The free MH Thump from Metric Halo is not your typical subharmonic enhancer. It can be used to enhance the low end on kicks, 808s and bass but it's capable of doing much more. Previously only available in AAX format for Protools, metric Halo has now made it available for AU and VST formats too. It runs on both Mac and Windows. All that is required is an email address.
From the website:
"Thump is a unique audio processor that allows you to synthesize low frequency audio to add low end to a track or generate another sound entirely. Thump looks at the pitch and dynamics of its audio input and uses this information to control its oscillators. You can add low end to drums, augment a bass or even create synthetic drones. Thump is ideal for beefing up a kick drum, add low end to percussive tracks, re-create classic drum synth sounds, and more."
- Two independent envelope driven oscillators
- Complete control over both pitch and amplitude envelopes
- Wet/Dry control for mixing synthesized sound with the source
- Detailed metering
- A dozen presets included to get you started
- Adjustable UI size / Disclosable Graphs
- MH Preset Manager - Provides cross-platform presets
- Cross Platform - Mac AU, Mac/Win VST & Mac/Win Pro Tools AAX (Native + DSP)
Watch this video of the MH Thump:
You can sign up and download Metric Halo's MH Thump here.
Also take a look at the Metric Halo Production Bundle which is a great set of plugins that I use often. It's currently on sale for $299 (regularly $699).