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Discussion Starter #1
I am kicking around building a sub that will try and serve two masters....music and home theater.
But here in lies the rub: I need at LEAST a 12" subwoofer with a respectable xmax in a ported enclosure to fill a large open living room with 2 story ceilings. But it has always been my understanding that the recovery time on a twelve with a large xmax is poor for music unless placed in a small sealed enclosure . There for a 10” sub driver is preferred for its speed but SPL is given up.

IS THIS STILL TRUE? Hell, it may have never been true but that is what other fellow AIS’s (audio idiot savants) have always told me.

Soooo……are there any 12” drivers available to the DIY world that can provide musicality to match my main speakers but rattle sheetrock off the walls?
If you were trying to replace a JL Audio Fathom F112 (which has become my benchmark) with a DIY project……..could you do it? This sub had a startling amount of bass but still did well when I asked it to play my favorite music. (And DeadSpace was great too)

Recommend a driver to me (if a retailer reads this and thinks they have what I need, then let me know too) so I can get started on research and developing!
 

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"Historically, 10” were the best size sub-drivers for music….Is this still true?"

No, Not any more. just for an example I have an SVS PB13 Ultra, it has a 13.5" driver and does music really well as a matter of fact I have one of those 10" subs you refer to and it did what I thought was a great job with music but the PB13U is even better. The smoothness of the lows below 20Hz is fantastic and is still very "fast" at the punchy bass in the 40Hz range.
 

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There is no truth to the 10" vs. 12" vs. 15" subwoofer having any direct correlation with sound quality outside of the obvious differences in headroom. Often, the limited bandwidth subs sound more musical because they don't excite as many room modes. It is as much to do with the room-subwoofer interface as anything so you should dedicate some time to learning about the issue. My standard recommendation is Toole's book. It covers subwoofers and a lot of other topics and it is based upon research, not opinion.

The Fathom is a good sub. It is essentially a small heavily equalized subwoofer with lots of power. If you are willing to live with a slightly larger enclosure you gain a lot. Read about Hoffman's Iron Law (Google).

I'd do some reading before I'd spend any money or talk to a company. There are so many people with different views in audio if you spend your time asking for opinions, you will come away more confused than when you started. Do your homework and buy Toole's book and do some reading about basic subwoofer design and room acoustics. That knowledge will take you a long ways and save you a ton of money.

Kevin Haskins
Exodus Audio
 

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I agree with Kevin, I should also add that the real reason that we now have subs as large as 18" is basically because of Movie soundtracks. The digital audio formats as well as uncompressed audio is giving listeners in there own home bass that goes well into the 10Hz range, unheard of in a home environment up until recently. A 10" sub simply can not go that low with a decent amount of SPL. For music thats just fine as the majority of music rarely goes lower than 30Hz and a good 10" sub can easily manage that.
 

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Discussion Starter #6
I am familiar with that Law. I bought The LoudSpeaker Design Cookbook after the first couple of DIY loudspeaker attempts. In basic terms (and please correct me if I am wrong) the law basically says
1. Low End extension
2. Small Box
3. Efficiency

you may have 2 of 3.

Most of the builds on here seem to be about chest thumping bass. I KNOW there are some true audiophiles who watch a lot of movies on here and figured I might be able to get a few to give my a starting point.

Hell, before I had joined another forum a few years ago, I had no idea who Scanspeak was or that some guy named "Zaph" Krutke (sp?) had designed some amazing speakers using them. And now I have a pair that I built that are my two channel beauties.
 

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Assuming the cone is small vs. wavelength, which is 11ft at 100Hz, it boils down to frequency response and distortion. If it has the frequency response, and doesn't distort, it's "fast" (not that useful a sonic concept, actually, except in marketing electrostats and such) enough... You want to move air, and to do it efficiently, especially at lower frequencies, the larger the cone, the better.

Without some work, larger cones with their accompanying larger motors naturally tend towards higher inductance, which, without some eq and a high-voltage (-power) amplifier, won't do higher frequencies as well. But add in Faraday rings and such, and big woofers will do midrange just fine, if beamily. Audiophilia nervosa is a funny thing: it leads people to trust their misleading intuitions and come up with "truisms" that are sometimes not. Or so I've heard... :innocent:

As others have alluded to, it all depends on what you're trying to achieve, what your mains will do, and your room situation.

Oh; concrete recommendation: Maelstrom 18" or 21". Better yet, multiples thereof. Assuming your mains can go below 100Hz (preferably lower) with authority, and your room can take the bass.
 

