XCON 15 sealed

[edouble101 314]

Unfortunitely I need to build a new home for my XCON 15. The current enclosure is 4^3ft net tuned to 32hz. I love it. The output is good and the sound quality is great. BUT!!! I need to get some cargo area back. After tossing around a few ideas I decided to sick with my XCON but build a 3.0^3ft sealed enclosure for it. I am really going to miss the ported output

How much polyfill should I add in the enclosure? Will the sub still handle 1750wrms daily?

[sefugi 166]

I would say it should still do the power. Try this sight for polyfill info: http://audiojunkies.com/forum/blog/4777-ultimate-polyfill-subwoofer-enclosure-resource.html

[Sir-Lancelot 216]

I don't think you would need any man. I ran a pair of 15" Xcons in 6cf and the box was maybe a little too big.

If anything you could go smaller on the box and stuff it with pollyfill. NP on that power either IMO.

I will say this, they will freaking pound in a sealed box and sound excellent doing so.

You will be VERY surprised with the output you will get. Excellent choice for sealed boxes and it was prolly was more their design even though everyone ports them.

[95Honda 486]

I don't know what the T/S parameters are, but if that box gives a Q of around .7 or less than polyfill won't make things any better. May even sound worse to alot of people....

[edouble101 314]

Thanks

[edouble101 314]

I don't know what the T/S parameters are, but if that box gives a Q of around .7 or less than polyfill won't make things any better. May even sound worse to alot of people....

Calculating vb with a qtc of 0.70 I get 1.75^3ft. This is much different than the recommended enclosure volumes.

EBP = 69.56 which indicates that the XCON 15 is suited for both ported and sealed

alpha x = 1.778 = (qtc/qts)^2-1) = (.70/.42)^2-1

Vb = 1.756^3ft = vas/x = 3.122/1.778

Resonant freq = 52hz = qtc/qts(fs) = .70/.42(31.3)

Are my calculations correct? Will the XCON 15 perform optimally in a 1.756^3ft net enclosure?

[Notorious97200 339]

I don't know for your calculations, but 3 ft3 is good for a sealed box. I ran mine in a box like that on 1500 watts, and it was sounding very very good. But you loose some output if you compare with a ported box.

Stick with the 3 ft3 box.

[edouble101 314]

I don't know for your calculations, but 3 ft3 is good for a sealed box. I ran mine in a box like that on 1500 watts, and it was sounding very very good. But you loose some output if you compare with a ported box.

Stick with the 3 ft3 box.

Why is a qtc of 0.60 with a vb of 3.0^3ft better than a qtc of 0.70 with a vb of 1.75^3ft?????

[REVpuggie 23]

Never met any goal using polyfill .. make a propper size box , no polyfill , the effects of polyfill aren't that big anyway

[edouble101 314]

Never met any goal using polyfill .. make a propper size box , no polyfill , the effects of polyfill aren't that big anyway

THanks

I don't know for your calculations, but 3 ft3 is good for a sealed box. I ran mine in a box like that on 1500 watts, and it was sounding very very good. But you loose some output if you compare with a ported box.

Stick with the 3 ft3 box.

Why is a qtc of 0.60 with a vb of 3.0^3ft better than a qtc of 0.70 with a vb of 1.75^3ft?????

Can anybody spread some knowledge on this?

[///M5 2,833]

I don't know for your calculations, but 3 ft3 is good for a sealed box. I ran mine in a box like that on 1500 watts, and it was sounding very very good. But you loose some output if you compare with a ported box.

Stick with the 3 ft3 box.

Why is a qtc of 0.60 with a vb of 3.0^3ft better than a qtc of 0.70 with a vb of 1.75^3ft?????

May or may not be for you, depends on your goals. Every manufacturer has to pick a Qtc for their recommended box sizes. Normally they end up having someone in marketing choose a number that the engineers present to them that they feel corresponds to their specific market. Generically speaking .7 is considered normal and lower numbers are more damped higher more "warm". On top of that the Q of the box will affect the roll off in the frequency domain. In the car audio world this can also be chosen such that it utilizes the "average" cabin gain effectively.

I think no one really answered because you said better or they don't understand Qtc. Different sure, better, maybe.

For sealed boxes in a listening area I would definitely encourage polyfill, for a trunk of a car not so much. It isn't only used for making the driver think its in a larger enclosure.

[edouble101 314]

I don't know for your calculations, but 3 ft3 is good for a sealed box. I ran mine in a box like that on 1500 watts, and it was sounding very very good. But you loose some output if you compare with a ported box.

Stick with the 3 ft3 box.

Why is a qtc of 0.60 with a vb of 3.0^3ft better than a qtc of 0.70 with a vb of 1.75^3ft?????

May or may not be for you, depends on your goals. Every manufacturer has to pick a Qtc for their recommended box sizes. Normally they end up having someone in marketing choose a number that the engineers present to them that they feel corresponds to their specific market. Generically speaking .7 is considered normal and lower numbers are more damped higher more "warm". On top of that the Q of the box will affect the roll off in the frequency domain. In the car audio world this can also be chosen such that it utilizes the "average" cabin gain effectively.

I think no one really answered because you said better or they don't understand Qtc. Different sure, better, maybe.

For sealed boxes in a listening area I would definitely encourage polyfill, for a trunk of a car not so much. It isn't only used for making the driver think its in a larger enclosure.

Ah, I somewhat understand this better now.

