15" vs 18" subwoofer - which to buy?

Porschecab: I have to agree that two subs do sound better than one if you can afford it and can place them. Two subs smooth the room response, that is why big line array speakers also provide the same benifit.
Otherwise your suggestion about one properly calibarted (aka Velodyne or other mic/eq sub) makes the most sense. But for Home Theater I would love to have two DD18's but my 2 channel takes priority and buying another Wilson Watch Dog is out of my budget right now.

Chris

Good day folks; I also am running two Bag End Infrasubs using my Plinius M8 preamps dual rca outs at line level. My system goals were to augment a full range speaker with a seemless blending full range fast, tight response along with left to right drum kit recreation.I also use Plinius SA102s in xlr dual mono with Mirage OM6s with a claimed response of 18 htz +-3db, Im running lots of power across my front two channels and with a Plinius P8 on my center channel another 400 watts through the use of my transparent ultras and splitter.Now while some may claim overkill Ive found all this power is not corrupting anything in my listening,actually quite the opposite as my significant other listened for nearly four hours one evening when we played Fleetwood Macs "The Dance" among others and Mics use of the kickdrum was recreated through my Bagends wonderfully with my Mirages midrange reponse and lower dual eightinchers recreating the drum kit, the Bagends are so seemless that the only time you know there on is if you unplug them, then instantly ambient spatial cues just disapeer and the stage becomes noticably more less real, somehow they impart a realism to the recorded event that allow one to "see" into the recording.Also a great reproducer of pipe recordings as listening to Saint Saens Boston Symphony on Living Stereo SACDs the shudder of the organs albeit very subtle again imparts that reality to recordings that get lost with just about any single full range speaker. I also have a Mirage BPS400 for huge .1 effects and yes all subs working in 5.1 dolby and dialed in low prefering to use my ear although I have measuring devices that assist I prefer my own ears when dialing in system. So most of my need for my Bagends were simply to augment my Mirages full range response and help provide more subtle spatial cues; that surpisingly found when adding my second sub.Its my belief that theyre are many great and badly designed products out theyre and this is one of the best for musicality purposes, hence the BPS400 is likewise in the effects camp, choose wisely and enjoy. Regards Tim W.

Bagend is the only way to go, the bagend infra sub 18 is not a sub you look at and say that's a great looking sub. The velodyne is a looker, but in sound!! does not compare to bagend. When you put one or two in your system you will "here" why it is so special. Dave

Dgw7000

Did you hear the DD-15 or 18? What do mean when you say "does not compare"?

Tim

Yes, I have heard both the dd 15 and 18 at my local hifi house, I feel the Velodyne is great for HT. I like the dd-18 much better than the dd-15, but for 2 channel the bagend with it's time alignment just becomes part of the music. The infra sub 18 blends so well with anying speaker, your speakers just open up and the bass is just there, so tight so controlled. When you turn off the bagend you say to yourself holly shit!!! This is what really good bass is all about, the music becomes very real. I would say the bagend is the most musical sub I have ever heard. The Vel. to me is one notey!!! Not Musical, but I love the way the Vel. looks!!! The sound is what really matters though!!
I also like 2 REL strada's, which at one point I had in my system. In the end the 18 inch bagend is the only way to go, if you can get it past your wife as your lugging in the room!!!