Two subs vs. one? My last question... (1 Viewer)

[Mark.Louis]

You guys have been very helpful in getting me started on my first DIY project. My last question is whether or not one sub will work in my room, vs two. I am looking for a sub that produces tight, non-boomy bass suitable for audio amplications, but also can get low to make the room rumble during home theater applications (I am not asking for much am I?). The room it will go in is 20' x 15', with 12' ceilings. Further, one of the 20' sides has no wall...it completely opens up to the kitchen and breakfast area and hallway...typical of Florida designed homes. Thus, I have a lot of space to fill with bass.

The folks at Adire suggested that I use one vented box with Tempest Driver, using the Adire Alignment. Their white paper states that this SW is 37.5" tall. This will not do with the spouse - TOO BIG!!! I was "hoping" to use a sealed design to save space, but Adire suggests it won't reach low enough or loud enough to fill the room.

I was wondering whether I could get the same or a similar result using 2 SWers, possibly 2 ported Shivas or 2 sealed Tempests? Would this give me the same effect, or maybe even better? Or, could I get away with one sealed Tempest? Any other ideas?

Any thoughts from you guys would be extremely helpful. I'll repay everyone by posting what will surely be hilarious/pathetic construction figures in this forum.

 

[Dave Milne]

Mark,
You can make the enclosure any shape you want, as long as the internal volume is the same. If two smaller enclosures are preferable, you can probably get similar results with two sealed tempests, but you'll need a linkwitz transform or other EQ to get the extension of the vented alignment.

 

[George W]

Mark,

if small size is what you want and your budget can take it, you might want to look into the new "Tumult" that Adire is putting out. It's designed for prodigious output in small boxes, but it needs a lot of power behind it.

 

[Javier_Huerta]

About using two different subs - is there any difference between having the drivers share the same airspace vs. building two different enclosures?

I can't figure this riddle out. I'd think it's a lot better to have the drivers share the enclosure... but it's just a hunch.

 

[Dave Milne]

Javier,
Two drivers in one big box are identical to two boxes -each half the volume. You need to use two ports or double the port area with one big box -just as you would have with two boxes. Put another way, if you built a big box with a driver and a port at each end you could put a partition in the middle and it wouldn't make any difference.
So I would go ahead and make two separate boxes. It will give you more placement options and the smaller panels will reduce wall-resonance problems.
By the way, I agree with George W on the Tumult --excellent driver for Stygian bass in a small enclosure, but you do need some power. I'm thinking of a pair of Tumults -each in 60 liter sealed boxes (with LT) driven by a Crown K2.

 

[Dave Milne]

Javier...one more thought...

Two subs in different parts of your room will cause some additional peaks and nulls beyond what your room is already doing to you. Be prepared for some lengthy measurement and placement-tweaking sessions and you may need to resort to a BFD to help flatten it out.

This is why many experts suggest stacking both subs in one corner. It reduces the number of modes and you get some "free" boundary gain in the process...

 

[Javier_Huerta]

Dave, I have experienced firsthand the placement of subs in different parts of the room. It's a nightmare. All the peaks and nulls are enough to drive you nuts!
I am about to start to build a pair of 15" subs, which have a lot of sensitivity (96 dB), so I thought building a *HUGE* enclosure might be overkill for the room I'm going to put it in. So I was thinking about building two smaller boxes and decide on-spot whether to use one or two subs (I can always use the other sub in another room).
It's a good thing I found out this thread. Now I'm pretty sure I'll build two different subs and, if I need to, stack them in the corner of my room. Thanks!!!!

 

[Carl Mulder]

don't waste your money, i'd just go for one powerful sub. Paradigms high end subs sound great, do your self a favour get a demo.

 

[Ben Ven]

Check this link out. I am running 2 subs in my HT at the moment. With my crude measuring device (Radio Shack SPL Meter), 2 subs in the locations I have now certainly seem to smooth out the FR and sound less localized.
http://www.harman.com/wp/index.jsp?articleId=1003[/url]

 

[Javier_Huerta]

don't waste your money, i'd just go for one powerful sub. Paradigms high end subs sound great, do your self a favour get a demo.

edit - thought the comment above was for me.