Less bass = more bass?! (high pass filter)

[tedmanzie]

I have recently purchased a Focusrite ISA 430mk2 mic pre/channel strip, I've been DI'ing my P-Bass into the mic-pre via a Radial JDI. The mic pre has low pass and high pass filter knobs, and I have been getting very nice results by setting the high pass to around 60/70 hz (filter is 18dB/oct). Gives a very 70s Paul Jackson kind of sound and makes the bass sit very nicely with the drums. Kind of cleans the whole thing up but still keeps a nice warm P-Bass sound.

It's different to just turning the bass down on my amp (Aguilar TH500). I like it so much I'm tempted to get a high pass filter in a more portable setup (pedal).

Anyone had similar experience?

Edited May 21, 2015 by tedmanzie

[BigRedX]

I have a [url=http://www.sfxsound.co.uk/microthumpinator/]Microthumpinator[/url] in my rig. It's a lower cutoff frequency 30-35Hz IIRC and probably a steeper filter slope but it works really well at removing the sub-audible frequencies and gives me a much more defined bass sound while still having lots of audible bottom end.

[tedmanzie]

I had one of those, I think you're right - it has a steep filter in that super subsonic region!. SFX are a good company, he could probably build me a variable high pass pedal.

[Sonic_Groove]

Don't SVT 8x10s do a similar thing? Well you said you wanted portable!!!

B

[tedmanzie]

[quote name='Sonic_Groove' timestamp='1432216019' post='2779289']
Don't SVT 8x10s do a similar thing? Well you said you wanted portable!!!
[/quote]

I was thinking more of my handbag, rather than my man van

[Adrenochrome]

Yes, many decent bassists that I know roll off much of the really low subsonic bass, as I do. Many PA desks have a filter for this.

[tedmanzie]

I'm rolling off around 60/70hz, which gives a very good 70s disco sound

[visog]

Interesting... presumably this works for 5 & 6 strings too where presumably, there's more rumble? Anyone vouch for positive or negative results on an extended range? What's a good frequency cut-off to remove rumble but preserve a punchy low 'B'?

BTW - I've been looking at a Tech21 VT Bass DI which also has a low-pass filter but I'm not sure how well it works (on a 5).

[chris_b]

+1 Ted, I think we're wrong to focus on bass frequencies. How low can your rig go, etc.

The emphasis of most recorded bass is in the mids and low mids so IMO we need less bass and more mids to get a better live tone.

I never have boom or mud in my sound and I put that down to my Berg cabs tightly controlling the bass frequencies.

[Guest bassman7755]

[quote name='visog' timestamp='1432220839' post='2779357']
Interesting... presumably this works for 5 & 6 strings too where presumably, there's more rumble? Anyone vouch for positive or negative results on an extended range? What's a good frequency cut-off to remove rumble but preserve a punchy low 'B'?

BTW - I've been looking at a Tech21 VT Bass DI which also has a low-pass filter but I'm not sure how well it works (on a 5).
[/quote]

My old amp (QSC) had switchable 25 and 50hz HPF, neither audibly changed the sound much even with a healthy amount of bass eq boost when using my 5 string, both settings however removed a lot of visible cone movement in the speakers which was presumably caused by sub sonics and so probably best removed.

Also I seem to get copious amounts of "bass" from my RH450 which supposedly has a 70hz HPF

Edited May 21, 2015 by bassman7755

[paul_5]

My current head (SWR SM400) has a 'Bass' control (preset to 30Hz) and I tend to roll it back from noon (no cut or boost) to roughly 8 or 9 o'clock.

[BigRedX]

[quote name='visog' timestamp='1432220839' post='2779357']
Interesting... presumably this works for 5 & 6 strings too where presumably, there's more rumble? Anyone vouch for positive or negative results on an extended range? What's a good frequency cut-off to remove rumble but preserve a punchy low 'B'?

