EBS Bass IQ Triple Envelope Filter Bass PedalEnvelope filter is in excellent condition. Works properly and fully tested. Comes with original box The EBS BassIQ Triple Envelope Filter delivers big, bad, and luscious funk bass sounds. It gives you 3 different modes to choose from: Hi Q, Up, and Down. Up mode is the classic envelope filter sound while Down, as you'd guess, is the opposite; it reverses the attack of the filter. Hi Q delivers auto wah type effects that react to your playing touch.