High Pass Filters

[Passinwind]

1 minute ago, adi77 said:

Cool, thanks passinwind  

if you decide to make one please let us know

I'll either do it myself or just hand the board layout off to someone else eventually. It'd be a fairly simple perfboard build in any case.

[Guest adi77]

2 minutes ago, Passinwind said:

I'll either do it myself or just hand the board layout off to someone else eventually. It'd be a fairly simple perfboard build in any case.

Just curious, is it kind of like the quad preamps ?

[Passinwind]

4 minutes ago, adi77 said:

Just curious, is it kind of like the quad preamps ?

Had to look that up, but yeah. It's a very old concept that dates to at least the ancient tube design books.

[Guest adi77]

4 minutes ago, Passinwind said:

Had to look that up, but yeah. It's a very old concept that dates to at least the ancient tube design books.

I noticed that the quad eq kind of not only changes the curve but also how in your face the mids are and that can be very useful, my 2 bits, i may be totally wrong.. 

Edited April 5, 2018 by adi77

[Guest adi77]

..of course thats in a stereo setup

[bartelby]

I’ll see what I can do in the morning.

[dannybuoy]

1 hour ago, adi77 said:

Does anybody still makes tilt eq's? (would be cool in a pedal format)

The Diamond and OvniFX smoothie compressors both feature tilt EQs.

[Guest adi77]

1 hour ago, dannybuoy said:

The Diamond and OvniFX smoothie compressors both feature tilt EQs.

Cool thanks dannybuoy i have the smoothie and didnt know that lol, there are no variables though its a fixed setting

[bartelby]

14 hours ago, Al Krow said:

Time to call in the cavalry!

@bartelby Hey buddy would you mind setting up a patch on your B3 with 3 PEQ effects, two centred at the lowest 20Hz setting and one a notch higher at 25 Hz? All three with Q=4 and maximum cut "-20" and posting what that looks like compared to clean by-pass please?

So 3 "pedals' at those settings and all running at the same time?

here's a sequence...

[bartelby]

13 hours ago, Passinwind said:

For extra credit do distortion and signal/noise testing as well...

And for better or worse, yeah, I have done this myself way too many times with my DIY stuff.

This the sort of thing your after , not worked out if this can do signal/noise as it's for room analysis.

Bypassed

1 20Hz PEQ

2 20Hz PEQs

2 20Hz + 25Hz PEQs

Edited April 6, 2018 by bartelby

[Al Krow]

35 minutes ago, bartelby said:

So 3 "pedals' at those settings and all running at the same time?

here's a sequence...

Hey buddy - just excellent thanks! 

So the bypassed bass note above is around 12 to 13dB

The B3n 'Triple' PEQ:

• is providing a circa -25dB (or more) cut in the 15Hz to 35Hz range and a -15dB cut even down to 10Hz. That for me is doing the job nicely in this range;
• we can see that there is also an increasing amount of cut in the 50Hz to 100Hz audible range with each additional effect being layered in - and this is exactly the impact on tone I was hearing and the 'tone trade-off' that I was referring to;
• this is a significantly better profile than the B3n GEQ with "-12" cut at 50Hz;
• a dedicated HPF pedal will have an even better profile along the lines that Passinwind posted above, but is obviously going to cost ££s / take up additional space on the pedal board (whereas an additional effects patch on the MS-60B won't) / potentially add additional noise into the signal chain depending on make / model

One final Q from me for @bartelby - what does the bypassed note look like below 10 Hz? I'm guessing that this falls off down to 0Hz i.e. there isn't too much energy being generated in this very low end sub range? If there is, then that would be another reason to go for a dedicated HPF, as the Triple PEQ becomes less and less effective below 10Hz from the profile above, whereas a dedicated HPF pedal should continue to be effective down at this very low end.

[bartelby]

I don’t know what happens below 10Hz as that’s where the signal generator starts. It’s also below the frequency range of the interface and the B3. So I’d take any results below 20Hz with a pinch of salt really.

[Opticaleye]

Remind me again, what's wrong with the HPF setting on the LO EQ patch on the B3n ?

[Al Krow]

1 minute ago, Opticaleye said:

Remind me again, what's wrong with the HPF setting on the LO EQ patch on the B3n ?

Didn't seem to do anything even when 'doubled up' with two LO EQ patches in series i.e. not delivering anything like as significant a reduction in speaker / air displacement as either the PEQ or GEQ effects. That's just me using my senses rather than measuring it scientifically.

[Skol303]

3 hours ago, bartelby said:

I don’t know what happens below 10Hz as that’s where the signal generator starts. It’s also below the frequency range of the interface and the B3. So I’d take any results below 20Hz with a pinch of salt really.

Absolutely. Anything below 20Hz is ignored in the vast majority of gear manufacturer's tests and quoted frequency ranges. Very difficult to capture accurate measurements that low without some serious kit and an anechoic chamber to work in.

[JohnDaBass]

13 minutes ago, Skol303 said:

Absolutely. Anything below 20Hz is ignored in the vast majority of gear manufacturer's tests and quoted frequency ranges. Very difficult to capture accurate measurements that low without some serious kit and an anechoic chamber to work in.