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Discussion Starter #11
The right corner beside the viewing area is has a sloping roof corner as well as the normal wall corner. The horn loading effect provided by this double corner provides a huge gain to the room. The downside is that I get a resonance dip right at 80Hz and a big bump up between 42Hz and 30Hz. But with the use of bass traps and the Anthems notch and resonance filters I can smooth these out quite nicely.

The ceilings sloping towards my Theater rig makes for very nice room gain to compensate for the size and openness. But EQ is a must on the low end. I ran two subs for many a moon, one for low end extension with music and one for movie and gaming bass.

And to be blunt about it, unless I accidentally, right from the start, build a subwoofer that has a red cape with an S on it and is susceptible to kryptonite...... I will most likely experiment and review and build and tweak, and finally post my results. This is because I love the search probably more than I like the results. Such is the life of a tinkering man.

Now, back to the discussion.

My wife has not put a limit on cabinet size. I have purchased a large mahogany folding screen that is very pretty and is big enough to "hide two or 'tree dead bodies behind it" <---said in a poor imitation of a gangsters voice
 

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Discussion Starter #12
I see constant mention of the Shiva but it looks as though Adire is out of business, according to it's web site at least.

Soundsplinter models well, but the specs make it seem as all its strength may lie in home theater use and not music. Am I wrong?

The CSS SD12 looks like it may be a good place to start.

I will hunt down the frequency response of my Faber's and post them. Maybe that will give you experts out there a bit more needed info.
 

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Shiva X - sold by DIY Cable, owned by Kevin Haskins, who has already replied to this thread.
Personally I'd go for a Maelstrom X 18" in your case. An 18" has to move far less than a 10" to move the same amount of air; which do you think will be "faster"?
 

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Discussion Starter #14
Whoops! Sorry Kevin, I had my head up my butt and my info wrong. Shiva X, thank you Zero for the heads up on DIY Cable as the site has some items I am in need of. (It is good to find a sponser that carries the Cardas silver RCA's...yay!!)


The Shiva looks very intresting. I think I am going to order a couple of different drivers and have my self a little shoot out between subs. I'll keep witch ever sounds the best as post my results!

Thank you all for your help. I have my starting points!

I might have to put an 18" in the line up and see how it does. It will be fun for me and the results will make for interesting forum reading anyway.
 

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Discussion Starter #15 (Edited)
The image didn't transfer very well but maybe this graph showing my mains will help.



Sorry it is so hard to read, I will load a cleaner copy when I get a chance.
 

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An 18" has to move far less than a 10" to move the same amount of air; which do you think will be "faster"?
At any given output level and frequency, the 10" cone will literally be moving faster. Has to. But that's neither here nor there, sonically.

On the other hand, because the 18" will be moving less, given the same motor, the voice coil is more likely to be in its linear range, meaning its box tuning will be closer to its (small-signal, presumably) design value, and boom less. Which many perceive as greater speed.

Eq, room treatment, placement, and even (gasp!) big cones are your friends in the fight against (unwanted) boom. Physical speed has nothing to do with it; it's only perception thereof. Oops; so it's actually real, QED. :bigsmile:
 

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It didn't transfer very well but maybe this graph showing my mains will help.
Looks like 130Hz or so sealed. Seems like you might want some co-located midbass units, and then a big sub or two. Or even a big sub on either side, near each speaker. But having all sub(s) only in the corner is gonna be tricky...
 

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Discussion Starter #18
Right now I am crossed over at 95Hz for music and at 80Hz for movies. I can offset the low end on them just a bit by proper placement distance from the walls. This combined with EQ to boost the bass a tad seem to work well the speakers.

I only have one actual corner in the room (besides one behind me). The other opens into a 180 degree fireplace and Dinning room and the last into my Bar. When the equipment was installed and room eq initally done by vendor, they determined it would be very difficult to place two subs. BUT, I am up for giving it a try.....why not?
 

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Discussion Starter #19
I have been in the house long enough to have most of the room peccadilloes worked out . But if someone has an idea for some new way to tackle a problem or implement a solution let me know!

Here are a couple of quick phone pics of the sub corner and opposite corner for your reference.

Here is where the sub currently sits. It has the flatest response where you see it in the pic so I have not placed it behind the wooden screen. Thanks to this screen I can put a cabinet the size of a refrigerator in and not have my wife complain.

--BTW. Disregard the other set of Sonus and the tube amp in this pic, they aren't for movie watching.:bigsmile:--




Here is the opposite corner that opens into a dining room. This will make placement of a second sub rough.

 
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