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Discussion Starter · #1 ·
So I have the old version of this sub leftover collecting dust in my dad's tool shed. I gave it to him as an Xmas gift to be used on his boat, but he ended up getting a new boat and never got around to installing it. It's just sitting there.


I just bought a brand new 1260 on ebay for $59. ( I need two subs).


They are to be used for different purposes. One is for my work office. Paired with pair of MTG's NEXUS MTM bookshelf and used only for music. The other is for my basement, Which will get used on my PC and also for music - I have a full Logitech 5.1 THX kit on my desktop but also run an output to an AVR for music through speakers in basement. I need a sub to go with that.


I'm interested in sound quality for the office set up volume isn't too important. I think I'm interested in good output for the basement.


I don't care about the size of the enclosure or how much wood it takes.


Suggestions ?
 

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Discussion Starter · #3 ·

Quote:
Originally Posted by A9X-308  /t/1525511/best-enclosure-box-design-for-a-59-infinity-1260-help-me-design-one/0_100#post_24560114


T/S parameters?


Here:
Quote:
Originally Posted by Mrkazador  /t/1524903/12-infinity-1260-file-fo...p-and-share-pretty-please/0_100#post_24545726

InfinityReference1260W.zip 1k .zip file

I am giving it a go now, see what I come up with.
 

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I don't use WinISD so I can't read that.
 

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Discussion Starter · #5 ·

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First of all, are you really sure you're only interested in music? If you don't have restrictions on how large the enclosure can be, a larger, lower-tuned box would get some pretty great results for movies if you ever decide to go that route. But since you said just for music...

 

For your basement to get the most output, a 2.6 cubic foot ported box, tuned to 23.5hz, gets you essentially flat response to 30hz and -3dB at 25hz. That's taking into account the high-pass filter a plate amp will have around 20hz. 300 watts rms gives you full driver excursion at 15hz, and amplifier apparent load power maxes at 288 watts, so you'd be set with a reliable plate amp with 300 watts rms at 4 ohms. A single 4 inch port, 21 inches long gives 26 m/s air velocity at 22.5 hz, but since you're not likely to play sine waves at 22.5 hz, you'll probably never hear port noise. Getting flared ports would also help with that. Now if you decide you want to do a more movie-focused sub (which would also be great for music), you could do a 5 cubic foot box tuned to 20hz, giving you -3dB somewhere below 20hz, but that's another story...

 

For the office, probably a smaller sealed box would be best, but I have very little experience with sealed boxes, so if someone else wants to help out with this one, that would be great. A 1.3 cubic foot box and one of the Dayton plate amps with parametric eq would give you -3dB at 30hz. A 250 watt rms amp would be enough to get full cone excursion, even taking into account the peq added. This is obviously going to get you less decibels than the ported design, but you said volume isn't important, and I'm guessing a smaller box in an office would be easier to place and work around. 

 

All of this is from plugging in the T/S values for that driver into WinISD and playing around with things. I hope this helps!
 

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Discussion Starter · #7 ·

Quote:
Originally Posted by TheGiantPeach  /t/1525511/best-enclosure-box-design-for-a-59-infinity-1260-help-me-design-one/0_100#post_24560323


First of all, are you really sure you're only interested in music? If you don't have restrictions on how large the enclosure can be, a larger, lower-tuned box would get some pretty great results for movies if you ever decide to go that route. But since you said just for music...


For your basement to get the most output, a 2.6 cubic foot ported box, tuned to 23.5hz, gets you essentially flat response to 30hz and -3dB at 25hz. That's taking into account the high-pass filter a plate amp will have around 20hz. 300 watts rms gives you full driver excursion at 15hz, and amplifier apparent load power maxes at 288 watts, so you'd be set with a reliable plate amp with 300 watts rms at 4 ohms. A single 4 inch port, 21 inches long gives 26 m/s air velocity at 22.5 hz, but since you're not likely to play sine waves at 22.5 hz, you'll probably never hear port noise. Getting flared ports would also help with that. Now if you decide you want to do a more movie-focused sub (which would also be great for music), you could do a 5 cubic foot box tuned to 20hz, giving you -3dB somewhere below 20hz, but that's another story...


