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

#1,701
So, last night I played a private party in a tent. Although I am running IEMs these days, I knew we would be able to literally drive into the (huge) tent for load in. So to make sure we had the room covered with bass, I grabbed the Mesa Walkabout Scout 15" combo and matching cab. I know all of the experts say not to run this rig at 2 ohms, but I've been doing it for years with incredible results. And those two 15s move a TON of air.

As always, I set my Broughton Always On HPF on top of the rig and run a nice 6" patch cable to the input on the amp.

And, as always, I turned the HPF all the way down (minimum setting) to remind myself of how muddy things can get without it. And then I use my ears to dial it back up to perfection.

Last night, a local renowned guitar player happened to be there helping to set up for the party (personal friend of the guest of honor). He was in there when I dialed the HPF in and began to noodle a bit.

He literally stopped what he was doing and as he was walking across the room asked "What kind of sorcery is in that little box???" He went on to explain that once I dialed it up, I had the perfect balance of old school warmth and clean punch. "It's like a P bass in the finest studio." "It's like Jamerson meets Duff McKagan." He was fascinated.

I usually goose the gain on the Walkabout until it breaks up and then back off a tiny bit. That allows me to have warmth when playing lightly and fur when I dig in. Old school. But the HPF just cleans it up so nicely. Then when it hit the PA he was literally laughing at how great it sounded.

During our set break he told me it was the finest live bass tone he had ever heard in 40+ years of playing. "Don't get me wrong.
Your playing is fantastic, and all of your gear is great. But that little box is your secret weapon, man! It's just amazing!"

These things live up to the hype. The room was shaking with bass. My rig sounded ridiculously good. My in-ears sounded amazing. I hadn't wussified my tone. It was just more focused and less flab.

It's the best $70 you'll ever spend on bass gear. I am not affiliated with Broughton in any way. I'm sure there are other great options out there.
https://www.broughtonaudio.com/product-page/always-on-high-pass-filter
 
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#1,702
I may just being dense here, but this last post has me thinking to move my HPF from before the last pedal on the board, currently a BDDI, to after it.

I mean, wouldn't a preamp in the final position potentially undo the effect a HPF has on the signal chain, at least partially?

But if you were to do that, the FOS signal would not get the HPF benefit.
 
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#1,703
I also have the Broughton always-on. I dial it in just like you do, with my ears. I have mine on my pedal board, right after my tuner. I don't worry too much about whether anything after it might be adding some subs back in. First of all I doubt it (except maybe my C4 synth), and second of all I don't care. The only thing I regularly have on after it is my compressor and my Geddy. Neither of those is going to add any subs that I don't want.
 
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#1,704
Btbp said:
I may just being dense here, but this last post has me thinking to move my HPF from before the last pedal on the board, currently a BDDI, to after it.

I mean, wouldn't a preamp in the final position potentially undo the effect a HPF has on the signal chain, at least partially?
Click to expand...
Only if the last pedal was boosting lows by a lot.

More of a concern is how it might rely on low end to make it work. In your case the BDDI functions nicely and you get the HPF goodness to FOH. Carry on.
 
#1,705
Btbp said:
I may just being dense here, but this last post has me thinking to move my HPF from before the last pedal on the board, currently a BDDI, to after it.

I mean, wouldn't a preamp in the final position potentially undo the effect a HPF has on the signal chain, at least partially?

But if you were to do that, the FOS signal would not get the HPF benefit.
Click to expand...

I'm assuming that you meant FOH when you types FOS - and in that case, IMO any pro soundman will already have you a little high passed at his board...
 
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#1,706
mesaplayer83 said:
any pro soundman
Click to expand...
It is surprising how widely that description gets applied. Take 2F's story of the 40 year veteran guitarist who surely worked with many a pro desk jockey yet never heard bass as good as when 2F dialed in the HPF. What were all those pro soundmen up to? Not a lot.

My local big venue has a hua of a resonance at 80hz. Necessitates extreme measures from my end.
 
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#1,709
Downunderwonder said:
It is surprising how widely that description gets applied. Take 2F's story of the 40 year veteran guitarist who surely worked with many a pro desk jockey yet never heard bass as good as when 2F dialed in the HPF. What were all those pro soundmen up to? Not a lot.

My local big venue has a hua of a resonance at 80hz. Necessitates extreme measures from my end.
Click to expand...


I guess that depends on the gigs that particular guitarist has played - at a certain level of gigs, it's pretty much guaranteed that some high passing is going on at the board - at least, IME...

Not to take away from 2F's glorious tone that night, but if that was truly the case, how many "pro soundmen", or great bass tones could that guitarist have encountered in his 40 years? Also, as someone who has also been gigging for 40 years, HPF weren't common at all for quite a few of those early years... These days, it's VERY common for most decent mixing boards...
 
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#1,710
Downunderwonder said:
It is surprising how widely that description gets applied. Take 2F's story of the 40 year veteran guitarist who surely worked with many a pro desk jockey yet never heard bass as good as when 2F dialed in the HPF. What were all those pro soundmen up to? Not a lot.

