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.
Can you comment on whether the box checks out for the tune I am looking at? If I'm not mistaken it would be easy to swap out the driver and the amp in the future and still use this box so that is what I am most concerned about right now. It is designed to fit behind my screen between my speakers and I'm maximizing every cubic inch.I mean- If you want a sub that will barely do anything under 20hz lol. Buy something junky from a store if you want that level of performance and limited power. Youd probably save money
Looks good to me Pixel!I have about $300 invested in materials and there's no "junky" from the store that can match the performance I am modeling at that price. If you have ideas on how to maximize the materials I have to improve the performance I am all ears.
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. 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.
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.Swapping the driver won't change the box tune, unfortunately.
The response look decent if you don't care about frequencies below 20Hz but if you do (which if you're doing this for home theater, you SHOULD) I would drop the tune to around 15Hz or so.
BUT! It's all up to you man, this is your build and your take on the hobby! Have fun how you see fit!
Lower the volume (power to the driver) until the chuffing goes away. Then see where the SPL is. Here’s an article that explains how to use WINISD to find the port velocity. Like most articles of this nature, there is more information than you really need. But eventually he shows how to find the velocity.OK, so what did I do wrong? I finally got it working after having some issues with the amp but the performance is, if anything, worse than the Klipsch R112SW. I'm pretty much only getting chuffing below 30hz and it isn't until 35hz that things actually start to sound smooth but even there I'm getting a bit of chuffing. I'm worried my port tune isn't right and the inlet is too small. It's about 31" long and 1.15 inches tall. Man, I don't want to tear this thing apart but it just isn't good right now.
Good news at 35hz it gets freaking loud, but I didn't build it for 35 hz on up...
Thanks for tips, buuuut…I think you forgot the link 😜Lower the volume (power to the driver) until the chuffing goes away. Then see where the SPL is. Here’s an article that explains how to use WINISD to find the port velocity. Like most articles of this nature, there is more information than you really need. But eventually he shows how to find the velocity.
Sorry about that!Thanks for tips, buuuut…I think you forgot the link 😜
Would the b-b-b-b pulsing below 30hz be a result of air leaking?What about a gasket between the driver flange and the enclosure? If not, could it possibly leaking enough air to cause problems?