Using subwoofer with large main speakers

[Godzilla]

I built two very large main speakers and find the system performs better when using a powered sub. Originally, i thought large mains would eliminate the need for a sub. Of course i am keeping the sub and enjoying the warmth and punch it adds. Is anyone else also using a sub with large main speakers? Now i am wondering about building an even larger sub to get even more performance.

Godzilla

[Thawach]

Godzilla u wii get more performance with the lower frequency more than the big front speaker. but the sub woofer driver should be respond lower than the front woofer drivers./

[GM]

Originally posted by Godzilla

Is anyone else also using a sub with large main speakers? Now i am wondering about building an even larger sub to get even more performance.

I use to run four subs even though the mains were tuned to 40 Hz since you want the mains BW to overlap the sub's somewhat and multiples to both increase acoustic efficiency down low and help somewhat with room modes, so recommend you do likewise rather than going for one big one.

GM

[Godzilla]

So two powered subs are better than one? My room is pretty small. How will two subs sound different than one?

[Thawach]

hi

So two powered subs are better than one?

the sound is bigger than one.

How will two subs sound different than one?

i remember that the sound is wide more than one.

My room is pretty small

it's sure to has the poor deep bass.it's like a big subwoofer driver set in the pick up car. it's difficult to hear the deep bass.

[Cal Weldon]

I run a 15" powered unit with 15" coax PA drivers to help with the bottom end. If I didn't, I'd really need to EQ.

I am of mixed minds about using more than 1 woofer unit.

[Brett]

Originally posted by Godzilla
I built two very large main speakers and find the system performs better when using a powered sub. Originally, i thought large mains would eliminate the need for a sub. Of course i am keeping the sub and enjoying the warmth and punch it adds. Is anyone else also using a sub with large main speakers?

Makes sense to me, especially if you're crossing to the sub higher, relieving the mains of some of their LF duties with the benefit of lower distortion.

With the new system I'm building the mains will be set to 40Hz via a Linkwitz xform for low level/late night music, and 60Hz and subs below that if I want to crank it. Perhaps I'll find a preference for the subs on always. Time will tell. When I added the LABhorns under my KHorns I thought I'd only use them for movies, but it turned out to be everything.

Originally posted by Godzilla
Now i am wondering about building an even larger sub to get even more performance.

Originally posted by Godzilla
So two powered subs are better than one? My room is pretty small. How will two subs sound different than one?

Build some more rather than one large one. It'll make it easier to spread out room modes. Look fro Toole's papers on the Harman site regarding subs and loudspeakers in rooms.Earl Geddes mentioned earlier today that he may post a how-to setup piece on this subject in the near future.

[GM]

Originally posted by Godzilla
So two powered subs are better than one? My room is pretty small. How will two subs sound different than one?

Yes, all typical rooms have standing waves and there's no place in a room where a ~flat response can be had with just one sub, so a 'stereo' pair is considered the absolute minimum regardless of room size. Really, due to room modes extending up into our acute hearing BW, smaller rooms typically need four or more subs spread around as does room ratios that fall too far outside a golden or acoustic one: http://www.harman.com/wp/pdf/multsubs.pdf

Since down low the WLs are long enough for fairly widely spaced subs to sum, they can be smaller with the trade-off of course being more expensive than a single large one due to the extra drivers (and plate amps in some apps).

GM

[Godzilla]

So two powered subs - one each next to or near my BIBs - would sound better than one sub all by itself. Or would one of the subs need to be in another part of the room for optimal performance?

http://www.zillaspeak.com/systems.asp

I have an old ACI sv12 sub. I understand i can buy another one from Meniscus Audio. Maybe two of these would really round out the already amazing sound i am getting from my stand alone BIBs. Might as well get the most performance i can while i am still alive and well! I want to treat myself really good since my operation. Do the subs have to be the same? Or can they be different. Say and 8 inch sub in a small box and a 12 inch sub in a big box. Or am i thinking about this too hard and being wasteful?

Godzilla

[GM]

Actually, per the Harmon paper, Dr. Geddes in another thread and numerous other papers, DIYers, subs near/next to the mains is almost never the best compromise positions and why wide BW mains and separate sub systems are preferred.

No, they don't and often need to be different since they're being used as much for acoustic room correction as for bass extension, a point I've periodically made. Still, unless you map the room to determine what's needed it's best to err on the conservative side and at least use the same size and adjust the tuning/level as required.

GM