For the office, probably a smaller sealed box would be best, but I have very little experience with sealed boxes, so if someone else wants to help out with this one, that would be great. A 1.3 cubic foot box and one of the Dayton plate amps with parametric eq would give you -3dB at 30hz. A 250 watt rms amp would be enough to get full cone excursion, even taking into account the peq added. This is obviously going to get you less decibels than the ported design, but you said volume isn't important, and I'm guessing a smaller box in an office would be easier to place and work around. 


All of this is from plugging in the T/S values for that driver into WinISD and playing around with things. I hope this helps!

For my office yes. This is where I work. It's only for music.


For the second one- I think I would like a balance of music and movies. This will be in my home, and will be multi purpose. Keep in mind I already own two subs in my theater, and this is not a dedicated theater sub. I am playing with the idea of sealed for the office.


It seems like a sealed sub is pretty simple construction wise; the power handling and low end extension are good- and the volume is enough.


For the other I am thinking ported - for extra output.
 

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Quote:
Originally Posted by Mfusick  /t/1525511/best-enclosure-box-design-for-a-59-infinity-1260-help-me-design-one#post_24560335



For my office yes. This is where I work. It's only for music.


For the second one- I think I would like a balance of music and movies. This will be in my home, and will be multi purpose. Keep in mind I already own two subs in my theater, and this is not a dedicated theater sub. I am playing with the idea of sealed for the office.


It seems like a sealed sub is pretty simple construction wise; the power handling and low end extension are good- and the volume is enough.


For the other I am thinking ported - for extra output.
 

For the multi purpose sub, if size really isn't an issue, you could do a 6 cubic foot box, tuned to 20hz, giving you -3dB at about 18.5 hz. The same 300 watt amp is still enough, but you would now need two 4 inch ports, each 25 inches long. Taking into account the volume lost to bracing and the ports, that's going to be a pretty large box. If you'd like, I can estimate some dimensions for you. It's also going to be a more complicated build, now requiring bracing of some kind. But hey, building it is half the fun, right? :)
 

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Discussion Starter · #10 ·

Quote:
Originally Posted by TheGiantPeach  /t/1525511/best-enclosure-box-design-for-a-59-infinity-1260-help-me-design-one/0_100#post_24560356


For the multi purpose sub, if size really isn't an issue, you could do a 6 cubic foot box, tuned to 20hz, giving you -3dB at about 18.5 hz. The same 300 watt amp is still enough, but you would now need two 4 inch ports, each 25 inches long. Taking into account the volume lost to bracing and the ports, that's going to be a pretty large box. If you'd like, I can estimate some dimensions for you. It's also going to be a more complicated build, now requiring bracing of some kind. But hey, building it is half the fun, right?

I don't mind the build. It's fun
 

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Quote:
Originally Posted by Mfusick  /t/1525511/best-enclosure-box-design-for-a-59-infinity-1260-help-me-design-one#post_24560405


Decisions... Decisions...



If you're really looking for down to or below 20hz performance, make sure to add a high pass filter to your models. I think the Bash amps at Parts Express has their at 18.5hz, or at least that's what I've heard before and based my models on. Adding that filter will change things a bit down around 20hz. But to my eyes, that red line is my favorite :)
 

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Red ported, yellow sealed.
 

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Quote:
Originally Posted by Mfusick  /t/1525511/best-enclosure-box-design-for-a-59-infinity-1260-help-me-design-one#post_24560443


I think I am leaning towards the BLUE one. 4.5 cubes and 23hz port. Perhaps 22.5hz ? Seems a good blend of everything. Yes?


Construction wise- I was thinking something simple like 30"x30"x30" with a slot port. 30" is 2.5' right ? So 2.5 x2.5x2.5 = 15.625 divided by 3 = 5.2 cubes before port, brace and woofer right ?


