y8s

iTrader: (8)

I know blaque posted a 15, but honestly I think that's too big for what you're looking for. I'd go with a 10 or 12. Actually, I have two different hardly used 12s here I'm not using that are taking up space. I could sell you one (I have to check them out and see what's what, it's been a few years) and design a box around them that you could build. The amp blaque posted would work perfectly. One is a Titanic MKIII and the other (I think?) is a Stryke SAE 1204 (archived product page). Stryke changed names a while back and doesn't sell it anymore but it's a solid sub that was highly recommended.

I'd probably keep the titanic and use it here eventually, but the stryke may be up for grabs.

or if you want to go new, I'd probably pick up a Dayton Reference series sub. They're at parts express and not very expensive.

patsmx5

iTrader: (16)

Hmm, so what would be the pros/cons of a 10, 12, or 15" sub? I think I want a big one, just because I've heard them before and it's awesome to hear some of the super low frequencies you don't normally hear. A Dayton 12" reference sub is on sale for 120 right now. I don't know, I'd kinda like to not spend a ton on this sub, so I'm interested in your other sub. The 15" blaque posted was like 75 I think. What's the difference between Dayton's regular cheapo subs and the reference series, other than they cost twice as much?

y8s

iTrader: (8)

lets see.. differences in subs...

power handling
distortion
motor strength (able to play louder in smaller boxes)
durability
xmax (this is important)

Example: the one he posted is a 15 with 8.5mm of xmax. the Titanic MKIII is a 12 with 18.7mm of xmax. Volume displacement is how much air a speaker moves... so if you take the cone area (a parameter known as Sd) and multiply it by the xmax, you get that volume displacement. A 12" has a cone area about 450 cm^2, a 15 has about 800cm^2. Convert the xmax to cm (8.5mm = .85 cm, 18.7mm = 1.87cm) and multiply it by the cone area. Cheap 15 = 800 * .85 = 680cm^3, Titanic = 450 * 1.87 = 842 cm^2. the 12 displaces 24% more air!

The size of the motor structure is important too. It has to be able to dissipate heat--which is what most power ratings are telling you--so it wont melt down.

But if you're trying to decide between different size subs of equal quality (say 10, 12 or 15 reference series for example), then maximum loudness is the difference. A simple calculation for how loud you need is based on the efficiency of the speaker and the power you're using (or power it can handle).

That BAMTM is probably maxed out at 105 db so your sub doesn't need to go much louder than that. your average 12 in a sealed box will get you to probably 110 which is plenty loud.

And "deep bass" is merely a function of the design of the box its in. Either of the ones I have will play into the 20 Hz range in a vented box.

rleete

iTrader: (21)

I have a Cerwin-Vega 12" sub I bought before the DX-9's. While it gives reasonably decent bass to otherwise strained bookshelf speakers, it doesn't have the tight punch associated with a 15".

One thing I did do to help it out was get a slab of stone (from a floor tile place) that was the same size as the box, and put the sub on top. It gives a nice flat surface for the bass to reflect off, instead of being absorbed by the carpet.

patsmx5

iTrader: (16)

Good info! Ok, well let me know what you want for your sub. I would definitely want a vented box.

y8s

iTrader: (8)

You can design "boom" or "punch" or whatever sound you want into a speaker box. I'd make his design for smooth response and he can crank the bass or EQ it however he wants to get punch.

you can make a side-firing sub too. No floor in the way.

blaque

iTrader: (1)

I wouldn't worry about flush mounting the tweeters and whatever else if you're gonna have them hanging off the ceiling :P

Get the plate amp I posted!!

patsmx5

iTrader: (16)

Well, I ordered a Dayton 15" DCS380-4 sub woofer and a 240W plate amp from Part-Express a couple days ago. Total was 212 shipped. Planning to build a good sub for my book shelf speakers. Anyone wanna design me a box for that sub? Anyone? Please? (Read: Y8S or someone help!) Links or anything would be nice.

I downloaded some speaker building software. It's confusing as hell. About what size box would I want? Is bigger always better? Any help's appreciated.

