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Single dual-opposed 15's, or dual single 15's

post #1 of 30
Thread Starter 
This is my first HT/music setup I've ever had, so this is very new to me. I'll give you guys what I'm working with here.

Large, open-floor plan (great room, kitchen, dining area) 22' w X 24' d X 10' h, with 13' deep opening to the hallway/front door entryway on left hand side.

Vizio 70" (soon) - Marantz 1402 - Polk Monitor 70s(mains) - Polk Monitor C2(center) - HTD HD-R65AIM(in-ceiling surrounds 5.1)

Polk 70s spaced 10' apart, listening/viewing position 10'. Large 11' wide (actual sitting area) sectional.

My initial plan was to use separate cabs housing a Dayton 390HO & Bash 500w plate amp in a sealed 3cf enclosure. placed next to each Monitor 70 on the outside. My dilemma is I basically only have one corner along the media wall to use for any type of boundary loading (on the right side). The left side is completely open to the hallway & entryway besides a 1' wall that "sections off" the great room.

Considering this, I then thought about using one cab in the right corner with a 6cf sealed, dual-opposed 390HO's & a pair of Bash 500's mounted on the back to gain more output from corner-loading.

As I mentioned, I'm a rookie when it comes to this, & probably won't purchase any measuring equipment for quite some time. I just want to take advantage of using a pair of subs for additional output in this huge room.

What would you guys suggest in my situation?

Please let me know if there's any vital info I left out, thanks.
post #2 of 30
It's tough to make a suggestion without knowing the in room response. Corner loading does increase the SPL, however, based on the room it might not be the best option. Separate cabs will also allow you to attack the FR more and get a more even response throughout the seating area.

The best way is to place the sub in the listening position/positions and see which one of those 2 areas is the best spot.
post #3 of 30
You can't smooth room modes with one cab.
post #4 of 30
Quote:
Originally Posted by Bill Fitzmaurice View Post

You can't smooth room modes with one cab as well as two.

Added some. smile.gif

Well technically neither smooth room nodes. They introduce them which is smoothed via eq'ing. It is easier to EQ room nodes with a pair than a single sub.
post #5 of 30
Thread Starter 
So, basically two separate cabs will help even out the frequency response, but not necessarily increase the SPL (depending on how my room behaves)? So my best bet would be to go with separate cabs equidistant to the listening position? After all, I would prefer a flatter response over certain frequencies being boosted in certain areas of the room.

How confident are you guys in a pair of sealed 390HO's w/500 watts each being enough to fill this 6,000 cf room? A bit subjective I know... smile.gif
post #6 of 30
Doubling driver, doubling wattage, or corner loading will each increase SPL. Seeing as you are not going to invest anything into EQ'ing at the moment, the separate cabs do make more sense.

"Enough" is all open to personal interpretation. I was running a PB12/2 Ultra in a 2100cf room and it wasn't enough, hence upgrading to 6 SI 18" powered by 2500 watts. So for me, no it wouldn't be enough, but for you it might be perfectly acceptable. That is a large area, and would require some serious firepower to reach reference levels.
post #7 of 30
I would go with the two single 15's for flexibility. You can always stack them both in the corner if you prefer, it should give you the same benefit of building a larger cab with dual drivers.

I would target 3.5 - 4 cu ft boxes. I also would consider a seperate pro amp vs plate amps if you can. It will save you money. Something like an iNuke3K DSP should be plenty for those boxes and it has DSP + EQ built in.
post #8 of 30
Thread Starter 
Quote:
Originally Posted by ack_bk View Post

I would go with the two single 15's for flexibility. You can always stack them both in the corner if you prefer, it should give you the same benefit of building a larger cab with dual drivers.
I would target 3.5 - 4 cu ft boxes. I also would consider a seperate pro amp vs plate amps if you can. It will save you money. Something like an iNuke3K DSP should be plenty for those boxes and it has DSP + EQ built in.


Some very good points I will definitely take into consideration.

