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

[Jefenator]

I use a HPF buffer preamp for my upright bass piezo pickups (fDeck's HPF-pre - highly recommended for that application). The HPF frequency knob is very relevant for that, as the pickups can produce a lot of rumble which in turn can wreak havoc with mix presence and feedback for a very large acoustic instrument.
I really dislike having to plug extra things in, but I also trust my ear and my upright basses pretty much always sound better with the HPF-pre than without. (Much of that also has to do with the input impedance - 10M - which is another topic for debate where my own ears get the final say.)
I do not currently use the HPF-pre with my electric basses. In spite of the buzz here on the forums, my ears/gut tell me there isn't anything broken needing fixing - at least not to an extent that will justify complicating my signal chain. (My Bergantino B|Amp does let me adjust HPF frequency, so I do play with that setting - along with compression, EQ and O/D. Lately I have been favoring tube amps which in many settings give me the response I crave naturally, without having to adjust hardly anything.)
If I used a pedalboard and there was an open spot on it nagging at me, I might drop in a HPF unit & see what it does for me. Cord into amp guy that I am, I'd be just as inclined to go low tech & try elevating my cab off the floor with a milk crate.

 

[SJan3]

If using standard engineering speak, 20Hz will only be -3dB, not even close to eliminated fully. And it will also depend on the filter slope, a first order filter would only be -9dB at 10Hz at best.

This is above my pay grade. Are you saying that a HPF will allow sound below it's setpoint?

 

[el murdoque]

By the way, I asked for information on the EQ center frequencies of the AMT A-Bass and O-Bass preamp pedals and the company tech support Alexander Korotaev kindly send me the following files. Can't really figure out what they mean, perhaps they do function as HPF or LPF filters to an extent.

No, the A-Bass does the opposite of HPF and LPF. Their curves basically do not cut off but simply extend past what is audible for humans. With the A-Bass, you have the Alembic/Fender Tonestack. Your neutral position would be
Lows: Nearly all the way off.
Mids: All the way on.
Highs: All the way off.
with the high switch off.
This gives a nearly flat EQ curve.

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.

I remember comparing Tonehammer and LMII once. The LMII had no LPF that I could register, while the Tonehammer did. I tried a 5 string with boosted lows, so my fundamental was around 30Hz.



I see the OP is based in UK, so buying from Germany might be an option. How is the brexit thing going these days? Last time I ordered a set of strings from the UK, I did not have to pay VAT and when the parcel arrived, I did not have to pay German tax, either - that was great. There is a pedal kit that is popular among the German bass community. It's called the 'Vong Filterung' by Schalltechnik_04 (the kit can be obtained here: VONG-Filterung - filter kit, 34,00 € ). This is a HPF + LPF +DI.
There are two mini Versions, an always-on HPF or LPF - but my advice is to get a pedal that does both. Once you see what a simple, yet powerful tool a HPF+LPF is, you'll be glad you got it right from the start. I had one to start, then bought the other, then bought a single pedal that does both.
These pedals are also easily found on the German second hand market.

There are quite a few in current circulation,

 

[Passinwind]

This is above my pay grade. Are you saying that a HPF will allow sound below it's setpoint?

Yes, lots of sound in some cases. Frequency rolloff below F3/the set point is not a brick wall, it's a slope that varies depending on filter order. So just saying "20Hz" is not super instructive, unfortunately.

 

[pglaser01]

If using standard engineering speak, 20Hz will only be -3dB, not even close to eliminated fully. And it will also depend on the filter slope, a first order filter would only be -9dB at 10Hz at best.

Interesting question…..I wonder then, if a situation arose where an HPF could theoretically shelf and completely eliminate all sound below a set frequency point, what (if anything) would that do to the efficiency and perceived volume of the amp’s production above that frequency setting if all other equipment settings remained the same?

 

[SJan3]

Yes, lots of sound in some cases. Frequency rolloff below F3/the set point is not a brick wall, it's a slope that varies depending on filter order. So just saying "20Hz" is not super instructive, unfortunately.

Interesting. Thanks for opening my eyes to this. I did think that the setpoint was a proverbial "brick wall". What in your mind would be an ideal setpoint for a HPF considering the rolloff you've described?

 

[Passinwind]

Interesting. Thanks for opening my eyes to this. I did think that the setpoint was a proverbial "brick wall". What in your mind would be an ideal setpoint for a HPF considering the rolloff you've described?

For a B tuned fiver set flat I tend to like right around 32Hz, 4th order. And then if I boost bass I generally sweep up into the 40-50Hz range to massage the bass control boost curve a bit.

 

[Passinwind]

Interesting question…..I wonder then, if a situation arose where an HPF could theoretically shelf and completely eliminate all sound below a set frequency point, what (if anything) would that do to the efficiency and perceived volume of the amp’s production above that frequency setting if all other equipment settings remained the same?

Paging @agedhorse, he may have gone beyond the relatively modest 48dB/octave rolloff format I've tried using a DSP based HPF.

 

[J33]

Don't, you'll start me gassing!

Hahaha. Wasn't my intention in the least. I really don't want you to think I'm dissing your decision either with MB's. I know some people who love the thing that they do...and there's nothing more valuable than finding your voice in things...whether it be a bass or gear. I'm more saying that if you are starting to get into very nuanced "micro" controlling of dynamics...you've got options that will lend your situation some ease. Money put into an outboard piece on top of money spent on the head...this stuff really starts to add up and in the long run and a lot of the time a little bit more spent upfront equals a lot less in the long term as I'm sure you most likely already know. Hope you get a great solution to your issue though. Cheers!

