Two questions about High-Pass Filters

[Deleted member 271037]

First of all, if you use a HPF in a way that works for YOU, great! I can only speak for myself, based on my experience. But a HPF can definitely be a way to ruin the tone, expecially if an inexperience player reads some of the misinformation about HPFs I've seen here on talkbass.

In my opinion HPFs are one of the most overhyped (and to some extent misunderstood) product here on talkbass. Sure, a HPF can have it's use, but it only does ONE very basic thing. It's not some kind of magic wand that will fix all kinds of tonal issues. It will definitely NOT "fix" a poor sounding room or eliminate standing waves, like I keep reading here on talkbass. At least not unless you go absolutely nuts with the cutoff frequency and most likely ruin your tone in the process.

A HPF can be a helpful tool to reduce sub-bass "boom" on-stage in some situations, but it comes at a cost: With most typical on-stage setups a HPF will also affect the tone you send to FOH. Any drastic eq settings on the signal you send to FOH are best left to the FOH engineer in my opinion. If you use a high cutoff frequency on a HPF to "fix" the tone, you're really just "fixing" the tone on stage. When you're on stage you aren't in a position where you can make any meaningful adjustments to the tone in the actual room (from the audience's perspective). If you use a very low cutoff frequency that will only reduce some sub-bass "boom" it's probably fine. But if you use a HPF with a higher cutoff frequency to get rid of lower mid "mud" you're in danger of completely ruining your tone unless you REALLY know what you're doing AND consult with the FOH engineer.

When I use a HPF (and sometimes I do) it's always with a rather low cutoff frequency, never higher than around 40 Hz. I want a minimal effect on my tone. My main use for a HPF pedal isn't even about the "room" at all. I use it right in front of my compressor pedal (and after all other effects), to avoid the compressor overshooting on low notes. Normally this isn't a problem with bass specific compressors (unless it's caused by user error, like boosting the lows too much on an active bass or somewhere else in your signal chain) but some pedals can have an inherent bass boost that can be problematic. For example the EBS Valvedrive that I often use when I go direct to FOH, will boost the lows a bit, even with the "Bass" knob all the way down. This can cause my compressor to overshoot on low notes. A HPF set to a rather low cutoff frequency (where it will have a minimal affect on the perceived tone) can eliminate this problem. This isn't really a huge problem with the Valvedrive, it can be far worse with many other pedals.

But using a HPF to "fix" the room? Never. I leave the room to the FOH engineer, who can actually hear what's going on in the room. If the amp/cab is boomy on stage... it's the wrong rig for me (which is why I got rid of my horribly boomy Ampeg 410HLF).

Some stages will always be boomy of course, no matter what amp/cab you use. But I still won't do any drastic eq cuts "blindly" and ruin the tone I send to FOH. A low shelf filter (which most amps have) will be far less intrusive than a HPF, and usually get the on-stage tone acceptable, even on boomy stages.

 

[JesterR]

I never used HPF when I was a gigging player, but I am imagine now, how much problem it could solved. Because I hated that too muddy/rumble tones on some stages. I like a big bottom end, but not that uncontrollable rumble.

But what I wonder. Since this problem is more related with room/FoH/Amp combination on some stage, is it really efficient to have HPF as pedal?
Because it comes early in your chain, before amp. So it cuts basically frequencies goes directly from the bass (which could work perfectly fine generating same frequency range in other applications), not introduced by preamp/amp. So, should it be more common feature for amps, rather then standalone pedal?

 

[Wasnex]

I never used a separate HPF on stage with my bass amps either. My approach was generally to try and strike a balance between clarity and focus VS fat lows. Usually the more I cranked the lows, the muddier the sound seemed...so I tended to run pretty lean on the lows.

I now own some amps that have variable HPFs and I adjust them to taste. Note the controls are not labeled HPF.

