15" Subwoofer recommendations (1 Viewer)

[Bud Huey]

I need some help from someone who has forgotten more about subwoofers than I will ever know. I am building a stage in front of my HT to house four (4) 15" subwoofers. The total volume of the stage is @ 44 cubic feet., therefore, I am trying to create an infinite baffle (IB) effect. I have had some people recommend using the Sound Splinter 15" RL-p 15, but at $250 each they are EXPENSIVE! Parts Express has their 15" IB subs - DAYTON IB385-8 15" IB SUBWOOFERs on sale for $110 each. My question is, is it worth spending 2X as much per speaker for the Sound Splinters? I am on a budget, but I will spend the money if it is worth it! Are there any other brands I should look at that will kick a** in my LFE application? Any input would be appreciated!

Thanks,
Bud

 

[SethH]

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.

 

[Bud Huey]

Here is a link to the Sound Splinter website.

http://www.soundsplinter.com/rlp15_p...rma tion.html

Thanks,
Bud

 

[Alan M]

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.

 

[Bud Huey]

Thanks for the info. I guess I will bite the bullet and buy the Sound Splinters. Maybe I will buy two at a time so the wife will have a hard time figuring out I just spent $1000 on subwoofers!!!

Thanks,
Bud

 

[John Garcia]

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.

 

[Brent_S]

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

 

[Mark Seaton]

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.

 

[Bud Huey]

Thanks for everyones help! Here are some additional details in case it helps in the decision making process.

1) The room is approximately 16' wide x 28' long x 10' high
2) My stage in front of the room is only set up to hold four 15" subs.
3) Approximate volume of the enclosure is 44 cubic feet.
4) I plan to buy a Behringer EP-2500 and Behringer DSP1124P to drive the subs.
5) I can port or vent the stage box if someone can give me some suggestions.
6) These subs will only be driven by the LFE output, so I am hoping to get a really low "chest rattling" effect.
7) I could add some subs to the back of the room if it would help.

Thanks,
Bud

 

[Ryan Schnacke]

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.

 

[Bud Huey]

Thanks for all of the help! I will give the RS-15s a try. If I wanted to port the enclosure to get even more output, as Brent mentiond, can anyone give me any recommendations on what frequency to shoot for and the best port design for my cabinet? Or would the RS-15s be better off in a closed cabinet?

Thanks,
Bud

 

[Brent_S]

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

 

[Ryan Schnacke]

(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

 

[Bud Huey]

Thanks for everyones help! Which port arrangement do you recommend out of the suggestions above? Does it matter where the ports are placed in the enclosure? How important is their mounting position? Is there someplace I can buy the ports premade, so I can just drill a hole in my enclosure and slide them in? Does it matter which way the ports are pointed?

Thanks,
Bud

 

[Bud Huey]

Does anyone know how I can post a picture of my enclosure in the thread? I have not put the top on yet, so a picture would show some good detail on the bracing and possible locations of the ports.

Thanks,
Bud

 

[Bud Huey]

In case it helps in the port decision, my enclosure is basically the size of a sheet of plywood with the corners sloted back 45 degrees to the 2 foot mark. Therefore, it is 4' across the front and 8' across the back. I play to put two drivers in the front and two in the angled sections.

Thanks,
Bud

 

[Mark Seaton]

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.

 

[Bud Huey]

Thanks for all of the suggestions! I think I will try using them sealed to see how it works considering that is the simplest thing to do. How much of a difference will the location of the 8" ports make? I can put one on each side of the enclosure behind the 45 degree angeled drivers. Would that work?

Thanks,
Bud

 

[DjSaneR]

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!

 

[Mark Seaton]

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.