't liked the midrange voicing of that amp. My guess is that's what you're experiencing with the Shuttle 6.0 . I love the Shuttle 3.0 for Double Bass because of it's midrange voicing, using the Shuttle 6.0 didn't work for me. I had always thought it was the difference in the tweeters between the 10T and 12T cabinets.

Ric

 

[anonymous02282011]

the way to remove as much mid range as possible on that amp is to:

1.) turn the MID knob all the way down to -15

2.) set the MID FREQ to noon, as it's pictured

3.) hit the MID SCOOP button under SIGNAL SHAPE

If you want to cut specific frequencies between 150Hz and 2Khz (?) you can do number 1. and 2. only, then slowly pan the MID FREQ knob, preferably while you're playing your bass, to determine at what point you want the mid cut.

 

[Ampig]

Helpful advice. Thanks.

 

[drurb]

the way to remove as much mid range as possible on that amp is to:

1.) turn the MID knob all the way down to -15

2.) set the MID FREQ to noon, as it's pictured

3.) hit the MID SCOOP button under SIGNAL SHAPE

If you want to cut specific frequencies between 150Hz and 2Khz (?) you can do number 1. and 2. only, then slowly pan the MID FREQ knob, preferably while you're playing your bass, to determine at what point you want the mid cut.

That ought to do it. It is a band centered in the region of 1 kHz or so to which listeners are most sensitive to changes within the spectral profile. Alterations to the relative level of a band in this region affects how "forward" sounding is the result. It also affects how "nasal" things sound. Try this: Make the sound "Shhhhhhhh" with your mouth and, as you do, bring your hands up to your face and cup them over your nose and mouth. Hear that? You've essentially created a relative boosted to frequencies in that range.

You may find this post helpful.

 

[agedhorse]

Befor assuming that you want to cut all the midrange out of your signal, you might want to experiment on what the midrange actually sounds like and what it does to your bass signal in context to the rest of the band in a mix. Midrange is important (in general) because each note consists of the fundamental PLUS the secone, third etc. harmonics and the total of the harmonics can be 50% of the signal's character. This is why in a mix, midrange contributes to the articulation and being able to hear each note in tonal context.

Now you may wish to reduce midrange to work with the voicing of a particular bass, cabinet or playing style. To do this, the midrange gain control adjusts the amount of midrange cut (or boosted if you go above noon) and the midrange frequency control adjusts the frequency range (it's NOT a specific frequency but a band of frequencies about an octave wide in practice) that the midrange cut is acting on. Begin by turning the midrange gain control to the 3:00 position (boosting the midrange) and sweep the frequency control while listening to identify the band of midrange that you would like to reduce, then once you are centered on that band, gradually reduce the midrange gain control until you have cut just enough midrange to suit your needs. Beware of over-cutting midrange.

Hope this helps.

 

[agedhorse]

the way to remove as much mid range as possible on that amp is to:

1.) turn the MID knob all the way down to -15

2.) set the MID FREQ to noon, as it's pictured

3.) hit the MID SCOOP button under SIGNAL SHAPE

If you want to cut specific frequencies between 150Hz and 2Khz (?) you can do number 1. and 2. only, then slowly pan the MID FREQ knob, preferably while you're playing your bass, to determine at what point you want the mid cut.

Note that in practice, this is likely to be pretty unuseable to the vast majority of players however.

 

[Mike Arnopol]

Man, with all that mid scoop are you going for a Marcus Miller slap tone?. Just kidding but you need SOME mids. When helping design the EA Doubler they asked what I would like in an amp. I said 5 fully parametric bands. They laughed and said that no one would buy it. Likely true. Your EQ is semi parametric. Which means that it is a fixed "q" or width or how much it boosts or cuts. Most likely one octave. An octave is double a frequency, like 500hz to 1000hz. Les can correct me here as far as specifics, but if you set the frequency at say, 750hz and cut some it will start at about 500 hz, the center of the dip will be at about 750 hz and it will reach no cut at about 1000hz. so even if you cut all the way, your cut will START at 500hz and end at 1000hz. The mid scoop is a pre-fixed mid cut curve independent of the parametric, and it's likely a bit extreme. You are looking for tone shaping, which in your case isn't so extreme, but in your case likely wider than an octave. Parametrics are not difficult if you take the time to find out which frequencies yield what tones. Give yourself a few hours at home and try cutting and boosting at different frequencies. You'll then get a handle on which frequencies are the culprits. In the design of the Doubler they followed my suggestion and put the midrange controls on each channel at different frequencies. One is centered about 550 and the other at 800hz. I've taken the time to train my ears of the difference in sound of 500 and 800 hz. If you want to get rid of the Jaco-type growl, its closer to 500 hz. Other midrange anomalies are (as far as upright) between there and say 2000hz. I use a Fishman parametric DI box and usually have it set at about 800hz to 1000hz (depending on the room) and remove about 4 to 6 db at a 2 octave width. this takes out most of the wank that I want to get rid of. Just take time and listen. Boost and cut a lot to get an idea of which midrange sounds are the ones you want. A single 1 octave semi-parametric isn't enough to get all of them, but you can likely find the worst offenders.

