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High Pass Filter (HPF) and Low Pass Filter (LPF) Mega Thread

I can shed a bit more light on this. I have two circuit designs. Series 1, 2, and 2M all have the same basic filter circuit, which is 12 dB/oct with the knob controlling the -3 dB point. It's intended to be "Butterworth" aligned, meaning that it's as flat as it can be above the corner frequency, without having a "hump" in the curve.

The Series 3 circuit is actually two 12 dB/oct filters chained together. One of the two filters is variable, and the other is fixed. When the knob is set to the lowest frequencies, the two filters function together as a 24 dB/oct filter with "Butterworth" response. When you turn the knob, the first filter starts moving up in frequency, and the second filter stays put. So a portion of its curve is 12 dB/oct, and then it transitions to 24 dB/oct around 35 Hz.
So, I've been to your 'site, and unless I missed it, do you sell just a simple variable HPF (without preamp)?

I'd like something to insert in my signal chain between my effects board and Ampeg SCR-DI/Tronographic Rusty Boxx preamps...

Feel Free to PM me as well.
 

@Al Kraft replies:
I have only experienced the (Audiokinesis)T version cabs and was instantly sold on the sound. Given Duke's (@DukeLeJeune ) inherent tuning for more of a focus at the first harmonic than the low fundamental, I think the taller cabs strike a perfect balance in the low register - very rich and full, but still tight.

It immediately reminded me of the Berg CN cabs and how I usually dial in a HPF to get a clean, full, punchy low end.

Duke's cabs take EQ well and can boom if you want that, but to me the natural voicing is simply perfect for slotting into a mix and keeping the mud out of the equation.
 
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@s_wood replies:FWIW I used to own a M9 Carbine, but I replaced it with a D800+. I agree with Wasnex’s observation above that the native voice of the D800+ is somewhat more neutral than that of the Carbine, which too my ears was a bit too aggressive in the upper mids. That said, the EQ options on the D800+ (especially the voicing knob) are very powerful and musical, and will get you very close the the Carbine’s sound.

And the HPF on the D800+ is incredibly useful - so much so that I now can’t imagine gigging without one in my signal chain somewhere.
 
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@byacey replies:
EQ in the right hands can make all the difference in the world.

Brute force volume may well make you heard, but at the expense of being too loud in the overall mix.

The trick is to find a sonic niche in the audio spectrum for each individual instrument or voice. This becomes challenging when a number of instrument / voices are all competing for the same sonic space.

I find the worst offenders with respect to bass are guitar players who dial up excessive amounts of bass on their guitar rig because they don't know their place in the mix, or roll in the context of the band.

One instance I found this so annoying that I told the would-be guitarist that since he wants to play bass so badly, "Have at it; I'll just go take a break, sit back and listen."

In this case, the high pass filter should have been used on the guitar.
 
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For bass guitar application its mainly the emerge of transient noise WHY we should protect our system with a HPF.

For left hand of a keyboard player the emerge of transient noise is widely predictable but its not predictable for a bass guitar player, its not predictable even for professional players!

On FOH side its an (almost always) easy job to fix too much of transient noise coming from the keyboard with some EQ adjustment but, its a very hard job to fix too much of transient noise coming from bass guitar ONLY with EQ.
 
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For bass guitar application its mainly the emerge of transient noise WHY we should protect our system with a HPF.

For left hand of a keyboard player the emerge of transient noise is widely predictable but its not predictable for a bass guitar player, its not predictable even for professional players!

On FOH side its an (almost always) easy job to fix too much of transient noise coming from the keyboard with some EQ adjustment but, its a very hard job to fix too much of transient noise coming from bass guitar ONLY with EQ.
IME, transient noise is one reason. Bad venue acoustics, boomy stages, bass tone and fine tuning the mix, especially what is sent to the FOH, are additional reasons.

Also, piano bass keys freqs can certainly impact bass guitar freqs, so using an HPF to significantly reduce the overlap can help clean up a mix.
 
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Maybe there is something wrong with me.
But I find the notion of using a HPF ridiculous.

Every bass player or sound guy should know how to use an eq or turn down the lows.

There are 2 important reasons for using a proper HPF.

The first, to prevent damage to speakers from high powered amps sending frequencies below the cabinet's capabilities (where power handling falls very quickly).

The second, to roll off low frequencies for tonal or clarity reasons.

Both of these applications use a totally different kind of filters than simple tone controls and eq, in fact, the slopes and Q's are generally MUCH higher.
 
:D

Breath into a paper bag.

If that doesn't help, huff ether.

Don't forget to place an open tube of model glue in the bag.

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