So lets call it 5.0 after woofer installed. Now let's figure out the port. That should take some volume off the 5.0 - might be a long port though.
You've done your maths wrong. You don't divide by three at the end. So that box would be 15.625 cubic feet minus material thickness, ports, driver, bracing. This might help:  http://www.hometheatershack.com/forums/enclosure-volume-calculator/
 

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Quote:
Originally Posted by Mfusick  /t/1525511/best-enclosure-box-design-for-a-59-infinity-1260-help-me-design-one#post_24560443


I think I am leaning towards the BLUE one. 4.5 cubes and 23hz port. Perhaps 22.5hz ? Seems a good blend of everything. Yes?


Construction wise- I was thinking something simple like 30"x30"x30" with a slot port. 30" is 2.5' right ? So 2.5 x2.5x2.5 = 15.625 divided by 3 = 5.2 cubes before port, brace and woofer right ?


So lets call it 5.0 after woofer installed. Now let's figure out the port. That should take some volume off the 5.0 - might be a long port though.
You've done your maths a little wrong. You don't divide by three at the end. So that size box would be 15.625 cubic feet minus material thickness, port, driver, bracing. I don't have permissions to post links, but search "enclosure volume calculator" and check out the one on hometheatershack
 

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Discussion Starter · #17 ·

Quote:
Originally Posted by TheGiantPeach  /t/1525511/best-enclosure-box-design-for-a-59-infinity-1260-help-me-design-one/0_100#post_24560485


You've done your maths a little wrong. You don't divide by three at the end. So that size box would be 15.625 cubic feet minus material thickness, port, driver, bracing. I don't have permissions to post links, but search "enclosure volume calculator" and check out the one on hometheatershack

Ok- so a 2' x 2' x 2' = 8 cubes right ? Minus woofer brings it to about 7.8 cubes right ?


Minus port would be ? Say 5.0 ? I'm just guessing. I guess I need to look at port design.
 

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Quote:
Originally Posted by Mfusick  /t/1525511/best-enclosure-box-design-for-a-59-infinity-1260-help-me-design-one#post_24560501



Ok- so a 2' x 2' x 2' = 8 cubes right ? Minus woofer brings it to about 7.8 cubes right ?


Minus port would be ? Say 5.0 ? I'm just guessing. I guess I need to look at port design.
Correct. But your port isn't going to be that big. Check this out. A 1.25 inch tall, 18 inch wide, 21 inch long slot port gets your tune to 23hz, and keep air velocity peaking at 21 m/s at 22hz. It takes up 496 cubic inches, according to that enclosure calculator I'm using from HTS. So a box that's using 3/4 inch thick wood could be 19.5 x 24 x 24 and would have an internal volume of 4.9 cubic feet (that's taking material thickness and port volume into consideration). That gives you almost half a cubic foot for bracing and the driver, which should be plenty. 
 

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125 litres net, 2 x 4" ports (with flares) tuned to 20Hz, ports 84cm long, 300W gets you to Xmax and you'll need at least a second order 18Hz HPF. The rest is geometry.
 

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Discussion Starter · #20 ·

Quote:
Originally Posted by TheGiantPeach  /t/1525511/best-enclosure-box-design-for-a-59-infinity-1260-help-me-design-one/0_100#post_24560530


Correct. But your port isn't going to be that big. Check this out. A 1.25 inch tall, 18 inch wide, 21 inch long slot port gets your tune to 23hz, and keep air velocity peaking at 21 m/s at 22hz. It takes up 496 cubic inches, according to that enclosure calculator I'm using from HTS. So a box that's using 3/4 inch thick wood could be 19.5 x 24 x 24 and would have an internal volume of 4.9 cubic feet (that's taking material thickness and port volume into consideration). That gives you almost half a cubic foot for bracing and the driver, which should be plenty. 

Ok- what is the value I want to stay under to avoid "CHUGGING" ?


I'm not sure if it's easier to use a square port or round ?


Look what I see with your results and only 100 watts:






Did I do something wrong ?


Or did you not bump up the wattage ?


I am thinking a slot port is easy construction. So if I just take the width and take off .75 for each side and another .75 for a brace down the center that dimension whatever it is seems best. Then just modify the length and height to match up to the tune I want. That makes sense ?
 
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