 

[TroyK]

Every few years in this forum, I ask a really stupid, eq-related question and guess what day it is today?

If I look at frequency range and let me just use what's on the face of an iAmp as an example;

4 Bands:
Lo : 40 - 85 - 135 - 180
Lo-Mid : 180 - 350 - 640 - 1k
High-Mid: 880 - 2k - 4k - 8k
High : 1k - 2k - 4k - 8k

I understand that with this type of parametric eq, I'm isolating one of those frequencies with the slider and then boosting or cutting it with the knob. The overlap between the bands gives me the ability to treat frequencies very close to one another differently.

Here comes the really stupid question: Do those frequencies relate to notes? Can I think of them over the spectrum of a keyboard 40 being relevant to something with my left pinky and 8k being related to something with my right? I know they are not the same thing, but...

Or, (as I suspect) if I pick a note in the middle somewhere is the tone of it made up of all or some combinations of those frequencies?

In other words, do these units of measure relate to pitch or timbre?

Sorry, guys, I'm admittedly an ill informed twiddler of eq knobs. I've gotten help here before and I'm better than I used to be, but still don't conceptually get it. It's tough for me too to play my bass while I sweep these frequencies and the ext input from a music player on my amp bypasses eq, I tried that a few years ago.

 

[Pat Harris]

Troy,

In short - Yes, 42Hz is the same as your open E string, 72 is your open D, etc. Those are the fundamentals for those given notes. There are many overtones that are also present and the overtones are what give any instrument its unique sound.

-Pat

 

[TroyK]

Troy,

In short - Yes, 42Hz is the same as your open E string, 72 is your open D, etc. Those are the fundamentals for those given notes. There are many overtones that are also present and the overtones are what give any instrument its unique sound.

-Pat

So, following that logic, If I isolate a frequency, let's 72 Hz, since you told me that's the D, then boosting it would make it ... louder.. and rolling it off would make it quieter? Is that right? I haven't really thought of them as isolated volume controls.

Assuming it is right, then that setting would only effect that note? So, with the 4 settings on an iAmp (continuing the example), I've only "eq'ed" 4 notes of the 3+ octaves on my instrument? That can't be right.

How dense am I? Give it to me straight, I can take it.

Sorry, if I'm hijacked. I've had some of the same struggles as the OP and my intention is to continue his thread, but I apologize if that's not the case. And I know, for those of you who have been answering these questions for years here that we've been through this before, I'm sorry. It's not that I've learned nothing over the years. I have gotten better, but I'm still not there.

 

[drurb]

...Assuming it is right, then that setting would only effect that note? So, with the 4 settings on an iAmp (continuing the example), I've only "eq'ed" 4 notes of the 3+ octaves on my instrument? That can't be right.

How dense am I? Give it to me straight, I can take it.

You are not dense. What you ask is a fine question. As Pat Harris pointed out, each note you play on your bass has a fundamental, say 41 Hz for the E and a series of (generally) harmonic overtones. In English, the note you play will contain 41 Hz, 82 Hz, 123 Hz, and so on for multiples of 41 Hz. The amplitude (strength) of each of those harmonics forms what is called the spectral profile and the specific "overtone series" is what gives the instrument its unique sound. Now, let's say that you boost the frequencies around, say 82 Hz. Well, you'll be boosting a range of frequencies into which falls the second harmonic of the E string, the fundamental of the octave E above that string, and the harmonics of many, many other notes that fall in that range. When you boost a band, it's easier to think of it, not as boosting individual notes and pitches but as, changing the tonal character of the entire sound. Suppose you boost a band of high frequencies. Well, it'll sound like you turned up the treble on the whole instrument... and you did! Now, pitch is a complex perceptual attribute and I won't go too near that subject here. Suffice it to say, however, that what you perceive as the pitch of an overtone series depends very much on the overtones themselves. A famous and simple example is the phenomenon of the "missing fundamental." Let's go back to that E string, the overtone series of which is 41, 82, 123,..... Hz. If you completely remove the energy at 41 Hz, guess what pitch you hear. 41 Hz!!!! That's because the difference between each harmonic is still 41 Hz and the brain figures that out. This is why when you listen to music on a crappy little radio that can't produce any appreciable low-frequency energy (all those fundamentals are gone), the pitches are are all still there!

Check out page 217 right here.

