Low-Level Sub-Sonic Filter

[Drunken.Swagger 10+ year member]

Does anyone have a schematic for a low-level subsonic filter? It needs to have a cutoff point suitable for a box tuned at 33Hz. My amp doesn't have one built in, and I don't want to damage my DD2512's.

Thanks,

-Ryan

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[PaulD 10+ year member]

there is a product called F-mod I think, they look like an elongated RCA plug, they plug inline with the rca's to the bass amp and do the cutoff before amplification.

 

[thch 10+ year member]

I would suggest using winISD to determine options. pre-amplifier options like f-mods tend to have poor slopes. I'm guessing the filters are all overdamped, making them less useful. (eg, the higher slope might be apparent at 5hz, but not at 20hz). winisd provides an estimate of excursion, allowing you to estimate the required filter slope. it also provides options for adding various filters.

it is possible that you can use the HU for this function as well. check to see if you can set the HU up in a 3-way mode or such. you might be able to use the "mid" output (rear?) with a very low highpass and low lowpass, and the "high" with a fairly low high pass. or use some combination of amplifier high/lowpass filters. or use some combination of amplifier filters, hu filters and EQ settings to get the desired effect.