Markbass - HPF or not? MB don't seem to know!

[crazyBassClown]

Interesting -- I never thought of it that way. Would you say, then, that most or all amps have (what is effectively) a HPF (as well as a LPF) "built in"?

Yes, and so does your speakers sound output. Your amp most likely produces signal both lower and higher than your speaker can reproduce as sound.

 

[Analogeezer]

Can a compressor or a booster also have - even if only approximately - the effect of a HPF?

No not really, some compressor pedals or boosters might have an effect on the overall EQ (boost pedals in particular) but compressors and boost pedals are designed to work in the DYNAMICS domain, "filters" whether they are HPF, LPF or even band pass filters work in the frequency domain.

Now an actual equalizer sorta works in both frequency and dynamics, by virtue of the fact if you boost or cut a particular band of EQ it will raise or lower the overall level. But filters only subtract, but of course if you cut enough lows with a HPF it will affect your volume level because you are taking part of the signal away.

Analogeezer

 

[Analogeezer]

Any rationally designed bass guitar amplifier has a high pass filter somewhere in its circuitry. If it didn't, the attack of every note (when you pull on the string, before you release it and it vibrates) generates sub sonic information - without a high pass, that information/signal will move your woofers a LOT (without creating usable sound). The odd thing is that this is something nobody ever talks about in their amplifier literature - the only amplifier I ever saw talk about it was a line of Acoustic amp heads that touted they DIDN'T have a high pass filter - they were DC coupled. It was a STUPID idea - a 100 watt amp that couldn't get very loud at all, as it wasted all it's headroom on those transients. That line and the marketing campaign quickly and quietly disappeared - once the amps were out in the real world, they realized their mistake, stopped making those models, and never spoke of DC coupling again.

That said, a lot of folks on here like their high pass frequency to be set higher than what's in the amp (whatever it is, which they for some reason don't tell you) - to reduce the amount of strain put on the speakers on the lowest notes. In that case, you need an external high pass filter.

The micro thumpinator is a good product for reducing subsonic stuff. It's not what you want if you're trying to lop off some of your fundamentals - it's designed to not do that.

I would suggest the serious sub-sonic frequencies are not produced by any bass guitar at meaningful levels; if you look at the frequency plots from that thread I asked about this a while back you see the harmonics below the fundamental are at very low levels.

I always got the impression HPF's in amps (well the built in ones, some power amps have select-able ones on the back panel) were there more to prevent sub-sonic/DC from hitting the speaker outputs when something goes wrong.

I am talking about whatever HPF's are built into an amp, not the ones that come on a lot of newer amps that actually let you dial in the HPF frequency point. Those are effectively the built in versions of the pedals we are talking about.

Analogeezer

p.s. It seems to me the main use of a HPF pedal or a built in adjustable circuit on an amp (like Mesas) is to tune the rig to the environment you are playing in. Boomy stages, sketchy venues can emphasize lows that might be adding mud and taking away clarity.

 

[gstaats]

Can a compressor or a booster also have - even if only approximately - the effect of a HPF?

Using an hpf helps most compressors as it allows them to work on audible frequencies.

 

[acubass]

Not to hijack the thread but does the Bass Eq on the head being at (what I consider too low) at 40hz have anything to do with the need for a HPF for Markbass heads? I think the Tonehammer series by Aguilar has it set at the same point too.

 

[seamonkey]

If you have a recording interface on your PC you can map your head's frequency response and see where the built in HPF frequency and slop is at.
https://www.roomeqwizard.com/
With EQ plugins on your PC you can play with raising the frequency above the built in HPF and listen to how it sounds. You can then search for a Hardware HPF that matches what you find.

 

[nnnnnn]

In my case I'm not hearing any unwanted low end noise, it's just that I want my stage rig and pa to be working as efficiently as possible, not amplifying stuff that no-one can hear.

Is there actually any problem with the stuff people can hear?

Why does it matter how efficiently your amp is working if you're getting the tone you want at the volume you want?

 

[PeaveyPlayer]

Now I’m curious

So far I’m running an aguilar DB680

into a stack of gk neo 2X12. ( two of them stacked)

where would I need to set my hpf? And as well would it make sense to have an inline one between the amp and cab

 

[Wasnex]

Is there actually any problem with the stuff people can hear?

Why does it matter how efficiently your amp is working if you're getting the tone you want at the volume you want?