 

[mouthmw]

I use mine (Broughton) for a simple reason. I don't like sub frequencies and my rig can produce a lot of low end easily. This simply tightens up my low end. I love it with my P + flats, I can get a very Motown like tone (they had HPF at like 70 Hz) and it fits my vintage sounding band. Almost makes my ported cab sound like a sealed cab. It's less needed for my Stingray 3 band (it has an HPF built into its preamp), but it's still great for fine tuning. I usually have it set at around 60 Hz. I love mine and it does exactly what I want from it because I don't care for super bass/sub bass heavy tones.

 

[retslock]

I have the Broughton. People who have this find it useful, never heard of anyone trying it and not keeping it and leaving it always on.

This exactly. Mine is always on. It takes a whole lot of pressure off your speakers. It didn’t change the tone so much but made it more forceful. I wind it up until I hear a loss at the bottom end then pull it back just past that point. My amp and cabinet are not trying to produce frequencies that I can’t hear anyway and that power is being used to push out frequencies that I can hear.

 

[Jay Corwin]

I can't say I've ever used mine in a BG rig, but it's an always on device in my UB rig. It can be a real life saver if you need to push more volume out of a rig, especially if you start clipping.

 

[eriky4003]

OP, maybe set your filter to about 40-60 Hz if you didn't like 60-80. As some folks have written, they set it to when they can hear it sucking out bass and dial it back a bit. This is the most unsexy pedal/device you can purchase for your tone.
I sold my Broughton Always-On HPF to fund a HPF/LPF. When I had received the always-on, I just set it to about 40 Hz and could hear the difference right away, even at low volumes. Just cleaned up mud. When selling this year, I demoed to the buyer with an active bass and the bass knob pinned and started to roll-up the HPF - you could really hear the difference. Sold right away!

 

[jw23mind]

60Hz, NOT 60kHz.

You won't hear the difference if your monitoring system can't reproduce, and besides they are hard to hear anyway.

All amps and pedals have varying degrees of hi-passing coupling caps throughout, and they have a cumulative effect; so, depending on the details of your particular signal-chain you may or may not need or hear the effects of a dedicated HPF.

 

[OneNut]

I've started reading comments about the benefits of using a high pass filter. Most seem to suggest that an HPF can accomplish just about anything... tighten the sound, clean up muddy sound, increase volume or at least gives the appearance of extra volume ... heck, it will probably make you look 20 pounds lighter and have a full head of hair.

But if they are such a marvel ... why are there relatively few manufacturers of these devices? I've only found a handful of manufacturers and none is one of what I would think of a major company, although others may disagree.

I'd like to try one ... but I don't want to just buy something that I will eventually use as a doorstop. I've watched Youtube videos and frankly I couldn't hear much of a difference.

I just now tried making a patch on my Zoom B1 Four using the Zoom Guitar Lab. I used that because that system has a low EQ filter which seems to be a simulation of a HPG filter. I used it and set the parameters as best I could with the cutoff at 60 kHz to 80 kHz. I didn't hear much of a change and what I did hear I didn't particularly like.

So my second question is this simulation I made in a patch anything like what I would expect in a pedal?

If you're using the Guitar Lab with the B1Four, you can load a HPF into the B1FOUR. This will act as a true HPF. It's been a while since I did it and tested so I don't recall the details. I do recall it not doing much as a home player, probably because the Rumble 40 I was using already had enough of HPF effect with the speaker/cabinet response curve.

 

[Stewie]

Bar gigs. My amp covered the house. Guitarist with a good ear says " too muddy". I could turn the bass knob down and be all middy, or turn on the HPF (Fdeck). Still have great tone, mud goes away. Win!

 

[brianrost]

Most seem to suggest that an HPF can accomplish just about anything...heck, it will probably make you look 20 pounds lighter and have a full head of hair.

I can tell you from personal experience it does not help bring your hair back

I use them for feedback control with upright bass and speaker protection for my busking amp. I usually have it set to 80Hz or higher. I start by increasing the frequency until my open E string starts to disappear, then I back off a bit. I fine tune it when I hear feedback or speaker farts creeping in.