BTW - I've been looking at a Tech21 VT Bass DI which also has a low-pass filter but I'm not sure how well it works (on a 5).
[/quote]

I'm a strictly 5-string player. The Thumpinator removes mostly frequencies that are below human hearing threshold. As others have said this stops a lot of the visible movement of the speaker cones but you still get the same sound but with more power since you're not wasting it on frequencies that can't be heard.

[dincz]

Much the same experience here. My channel strip has a 75Hz (12dB/oct) HPF and to be honest it barely affects the sound of my bass while keeping out the nasty subsonic stuff.

[visog]

[quote name='dincz' timestamp='1432230308' post='2779521']
Much the same experience here. My channel strip has a 75Hz (12dB/oct) HPF and to be honest it barely affects the sound of my bass while keeping out the nasty subsonic stuff.
[/quote]

Interesting. A low 'B' has a frequency of 31Hz so in theory the channel you mention should rip the fundamental right out of it? I know that our ears work more off the overtones to deduce the actual note played but even so, it's slightly counter-intuitive (to me at least) to filter out frequencies higher than 30Hz?

[Guest bassman7755]

[quote name='visog' timestamp='1432231562' post='2779544']
Interesting. A low 'B' has a frequency of 31Hz so in theory the channel you mention should rip the fundamental right out of it? I know that our ears work more off the overtones to deduce the actual note played but even so, it's slightly counter-intuitive (to me at least) to filter out frequencies higher than 30Hz?
[/quote]

Try running this with settings 100/30/30 into your amp.

[url="http://onlinetonegenerator.com/frequency-sweep-generator.html"]http://onlinetonegen...-generator.html[/url]

Very instructive.

(works on android phones as well)

Edited May 21, 2015 by bassman7755

[dincz]

[quote name='visog' timestamp='1432231562' post='2779544']
Interesting. A low 'B' has a frequency of 31Hz so in theory the channel you mention should rip the fundamental right out of it? I know that our ears work more off the overtones to deduce the actual note played but even so, it's slightly counter-intuitive (to me at least) to filter out frequencies higher than 30Hz?
[/quote]

I play only a 4-string but even the fundamental of the low E should drop almost 12dB with the filter on.

I agree that it seems counter-intuitive. I was originally planning to mod the filter to operate
at 40Hz but after hearing how little tonal difference it makes at 75Hz, decided it wasn't worth bothering.

[Mottlefeeder]

I designed a small 1 by 10 for busking with a 5-string (low B), and the compromise to get it small was a cabinet resonance of 55Hz. I use an HPF set to 55 Hz to make sure I do not overdrive the speakers, but I still get plenty of low end and low end clarity from it. At the Moffat bass bash a heavy metal player was playing an F below bottom E through it, and you could hear the note without the mud that you usually get when speakers struggle to get that low.

Another benefit is that you use less power if you filter out the fundamental - my battery rig lasts about 25% longer with the HPF than without.

For those of you who are interested in getting an HPF, Fdeck over on talkbass designed one, but only markets it in the USA. There are threads on this forum about getting a friendly talkbass member to buy there and post it to you, or alternatively, someone in the UK is making them to Fdeck's design.

David
[Edited to remove rogue emoticon]

Edited May 21, 2015 by Mottlefeeder

[tedmanzie]

[quote name='Mottlefeeder' timestamp='1432234492' post='2779605']
I designed a small 1 by 10 for busking with a 5-string (low , and the compromise to get it small was a cabinet resonance of 55Hz. I use an HPF set to 55 Hz to make sure I do not overdrive the speakers, but I still get plenty of low end and low end clarity from it. At the Moffat bass bash a heavy metal player was playing an F below bottom E through it, and you could hear the note without the mud that you usually get when speakers struggle to get that low.

Another benefit is that you use less power if you filter out the fundamental - my battery rig lasts about 25% longer with the HPF than without.

For those of you who are interested in getting an HPF, Fdeck over on talkbass designed one, but only markets it in the USA. There are threads on this forum about getting a friendly talkbass member to buy there and post it to you, or alternatively, someone in the UK is making them to Fdeck's design.

