Feature:
Crossover from 50 to 130hz, suggested is 80. Minimum volume on the sub (-30db) is awfully loud. -60db would have been a better choice.

Quality:
The first one I purchased had a bad output, the crossover frequency was virtually unresponsive, and the volume knob distorted quickly. I took it back and exchanged for a new one, which corrected these malfunctions plus provided a much smoother sounding sub.

Value:
Don't know if there's a better cheap sub out there. I like it because it matches my monitors.

Desirability:
Subs have always been a "wow" item. It's huge and it thumps. I don't know how I've lived so long without it.

Sound:
This sub helps out the rp8's significantly in the low end. Bass is smooth and full, no boominess.

Ease of Use:
I'm inclined to think that those who have had issues with this sub are not setting it up correctly. There are a few keys to making this sub sound good. 1) Location: I prefer mine at floor level, in the center of my monitors. 2) Level Matching: sub's minimum volume is designed for a loud volume from your monitors. Turn your monitors up until you get a good mix between monitors and sub, then reduce your output volume from the signal source. 3) Sound transfer dampening: I folded up a blanket about 3 inches thick and set the sub on it. Drastically improved the sound.

Support:
Have never dealt.

Overall:
I was having a difficult time judging bass lines, toms, and kick in my mixes. This sub makes it a lot easier. I do a lot of casual listening as recording is merely a hobby of mine, and sub is very impressive for that also.

Feature:
Some of the best things about this is its SOLID and has different input/output jacks.

Quality:
built solid; no seams except the back where you could service the unit.

Value:
I think it's worth what you pay for.

Desirability:
It's a must have for any home project studio; along with any other monitoring system. No matter what the monitor speakers are, without the subwoofer, you'll find you'll be spending more time and resources remixing a final project without the sub.

Sound:
Very clean sub-woofer. Makes a big difference during mix downs for truth response in other players (cars, stereos, etc)

Ease of Use:
plug it in and go. Volume knob on the back of the unit to adjust level of bass (which is very helpful to help you determine where you need to be at when mixing).

Support:
n/a

Overall:
I use this in conjunction with the RP8's. I just got it a couple days ago, working on a project. Without it, I mixed a project using just the pair of RP8s. What I thought had sufficient bass ended up being way too much; even though the RP8s have a great response across the frequency range. I "installed" the subwoofer, mixed and burned a CD, found it alot closer; made a slight adjustment to the subwoofer volume, mixed and done it again; dead on. A DEFINITE MUST.

Feature:
Some of the best things about this is its SOLID and has different input/output jacks.

Quality:
built solid; no seams except the back where you could service the unit.

Value:
I think it's worth what you pay for.

Desirability:
It's a must have for any home project studio; along with any other monitoring system. No matter what the monitor speakers are, without the subwoofer, you'll find you'll be spending more time and resources remixing a final project without the sub.

Sound:
Very clean sub-woofer. Makes a big difference during mix downs for truth response in other players (cars, stereos, etc)

Ease of Use:
plug it in and go. Volume knob on the back of the unit to adjust level of bass (which is very helpful to help you determine where you need to be at when mixing).

Support:
n/a

Overall:
I use this in conjunction with the RP8's. I just got it a couple days ago, working on a project. Without it, I mixed a project using just the pair of RP8s. What I thought had sufficient bass ended up being way too much; even though the RP8s have a great response across the frequency range. I "installed" the subwoofer, mixed and burned a CD, found it alot closer; made a slight adjustment to the subwoofer volume, mixed and done it again; dead on. A DEFINITE MUST.

Feature:
it does have all the features needed, high pass filter for monitors, polarity reverse switch, inputs for any application. i only wish it allowed the signal to pass through to the monitors when it is off. i use it with a pair of Alesis M1Active 520 and they sound great together. most people who dont see the sub ask me, "those things produce that much bass?"

Quality:
built like a tank, heavy, sturdy, and it looks nice

Value:
for 300 dollars i dont think you could get a better sub

Desirability:
anyone with monitors that dont go below 50hz will know that this thing is very apealing, u dont realize what your missing untill u hear this

Sound:
The sub creates very clear bass with very little distortion, hits hard, very natural

Ease of Use:
very easy, run a line to the sub and plug it in. adjust the level (mine is close to -30db) and you are set. for more advanced people buy a decibel reader so that the frequency response is level with the monitors

Support:
never had to use it, product is great

Overall:
i think i will be happy with this for a long while, at least in my project studio

Feature:
Accepts all kinds of different input and output configurations, Balanced and Unbalanced XLR, 1/4", and RCA. Included Removable Grill to protect that yellow beast of a woofer from your feet if you want to keep it under the desk. Manual is usefull, somewhat confusing, but they all are, to some degree, and this one is no worse than any of them.

Quality:
Beautiful, solid, and can't see a single fault.

Value:
For what I pais this is a great deal.

Desirability:
They should make pinups of these things they are so sexy.

Sound:
This is the answer to my prayers. Sounds Fantastic, smooth response with all the punch you need. Matches up with my Alesis M1 Active MK2's nicely.

Ease of Use:
No brainer, Just plug it in and adjust the HP filter to taste and you are set.

Support:
From what I can tell, they are good if you ever need them, even inclluding a Number to call to order the parts you may need to fix it yourself!

Overall:
I'll be happy until it breaks or my hearing is so gone that I can no longer hear it.

Feature:
The crossovers are great

Quality:
It built pretty well

Value:
this is definatley worth what i paid for it

Desirability:
This is a very nice looking beast

Sound:
the sub can distort pretty fast but still sounds exellent

Ease of Use:
this sub was very easy to setup

Support:
Never had to call the product works great

Overall:
Im pretty happy with this product along with my KRK ST6 passive monitors

Feature:
The sub volume never goes to 0. It only attenuates to really low, but never off. I found this annoying.

Quality:
Nice finish, feels solid. It looked better than it sounded.

Value:
For my purposes I could throw $300 into monitors with lower end punch.

Desirability:
Oooo, shiny black and glossy.

Sound:
It seemed middle of the road. I tried pairing this with Alesis Monitor One MKIIs to give some low end punch. Even after lots of tuning, the mixes sounded better with the sub volume turned really really low. It just didn't mix well. I think the best solution for me would be to buy a set of powered monitors with 8" woofers. This would probably give me the low, clear sound I'm looking for

Ease of Use:
Subs aren't too hard to use in the first place.