So for the XCON 15 in the trunk of my car, forward facing, which qtc value should I use with it's corresponding vb? I want good low end extension with smooth frequency responce. I also do not want to limit power handling due to an improper enclosure size.

[Sir-Lancelot 216]

Why not build a box on the bigger side (3cf) and add mdf to the inside until you get what your after. Then you can rebuild to that size to reduce the space.

Best I can tell you is 3cf sounded very good, but could have been a little smaller with no issues.

[edouble101 314]

Why not build a box on the bigger side (3cf) and add mdf to the inside until you get what your after. Then you can rebuild to that size to reduce the space.

Best I can tell you is 3cf sounded very good, but could have been a little smaller with no issues.

I already "guessed" at an enclosure which sounds great and sends my car into a state of destruction but ate my trunk area in the process. So this time around I am trying to think a little more about it so I do not have to redo it again. Honestly Lance, I do not want to have to spend hours/days/weeks tuning this and changing box volumes. I would rather use a little math and help form you guys to do it right the second time aorund. I really do not want to drop $250 for Term-pro either. I do not have the knowledge just yet(!) to predict power handling based on vb and to be able to accurately guesstimate frequency response. I do have Winisd but ehh....

Your experience helps alot, as you stated 3 cubes (qtc of .6) is a start but could be better. OK, how much better.... 1.75 cubes (qtc.7), is better yet. Optimal?

[Sir-Lancelot 216]

Why not build a box on the bigger side (3cf) and add mdf to the inside until you get what your after. Then you can rebuild to that size to reduce the space.

Best I can tell you is 3cf sounded very good, but could have been a little smaller with no issues.

I already "guessed" at an enclosure which sounds great and sends my car into a state of destruction but ate my trunk area in the process. So this time around I am trying to think a little more about it so I do not have to redo it again. Honestly Lance, I do not want to have to spend hours/days/weeks tuning this and changing box volumes. I would rather use a little math and help form you guys to do it right the second time aorund. I really do not want to drop $250 for Term-pro either. I do not have the knowledge just yet(!) to predict power handling based on vb and to be able to accurately guesstimate frequency response. I do have Winisd but ehh....

Your experience helps alot, as you stated 3 cubes (qtc of .6) is a start but could be better. OK, how much better.... 1.75 cubes (qtc.7), is better yet. Optimal?

I wish I had the answer for you Buddy. I am old school and just build and build again until I like it.

Hopefully someone with some good modeling software will chime in and give you some guidance. I aint your man for that, but feel sure someone will help out shortly.

[liljestrand 244]

I have 2 in 3cf sealed chambers off 1500 watts a piece and I love it

[95Honda 486]

I think you will be happy anywhere between 2-3 ft3. Another nice thing about sealed boxes is that they are very forgiving as far as miss-alignments...

Personally, I would put it in a 2ft3 ish box with no fill.... The only type of dampening I use in a sealed box that already has a target Q is to line the walls with an inch or so of fiberglass for the sole reason of cutting down distortion caused by mechanical driver noise/upper harmonics...

[edouble101 314]

I have 2 in 3cf sealed chambers off 1500 watts a piece and I love it

Thanks for posting!

I think you will be happy anywhere between 2-3 ft3. Another nice thing about sealed boxes is that they are very forgiving as far as miss-alignments...

Personally, I would put it in a 2ft3 ish box with no fill.... The only type of dampening I use in a sealed box that already has a target Q is to line the walls with an inch or so of fiberglass for the sole reason of cutting down distortion caused by mechanical driver noise/upper harmonics...

Thanks. I plan on mounting the driver with the magnet out so no need to try to reduce mechanical noise.

I am going to pick up The Loudspeaker Design Cookbook. Hopefully a 'lil reading will clear out some of the questions I have floating around in my brain.

[///M5 2,833]

Be a little wary, it isn't bathroom reading. If you take the time to read AND understand it though, everything will be much clearer.

[95Honda 486]

Just FYI, if you mount the driver with the magnet out you will hear the maximum amount of mechanical noise..... But, I haven't ever heard of this to be an issue with your drivers, so it is probably won't even be discernable at most...

[edouble101 314]

Be a little wary, it isn't bathroom reading. If you take the time to read AND understand it though, everything will be much clearer.

Gotcha

Just FYI, if you mount the driver with the magnet out you will hear the maximum amount of mechanical noise..... But, I haven't ever heard of this to be an issue with your drivers, so it is probably won't even be discernable at most...

Perfect!

[eggyhustles 33]

Hmm..didn't know the 15's worked in small sealed

[///M5 2,833]

Hmm..didn't know the 15's worked in small sealed

Enclosure Recommendations:

* Sealed: 2.0 - 2.25 cu.ft.

* Sealed: 2.75 - 3.0 cu.ft. optimal

* Ported: 3.0 - 3.25 cu.ft. @ 26-33 hz

* Ported: 4.0 cu.ft. @ 26-33hz opt.

* Sub Outside Dia.: 15.625”

* Cut Inside Dia.: 14.125”

* Displacement: 0.20 cu.ft.

From : http://www.soundsolutionsaudio.com/store/products/15%22-SSA-XCON-D1%7B47%7DD2.html

[tc300 2]

Anybody know of some other 15's that work in small sealed boxes..??

I'm wanting to do a dual 15 sealed setup..

Right now I'm lookn at the DC lvl 3 15's.

I have around 4.2ish cuft to work with...