So we can ignore everything below 20Hz as amps range between 20Hz to 20KHz. Are we all agreed that the amp and speaker will NOT be "trying" to deliver anything below 20Hz? ( so not sapping energy)

 If so what we need now is a shoot- out between

1) PEQ 

2) GEQ

3) LO EQ

4) Ac Bs Pre.

And the winner is-------  ?

 

[Al Krow]

7 minutes ago, JohnDaBass said:

So we can ignore everything below 20Hz as amps range between 20Hz to 20KHz. Are we all agreed that the amp and speaker will NOT be "trying" to deliver anything below 20Hz? ( so not sapping energy)

Is that correct? Or is it just that it's difficult to measure?

7 minutes ago, JohnDaBass said:

 If so what we need now is a shoot- out between

1) PEQ 

2) GEQ

3) LO EQ

4) Ac Bs Pre.

And the winner is-------  ?

For me it's a straightforward choice between PEQ and AcBsPre - I think someone may have posted the curve for AcBsPre already, earlier in the thread, and shown it to be effective. But I don't think the AcBsPre is available on the B3n hence my using (and being happy with) the PEQ on the B3n.

 

Edited April 6, 2018 by Al Krow

[Guest adi77]

isnt that what a transformer does, a very low high pass and a very high low pass?

[dannybuoy]

5 minutes ago, adi77 said:

isnt that what a transformer does, a very low high pass and a very high low pass?

But how low and how high, and does your amp even have a transformer?!

I would not be surprised if there were some amps out there that would try to deliver 10Hz to a speaker. Just because manufacturer specs only quote from 20Hz-20kHz doesn't mean anything!

[Guest adi77]

2 minutes ago, dannybuoy said:

But how low and how high, and does your amp even have a transformer?!

I would not be surprised if there were some amps out there that would try to deliver 10Hz to a speaker. Just because manufacturer specs only quote from 20Hz-20kHz doesn't mean anything!

very 

 

the 135 has one, cant miss it, the class D ones dont, right?

10hz?! i seriously doubt it those are not easy frequencies to push (i have close to zero technical knowledge this is what i feel)

[dannybuoy]

Only real way to test is a signal generator into your amp, then view the visible movement of the cones.

[Skol303]

31 minutes ago, JohnDaBass said:

So we can ignore everything below 20Hz as amps range between 20Hz to 20KHz.

Not necessarily that you should ignore everything below 20Hz… more that it’s very difficult to accurately measure anything at the lowest frequencies, so it’s mostly guesswork. Or rather, it’s even more guesswork than usual.

Speakers are very rarely quoted as being accurate down to 20Hz. But larger speakers will certainly produce low frequency energy sub-20Hz and for this reason - when mixing - I always eradicate everything below 20Hz and sometimes closer to 30Hz (depending on the genre). We humans don’t really ‘hear’ these low frequencies as much as ‘feel’ them - and in the majority of live music settings, much of what’s happening around 20Hz is unwanted rumble that plays havoc with room acoustics.

So my own recommendation would certainly be to kill off everything sub-20Hz as far as possible. Unless you’re running a dub sound system and wanting to forcibly shake people’s fillings from their teeth  

PS: just been reading this thread. Great discussion and detail. Good work!

[PaulWarning]

On 31/01/2018 at 13:42, bartelby said:

Here you go. Top line is off, then Depth 10 - 0 (gain 50, bass toTreble  0) . Looks like once you get down to 15Hz and lower the white noise is a little less stable. 

But it gives you the idea.

EDIT: If you want a bigger chart with compensation for the drop in signal, from 600Hz up, let me know. But that'll take a little while to knock up

 

44 minutes ago, Al Krow said:

Is that correct? Or is it just that it's difficult to measure?

For me it's a straightforward choice between PEQ and AcBsPre - I think someone may have posted the curve for AcBsPre already, earlier in the thread, and shown it to be effective. But I don't think the AcBsPre is available on the B3n hence my using (and being happy with) the PEQ on the B3n.

 

this one? does seem to start rolling off early, if you boosted 100hz with the PEQ would this compensate for this?

[Opticaleye]

1 hour ago, Al Krow said:

Didn't seem to do anything even when 'doubled up' with two LO EQ patches in series i.e. not delivering anything like as significant a reduction in speaker / air displacement as either the PEQ or GEQ effects. That's just me using my senses rather than measuring it scientifically.

But weren't you comparing an HPF at 25hz to a bell curve cut on a PEQ that would start considerably higher? If you compared an HPF at 80hz you would notice it and no extraneous frequencies below 25hz at all. You won't hear much if you set the HPF at 30hz or below just like you won't on a Thumpinator.

 

Oh and btw the gain parameter on the LoEq effect doesn't work in HPF mode on the B3n.

[bartelby]

13 minutes ago, PaulWarning said:

 

this one? does seem to start rolling off early, if you boosted 100hz with the PEQ would this compensate for this?

You can compensate in the AcBsPre itself. Set the low-mid to 100Hz and boost.