 

[Robscott]

Here for a kit : High Pass Filter / HPF kit PRO

the owner offers also fully built units. I bought one and it's super quality.

his shop for built pedals : Kanał YOUTUBE już dostępny

but you will not find the hpf there, just contqct him and he will build one for you

Thanks for the info. I've just ordered a kit and I'm going to try to make it as a rackmount unit

 

[nanbanpapa]

Here's an excellent video explaining the utility of HPFs. If you watch from 9:12, you can see the differences in the speaker.

 

[J.Wolf]

Not all heads current or otherwise have a HPF built in, but that doesnt mean theyre flat to 0 Hz. The problem area for amps with no HPF seem to exist in the 20-30 Hz region. I have an Fdeck S3 I use with the amps I have which dont have an HPF built in (Eich T900 and Demeter VTBP201>CA9), or with any other amp/rig where I want to be able to cut the boom without gutting the low end.

Most people use an Fdeck for either cutting the subsonic/unusable lows, thus tightening up the amps sound and reducing its "workload", which gives the amp more usable power and protects speakers to some degree, OR as a tone shaping tool, and rolling off low end to an audible degree to make the bass tone less deep on purpose, for aesthetic purposes. Bass controls on amps are often not ideal for this, either because theyre "band pass" or shelving as opposed to "high pass", or theyre not flexible enough in their freq and Q to do it well.

As far as the 680 rig, if you wanted to implement a HPF, I would either put it in the 680's FX loop, or between the bass and 680. I'd be reluctant to put it between the 680 and the amp, for tonal/gain staging reasons. But it's easy enough to experiment and see what you like best.

 

[Mushroo]

Interesting. Thanks for opening my eyes to this. I did think that the setpoint was a proverbial "brick wall". What in your mind would be an ideal setpoint for a HPF considering the rolloff you've described?

Most pro studio-gear HPF's are in the 80-120hz range. The highly-rated Noble Preamp (for example) is at 90hz.

I personally feel 80hz is perfect for a 4-string EADG bass. Assuming a 12db/octave HPF that gives you about -9dB at 40hz (if my maths are accurate). This is in the ballpark of an Ampeg 810 cabinet, which is generally considered a highly desirable bass tone.

 

[SJan3]

Most pro studio-gear HPF's are in the 80-120hz range. The highly-rated Noble Preamp (for example) is at 90hz.

I personally feel 80hz is perfect for a 4-string EADG bass. Assuming a 12db/octave HPF that gives you about -9dB at 40hz (if my maths are accurate). This is in the ballpark of an Ampeg 810 cabinet, which is generally considered a highly desirable bass tone.

I might prefer a bit more bottom than the fridge, but I see your point. MarkBass just raised it bass center frequency form 40hz to 68hz. This may explain why??

 

[Mushroo]

I think the conversation comes down to, there are different ways to use HPF's, and depending what purpose you are using it for, what problem you are trying to solve, you might choose a totally different frequency.

For example the bassist using an HPF pedal for their stage rig might choose the knee frequency based on the frequency response of their bass cabinet whereas the sound engineer mixing the band chooses the frequency based on the frequency response of the listener's ear.

I don't personally use an HPF in my stage rig, when I'm playing with an amp. (To my ear, my cabinets do a perfectly good job filtering out sub-lows.) But for home recording, or playing through a DI, I find them really helpful. So I should probably do a better job being transparent with my fellow TB'ers, that when I answer HPF-related questions, that I'm coming from the perspective of EQ'ing the bass to sound good to the listener, not from the perspective of trying to reduce my speaker-cone excursion. In other words, I am using my HPF as a type of EQ to make my bass sit well in the mix (not as a "utility" pedal to protect my cabinet).

 

[SJan3]

I think the conversation comes down to, there are different ways to use HPF's, and depending what purpose you are using it for, what problem you are trying to solve, you might choose a totally different frequency.

For example the bassist using an HPF pedal for their stage rig might choose the knee frequency based on the frequency response of their bass cabinet whereas the sound engineer mixing the band chooses the frequency based on the frequency response of the listener's ear.

I don't personally use an HPF in my stage rig, when I'm playing with an amp. (To my ear, my cabinets do a perfectly good job filtering out sub-lows.) But for home recording, or playing through a DI, I find them really helpful. So I should probably do a better job being transparent with my fellow TB'ers, that when I answer HPF-related questions, that I'm coming from the perspective of EQ'ing the bass to sound good to the listener, not from the perspective of trying to reduce my speaker-cone excursion. In other words, I am using my HPF as a type of EQ to make my bass sit well in the mix (not as a "utility" pedal to protect my cabinet).

May I ask what cabinets you use?

 

[Mushroo]

May I ask what cabinets you use?

I have a Peavey 4x10, a couple of Carvin 15's, a RevSound 1x8, an Acoustic Image combo, and a Fender Rumble combo.

 

[byacey]

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 put together a variable high and low pass filter. The high pass is nice because if there is a low frequency issue in a particular room, it's simple to raise the low frequency corner to eliminate exciting those problem frequencies. The low pass filter I find is more of a to-taste adjustment to minimize twang and brightness in the higher frequencies.

 

[SJan3]

I have a Peavey 4x10, a couple of Carvin 15's, a RevSound 1x8, an Acoustic Image combo, and a Fender Rumble combo.

A broad selection! I have casual interest in Revsound cabs. Are you liking yours?

 

[SJan3]

I put together a variable high and low pass filter. The high pass is nice because if there is a low frequency issue in a particular room, it's simple to raise the low frequency corner to eliminate exciting those problem frequencies. The low pass filter I find is more of a to-taste adjustment to minimize twang and brightness in the higher frequencies.

The VLE feature on most Markbass heads deals with the low pass issue.