...Most likely one octave. An octave is double a frequency, like 500hz to 1000hz. Les can correct me here as far as specifics, but if you set the frequency at say, 750hz and cut some it will start at about 500 hz, the center of the dip will be at about 750 hz and it will reach no cut at about 1000hz. so even if you cut all the way, your cut will START at 500hz and end at 1000hz.

Right you are. The "center frequency" of the control of such an octave band running from 500 to 1000 Hz would be 707 Hz (sqrt(500*1000)).

 

[GrowlerBox]

As always, an excellent and practical description of a topic vital to sound reproduction from drurb.

I would like to stress a point that was alluded to regarding the relative sensitivity to midrange frequencies of the human auditory apparatus (which is, of course, why they're the "midrange"): when you cut these, there is an accompanying need to increase the overall volume to compensate, especially in a live situation. This in turn boosts the low frequency end of the spectrum, the reproduction of which requires large movements of your speaker cones and markedly increases the risk of distortion and ultimately, damage to your drivers. This problem can be ameliorated in large part by the use of a good high-pass filter (e.g. fdeck's device), but it is important to remember that good stage tone doesn't always correspond to good "bedroom" tone, and more mids is often the answer to volume problems. Until you start to feedback, of course ....

 

[agedhorse]

As always, an excellent and practical description of a topic vital to sound reproduction from drurb.

I would have to agree. This is a concept everybody designing products for the guitar/bass industry should have a firm and complete grasp of. Sadly, it appears that many do not.

This, folks, is what makes the sound different for every instrument and amplification even though the same physical note is being played.

 

[Mike Arnopol]

You guys have to realize that the fundamental pitches of the notes goes from 42hz to 320 for your high E. The first harmonic is double that. When you hear a big thick E string you are really hearing more 84hz. But when you get to the second octave E you are hearing a larger percentage of the fundamental due to the fact that most speakers are down 4 to 6 db at 42 hz. As Les stated it's the relationships of the upper partials that give us the timbre or quality of our sound.(and pitch definition) Some of these partials as they get into the 500 to 1500 hz ranges are too exaggerated, giving us an aggressive sound that we don't want. Could be the voicing of the pickup or the speaker. But you have to learn from listening which frequencies yield what sound. I've found that a gentle boost at around 300hz gives me a thicker tubey "warmth". I wasn't sure of that a while ago---I took the time to figure it out.

 

[drurb]

You guys have to realize that the fundamental pitches of the notes goes from 42hz to 320 for your high E. The first harmonic is double that. When you hear a big thick E string you are really hearing more 84hz. But when you get to the second octave E you are hearing a larger percentage of the fundamental due to the fact that most speakers are down 4 to 6 db at 42 hz. As Les stated it's the relationships of the upper partials that give us the timbre or quality of our sound.(and pitch definition) Some of these partials as they get into the 500 to 1500 hz ranges are too exaggerated, giving us an aggressive sound that we don't want. Could be the voicing of the pickup or the speaker. But you have to learn from listening which frequencies yield what sound. I've found that a gentle boost at around 300hz gives me a thicker tubey "warmth". I wasn't sure of that a while ago---I took the time to figure it out.

Thanks, Mike, for helpful clarification. Just a few details:

With regard to pitch, it's generally the lower partials, and not the upper, that define it. These are the partials in the so-called "existence region." (Google that term and you'll get a glimpse into the complexity of this subject which has defined whole careers. ).

The first harmonic is the fundamental itself. The second harmonic is double that.

As for the 300-Hz region, you are right on target! A boost in the upper-bass region is what many associate with "tube warmth." That's mostly a result of the typical transformer coupling and speaker-cabinet response of the tube era. It opens another interesting discussion about how the classic "tube warmth" can be reproduced essentially perfectly by simply building in the appropriate transfer function (think frequency response) to an amplifier circuit, be it tube or solid-state. That is, "tube warmth" is really about frequency response. This leads to another discussion about manufacturers who intentionally "voice" their electronics or speaker cabs. You touched on that as well.

Finally, you mentioned timbre. As it turns out, timbre can be greatly affected by the relative phase of overtones. Okay, now we've gone down the wormhole.

 

[TroyK]

You know, I think I may be starting to get this, though. Thanks guys. I've seen some next explanations here and it gives me some new things to think about. Going to go play with my amplifier.

 

[agedhorse]

Finally, you mentioned timbre. As it turns out, timbre can be greatly affected by the relative phase of overtones. Okay, now we've gone down the wormhole.

Yes, phase and the sum & difference products they result in adds yet another whole dimension.

 

[drurb]

Yes, phase and the sum & difference products they result in adds yet another whole dimension.

Well, no, sum and difference products (especially 2f1-f2) would be distortion products as they would represent components not in the original spectrum. They could sure change timbre if they were extreme. The overtone series does not result in sum and difference products unless there is a non-linear process involved, such as a poorly designed amplifier. Of course, such would never be the case with Genz Benz products.