The HPF potentially has multiple benefits. They are not necessarily all relevant all the time.

If you are getting the perfect tone at the required volume, the HPF is not necessary.

It can be beneficial to reduce the strength of super low frequencies...and yes you can hear the difference.

Your amp may sound great up close. But really strong lows tend to carry further and they can build up and mask other frequencies.

 

[Wasnex]

Now I’m curious

So far I’m running an aguilar DB680

into a stack of gk neo 2X12. ( two of them stacked)

where would I need to set my hpf? And as well would it make sense to have an inline one between the amp and cab

AFAIK, It's not practical to build an HPF that works at speaker level.

The devices we are discussing are typically used between the bass and preamp.

The Neo 212 specs say -3dB occurs at 53hz. I suggest you start with the HPF at about 50hz and adjust to taste. You might like it a bit higher or a bit lower.

 

[gstaats]

Now I’m curious

So far I’m running an aguilar DB680

into a stack of gk neo 2X12. ( two of them stacked)

where would I need to set my hpf? And as well would it make sense to have an inline one between the amp and cab

One between the amp and cab isn't needed. Part of the benefit of an HPF is that reducing the sub-sonic lows will make the power amp work more efficiently. Also, depending on pedals used or the how the amp responds (like gain settings, clipping, and any type of compression), there is more benefit running the HPF earlier in the signal chain. Not to mention, HPFs on the preamp side tend to be adjustable.

 

[J33]

Mesa/Boogie Subway WD-800 Lightweight Hybrid 800-watt Bass Head

I'd definitely consider looking into a head like this and selling your current setup to offset costs to you. This gives you full control and will solve a lot of issues for the future. I'm happy you like what you like but in my experience with them... there are a lot better options out there than MB with much more shaping control. Food for thought.

 

[JOME77]

I have one of these.

https://reverb.com/item/4750608-fdeck-hpf-pre-series-3-hpf

Great HPF for bass. I believe that the guy that makes them is a TB’er.

 

[KJMO]

I think Mr. Genzler said all the bass amps he knew of had an HPF. He said Genzlers are set at 30hz, if I remember right. I usually start at 40hz and have gone as high as 100hz. Never needed much happening below 40hz. It's probably the single biggest lesson I've learned re: live sound. It can really tighten things up a lot.

The Markbass amp I had could get really unruly in the low end, especially with the filter deals (VLF and the other one, I always get them mixed up). One of them scoops mids, the other pulls out highs and lows. I would think the one that pulls out highs and lows would work a little like having a HPF and a LPF, with maybe a little less steep of a roll off (or maybe not, depending, idk).

 

[Zbysek]

You're right, they do ship internationally but in this case (namely, not purchased from an EU distributor) shipping plus import taxes means more than double the retail price, so about US$250 for the HPF pedal...

It's still worth it, IMO.

I am based in Europe too. When I order Broughton pedal, I pay USD 60 for shipping plus 21% VAT. That would make it USD 160 for the Always on HPF and USD 190 for the switchable HPF.

I am not sure where does the USD 250 figure come from...

 

[MarkA]

I've not tried it, but for those looking for a variable HPF made (and available) in Europe, this seems worth a look:Zorg Effects releases Küth

 

[mcnach]

@Wasnex

Thanks but you can't get Broughton in continental Europe, it seems. Could you perhaps suggest some other brand?

They sell directly from Canada. I bought a couple of pedals in the past year, I'm in the UK.

 

[JimChjones]

I would suggest the serious sub-sonic frequencies are not produced by any bass guitar at meaningful levels;

From conventional playing of the strings no, I imagine you are correct, but there are other sources of LF sound, mechanical, percussive etc depending on the player's style.

 

[Sparky Mark]

Rafferty is UK based and makes what looks like the Fdeck HPF design. I've got one and it also takes a PP3 so you don't need external power.
Rafferty HPF Pre 2 Bass Preamp / Adjustable High Pass Filter / Phase Switch | eBay

 

[Phaidrus]

It's still worth it, IMO.

I am based in Europe too. When I order Broughton pedal, I pay USD 60 for shipping plus 21% VAT. That would make it USD 160 for the Always on HPF and USD 190 for the switchable HPF.

I am not sure where does the USD 250 figure come from...

@mcnach

Where I live it would be: unit price + shipping + VAT + (most probably) customs handling fee = over USD200. Still OK if one really wants it.