Best way to low-pass filter line level?

[tsvisser]

I am trying to find a way to low-pass 1 mic and mix it together with another full range signal. My location mixer has zero EQ. This needs to be a hi-fidelity solution, so using one of the effects boxes that LPFs a signal is not really an option.

My ideal performance characteristics would be something like a mild 1st order crossover at about 80Hz. If it has to be 2nd order, so be it.

I could use the EQ on a Millennia STT-1, a combination of high shelf, a wide-Q parametric, and then a narrow-Q parametric to more or less low pass everything, my concerns are the potential phase mess that using such filters could have to the signal, the fact that higher frequencies would not be totally filtered, just attenuated, and the final issue that there would be some anomalies.

I could also use a traditional electronic crossover, such as the Bryston models, but they are pretty expensive.

PSC makes an in-line filter for mic level, which would be just fine, except its filter frequency is much higher than my application.

Does anyone know of a high quality outboard piece (prefer battery / DC power option, but not mandatory) that has a simple LPF with a selectable frequency from around 80Hz to 120Hz?

Or an in-line mic level filter like the PSC but with lower F?

It sounds like I just need to build an active crossover and put it into a project box, but because this is not speaker level and requires input and output buffers, it may be stretching the limits of my electronics capability, since its not just a simple RLC network.

[NorseHorse]

Just to be clear...

Are you looking for a low-cut filter?

Or a low-pass filter?

[tsvisser]

low pass.... I want the frequencies up to about 80Hz, then a 6db/octave attenuation above that, or you traditional 1st order crossover performance.

[Jim vanBergen]

Originally Posted by tsvisser

low pass.... I want the frequencies up to about 80Hz, then a 6db/octave attenuation above that, or you traditional 1st order crossover performance.

Wow, I was certain you really wanted a HPF, but no, you really want a LPF. Yes, a crossover is ideal, and after that, a digital drive device like BSS or XTA might be easiest. But none of these come in an XLR barrel. Have you considered just using a clean parametric equalizer, like a Meyer CP10 or Klark-Teknik 410? Just thinking about options.

Cheers,

JvB

[tsvisser]

I will try the parametric . shelving EQ route first and see if it meets my needs. If not, I'll try my hand at a passive line filter of my own design, since it is an easy and cheap experiment. Barring that, looks like I will be in the market for an active crossover some time in the near future. Thanks.

[tsvisser]

finally found what I was looking for...

Schoeps LP 40 U
SCHOEPS acc-gen-electric