David
[/quote]

Sounds interesting thanks. I also emailed sfxsound to see how much a custom high quality variable hi-pass filter pedal would work out at.

[chris_b]

[quote name='visog' timestamp='1432231562' post='2779544']
Interesting. A low 'B' has a frequency of 31Hz so in theory the channel you mention should rip the fundamental right out of it? I know that our ears work more off the overtones to deduce the actual note played but even so, it's slightly counter-intuitive (to me at least) to filter out frequencies higher than 30Hz?
[/quote]

Your logic is not correct. Check Ampeg cabs. At normal volume levels most are only rated down to 40ish hz including the 810. That doesn't seem to impair their E and B string handling capabilities.

[Ziphoblat]

Think of your string as a waveform. The fundamental frequency has a wavelength twice the length of your string. In other words, it is the loudest at the 12th fret (the peak), gradually fading in both directions to nothing at the bridge and the nut (the node). Now picture your pickup placements relative to this. The bridge pickup is barely away from the node, and the neck pickup isn't doing much better (unless you're playing an EB-3 ). The point being that your pickups are already attenuating the fundamental frequency enormously, to the extent that the fact that you perceive that note is already almost solely down to psychoacoustics. Cut out the fundamental altogether, and what difference do you hear? In the vast majority of cases; none.*

Reproduction of fundamental frequencies as a measure of the performance or viability of a cabinet is, I feel, entirely arbitrary, and usually the product of misunderstanding. It can be useful to know how low a speaker cabinet can go +/- 3dB as this offers an insight into the ability of the cabinet to handle low frequencies in general. The fundamental frequency of your lowest note is largely irrelevant.

I personally prefer the sound of a bass high-passed somewhere in the 60-80 Hz region. It's something which a lot mix engineers will routinely do to a bass guitar track, to my understanding. Almost all of the content down there is useless mud. Removing it changes the sound of the bass very subtly but has a very pleasing effect on the overall mix, in both a live and studio environment.

[size=2]*Disclaimer: It's been a while since I've done this physics stuff, it's quite possible that some or all of my understanding is wrong. Apply a pinch of salt.[/size]

[nugget]

[font="Calibri"][size="3"][color="#000000"]http://basschat.co.uk/topic/232358-fdeck-clone-made-in-uk/http://basschat.co.uk/topic/232358-fdeck-clone-made-in-uk/[/color][/size][/font]

These really work well

[jonnythenotes]

I use a couple of Ashdown 4x8 neo cabs.... When I first started using them, I was convinced that they could not handle the really low notes on my five string...( it turns out they can, quite easily.) Anyway, By removing a lot of the really low stuff, I found that it massively improved the ability of the bass to cut thru, and also, the speakers were more responsive and sounded clearer and livelier as they weren't faffing about trying to handle unnecessary super lows, and the speaker excursion time, or whatever its called, seemed quicker in its return, and ready for the next note or signal to hit it. I have probably imagined some of this, but there is without doubt, significant benefits in taking away some of the really low frequencies. I don't know all the technical reasons as to why, but it is exactly as the thread header says....Less bass = more bass.

[Guest bassman7755]

Its also worth noting that most bass cabs start to attenuate lows below 90-100hz so the difference you are hearing in bass response between a cab that goes "down to 35hz" vs one that only "goes down to 45hz" is likely more to do with the former being more efficient in the 60-90 ish hz range than the fact that its response extends lower.

Edited May 22, 2015 by bassman7755

[Truckstop]

I have been cutting everything under 100hz for the last year or so and its made such an improvement to my live sound. The whole band sounds better, I never have boom issues, I get more volume out of my rig, there's a clearer balance between all the notes on all the strings and the clarity is unreal.

[visog]

Good thread - v. educational. Will investigate the High-pass filter on the VT DI further then as it sounds like 'psycho-acoustics' will preserve my 'B' and possibly enhance the overall sound by reducing the workload on the speakers.