Vashthestampede

iTrader: (17)

I had Onkyo's 7.1 system and loved it. Granted I'm not a big TV person, but I enjoyed it.

Vash-

hustler

iTrader: (6)

I have a sony reciever, focal front stage, cheap jbl surrounds, and a 15" focal sub in the coffee table. my **** goes "bump."

fmowry

iTrader: (8)

Just throw the specs from the spec sheet at PE in WinISD and see what internal volume and port size it comes up with.

This would have probably worked well for you for a similar price (after the box supplies, finish, and labor):

http://www.parts-express.com/pe/psho...number=309-175

Frank

y8s

iTrader: (8)

what frank said. without measurement equipment, just pop it into win isd. post the graphs you get and i'll critique for you.

fmowry

iTrader: (8)

Depending on how much you care about aesthetics, a sonotube based sub might work for you.

Frank

patsmx5

iTrader: (16)

Downloaded that program but man it's confusing. I created my own speaker and entered every spec it asked for from the spec sheet on my sub. It says I need a 16.77 cubic foot box! WTF? There's no way in hell that will fit anywhere. Anyways here's a screen shot of what the program said and to the right is the spec sheet on my sub.

patsmx5

iTrader: (16)

FWIW, Dayton recommends a 3.38 ft^3 sealed box with a F3 of 38 Hz or a vented box at 10.6 ft^3 and a F3 of 21. Weird that the size is so different. I would like to build a box to get that low low bass. Seems like you need cubic footage to make that happen. Gotta run the math but I have at least 5 cubic feet to work with, maybe more.

fmowry

iTrader: (8)

Vented boxes are always a decent amount bigger than sealed boxes. And generally it takes a bigger box to reach a lower Hz.

You don't need to hit 21 Hz to feel low, low bass. I built a ported box (tube actually) for a 12 inch Adire Shiva that impresses many people when I play DVD demos like the depth charge scene in the movie U571 or the tapping on the fish tank in Finding Nemo. Don't get caught up in the numbers.

Frank

patsmx5

iTrader: (16)

Well, I need something to go with. Not too farmiliar with building stuff like this. The space I have to work with is 18" tall x 36.5" wide x 26" deep. That's 9.89 ft^3 possible space. However I understand the golden ratio should be followed. So knock 1.5" off of 36.5 and that gives you 35. Following the golden ratio my internal size should be...

35 x 21.875 x 13.125

So that's 5.82 ft^3.

Would I be better off to build the box 5.8 ft^3 and follow the golden ratio or just build it 9.89 ft^3 without following the golden ratio? Would 5.8 be good, fair, poor, etc?

y8s

iTrader: (8)

forget the golden ratio. and actually forget 20 Hz -3db points.

What do you want to do with the sub? rock your socks off? listen to tchaikovsky?

build the sealed box and it'll be awesome. the amount of music content below 38 hz is pretty marginal.

fmowry

iTrader: (8)

As I said an y8s reiterated, don't get caught up in numbers. Define what you want the box to do and you can get an idea of the size and porting potential from us.


Frank

patsmx5

iTrader: (16)

Well I want it to sound very good. When I say good, I want the bass to be the same volume throughout the range that the sub plays. Not loud, but full. I would like to hear the lower notes that your typical sub would not play. My Uncle has a nice Acoustic Research setup. His sub is an 18" 2K watt setup. It plays low notes I've never even heard in songs. Granted his setup costed 15K, but I would like to have something similar so to speak.

Poor example: Rascal Flatts "What hurts the most" has low notes in it that my 10" sub in my car will NEVER play. I can hear the faintest sound of the really low bass. Just enough to know it's there, but that's it. It comes through perfectly on my uncles setup. His the bass stays the same volume on lower notes, and does not drop off in volume like ever other setups I hear.

I have the BAMTM Zaph speakers powered by a G4700 Sansui. They don't get that loud (like my Cerwin Vegas), but they sound GREAT. I want a sub that sounds great, even if it's not really loud. I'd rather have say 105 DB's and hear the lower notes then have 115 DB's on your typical country song bass but have lose the lower notes.