15" vs 18" subwoofer - which to buy?


If price and room space/aesthetics were not a big issue, is there any reason to get a 15" subwoofer over an 18" one? My main issue is not disturbing the neighbors too much. I'm confused about the difference between a 15" and 18" subwoofer. I want to get the best sound quality possible for low-to-medium volume use.

I've heard that an 18" subwoofer can be played at low decibels and provide good bass resolution and fullness of sound, while to achieve the same volume with a 15" subwoofer, the power has to be much higher. So for any given sound volume, the main difference is in distortion- and higher distortion sound may be more obtrusive. Is this true? it seems counterintuitive that an 18" subwoofer could be better for neighbors than a 15" subwoofer.

However, I compared a B&W800 (12") vs B&W850 (15"). I listened from the other side of the store wall (not as thick as my apt), and at minimum levels which I found satisfying for HT, I found the 12" more obvious and 'boomy' sounding while the 18" produced a more subtle (though actually more powerful), lower frequency vibration, like a very low-level rumbling background earthquake. The 15" subwoofer did seem more of a disturbance because of it's 'obvious' sound. However, I worry that an 18" won't even start producing quality sound until a certain volume that was much higher than a 15", and consequently potentially more disruptive for neighbors. Is this true? What is the relationship between subwoofer size, low sound volume, and subjective listening experience?

Unfortunately, it will be difficult to get an opportunity to hear both the DD-15 and DD-18 which I am considering, so I hope someone can help out here.
no_slouch

Showing 3 responses by dgw7000

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
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!!!
The dd18 at the hifi house may not be set up right!!! and I bet over 60% of all people that own the dd18 do not have them set up correcty. That's just another thing that makes the infra sub 18 so great, it's easy to get great sound in any room. The servo chip and eq circuit rob the dd18 from fine detail of music, to much money went into the development of this. Servo's on subs in my view hurt instead of helping the sound. The signal is split apart so many times befor it gets to part of the sub that makes sound "the woofer".
The bagend sub extends to 8hz, even though you can't here it, it allows the sub with it's 400 watt class a/b amp enough headroom a full octave up to handle 16 hz pipe organ. Bagend uses ELF "extended low frequency'. It just works better by getting out of it's own way!!!