funkle

The Puma 900 I run has probably the world's most useless bass boost knob - centred around 30 Hz. However, a smidge of cut makes the sound in many small rooms much better - a sort of ersatz HPF. Boosting there is not that useful IMO though EDIT: In fact, the more I think about it, it's probably quite a dangerous knob. A noob player looking to get more bass out of a cabinet not designed for it could easily put quite a lot of power through the woofer, if the maxed out that particular knob. Alex will know more about the power tolerances and voltages etc, but I imagine enough low end boost at high power could damage a woofer.

I'd agree. It's a useful tool, assuming, like most tools, you know what you're doing with it, and you understand your signal chain. Like Alex says, often there are HPF filters in there anyway.

[quote name='alexclaber' timestamp='1503657141' post='3359999'] I like high pass filters for taking out the pointlessly low stuff that just sucks amp power and wastes cone excursion - but if a cab is well designed then it shouldn't need highpassing to remove audible lows that are part of the sound of bass guitar. I suspect a lot of the popularity of highpass filters is because bassists going tiny with rigs often end up pushing the speakers beyond what they can handle, which messes with the tone. Remove the deepest lows and that lets the cabs work as intended. I think there's also a a technique issues - you are in control of the sounds coming out, if you don't want deep rumble then don't play like that! But that woolliness that can happen, I don't think that's always (or even often) because of the presence of the deepest lows but because making those deepest lows is forcing the woofers to over-excurse and thus their transient response is no longer half as good as it should be. There aren't many bass amps on the market that let the lowest lows through anyway, almost all have some degree of highpass filtering built in! [/quote] Sounds sensible to me. I have tested in my home studio about what frequencies I like in bass and, of course, done the same live. In the studio, turns out anything below 50Hz is basically non-essential for my listening pleasure (so low B fundamental and even low E fundamental aren't that important), so I high pass stuff in the studio at 50Hz for bass, as a rule. I really like bass sounds with a boost at 80 - 100Hz, especially Jazz type basses. Live, too much bass seems to swamp the mids/clarity (of course). The John East preamps need some care with the bass boost, as the higher you turn it, the lower the frequency of boost goes. Some rooms have resonances that can be a problem at anything up to 100Hz, and the Zoom pedal HPF is helpful in those situations. I don't like cutting signal at that frequency, but it has rarely been needed. Apart from that, the tone is mostly in your hands anyway

[quote name='alexclaber' timestamp='1503514143' post='3358886'] Hopefully months rather than years! But we haven't done this before and no corners will be cut so it could take a long time... [/quote] Good luck. Your cabs have been labours of love; I have no doubt of your ability to come up with an amp that matches the passion for the cabs.

I think an adjustable HPF is essential for a cab with a big low end. I'm not sure if the slope of the shelf needs adjusted, just the ability to move the cutoff frequency and db of cut. It just needs to be a steep cutoff in the first place. I use the one built into the Zoom B3 and MS60 pedals. It's in there under the Fishman Preamp emulator - Ac Bs Pre. Works exactly the same as the Fishman. Plonk one in the front of the signal chain, leave all other EQ alone before adjusting, find the sweet spot where the signal sounds right/bassy enough but removes any low end woof/boom from the sound, and then you can tweak the rest of the EQ to your liking. That's how I use it with the Fearless stuff anyway. The F112 has a huge low end, arguably more than what is needed for most gigs. Which begs the question...why carry a cab with that much low end, only to have to remove it with EQ? lol

Sold Dean My Modulus Q5. Very straightforward - easy communications, quick payment. Deal with in confidence!

I'm seeing him this Wednesday at the Edinburgh Fringe. Looking forward to it.