15" Subwoofer recommendations

Re: 15" Subwoofer recommendations

The adire tempest would fall between those two prices and is often used in the diy projects seen on this and other forums. I'm not familiar with the sound splinter driver.

Re: 15" Subwoofer recommendations

On most of the audio sites I visit,DIY'ers are switching to the sound splinter.

The cost is supposed to be well worth it,as its gotten rave reviews.

Re: 15" Subwoofer recommendations

TC sounds just released a new 15":

http://www.tcsounds.com/tc3000.htm

I have the Adire Tempest and it makes for one heck of a sub.

Re: 15" Subwoofer recommendations

Whoah, Nelly!

For an IB, the recommended minimum is 4x Vas for "cabinet" volume, optimum recommended is 10x or more. You've got 44 ft^3 total? The Vas on the SS dual 2 is about 5.75 ft^3. Multiply x 4 = 24 (rounding) * 4 = 96 ft^3 for a minimum IB with four SSd2 drivers.

With 44 ft^3 and trying to use four drivers, you're looking at big sealed or bass reflex box. Not entirely a bad thing. And now, it' easier to compare different drivers in your tool of choice like WinISD or Unibox.

How's big's your room? How much power will you have? Do you know what your idea of loud and too loud is in db? Is that 44 ft^3 net of all bracing?

Here's a quick comparison using WinISD:
The Dayton RS15-HiFi, currently on sale for $139/each.
30 ft^3 sealed w/500 watts: 112db @ 20hz, 117db @ 30hz, 118.5 @ 40hz

SS 15d2 in 30 ft^3 sealed w/500 watts: 110.5 db @ 20hz, 115 @ 30, 118 @ 40

The SS15d2 will handle 2800 watts to below 20hz, so despite having slightly less efficiency than the RS15HF, will actually play louder if you give it enough power. The RS15 is excursion limited to about 685 watts at 20hz, going up to 2000 watts at 36hz and up. At max power for each, the SS has about a 5db advantage at 20hz...diminishing to less than 1db by 40hz.

Going ported with either driver, or any other decent 15" like the DVC15, Titanic 15", various TC Sounds models will get you even more output.

-Brent

Re: 15" Subwoofer recommendations

Hi Bud,

The RL-p15s are more robust drivers, but with as much volume as you have, that's not necessarily what you need. The sale on the RS390 HF drivers would be my pic, still at just under 1/2 the price of the RL-p15s. The IB and DVC drivers from PE will be very good, but don't like being driven to their limits.

The real question here is how big is your room and how many 15s could you eventually install? 4x even the Reference Series HiFi driver would be quite potent and need very little power. If you started with 4 and allowed for 8, I think that would be a pretty outrageous system.

Re: 15" Subwoofer recommendations

As Brent mentioned, the RS15 is a bit more sensitive than the RLp15. 4 RS15's with 500 watts is pretty close to 4 RLp15's with 1000 watts (at least in the lower frequencies).

I think Mark's right (and Mark truly meets the qualifications of "someone who has forgotten more about subwoofers than I will ever know"). 4 RS15's with 400 - 500 watts would get really loud and go really low. Though they're similar in Xmax to the DVC and the IB15, I think these are in a higher class of quality. There's no question that they'd be my choice at the present sale price.

Re: 15" Subwoofer recommendations

For four RS15-HiFi's...quick noodling with WinISD.

I like the looks of 40 ft^3 tuned to 15 hz with two 10" x 39.55" ports. Remember that's 40 ft^3 of air...the drivers, bracing, and volume of the port (treat it as a solid) are extra. Dropping to 35 ft^3 tuned to 15 hz, doesn't really change anything below except lengthening your ports to 46.28".

You only need about 200 watts per driver to reach Xmax in the mid 20hz range. I'd consider a pair of the Behringer A500s with one driver per channel. But really, any decent amp combination that gets you in the neighborhood of 200 watts into 4 Ohms is fine. You could wire each pair in series for an 8 ohm load and mate pretty well with the Behringer 2500 you suggested, but you've still got to deal with the fan noise.

With 920 watts into four drivers, you'll be good for 113db @ 12hz, 120.5 @ 20hz, 122db @ 30hz...pretty much flat from there up to your low pass filter.

The SS 15d2 in 35 ft^3 tuned to 15 hz with 2500 watts only gives you about 3db (+/- depending on frequency) more output than the RS15. There may be alignments that give it more of an advantage, but for me, the RS15 would be a no brainer, even at its regular price.

To experiment with sealed, just find something to stuff the ports. With the RS15 you'll be looking at a nice low Q of .609. Max power at 20hz is 600 watts, rising from there up to 1300 by 30hz and 2000 by 36hz.

Sealed output with 600 watts is 114db @ 20, 117.5 @ 30, 119 @ 40.


-Brent

Re: 15" Subwoofer recommendations

(Edit: Brent's post slipped in before I posted, but it looks like we were thinking almost exactly the same thing)

When I model them, the RS-15's seem like they really want to be tuned deep. 4 RS-15's in a 44 cu ft cabinet tuned to 15Hz looks pretty good. Gives you noticeably more output from about 35Hz and down compared to a sealed cabinet of the same size. +2.5dB at 30Hz. +5dB at 20Hz.