About the pro amps... I've read comments mentioning some receivers can't supply enough voltage(?) to get the true power ratings out of them, & fan modifications are most likely needed. I could see the fan replacement maybe, but what's the story on the output voltage? I think that's what I read.
post #9 of 30
there is no replacement for displacement.... then its not so critical to take into consideration all of the little things like acoustic coupling and in the corner, or separated without any of those benefits.... its always easier to throw more money and power at it, unless you dont got the coin.... then we need to scrape every last quality decible out of our systems.... good luck
post #10 of 30
And not a single person suggested two dual-opposed 15's. You guys are slipping. biggrin.gif
post #11 of 30
I watched a sealed mega-$$$ 18" sub running off a powerful amp, doing maximum excursion yet have almost no impact while a well-placed ported 12" sub running off 200 watts slams hard so long as those 'little things' are accounted for.

"If you waste your subs displacement, you can't replace the bass"

Quote:
Originally Posted by mrflamboynt View Post

there is no replacement for displacement.... then its not so critical to take into consideration all of the little things like acoustic coupling and in the corner, or separated without any of those benefits.... its always easier to throw more money and power at it, unless you dont got the coin.... then we need to scrape every last quality decible out of our systems.... good luck

Edited by imagic - 12/19/12 at 5:19am
post #12 of 30
in my estimation the op will get a whole lot more out of two ported enclosures than two sealed enclosures in that big room.

pressure vessel gain isn't likely to kick in until the upper teens.

plate amps typically have a high pass filter around 20hz. i'm not sure about that one in particular, but that is what i plopped in the model.

three configurations:

1. yellow, 3 cubic feet sealed, 15" rss390ho driver

2. red, 5 cubic feet ported, tuned to 20hz, 15" rss390ho driver

3. blue, 9 cubic feet ported, tuned to 20hz, 18" rss460ho driver (just for comparison if you have the space to go big)

these are for 500 watts and 1 enclosure each. two enclosures will provide more spl as will corner or wall loading.

the old mfw15 might not be too bad. have a search on google images for "mfw 15 subwoofer" for some ideas.

post #13 of 30
Quote:
Originally Posted by fish323 View Post

Some very good points I will definitely take into consideration.
About the pro amps... I've read comments mentioning some receivers can't supply enough voltage(?) to get the true power ratings out of them, & fan modifications are most likely needed. I could see the fan replacement maybe, but what's the story on the output voltage? I think that's what I read.

Almost any avr should be able to output more than enough voltage for a pro amp. What avr do you have?

The fan mod on the iNuke is not that hard. Pick the glue off the connector and then pull the whole connector off the board. Then you can jam the 80mm pc fan's connector onto the posts coming out of the board.

+1 to what LTD02 said. I would build 2 5-6cu ft 20hz boxes. You won't be getting significant output below 20 in that room with sealed alignments without enormous displacement.
post #14 of 30
Quote:
Originally Posted by imagic View Post

I watched a sealed mega-$$$ 18" sub running off a powerful amp, doing maximum excursion yet have almost no impact while a well-placed ported 12" sub running off 200 watts slams hard so long as those 'little things' are accounted for.

"If you waste your subs displacement, you can't replace the bass"

so you are comparing what? to what now?
post #15 of 30
Quote:
Originally Posted by mrflamboynt View Post

there is no replacement for displacement.... then its not so critical to take into consideration all of the little things like acoustic coupling and in the corner, or separated without any of those benefits.... its always easier to throw more money and power at it, unless you dont got the coin.... then we need to scrape every last quality decible out of our systems.... good luck

Quote:
Originally Posted by mrflamboynt View Post

so you are comparing what? to what now?

He's just pointing out gross error.

You put a 500 watt, 18" sub in the middle of a room it's not going to do what a 12" 200 watt sub properly corner loaded (4pi) is going to do. There's no replacement for proper placement.
post #16 of 30
Thread Starter 
Quote:
Originally Posted by nograveconcern View Post

Almost any avr should be able to output more than enough voltage for a pro amp. What avr do you have?
The fan mod on the iNuke is not that hard. Pick the glue off the connector and then pull the whole connector off the board. Then you can jam the 80mm pc fan's connector onto the posts coming out of the board.
+1 to what LTD02 said. I would build 2 5-6cu ft 20hz boxes. You won't be getting significant output below 20 in that room with sealed alignments without enormous displacement.



I have a Marantz NR1402.

