High Pass Filter (HPF) and Low Pass Filter (LPF) Mega Thread

[Stumbo]

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@Jeff Bonny asked:

I just did a gig where I got stuck on a really awful sounding stage. No definition from a rig I know sounds fine. But being of the "I'd rather be prepared than surprised" school I always carry an FDeck HPF Pre and even if I rarely use it tonight it saved my ass.

So my question (and the reason this is posted in amps not effects) is why do you see adjustable HPF's onboard so few bass amps when it's something that should be built into every professional quality bass amp?

And started a thread: In praise of the HPF

Note: for those TBrs interested in HPF/LPF details, this is an excellent thread.​

 

[jazzyvee]

I recently acquired a Micro Thumpinator on the advice of a really good pro who described it as his secret weapon for clear sound (and he does sound great). Anyway I wondered where is the best place for it in my signal chain. Before the input channel of my preamp, in the send and return loop or between pre amp and my separate power amp. I don't use effects.

 

[Stumbo]

I recently acquired a Micro Thumpinator on the advice of a really good pro who described it as his secret weapon for clear sound (and he does sound great). Anyway I wondered where is the best place for it in my signal chain. Before the input channel of my preamp, in the send and return loop or between pre amp and my separate power amp. I don't use effects.

Why put any unwanted frequencies into your signal chain? I use my HPF after my bass.

If the fixed frequency Micro Thumpinator is not enough cut, Broughton Audio builds adjustable HPFs (and LPFs) and ships worldwide.

 

[Zbysek]

I recently acquired a Micro Thumpinator on the advice of a really good pro who described it as his secret weapon for clear sound (and he does sound great). Anyway I wondered where is the best place for it in my signal chain. Before the input channel of my preamp, in the send and return loop or between pre amp and my separate power amp. I don't use effects.

I understand that you feed FOH from your preamp. I would put thumpinator in its FX loop...

 

[Stumbo]

v

@joebeadg asks:

OK, so I'm not really up on these things, didn't even know about them until recently saw a post here.

U guys say HPS takes away low lows that r not needed .

But I have a Hartke HA7000 that has low pas and hi pass contour controls. And they say the low pass cuts the low freq.

(NOTE: THE MANUAL HAS THE EXPLANATONS REVERSED FOR HPF AND LPF)

The opposite of what I read here.

Maybe that's just how they r labeling the controls? I've always thought of them as low boost and hi boost.

Probably mistakenly. Never thought of cutting them instead of boosting them for a cleaner sound at high volumes. Can anyone shed some light on this for me. Maybe I don't have to buy a HPF?

And started a thread: HPF LPF @ hartke

 

[agedhorse]

A high pass (the same as low cut) filter cuts everything BELOW the corner frequency. A real HPF sweeps the filter FREQUENCY, the rate that the filter rolls off (or cuts) is fixed by the topology of the filter. A true HPF does not have any boost.

These filters boost and cut, the AMOUNT (LEVEL,) not frequency,
Can be adjusted.

Also, a typical HPF has a slope of 12dB/octave or greater. A typical low/high eq section has a slope of 6dB/octave.

 

[Downunderwonder]

@Wasnex :
I agree with @Downunderwonder about letting the PA distribute the sound to the back seats.

The PA does not have to pump up the low end. When I am mixing, I often run the high pass on the bass channel up to 400hz or so, and just use the PA to sweeten the mids and high end. Delaying the mains to the backline is necessary for this to work well.

This can easily be achieved with most digital mixers. If the mixer is analog, you're probably stuck. Also if the audio tech is unwilling to explore options, you're probably stuck.

That's way different to what I was suggesting and a very different way to skin the cat! Hats off if you can get it to work though.

 

[Stumbo]

I have two RS210T cabs, which sound absolutely amazing, connected to a Markbass LMIII Tube 800 which is 800W at 4 Ohms. I found a great deal on a new Hartke LH1000 that I could not pass up. The LH1000 is 1000W at 4 Ohms.

The RS210T cabs are 8 Ohms each which I connect parallel for 4 Ohms. My question, is the LH1000 at 1000W at 4 Ohms too much for the RS210T cabs? The RS210T cabs are rated at 650W/800W peak. I haven't had any issues at all with the cabs connected to my Markbass, and my band is a power trio so we can get pretty loud.

I just want to make I don't damage these awesome cabs. I know I could always the keep overall volume in check when using the LH1000.

I suggest adding a HPF/LPF to your signal chain to protect the speakers by reducing cone movement, increasing clarity and reducing stage/foh volume necessary to cut through. See my TB Wiki for more info on the topic. You'll also be able to use more of the amp's onboard tone controls without adding distortion.

Thx Stumbo for mentioning this. I just started using an always-on HPF with my rig (for upright bass) and I've played two gigs with it, one with an RS28 and this past weekend, with a RS210. It made a big difference in being heard without worrying about farting out. If you occasionally encounter that with an electric bass, just imagine what happens when you hit an open 42" E string on an electric upright bass!

​

 

[Dj Bebel]

Hey all !

I've been talking about fuzz and tweeter issues recently and the first and only answer i had was "Get an almighty LPF.". Guess after that everything has been said. First reaction was "meh" but then i realize i might need one... like, everybody i guess.

I need a LPF that cuts around 8 to 12 Khz and it's tough to find one , small pedal, that cuts that high. Actually i guess there's only one : the actually out of stock and we really don't understand why, Broughton Audio LPF !
Broughton Audio has a low + high pass version too. And, just skimmed the (very) long first post of the thread cause... well it's 3 a.m.

Kind of understood that a HPF could also be useful because some cabs don't handle well the sub frequencies and get muddy or just sound bad. Am i right ?