My local big venue has a hua of a resonance at 80hz. Necessitates extreme measures from my end.
Click to expand...

mesaplayer83 said:
I guess that depends on the gigs that particular guitarist has played - at a certain level of gigs, it's pretty much guaranteed that some high passing is going on at the board - at least, IME...

Not to take away from 2F's glorious tone that night, but if that was truly the case, how many "pro soundmen", or great bass tones could that guitarist have encountered in his 40 years? Also, as someone who has also been gigging for 40 years, HPF weren't common at all for quite a few of those early years... These days, it's VERY common for most decent mixing boards...
Click to expand...

I can't really explain it. But there's a difference when the HPF is in front of the amp. I realize there "shouldn't be" a difference. But there is. It's kinda like the many discussions about the order of pedals on a board. Compressors function differently in front of and behind drives.

I sometimes run sound as well. I've run sound for bassists with and without. Of course I filter them at my end if need be. But there's something "better" about mixing a bass tone that doesn't need an HPF at the board. Sure I can handle it either way.
 
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#1,711
two fingers said:
I can't really explain it. But there's a difference when the HPF is in front of the amp. I realize there "shouldn't be" a difference. But there is. It's kinda like the many discussions about the order of pedals on a board. Compressors function differently in front of and behind drives.

I sometimes run sound as well. I've run sound for bassists with and without. Of course I filter them at my end if need be. But there's something "better" about mixing a bass tone that doesn't need an HPF at the board. Sure I can handle it either way.
Click to expand...

I hear ya - I definitely don't get any complaints from soundmen when they get a P Bass pre-EQ send from this:
Bass Pedalboard 10-18-19.jpeg
 
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#1,712
In the summer when I was assembling 2 boards and refreshing the TB effects classifieds page 10-20× per day, I was first to find a Broughton H/Lpf at a good price that had just been posted only minutes prior... It was the one previous brighter red model with 2 knobs over 1 and the side jacks.

Even though I've not had a problem with room boom, I knew with all the recent TB hype it wouldn't be available for long and figured if I didn't jive with it, I'd have zero problem recouping cost.

It seemed intuitive to me to slap it at the very end of the chain so that's where it went. At first the HP thing didn't really wow me all that much in relation to my active bass and GenzBenz classD head that has a ton of tone shaping options between them. I DID find the LPF side to be helpful in removing some of the unwanted hi fi/piano like quantities that are ever present on the G&D strings of my active Spector with the EMG soaps.

I've since come to learn that my classD GenzBenz Shuttle HAS a built in high pass filter, which makes it redundant, and likely explains what I was missing by not missing, if that makes sense :wacky:

I moved the Broughton to the smaller board that goes to a different band's rehearsal space. There lives the Ampeg V4B which does NOT have a built in HPF, and the benefits were immediately apparent to me with the 5 of us crammed into our 10×12 space. At least the ceiling is super high (too bad the bathrooms there are literally always a crapshoot :vomit:) No boom in the room, just plenty of vintage tubey heft to hear and feel with each lick of the pick!

That band meets weekly but I plan to spend a bit more time by myself down there with it testing out different settings with different pedals on in front of it.

It doesn't make much sense to me to place it anywhere else in the chain unless there's a problem pedal somewhere in particular. I'm sure it's been previously discussed somewhere in the 85 pages of this thread, which I'll go back and skim.

Just wanted to share that I'm finally getting what all the hype is about. Thanks @Stumbo for spreading the word so much (although the way this thing was given so much praise, I half expected that it might wash my dishes after dinner and warm up my car on a chilly morning :p)
 
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#1,713
I read a lot of this thread but not all of it, sorry! Just had a question about passive HPF and LPF versus active. I would imagine that active is better, but are passive ones useful as well? I see passive ones on Reverb for relatively low $$$ but wonder if they're not even worth the time.
 
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#1,715
timendous said:
I read a lot of this thread but not all of it, sorry! Just had a question about passive HPF and LPF versus active. I would imagine that active is better, but are passive ones useful as well? I see passive ones on Reverb for relatively low $$$ but wonder if they're not even worth the time.
Click to expand...
A passive HPF on low frequencies is quite pricey if you want it to handle any power. It's a lot of copper so it's heavy. It chews up amp power.

Active does it with the low power signal before it gets the big amplification, with itty bitty components.
 
#1,716
I have an fdeck HPF-Pre and a built in HPF in my Shuttle head, so my HPF needs are pretty well covered. Now I covet an LPF to conceal my poor technique and string noise. But when I look at the Broughton site, well the LPF is nearly as expensive as the LPF + HPF, and then I might as well step up to the one with the sweepable mid filter, and pretty soon I’m considering going all out on the Messenger preamp with all the goodies. Decisions, decisions.
 
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#1,717
#1,718
timendous said:
I read a lot of this thread but not all of it, sorry! Just had a question about passive HPF and LPF versus active. I would imagine that active is better, but are passive ones useful as well? I see passive ones on Reverb for relatively low $$$ but wonder if they're not even worth the time.
Click to expand...
I've wondered about this too. I have an active Broughton as my main HPF but also picked up a passive variable HPF along the way from Cave Pedals, which I'm currently using in a loop to tame the low sweep of a phaser. I know a lot of guys here in Aus use the Cave as their main HPF, but I've never heard the active vs passive thing explained.
 

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