Yeah, the ported models LTD02 sim'd look much more impressive, 6 cf is about as big as the wife will allow.

I should mention, I have a friend that does custom woodworking, so he would build the enclosures. I'm thinking after all is said & done I'd be spending about the same if I just went with a pair of PSA XV15's.
post #17 of 30
Quote:
Originally Posted by fish323 View Post

I have a Marantz NR1402.
Yeah, the ported models LTD02 sim'd look much more impressive, 6 cf is about as big as the wife will allow.
I should mention, I have a friend that does custom woodworking, so he would build the enclosures. I'm thinking after all is said & done I'd be spending about the same if I just went with a pair of PSA XV15's.

Unless your friend charges a lot for the cabinets, you should be spending considerably less than 2 PSA XV15's.

Two shipped XV15's are $1600 or so.


Two 15" Dayton HO drivers are $300 for the pair. Something like the iNuke 3K DSP to power them is about $350 (I just bought one for $299 at Amazon, so watch for sales). You are at $650 for drivers and amp. Wood for both subs should be less than $100 depending on what types of wood you use. Additional accessories (paint, primer, connectors, etc) figure about $100 or so. You are only at $850 or so for two subwoofers....

If you are going with dual opposed, you are still well under $1600..
post #18 of 30
Thread Starter 
Quote:
Originally Posted by ack_bk View Post

Unless your friend charges a lot for the cabinets, you should be spending considerably less than 2 PSA XV15's.
Two shipped XV15's are $1600 or so.
Two 15" Dayton HO drivers are $300 for the pair. Something like the iNuke 3K DSP to power them is about $350 (I just bought one for $299 at Amazon, so watch for sales). You are at $650 for drivers and amp. Wood for both subs should be less than $100 depending on what types of wood you use. Additional accessories (paint, primer, connectors, etc) figure about $100 or so. You are only at $850 or so for two subwoofers....
If you are going with dual opposed, you are still well under $1600..

Sorry, I was referring to two dual-opposed cabs.

I have a couple questions regarding using a pro audio amp with the Marantz...

Say I get a pro amp that has built-in DSP, make my adjustments to the subs, then run Audyssey from the Marantz... are the pro amp's settings still in place along with the AVR's auto-calibrations?

The Marantz has a single mono output. If I used a pair of HO15's per side that gives me a 2 ohm load per side. Will the pro amp still see this as running in 2 channel mode @2 ohms/channel, or 1 ohm mono(below impedance rating)?
post #19 of 30
Thread Starter 
I've been eying these http://www.crutchfield.com/p_107MM1540/Polk-Audio-MM1540.html?tp=111, for $90 each they may not be a bad deal for dual cabs, dual-opposed sealed.

Could someone please model a pair of these (I suck at modeling) in a sealed cab with a Qtc of .707, 500 watts/pair?
post #20 of 30
Quote:
Originally Posted by fish323 View Post

I've been eying these http://www.crutchfield.com/p_107MM1540/Polk-Audio-MM1540.html?tp=111, for $90 each they may not be a bad deal for dual cabs, dual-opposed sealed.

Could someone please model a pair of these (I suck at modeling) in a sealed cab with a Qtc of .707, 500 watts/pair?

A little research will show that these drivers don't meet specs and will not be the best choice for a quality HT subwoofer. Get a few Fi, Dayton, Stereo Integrity or other drivers and pound away!
post #21 of 30
Personally, I think you should go for dual ported boxes. The Dayton 390HO's don't do well in dual opposed sealed because of their lack of power handling and lack of excursion (Xmax). This alignment typically needs a LT circuit and lots of power for best results. A dual opposed sealed build with Dayton drivers will not give you the SPL you need for that large room. The Dayton's best qualities are relatively good sensitivity and low distortion. They make great low tuned (5-7 cu. ft.) ported boxes with relatively low power (~350W-500W/ea, depending on tuning and HPF).
post #22 of 30
Quote:
Originally Posted by SXRDork View Post

Personally, I think you should go for dual ported boxes. The Dayton 390HO's don't do well in dual opposed sealed because of their lack of power handling and lack of excursion (Xmax).
A dual opposed box will give exactly the same result as a close coupled pair of single driver boxes of half the size. There's nothing at all wrong with the 390HO, if it meets your design goals. The only advantage to two single loaded cabs versus one dual opposed is the room mode smoothing that can be realized with two cabs.
post #23 of 30
Quote:
Originally Posted by Bill Fitzmaurice View Post

A dual opposed box will give exactly the same result as a close coupled pair of single driver boxes of half the size. There's nothing at all wrong with the 390HO, if it meets your design goals. The only advantage to two single loaded cabs versus one dual opposed is the room mode smoothing that can be realized with two cabs.

