Very good powered sub!
I purchased this sub from another source and am writing this review since there are no others. in fact, there are very few reviews for these fine speakers on the web...not sure why. my back ground: a part time armature musician, some time dj and regular home theater enthusiast. my quest last year started when i initiated a search for a sub-woofer that would be a perfect balance for all my applications. the first part of this review was copied from an earlier post on another site, followed by an update. well i got the 18sai and calibrated it to my receiver and room with audyssey. much to my surprise, the unbalanced direct connection via 40 feet of shielded coax is producing a very clean signal throughout the full range of the level adjustment. i needed no ground lift. i have this plugged into a wireless controlled outlet, and there is absolutely no pops or clicks when i power it up or down. the first movie i put in was the lord of the rings (return of the king) bluray. the 18sai did a very good job of reproducing the lfe channel once i made a small adjustment (1.5db lfe increase) after audyssey. it does a good job with deep bass, but i am still not quite sure yet how low it will go. i will run some test tones through it when i get a chance. i do know it was rocking the sofa pretty good :d concert blurays sounded quite good as well. i think a an adjustment with the delay settings on the receiver will bring it all together quite nicely, as the music sounded a little "loose" on some discs. i haven't had this out in a live venue yet, but i am confident that it will be a performer. all in all, i am real happy with this unit thus far, and i am looking forward to getting it zero'd in over the next few weeks. since that last review i have had the opportunity to dj with this sub a couple times now. i teamed the 18sai up with a pair of mackie srm450's (original version) in a hall with 75 to 100 people. the mackeis were on the stage and the presonus was centered on the floor at the base of the stage. i had the delay setting set at 2 meters to compensate for the distance offset with the mains. i did not engage the high pass filter on the mains, as i did not seem to have cancellation issues in this particular setup and venue. it did not take long to get everything zeroed in, as i was able to get a good sound right off the bat. i started off with the input gain on both, the makies and the presonus set at the 12:00 position. i ended up with the mackies at 1:00 and the presonus at 3:00. the music sounded great at a medium volume. i was really happy that the 18sai really dug deep with some clean bass. i did not have the volume up loud enough to get that chest thumping bass, but i am pretty sure i had the capability to get there. at the end of the night, the mackies were very warm to the touch, whereas the presonus was lukewarm. i will note a little anomaly (perhaps) i had before my first dj gig. while at home doing a test on the rig at high volume, i noticed that i was clipping the presonus pretty good. i immediately turned it down and it wasn't long after that i had that familiar electrical burnt smell. i was concerned that i may have started to burn the voice coil, but if that was the case, i'm not sure why the over-temperature protection did not kick in. i have not pushed it to that level again and it is performing great ever since. since this sub was still a virgin at any type of high levels, i'm hoping that it was just breaking in, or, if the voice coil did start to over heat that i stopped it before any real damage was done. at any rate, i have had it at some moderate levels since, with a good clean sound and no problems. i really wish i had some experience with some of the other manufacturers subs in this class, but unfortunately i don't. if you are reading this i'm sure you know there are some good units out there. i'm sure i would be satisfied with a qsc kw1801, jbl prx718xlf or an electro voice etx 18sp. for me, this 18sai fits the bill for use in my home theater as well as live gig setups. i'm not sure if some of the others would be able to reach quite as deep. next on my wish list to complement this presonus would be a pair of presonus 328ai tops and a soundcraft ui16 digital mixer that would allow me to walk around the venue and eq with an ipad. hey, what the heck...since i'm filling out my wish list, i might as well include another 18sai.