If your Zoom pedal has a crossover effect (my original B3 does, Zoom calls it a “splitter") this can be used to create a HPF. I set the low frequency level off and then adjust the crossover frequency until speaker farting goes away. Notice that on my B3 it can’t be tuned below 80Hz.

An inexpensive “always on” HPF is the fdeck, built by a TB member. He has four versions ranging from $50 to $100 and if you like DIY electronics, the schematics can be downloaded free.

 

[logdrum]

Essential for double bass in loud situations and loud situation are 95% of my gigs. Used them before they became popular on TB because of AI amps which always had them seems the first amp they made.

 

[2saddleslab]

I can tell you from personal experience it does not help bring your hair back

Doesn't bring it back. Keeps it from coming loose in the 1st place.

 

[Cleezmo]

I have a Broughton Always On HPF, and it is indeed always on. I see two main benefits. One, it stops your amp from producing frequencies your cabinet can't reproduce; if you cab is rated at 40hz or 45hz or whatever, without a HPF your amp is amplifying those sub-tones that your cab can't physically reproduce, so essentially that's wasted energy. I don't have a monster amp (only 250W at 8ohms), so I'll take any efficiency I can get. Two, by doing that, it makes the sound just a bit tighter. Like many have said, it's not black and white, night and day, etc., it's subtle, but I can hear it. TBH I don't know if my bandmates can, but I can, so I'm happy regardless.

I'm not a touring pro, I play bars and clubs. I'm running amp only, no FOH support, for 80%-90% of our gigs. So not having those sub-lows going to a PA is not a concern for me generally. For the occasions where we do have a FOH guy or gal, I'll ask them if they want me to tweak anything.

 

[dbsfgyd1]

I've started reading comments about the benefits of using a high pass filter. Most seem to suggest that an HPF can accomplish just about anything... tighten the sound, clean up muddy sound, increase volume or at least gives the appearance of extra volume ... heck, it will probably make you look 20 pounds lighter and have a full head of hair.

But if they are such a marvel ... why are there relatively few manufacturers of these devices? I've only found a handful of manufacturers and none is one of what I would think of a major company, although others may disagree.

I'd like to try one ... but I don't want to just buy something that I will eventually use as a doorstop. I've watched Youtube videos and frankly I couldn't hear much of a difference.

I just now tried making a patch on my Zoom B1 Four using the Zoom Guitar Lab. I used that because that system has a low EQ filter which seems to be a simulation of a HPG filter. I used it and set the parameters as best I could with the cutoff at 60 kHz to 80 kHz. I didn't hear much of a change and what I did hear I didn't particularly like.

So my second question is this simulation I made in a patch anything like what I would expect in a pedal?

I wouldn't exactly say they are a marvel as much as they are a useful tool IF you know how and why to apply that filtration. If you start from that vantage point you will understand the benefits.

FYI. IMO, if you can hear the difference you've probably cut too much.

 

[Wfrance3]

Ok, so 30 odd posts in, this is my 2-cents worth...
I've played a bunch of bass over the years and think HPFs are great! Here's what I do, so you can see if this is a good fit for your profile:

I play pretty much silent stage live.
I practice at home with AKG Full Headphones.

If that's similar or applicable to you, this may be helpful.
My pedalboard arrangement is TUNER - THUMPINATOR (Fixed setting high pass filter) - MS60B+ (For compression or whatever else) - MAGELLAN DI (For EQ, and also has an adjustable high pass filter) - Out to amp, house, or head phones.

Here's my story:
I've read Max's info on his website for his product, the Thumpinator.
Link Removed
I was practicing on a Saturday a while back and had taken apart my little pedalboard that I use for playing out. On a whim I stuck the thumpinator on my headphone practice rig. What happened next was pretty great. I was getting ear fatigue I didn't even know about. Everything sounded tighter, cleaner, and just overall better. Not to be drama but it was really like when a room is getting a little stuffy and then the air conditioning kicks on and then it just feels better to be in that room. So I ordered a second thumpinator for my rig that stays home.