 

[Downunderwonder]

Hey all !

I've been talking about fuzz and tweeter issues recently and the first and only answer i had was "Get an almighty LPF.". Guess after that everything has been said. First reaction was "meh" but then i realize i might need one... like, everybody i guess.

I need a LPF that cuts around 8 to 12 Khz and it's tough to find one , small pedal, that cuts that high. Actually i guess there's only one : the actually out of stock and we really don't understand why, Broughton Audio LPF !
Broughton Audio has a low + high pass version too. And, just skimmed the (very) long first post of the thread cause... well it's 3 a.m.

Kind of understood that a HPF could also be useful because some cabs don't handle well the sub frequencies and get muddy or just sound bad. Am i right ?

That is the guts of it. HPF also gives life to your bass knob when it can sometimes be commandeered to do that job.

 

[Stumbo]

Hey all !

I've been talking about fuzz and tweeter issues recently and the first and only answer i had was "Get an almighty LPF.". Guess after that everything has been said. First reaction was "meh" but then i realize i might need one... like, everybody i guess.

I need a LPF that cuts around 8 to 12 Khz and it's tough to find one , small pedal, that cuts that high. Actually i guess there's only one : the actually out of stock and we really don't understand why, Broughton Audio LPF !
Broughton Audio has a low + high pass version too. And, just skimmed the (very) long first post of the thread cause... well it's 3 a.m.

Kind of understood that a HPF could also be useful because some cabs don't handle well the sub frequencies and get muddy or just sound bad. Am i right ?

Get the HPF/LPF.

 

[Dj Bebel]

Aight ! Imma take it ! Thanks guys

 

[Stugilliam]

Get the HPF/LPF.

I whole heartily agree with Stumbo. I did and my basses don't sound right without it!!

 

[Balog]

If you don’t mind the DIY the Schalltechnik Vong Filterung has a LPF adjustable up to 22Khz.

VONG-Filterung – Schalltechnik_04

 

[Stumbo]

Aight ! Imma take it ! Thanks guys

Let us know how it goes.

Also, take a look at Order of effects

 

[JimmyM]

Hey all !

I've been talking about fuzz and tweeter issues recently and the first and only answer i had was "Get an almighty LPF.". Guess after that everything has been said. First reaction was "meh" but then i realize i might need one... like, everybody i guess.

I need a LPF that cuts around 8 to 12 Khz and it's tough to find one , small pedal, that cuts that high. Actually i guess there's only one : the actually out of stock and we really don't understand why, Broughton Audio LPF !
Broughton Audio has a low + high pass version too. And, just skimmed the (very) long first post of the thread cause... well it's 3 a.m.

Kind of understood that a HPF could also be useful because some cabs don't handle well the sub frequencies and get muddy or just sound bad. Am i right ?

That's what I use them for, but I go for a much lower high cutoff than you. I can't stand anything over 5k. But I wouldn't worry too much about the Broughton LPF being out of stock. It's an item he usually has in stock all the time, and he'll be back from vacation in a week. You waited this long, you can wait a little while longer And really, if you're going to use them both and don't need separates for different instruments like I did, the combination pedal is the way to go, and he has them.

 

[JimmyM]

Haven't needed my H and LPF's much lately since my latest band does rootsy light rock type gigs at semi-low volumes and doesn't run instruments in the PA. And since I don't use tweeters and my cabs roll off low end and I don't need to eke out half a db out of an underpowered rig I just let the cab do it all for me.

But we just started recording an album, and they've been a huge help already. My original plan was to go direct with my PF-50T to guide the drummer then replace them with a mic'ed B-15 + REDDI once we get the drums down. But now I'm not so sure. I've got such a great sound going direct that I may just keep what I did, except for this one song where I cranked the amp into overdrive and used an MXR Vintage Bass Octave and made a really fat synth sound. Would be cool to do two tracks and separate out the octaves and pan them a little L and R, I think. We may be rootsy but we're not purists...except about tubes and real drums. And I always like to deliver a track as finished as possible for two reasons...cuts way down on decision making come mix time, and whenever an engineer tells you they'll add stuff in the mixing stage, you can bet that 95% of the time they won't. Fortunately, our guitarist/vocalist is the main songwriter and producer, although I'm spotting her

I think there's a lesson here...take the sound of your guide tracks seriously in case they may be keepers. Now if I decide I had the magic in these tracks, I won't have to worry about re-recording or re-amping, which always sounds inferior to amping them right the first time. I think they might...might have to make a handful of edits to keep them, but like I said, we're not purists. And I will deny with my hand on a stack of Bibles that edits ever happened!

 

[sonofshel]

Funny enough, there are 2 Broughton LPF pedals listed on reverb right now. I totally recommend the combo pedal myself.

 

[Downunderwonder]

I don't need to eke out half a db out of an underpowered rig

I think there's a helluva lot more on the bone than half a dB of low end when HPF'ing for extra punch from a barely adequate rig. Flippancy is discouraged when using proper terms.

In my case I have oodles of headroom to get as loud as I like, still HPF'ing gets me a better tone.

 

[aproud1]

I think there's a helluva lot more on the bone than half a dB of low end when HPF'ing for extra punch from a barely adequate rig. Flippancy is discouraged when using proper terms.

In my case I have oodles of headroom to get as loud as I like, still HPF'ing gets me a better tone.

I find my HPF allows me to better use the tone controls on my amp which gets me a better tone at a lower position on my volume control. Without my HPF I tend to broadly cut and lose a lot of the "meat" to the tone. I played around with HPF and always have one on my computer input. It wasn't until I did a gig in a bad room that i truly came to appreciate how valuable the little pedal can be. I can't imagine playing out without a HPF.