I should add that my BASH amp will be used externally so I can have the option later of adding a Behringer amp or similar.
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[Update: Need help, it’s a chuffy mess] Does this build look good? Its my first. MX15 with BASH 300S
I'm having a really hard time designing the box for my build on both SubBox.pro and speakerboxlite.com. On SubBox.pro I clearly am struggling because everytime I try a new build it ends up looking different and half the time the port sticks out the side 
I've already worked a bit with @Stephen Hopkins and came up with a ~18.5hz tune on a 6 cu ft box, a 15.1hz HPF and a 2db boost at 22hz on the BASH amp. Here's what that all looks like in WinISD:
![3155636]()
![3155637]()
![3155638]()
That's mostly just for background though because I think I'm pretty happy with the modeling.
Here's what I came up with on speaker box lite for the box. Please let me know if all of this looks good or not. What threw me off is that my enclosure size and tune isn't very different than the VBSS build but my port looks pretty different. I'm not sure if that's fine or not or if I just don't understand something else that's going on. Thanks for the help!
![3155641]()
![3155642]()
![3155643]()
I've already worked a bit with @Stephen Hopkins and came up with a ~18.5hz tune on a 6 cu ft box, a 15.1hz HPF and a 2db boost at 22hz on the BASH amp. Here's what that all looks like in WinISD:
That's mostly just for background though because I think I'm pretty happy with the modeling.
Here's what I came up with on speaker box lite for the box. Please let me know if all of this looks good or not. What threw me off is that my enclosure size and tune isn't very different than the VBSS build but my port looks pretty different. I'm not sure if that's fine or not or if I just don't understand something else that's going on. Thanks for the help!
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Looks good to me Pixel!
I just happen to have two end tables I built to hold 15's at 6.1 cubic feet and a huge slot port. Oddly enough, the original 15 I planned on using I have only one of....then it vanished. No biggie, that lone 15 won't be an orphan because it works brilliantly in the F20 tapped horn remodeled to a 22Hz knee for my garage. Yeah, Plan B.
So I'm looking at a pair of the MX15's in a 6.1 cubic box net with a port that stays under 18 meters per second with 20mm of Xmax--built that way for upgrades in the future--the future is now! The reasoning is to tune it for 18Hz with a HP at 15Hz or lower depending on available Xmax so room gain (in my case below 22Hz) kicks in to give me some 16Hz love. My pro amp will push 500 watts each so no worries about blowing the cone across the room.
Your design looks good, stout box construction and the driver operates well within it's specs with the Bash 300. Nothing wrong with not hammering a sub driver to it's limits--it is actually a GOOD thing! After all, the harder you drive a subwoofer with power, the distortion jumps and so does power compression. I've always defaulted to add more subs to get SPL than one big one running at it's limits--the lowered distortion, more even bass response using multiples and increased reliability make up for watching a cone jump around. I hide my subs so don't get to watch it stroking anyway--YMMV.
The thing to look at is the meters per second of airflow through the port--if anyway possible, it is best to keep it below 18 to 20 meters per second at max output. Then model your build with increased power until it exceeds rated Xmax +10% to see if it stays below 20 m/Sec. If it does, then you are golden! You don't HAVE to run a sub at Xmax, I have four 15's in my garage that won't reach Xmax due to lack of power. They cleanly shake the garage, attached house and my neighbors house and I get a visit from local law enforcement.
The sheriff told me he really liked the subs though. If/when I so choose, I can double the wattage to them to gain 3dB but.. they hit 117dB measured 12 feet back so.... stuff starts falling off the shelves and my garage door resonates like a gong so I need to fix all that first. The audiophile police have not arrested me in the last 7 years for not driving my subs to Xmax....yet. After making sure the port flow is good, what about braces for the box? Generally two or more braces on the front bezel to the back and throw a cross brace (or two) top to bottom and left to right to make the box rigid. Plenty of threads on box bracing to help.
In summation, since it is for background sound the SPL capabilities with the Bash amp should be more than enough. In room, you should have the ability to "tickle" 16Hz (16Hz -6dB) if you have any form of room gain so enjoy the fruits of your labor. Always the option to build another one to gain another 3 to 6dB...or max out the driver to get 3 or 4dB if you like. I tend towards more cones and quantity to boost efficiency, lower distortion and run multiple channels for backup over throwing max power at one sub. For the record, my garage subs are four 15's with 3 inch voice coils running at 400 watts...combined---as in 100 watts each.
My garage is "active" in that my circular saws, lights, tool chargers etc. all share the same 20A breaker so the sound system can't suck up the power! The saw can pull 13 amps, the other stuff in the garage a few amps and although the subs can handle 3 times the power, my breaker won't! Hence why four subs at 400 watts VS a single sub at 1,600 watts wins. Rock on!
Awesome, thanks for the input! Do you know a way to check out airflow? Will WinISD do that?Looks good to me Pixel!
