guitar pedals low end attenuation

[jdom84]

HI i noticed on a few pedal when I pluf them in they cut out a lot of the low end, but if I use the distortion built into my orange amp it does not... I found it very irritating I love bass and low end...
Why would they take so much low end out.
I want a grungy dirty distortion but not a fuzz as I have one of those.
A RAT would be best?

anyway I found that low end attentuation with a lot of pedal and it destroy my sound.

[TheLegit]

Does happen sadly I have some nice pedals in the loop that shave off the low end, I increase the bass on the distortion channel to compensate. Try an EQ pedal after the offending ones to re-apply the low end to taste

[Folderol]

Does happen sadly I have some nice pedals in the loop that shave off the low end, I increase the bass on the distortion channel to compensate. Try an EQ pedal after the offending ones to re-apply the low end to taste

It may be quite simply that their input impedance is too low, in which case a buffer of some sort on the input would solve this and get a better matching for the guitar's pickups too. Guitars like to see an impedance of 1 to 2 Meg. I've come across pedals as low as 100k (i.e. a tenth of that!

[Wonks]

Almost all distortion pedals will have both low pass and high pass filters in. The high pass filters drop off some low end to keep the low end tight and stop it being flabby due to the high levels of gain used.

Lots of bass in a high gain guitar sound may sound fine when it’s on its own, but in a band situation it can really mess things up and it all becomes muddy. You need to leave room for the bass and kick to be heard.

There will be pedals that leave the bass pretty much untouched, but you need to find them. Avoid pedals with a single tone control, but look for ones with at least bass and treble tone controls as any fixed bass roll off is then likely to be minimal and left to the bass tone control.

But do think about how your guitar sounds in a band or track context. Most instruments in a mix need ‘sculpting’ with EQ to give each one some space to be heard, and rolling off the bass end on guitars is pretty standard. I know a lot of low thump to the guitar sounds great on its own, but in a typical band, it’s not a good idea.

[Wonks]

I have a Bogner Burnley pedal that has a mode switch. One mode is for rhythm/chord playing and cuts a lot of bass. The other mode is for solos which keeps the bass end full. And the two modes do work well. The solo mode is far too muddy for chord work, but the extra bass fills out the single notes nicely.

The annoying thing about the mode thing is that its not foot-switchable, just a small toggle switch.

[Folderol]

Push a length of coil spring (about 3mm dia) over the toggle. You can then just swipe that with your foot without risk of breaking the switch

[Wonks]

I‘ve just read up a bit on the input filters, and the input circuit high pass filter is mainly there to avoid overloading the op-amp, prevent instability and reduce hum (any 50/60Hz hum on the guitar signal.

Even when the hum signal is low compared to the guitar signal, adding up to 60dB of gain in a distortion circuit that clips the top off the signal which also volume limits the overall signal in the process, means that the hum can be be boosted so that it’s as loud, or almost as loud, as the distorted guitar signal.

Your boosted 50/60 Hz hum signal can then also get distorted, producing lots of high frequency harmonics in the process. These have no harmonic relation to the notes you play, so it sounds really bad.

So a simple CR high pass filter is introduced to gently roll off the low end. Typically this has its -3dB point up around the 700-800Hz area, with a 6dB/octave roll off, which means that 50/60Hz hum levels are reduced by around 20dB. It doesn’t completely cure the problem, but it reduces it a lot.

[Funkyflash5]

Consider looking at Distortions aimed at bass, as they tend to either roll off less of the lows, or include a dry or low pass blend to help bring back in the otherwise missing lows. On the couple of dirt pedals I've built, I've included a switch to optionally use a bigger input decoupling capacitor for when I want to use it with bass or baritone.

[Arpangel]

Some do reduce bass, absolutely, I use them for keyboards, my Moog through a pedal doesn’t have quite as much impact, but it’s not a big deal, you can’t have everything.
That’s why I try and use most of my pedals on aux sends, you can still mix in a bit of the original sound, not so easy sometimes if you’re a guitarist.

[ef37a]

I have just had a look at the spec' of one of 'our' distortion pedal and the bass control range is some -5dB to -30 dB ref 1kHz at 100Hz so yes, I would say guitar pedals in general will have a net bass cut but then guitar speakers generally do very little at 80-100Hz (and even less past ~8kHz) .

If you are using guitar pedals NOT in 'guitar' circuits there might be an additional bass loss if they have been a bit mean with the output coupling capacitor? They are designed to 'see' 1 meg of so and into a 10k line input will for a HPF.
The pedal I specified above gives you a generous 10uF so no worries there!

Dave.

[Drew Stephenson]

But do think about how your guitar sounds in a band or track context. Most instruments in a mix need ‘sculpting’ with EQ to give each one some space to be heard, and rolling off the bass end on guitars is pretty standard. I know a lot of low thump to the guitar sounds great on its own, but in a typical band, it’s not a good idea.

Understanding this was a revelation for our live sound. Before I started hanging around here I thought the key to getting a good overall sound (for live and recording) was getting each individual instrument to sound as good as they could on their own. (Hey, it made sense in my head).
Carving off the bottom end of my guitars (especially the acoustic) suddenly meant that everything was clearer and we could all turn down.
Now when we're coming up with new material we're actually thinking about where parts sit in the frequency spectrum and how we avoid stepping on each other's toes right from the start.

[jdom84]

hey thanks for all the replies yes I see that there is a natural want for some bass roll of and its all personal preference I guess I would rather they left that up to me with my eq and stuff... I worked as a sound engineer for many years and also built a pedal. I am not a super scientific expert on it all but I have a certain sound in mind and I love a lot of bass, its mostly me playing on my own in my room so not too worried about the stage/live/band situation for it. And yeah would just get a high pass filter or eq pedal..

