Low-Passing your live rig?

Discussion in 'Effects [BG]' started by Grahams Groove, Aug 14, 2021.

  1. Grahams Groove

    Grahams Groove Never succinct... Supporting Member

    Apr 13, 2001
    I know there are myriad threads on HPFs and the benefits/uses. But I think there is much less of a dialog regarding LPFs for live/amp setups.

    I'm in the process of possibly switching amps (trialing the old and new to decide what I like best). I like using an HPF & LPF for recording and getting some of that tightness and cab-sim feel. However, I'm wrestling with whether or not I really want/need an LPF for my live rig. My old/existing amp has HPF & LPF controls, but my new amp has only HPF - which is far more typical if an amp has any specific control over filtering.

    Part of me feels like it's nice having the LPF for taming the bees on fuzz/distortion pedals. Then again, there's something nice about that big raucous sound of unbridled dirt pedals. I have tweeters on both of my cabs, and I turn one off and roll the other one down a few dBs to tame it. I just can't decide if its worth the board space and addition to the signal chain to add an LPF box, or if I just want to let my cabs do whatever rolling off they can...

    Anyone toyed with this back and forth and find any major benefits going one way vs the other? I know it's all personal preference, YMMV, etc. Still, interested to hear any perspectives on this that I haven't considered.
  2. Bob_Ross

    Bob_Ross Gold Supporting Member

    Dec 29, 2012
    This doesn't quite answer your question, but the OP reminded me of two things:

    - disabling the tweeter horn in my Eden D-series cabinets was an epiphany. I never could put my finger on what it was that wasn't quite right with the sound I was getting, but I did know that the lower I set the level for the tweeter the happier I was. Finally just pulled the optical circuit breaker, completely disabling the tweeter...and voila! there's the sound I'd been looking for. Now, tbh I don't know whether the crossover in those cabs is genuinely 2-way; it may just be the natural roll-off of the 10" drivers that's working for my ears, rather than some actual low-pass filtering.
    - 35 or 40 years ago when I first started working as an audio engineer in commercial recording studios one of the pros who was helpful in mentoring me told me -- and I remember this sentence verbatim -- "there's nothing of interest above 10kHz in an electric bass track". He used to low-pass his bass channel as a matter of course, and often well below 10k. I still find myself doing that on occasion when I'm mixing

    ...but it honestly never occured to me to LPF my onstage rig.
    Grahams Groove likes this.
  3. GMC


    Jan 1, 2006
    Wiltshire, UK
    Yep, your trusty 10” drivers probably don’t produce much over 5khz, 15” drivers often max out at around 3.5khz.
    When I specked and built my two bass cabs (about 20 years ago), I used a soft dome mid driver that maxed out at about 10khz. I used a 2 way crossover unit at 1.6khz because the large soft dome has a really flat response and sounds very smooth. I’ve never really needed anything over 10khz on bass either, which is really useful as above 12khz is usually where all the hiss and noise is!
    Last edited: Aug 14, 2021
  4. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    I hate hate hate tweeters on distortion, nor am I very fond of it on electric bass at all, so an LPF is a necessity in my DI line.
  5. NoiseNinja

    NoiseNinja Experimental-psychedelic-ambient-noise-drone Inactive

    Feb 23, 2011
    Well, not quite that same, since I actually run my setup through a poweramp and then a full range PA speaker, but I sort of emulate a cab using equalizers, including what equals a LPF set to about 3.5kHz (-3dB) with a 12db/Oct downwards slope.

    Personally I prefer that to the sound of a much more detailed, but therefor also more intrusive, IR cab simulation, or even a real bass cab.

    Weather a LPF is useful when actually running through a real bass amp and bass cab, I guess that depends of the specific amp and cab(s), and not least personal preferences.
    GMC likes this.
  6. YawningJorin


    Feb 14, 2020
    I used to run a Warwick BC80, which has a tweeter that cannot be disabled to my knowledge. It didn't play nice with dirt and I ended up running a cab sim in the effects loop. It sounds like you're on the fence with regards to whether you want a LPF or not. If you find having one useful only sometimes, I'd say being able to toggle it via a pedal would be very much beneficial.
  7. Grahams Groove

    Grahams Groove Never succinct... Supporting Member

    Apr 13, 2001
    Thanks for the feedback. This kind of reiterates how much of a taste thing it is.

    For me, I like some bite and top end in my cleaner sounds. The flip side is dirt, which has come up in multiple responses. That’s where I tend to find it most useful. That’s also why I ran the lpf on my previous amp ~5k.

    My thought is to maybe run a two-loop switcher. One loop for dirt with an lpf last in line before the return, and a second loop for my phaser and delay. Then it’s always in play to tame the fizz/bees.

    I know I ultimately have to play around with it a bit, but it’s helpful to get some other insights.
    YawningJorin likes this.
  8. Zbysek


    Mar 23, 2017
    Czech Republic
    I use LPF in my signal chain (in the form of Broughton RFE, Broughton Messenger or the VLE filter on my Markbass amp). I consider it a useful tool.

    Whether you need it, I don't know....
    Last edited: Sep 1, 2021
  9. Wasnex


    Dec 25, 2011

    I normally like tweeters, but I found Eden D*10XLT tweeters to be particularly harsh and abrasive. I did not turn my tweeters totally off, but I did run them at a very low level. Too my ears, running the tweeter too hot in these cabs causes a nasty phasey sound around the crossover frequency. But if you turn them down enough, they seem to relax into the 10s. Pretty sure the claimed crossover frequency was 3.5khz, but the actual crossover frequency will vary somewhat with the level of the tweeter relative to the 10s.
    allintime likes this.
  10. Johno Dunn

    Johno Dunn Supporting Member

    Mar 22, 2007
    Carpinteria, Ca.
    I most certainly run a LP on my rig. I'm either on IEM's or an FRFR powered monitor. I set my LP pretty aggressively at around 600-800 hz, depending on how new my strings are.
  11. Bob_Ross

    Bob_Ross Gold Supporting Member

    Dec 29, 2012
    Wow... that strikes me as atypically low ...unless you're in a reggae band?
    Zbysek and Wasnex like this.
  12. Johno Dunn

    Johno Dunn Supporting Member

    Mar 22, 2007
    Carpinteria, Ca.
    Nope, Funk and worship. HP is set at 35-40, and I boost my mids.
  13. cavemanbass


    Nov 5, 2010
    LPF @ 5k
  14. el murdoque

    el murdoque

    Mar 10, 2013
    I've no idea where mine is at, but I tune it by turning it down until the unwanted noise is gone, I'd say in the hood of 7-10k - which I do when I play without cabinets.

    This serves two things: I like my bass sound rather dark and warm, and some FOH people around here like the clicky noise and push upper mids and highs like mad.
    Since you can't amplify what is not there, my LPF is in the line that gets sent to FOH.
    The other reason is to simply tame my IEM sound - same reason. Neither IEMs nor FOH speakers are tweeterless bass cabs and both are very capable of doing sound above 8k.
    Johno Dunn likes this.
  15. JES

    JES Supporting Member

    I use distortion a lot — multiple flavours, and if I’m on a full range system, I consider a LPF essential. Clean, depending on what you’re going for, it might not be right. For clean pianoy bass sounds I usually prefer full range.
    Wasnex likes this.