I just happen to have two end tables I built to hold 15's at 6.1 cubic feet and a huge slot port. Oddly enough, the original 15 I planned on using I have only one of....then it vanished. No biggie, that lone 15 won't be an orphan because it works brilliantly in the F20 tapped horn remodeled to a 22Hz knee for my garage. Yeah, Plan B.
So I'm looking at a pair of the MX15's in a 6.1 cubic box net with a port that stays under 18 meters per second with 20mm of Xmax--built that way for upgrades in the future--the future is now! The reasoning is to tune it for 18Hz with a HP at 15Hz or lower depending on available Xmax so room gain (in my case below 22Hz) kicks in to give me some 16Hz love. My pro amp will push 500 watts each so no worries about blowing the cone across the room.
Your design looks good, stout box construction and the driver operates well within it's specs with the Bash 300. Nothing wrong with not hammering a sub driver to it's limits--it is actually a GOOD thing! After all, the harder you drive a subwoofer with power, the distortion jumps and so does power compression. I've always defaulted to add more subs to get SPL than one big one running at it's limits--the lowered distortion, more even bass response using multiples and increased reliability make up for watching a cone jump around. I hide my subs so don't get to watch it stroking anyway--YMMV.
The thing to look at is the meters per second of airflow through the port--if anyway possible, it is best to keep it below 18 to 20 meters per second at max output. Then model your build with increased power until it exceeds rated Xmax +10% to see if it stays below 20 m/Sec. If it does, then you are golden! You don't HAVE to run a sub at Xmax, I have four 15's in my garage that won't reach Xmax due to lack of power. They cleanly shake the garage, attached house and my neighbors house and I get a visit from local law enforcement.
After making sure the port flow is good, what about braces for the box? Generally two or more braces on the front bezel to the back and throw a cross brace (or two) top to bottom and left to right to make the box rigid. Plenty of threads on box bracing to help.
In summation, since it is for background sound the SPL capabilities with the Bash amp should be more than enough. In room, you should have the ability to "tickle" 16Hz (16Hz -6dB) if you have any form of room gain so enjoy the fruits of your labor. Always the option to build another one to gain another 3 to 6dB...or max out the driver to get 3 or 4dB if you like. I tend towards more cones and quantity to boost efficiency, lower distortion and run multiple channels for backup over throwing max power at one sub. For the record, my garage subs are four 15's with 3 inch voice coils running at 400 watts...combined---as in 100 watts each.
Rock on!
I recall playing around with dropping the tune and while I could eek out a bit more for the -10/-6db point but I would lose output in the 20-40hz range. As 18Hurts said I am hoping for a bit of room gain to help me "tickle" the mid teens. It's not a large room at 1100 cu ft.
@drewp29 Thank you for very much for the input. It is an MX15-22. I ran Audyssey and actually tried to integrate the sub to see how it performed. I then ran a sweep in REW from 15hz to 200hz and this is what happens:
![3163334]()
I'm not educated enough to know how exactly to read this but what I can say is that below 30hz the sub is all sorts of thumps-bumpy. Trying to figure out how to explain it. It sounds like someone with a stutter saying b-b-b-b over and over until it hits 30hz. It sounds like a smidge of chuffing now and not as bad before...I think I just had it turned up too loud. I honestly have no clue what is wrong. I've looked over the sub and it is pretty darn solid. I remember using a ton of glue too because I cared more about it being solid than pretty. I used screws to hold it together instead of clamps too.
I haven't checked the wiring because I made the hole just a smidge too large and the screws just barely grabbed the MDF all the way around. I didn't want to have to unscrew it all if I didn't need to, just in case I have issues putting it back together. In case the question comes up of whether the woofer is secure and sealed or not, I do believe it is upon inspection. Here's a couple shots of the build
![3163333]()
![3163332]()
I tried flipping the phase switch on the BASH amp (because I barely know what I'm doing) and I got this in REW which the FR is nice that it goes so low but it is still super distorted and sounds pretty much the same as before:
![3163329]()
I'm not educated enough to know how exactly to read this but what I can say is that below 30hz the sub is all sorts of thumps-bumpy. Trying to figure out how to explain it. It sounds like someone with a stutter saying b-b-b-b over and over until it hits 30hz. It sounds like a smidge of chuffing now and not as bad before...I think I just had it turned up too loud. I honestly have no clue what is wrong. I've looked over the sub and it is pretty darn solid. I remember using a ton of glue too because I cared more about it being solid than pretty. I used screws to hold it together instead of clamps too.
I haven't checked the wiring because I made the hole just a smidge too large and the screws just barely grabbed the MDF all the way around. I didn't want to have to unscrew it all if I didn't need to, just in case I have issues putting it back together. In case the question comes up of whether the woofer is secure and sealed or not, I do believe it is upon inspection. Here's a couple shots of the build
I tried flipping the phase switch on the BASH amp (because I barely know what I'm doing) and I got this in REW which the FR is nice that it goes so low but it is still super distorted and sounds pretty much the same as before:
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