Plus this would generally increase your power handling since the ports load the woofers near the tuning point. And you'd have to get a crazy low note (13Hz or less) before you'd have to worry about the woofers unloading. Looks like 600-700 watts would be okay. The extra power would add another 1dB or so. Now we're talking nearly 120dB @ 20Hz anechoic!!!!

To achieve this you could do one of the following port arrangements:

6 4inch ports 17.5 inches long
8 4inch ports 24.25 inches long
3 6inch ports 18.5 inches long
4 6inch ports 26 inches long
2 8inch ports 21.25 inches long

Re: 15" Subwoofer recommendations

Hi Bud,

I don't have a lot of time at the moment, but here's some quick points of comparison...

Basically the RS15" from PE is a great deal, and should be the easiest to get great sound. 4 of these in your room should be just about right in a sealed config, where you need some healthy main speakers to keep up with any more capability. The big ported option with the RS15 is an interesting one and I do like the response curve. You could either make a large 10-12" wide duct in between the two center drivers or just stack two large diameter ports made of sonotube or equivalent.

Since you do have a limit of 4 drivers, the RL-p15 does offer benefit to the IB option, but is less efficient and will require more EQ to get as nice a response. With 2-3x the power (that's a lot more), it does offer ~3-4dB more output over most of the range. The un-EQ'd response has a slope that starts around 50Hz and is why you will need to measure and employ some EQ, but both systems will need this to balance out interaction with the room.

For the price, I do think the RS15s are a good choice here. I think you would likely enjoy keeping them sealed, but if you want to port them, I would probably go for a pair of 8" ports. A pair of 8" ports at about 35-36" will give a tune in the 12Hz range and a very nice response with plenty of real-world air-flow. You could go to 10", but the port starts approaching 60" for that low a tuning and give you at best 1dB of addtional output in the 12Hz range. In real world use, I'd go with the 8" ports.

My suggestion is to start with the system sealed and 800-1200W total into all 4 drivers.

Re: 15" Subwoofer recommendations

WHOA! 4 15" woofers?! That's going to sound awesome!
Sorry, I have no advice to offer since I'm a newbie. I just want to say that if I could do it like that, I would. Good luck!

Re: 15" Subwoofer recommendations

Hi Bud,

I would start sealed. The location of the 8" ports isn't crucial, but you need to give either end of the ports appropriate open space at their ends. Ideal might be putting the ports at the outer corners against the walls where you might be able to get away with not covering them with grill cloth. If you do cover them with grill cloth, make sure the part over the port is a fairly open weave. The drivers won't really care about what fabric is used. Only thing to watch for is to make sure and glue down the fabric to the frame with something like Super77 so that it doesn't flap against the frame at high levels.

Re: 15" Subwoofer recommendations

So now 36" length with a 188hz first port resonance IS ok? I see how it works.

Bud, if you do go ported, which I would recommend you do, use all of the available space, no need or want to decrease it at all. I'd also go with two 8" diameter ports, but I'd tune a bit higher, ~13hz with the ports being 30" in length. Sonotube would probably be the best choice of matrial to use for these ports considering the size. You'd want to add a 3/4" or larger roundover to outer layer of (MDF?) to act as a semi flare.....what are you building this out of by the way, I think I missed that. You'll also want to make the baffles - the walls the drivers are attached to - a few inches thick.

Aside from the obvious advantages of greater output and less distortion by going ported, the resulting natural FR will mesh extremely well with typical room gain, and you will likely need minimal EQ, if any at all. I can show you some real world examples of this if you like.

Re: 15" Subwoofer recommendations

Bud: You've got 33+ posts at the HTF now, so you are eligible to post pictures and links (you need at least 15).

You just need to take the digital images (or if they are film photos, scan them and digitize them) and get the hosted on a free photo-hosting site like PhotoBucket. Once there, you will get a link to where the photos are hosted and be able to put them into a post in your thread so everyone can see what you are talking about.

When you enter the link in your post, it will look something like this:

[ img ]www.photobucket.com/BudsPhotoofsubwoofers123[ /img ]

except that there wouldn't be spaces on each side of the "img" tags. I just put them there so you could see the code...otherwise it would have disappeared.

Good luck!

P.S. If you use PhotoBucket, they actually provide you a link witht he "img" tags already in place. or, if you just have the URL where the photo is sitting, you click on paste the URL into the pop-up box and the software will add the "img" tags for you.

P.P.S. BTW, Welcome to the HTF! Have fun here!

Re: 15" Subwoofer recommendations

Just remember - there is no replacement for displacement...

FWIW, just modeled 4 Peavey 18" Lowrider pro speaks in a sealed 44 cubic foot box, and with under 300 watts total, they looked darn interesting.

Re: 15" Subwoofer recommendations

Looks pretty well braced, but you will still want to add a layer of MDF to the walls, and probably two to the front walls the drivers will be mounted to.

Here are some in room FR measurements of single-driver large and low tuned ported subs without any EQ or with minimal EQ.











With a tuning around 13hz, as long as your room isn't extremely difficult, results like the first and last graphs shouldn't be too hard, and with 4 drivers, you'll have tons of headroom and extremely low distortion.

Re: 15" Subwoofer recommendations

No stuffing needed. Just line the enclosure with acoustic foam. Or the cheaper method open cell foam from Wal-Mart. It's the egg crate foam mattress tops in the home section.

The porting recommendations are above. For an Fb of 15hz, the 8" ports need to be around 22". 36" ports are tuned lower. Have you modeled this?

-Robert