Right. And neither configuration will meet the design goals of the OP, which is why I recommend two large ported boxes.

Perhaps two dual opposed or four small sealed would be adequate for 6000 cu. ft.
post #24 of 30
Quote:
Originally Posted by SXRDork View Post

Right. And neither configuration will meet the design goals of the OP, which is why I recommend two large ported boxes.
.
That has nothing to do with the suitability of dual opposed versus single loaded, or the capability of the 390HO. Optimally loaded two 390HO will have no problem matching the output of his Polk mains. Whether he decides to optimally load them and to use split placement is a different matter.
post #25 of 30
Quote:
Originally Posted by Bill Fitzmaurice View Post

That has nothing to do with the suitability of dual opposed versus single loaded, or the capability of the 390HO.

Oh I see, you're taking issue with my statement that the 390HO is not a good candidate for dual opposed. I would agree with your argument.

What I really mean is that in this particular instance dual opposed would not be the choice I would make if my drivers were two Dayton RS390HO's. The reason is that one could get more low frequency SPL in that large space using two ported subs, as was pointed out earlier in the thread.
post #26 of 30
Quote:
Originally Posted by SXRDork View Post

What I really mean is that in this particular instance dual opposed would not be the choice I would make if my drivers were two Dayton RS390HO's. The reason is that one could get more low frequency SPL in that large space using two ported subs, as was pointed out earlier in the thread.
I wouldn't use them in a dual opposed either, unless making two, a point I made quite a while back. But as to dual opposed versus the same two drivers in separate boxes, the result would be the same as far as SPL is concerned, it's only the room mode issue that's better addressed by having the drivers in two boxes rather than one.
post #27 of 30
Thread Starter 
At this point, it looks like I'll have to hold off on multiple 15's due to finances. But, I do have a few Audiomobile MASS 2012's not in use at the moment I can use. I do plan on getting the Dayton SA1000 for amplification also. I'd like to use a single 12" in dual ported cabs. If some of you guys wouldn't mind modeling these for me I'd much appreciate it.

Qts: 0.42 Qms: 5.80
Vas: 92L Qes: 0.45
Fs: 22Hz SPL: 90dB
Re: 7.6ohm Pe: 600w
Le: 0.507mH BL: 19.80
Xmax 20.0mm Diam: 12in
Z: 4.0ohm Sd: 0.046m^2
Mms: 160g
post #28 of 30
Thread Starter 
After talking to the wife & showing here how large these enclosures would be approximately, she won't go for dual cabs. I can, however, use my only corner (right side) along the front wall with whatever I want. I'm thinking for now a simple sealed design with dual woofers in a vertical array.

Any suggestions on a sealed cab size for a pair of the Audiomobile's (specs in above post) with 950 watts, with no high-pass filter preferably? Although the SA1000 has a switchable 18hz -3db filter.
post #29 of 30
1000 watts into 3 cubic foot sealed (green), 5 cubic foot sealed (red, overshoots xmax a bit on the low end), 5 cubic foot tuned to 20hz (blue). blue would need a high pass, but that comes standard on most plate amps. dual drivers in each cab.

the bash 500 watt amp will work too and its only $200. it will just have a 3db reduction in spl.

for a little more money, this one fits what you are looking for:
http://www.parts-express.com/pe/showdetl.cfm?partnumber=300-811


Edited by LTD02 - 7/10/13 at 4:28pm
post #30 of 30
Thread Starter 
Thanks LTD! What's the high-pass set at on the PE Bash 500, 18hz? Also, it looks like the graph on the Audiomobiles have a higher SPL than the Dayton drivers in the graph above. I'm curious how that could be? Or did I overlook something?
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