I mean I thought it should not have any hum if its a decent grounded set up surely.. I see on pedal diagrams when I made a couple that the early resistors/capacitors were basically high pass filters.. So yea it is a typical set up to roll some off, but not for bass I guess.

Yeah anyway a lot of personal preference would just rather they left the up to me. I will see about any pedals with those options on a switch. I am looking at the very cheapest pedals tbh. Might for for the pink behringer as it has a lot of tone control built in.

[jdom84]

Consider looking at Distortions aimed at bass, as they tend to either roll off less of the lows, or include a dry or low pass blend to help bring back in the otherwise missing lows. On the couple of dirt pedals I've built, I've included a switch to optionally use a bigger input decoupling capacitor for when I want to use it with bass or baritone.

yeah I will try a cheap bass distortion... thanks its kinda obvious now hahaha

[jdom84]

Does happen sadly I have some nice pedals in the loop that shave off the low end, I increase the bass on the distortion channel to compensate. Try an EQ pedal after the offending ones to re-apply the low end to taste

It may be quite simply that their input impedance is too low, in which case a buffer of some sort on the input would solve this and get a better matching for the guitar's pickups too. Guitars like to see an impedance of 1 to 2 Meg. I've come across pedals as low as 100k (i.e. a tenth of that!

it is 1m ohm for the pedals input and 1kohm for output

[Folderol]

OK. That's good, so they definitely are filtering it. I don't know the pedal, but it may be practical to fit a switch somewhere that (as someone else suggested) adds a fatter cap across the input one.

[BigRedX]

As a (bad) multi-instrumentalist whose least awful instrument is bass, I would say that many guitarists, especially those in the rock/metal genres have too many bass frequencies in their sound already, and anything that goes some way to taming them and allowing the instruments which should be operating in those frequencies, room to breath should be seen as a good thing.

What sounds good playing solo in your bedroom does not necessarily sound good as part of a band or arrangement.

[Wonks]

Most of the distortion circuit schematics I’ve seen so far have a DC blocking cap that, in conjunction with tan anti-popping pull-down resistor of between 1 and 2.2megs, almost always has a frequency knee of 7.2Hz, so it won’t be that rolling off the bass end of the guitar.

It will almost certainly be the pre-gain stage filtering that’s doing the low-end ‘removal’.

On an older pedal, or a self-build, that uses discrete components, then it’s relatively easy to try out a few different component values, but not at all easy on a modern pedal with surface mount components.

[Wonks]

I mean I thought it should not have any hum if its a decent grounded set up surely..

The hum will mainly come from the guitar pickups. Even humbuckers will pick up some hum. Because the two coils are physically displaced, even though it's by just a very small distance, they'll pick up the noise waves at very slightly different phase angles, so hum cancellation isn't 100%. Active pickups are quieter, but even then, its hard for them to not pick up any hum at all.

On a clean guitar signal, the hum may be so low in level as to be unnoticeable. But it's because a distortion pedal can apply so much gain, that the hum still needs to be taken into account. And just because your guitar may be almost hum-free doesn't mean that someone else's is as quiet, so the pedal designer needs to assume a fairly bad worse case.



In the above crude sketch, fig 1. is supposed to be a guitar signal with a low level of hum .

In fig 2, a reasonable amount of gain has been applied, making the both the guitar signal and the hum signal much larger in amplitude. The hum and the signal level are still in the same ratio as before though.

In fig.3, the amplified signal has been passed through the diode clipping stage. This cuts the signal peaks off and limits them to the diodes forward voltage value (about ±0.7v for silicone diodes). So although the signal peaks were a lot greater than the hum, now they've been clipped and limited to a value that's only just greater than the hum level. Now the hum is very noticeable and it will interfere with the guitar signal.

That's all very simplified, and it may well be that in some instances that you'd still not notice the level of hum, but in many situations, you most definitely would. So that's where the high pass filter comes in, reducing the hum level (but also the overall amount of low-end in the guitar signal).

This reduced low end is generally seen as beneficial, so is accepted by most, but there are times (as when you play solo) when more low-end would be welcome to the player.

[jdom84]

yeah sorry its a tiny pedal so that would be impossible...

I will sell it and get another pedal with more tone controll I guess..

Are behringer pedal really awfiul? I was looking at the pink distortion pedal..

[Murray B]

Almost all distortion pedals will have both low pass and high pass filters in. The high pass filters drop off some low end to keep the low end tight and stop it being flabby due to the high levels of gain used.

Lots of bass in a high gain guitar sound may sound fine when it’s on its own, but in a band situation it can really mess things up and it all becomes muddy. You need to leave room for the bass and kick to be heard.

There will be pedals that leave the bass pretty much untouched, but you need to find them. Avoid pedals with a single tone control, but look for ones with at least bass and treble tone controls as any fixed bass roll off is then likely to be minimal and left to the bass tone control.

But do think about how your guitar sounds in a band or track context. Most instruments in a mix need ‘sculpting’ with EQ to give each one some space to be heard, and rolling off the bass end on guitars is pretty standard. I know a lot of low thump to the guitar sounds great on its own, but in a typical band, it’s not a good idea.

All of the above +1

I played bass in a band with a guitarist who a one time used a modeller into a small powered speaker (brilliant) and then got himself a new amp and had what he thought was a rich full tone.

I could not longer clearly hear my bass parts and the resultant low end mess eventually resulted in me no longer wanting to be part of the band as we couldn't seem to find a compromise.

For guitar duties I use a 1x10 combo and many sound engineers have commented on how easy it is to mix the guitar sound into the rest of the band. So I would also advise being bold, loud, soaring and powerful, but don't trample all over the sonic space of other instruments.