I have a board that goes out, it's pretty similar: TUNER - THUMPINATOR - ZOOM B1 FOUR - ZOOM MS70 CDR+ GENZLER MAGELLAN - OUT.
Yes I am lazy and don't want to unpack-repack/unhook-rehookup things just to have a practice session and then take it all back apart over and over...

You've probably read all the info about where in the effects chain to place the HPF. Some say at the end, more will say in the beginning. I have the Thumpinator in the beginning in order to give everything downstream a clean and efficient signal to process. Next comes compression, and then whatever else. In my case usually nothing, but sometimes it might be a little trem or reverb or something. Then at the end, eq shaping and some adjustment of the HPF on the Magellan. FWIW, mine usually is at about 7-8 o'clock...

There are lots of threads that talk about dB per octave and shelving frequencies, etc. I think knowing a little about that stuff is good for a bass player. Overall though I vote with my ears an the results I get. Bottom line is that I think that the Magellan does a great job of cleaning up or whatever their HPF does. Also the Thumpinator is a must have. For me, together the Thumpinator/HPF on the Magellan make dialing in eq and putting together a good sound for other effects 10 times easier. I think it's because when you start with a solid pass filter regulated initial bass tone. It just feels like when you change effects settings it's a much less twitchy of a process. YMMV, but that's my story and I'm sticking to it.

One more thing...
Didn't want to get out the door without mentioning Broughton. I like the stuff that Josh makes. It's definitely popular and well respected here on TB. I have owned their LPF and also had a HPF/LPF combo pedal. I don't have any of my Broughton stuff currently, but do think you could probably do what I did with my Thumpinator-Magellan strategy using a Thumpinator Broughton combo.

 

[vvvmmm]

It doesn't bring yer hair back, but as my dad used the phrase, it puts hair on yer chest.

By which I mean, it can let you get a bit louder as energy is not wasted on inaudible stuff.

It also can protect yer speakers.

I find it useful when using a EBMM Stingray V thru a tube amp (PF50t) into a ported 1x10", as we use for live living-room recordings - allows for a much cleaner, higher, no-fart level.

I actually bought a second Broughton to gift my bassist inna band where I'm the too-many-strings player and warbler. He leaves it here to use for recording, not on stage in his cover band(s).

 

[mrjim123]

I LOVE my Broughton adjustable, always-on HPF. I've had a few bad experiences with sound men who think they need to flex their subs to the max; they either have no idea of what a bass guitar sounds like, or they simply don't care. With the HPF in my signal chain my amp is not seeing those mud frequencies.

I think the reason HPF's are not more popular is that their function seems counter-intuitive to bass reproduction - "Wait a minute. What? You want to REDUCE your low bass output?" But, they WILL make your bass sound better, and offer some speaker protection. Best $80 I have spent on gear.

 

[HolmeBass]

Many bass amps have a built-in HPF, but not all of them do. Mixing consoles have full-featured HPFs.

An HPF differs from a low shelving EQ due to the extreme slope of the filter’s cut - often 24 dB/octave, or at least 12 dB/octave.

The reason they are not more common is that most people don’t really need one. They don’t play loud enough that the added efficiency and speaker protection is needed. Often if they are playing larger halls the FOH is still doing the heavy lifting, and the FOH engineer applies the HPF as he sees fit.

I have a Mesa D-800+ and the variable HPF is definitely useful, but no more so than any of the other controls on the amp. I do like having it though.

 

[Monkey]

I have used an Fdeck Series 3 HPF for a long time. I use a Tech 21 Q/Strip, which has a fixed HPF (45hz), but I don't use it. I run my pedals into the Q/Strip, then send its DI to FOH, so the soundperson can do what they need to do with the full signal. I then run the 1/4" out to the Fdeck and on to my amp, so that I can adjust the HPF for onstage sound.