Getting more bottom end in the mix has been the holy grail for many producers and there are various ways to do it. One way is to use a hardware enhancer specifically designed for the job. dbx, Waves and Aphex all have products that spring to mind.
Peavey has also had the Kosmos available for several years but it's now available as the Kosmos V2. The unit is designed to be used in the studio either on individual tracks or a whole mix. It can also be used in a live context to enhance the sound coming out of a PA system.
Peavey describes the Kosmos V2 as a sub harmonic and stereo enhancement system that drastically improves the listening experience in any space. There are two processes that the Kosmos carries out simultaneously.
The first is low-end processing: it analyses the bass in the source material and generates additional phase-synced low frequencies an octave below it. The amount of low end added is controlled by a rotary knob and there are two preset ranges for the tracking with no processing occurring outside the defined range so that only bass content is effected.
In default mode, the sub-harmonics closely follow the envelope of the bass signal but if the Low Damping switch is engaged, the harmonics don't follow the envelope quite so tightly and ring out with less damping.
The bass can be further enhanced with a low frequency knob that can be used in conjunction with the sub-harmonics or on its own to boost bass. The stereo enhancement process is carried out with a High Frequency control designed to boost the top end and increase stereo width simultaneously.
The Kosmos V2 has stereo operation but can be used in mono and has an additional sub output on 1/4-inch jack that can supply a line level signal to a subwoofer. You can remove the sub-harmonics and low frequency effects from the main outputs and route them solely to the subwoofer output, which is really useful.
In studio use, the Low Frequency knob is very useful for adding power and thump - the specific band of bass frequencies that it works on being just right for kick drums and basses. The sub-harmonic processing also works well, adding really earth-shaking bass that would sound great through a powerful sound system in a club or live venue.
It has to be said, though, that it's difficult to judge just what the effect is in a home studio context using medium-sized near-field monitors that don't go down that low, so it may be better to err on the side of caution. If you put a sound, perhaps a bassline, through the Kosmos you can always record just the bottom end enhancement onto a spare track via the subwoofer output so you can choose how much of it to use in the mix.
Tweaking the High Frequency knob racks up the psycho-acoustic effect and your top end will come through prominently with extra clarity. This can certainly liven up drum loops, especially when combined with a bit of the low frequency boost to bolster the bottom.
It's also pretty good for drawing vocals to the front of a mix too but the promised stereo width enhancement is subtle to say the least.
In summary, The Kosmos V2 will beef up the sound of a PA and has several applications in the studio. It might be just what you need to significantly transform your bottom end and/or enhance the top, be it on a whole mix, group of a mix or a single instrument.