Sub Box Help

[pwmin]

Since my MTX RT12 seems like it's going out and is in a generic truck box, I'm wanting to build a box correctly for the RT10-04 I have sitting around that I forgot about. The amp is a Lightning Audio B.200.2. I'm just going to go side-fire and I'm just looking for a box w/ no angles. I don't necessarily need dimensions as I can figure that out, mostly just cubic inches.

 

sub: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=293-350

amp: http://www.crutchfield.com/S-jF2JLdR52nW/p_495B2002/Lightning-Audio-B200-2.html?tab=other_items#accessories-tab

Edited December 24, 2012 by pwmin

[xtremerevolution]

Since my MTX RT12 seems like it's going out and is in a generic truck box, I'm wanting to build a box correctly for the RT10-04 I have sitting around that I forgot about. The amp is a Lightning Audio B.200.2. I'm just going to go side-fire and I'm just looking for a box w/ no angles. I don't necessarily need dimensions as I can figure that out, mostly just cubic inches.

 

sub: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=293-350

amp: http://www.crutchfield.com/S-jF2JLdR52nW/p_495B2002/Lightning-Audio-B200-2.html?tab=other_items#accessories-tab

 

Give me a couple days and I'll get a sub box model set up for you.

[pwmin]

sweet...thanks!

[pwmin]

Give me a couple days and I'll get a sub box model set up for you.

make any headway on this? My sub is starting to sound like shit off and on, but it's getting more frequently bad.

[xtremerevolution]

make any headway on this? My sub is starting to sound like shit off and on, but it's getting more frequently bad.

 

Shit, I forgot about this. I'll get you one soon, like asap.

 

Sent from my HTC Awesome using Tapatalk

[pwmin]

Shit, I forgot about this. I'll get you one soon, like asap.

 

Sent from my HTC Awesome using Tapatalk

It's cool. Thanks.

[MonteCarloChick]

http://audio.manualsonline.com/manuals/mfg/mtx_audio/rt1004.html?idRes=12776842 ?

[xtremerevolution]

http://audio.manualsonline.com/manuals/mfg/mtx_audio/rt1004.html?idRes=12776842 ?

 

Online calculators and manufacturer specified sub boxes are beyond terrible. They make those to suit the vast majority of people who just want loud and to save themselves from warranty returns.

 

It was my wife's birthday yesterday so I didn't get around to it, but I have time today so you'll get a proper sub box design by tonight.

 

Sent from my HTC Awesome using Tapatalk

[pwmin]

that's fine. I'm away for work and won't be back until late thursday anyway. I was hoping I would be back tomorrow, but no

[xtremerevolution]

Alright, finally got some time to work on this. Sealed is not an option as the sub is made for a ported box, so you'll have to go vented. Unfortunately, it also needs a bit of a large-ish box.

 

You'll need one 4" port at 17" in length. Use one of these and just glue it all together, or use 4" PVC pipe. This kit will give you a port length of exactly 17":

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=268-352

 

NET volume is 1.85 cubic feet

Port displaces .14 cubic feet

Sub displaces .08 cubic feet

 

Total GROSS volume is 2.07 cubic feet. Its bigger than your other box, but this sub doesn't play very nice in smallish boxes and unless you're willing to give up some of that bottom end you get in dubstep, rap/hip-hop and techno, it will have to be this big.

 

One box example would be 15" Height x 15" Depth x 21" Width with 3/4" MDF. Fire the sub out the front of the box, and the port out the side. I think you will be thoroughly impressed with the way this box sounds. I can get you a different box dimension if you'd like. I would recommend some bracing or a double thick baffle. You can use 1" coat hanger rods or 2x4s.

 

Image models are attached with cabin gain included.

Edited November 10, 2011 by xtremerevolution

[pwmin]

Thanks, man. I'll check into the dimensions and see if they'll work. Hopefully I'll be able to start on this Monday as I won't have any time this weekend. I'm willing to give a ported box a chance. I actually do remember now trying to make one once but it was a miserable attempt as I had absolutely no clue what I was doing, lol.

[xtremerevolution]

Thanks, man. I'll check into the dimensions and see if they'll work. Hopefully I'll be able to start on this Monday as I won't have any time this weekend. I'm willing to give a ported box a chance. I actually do remember now trying to make one once but it was a miserable attempt as I had absolutely no clue what I was doing, lol.

 

Well, if you want to use this sub, its going to have to be a ported box. It will bottom out in a sealed box on low notes. I do think you will like it though. The model looked real nice.

 

Sent from my HTC Awesome using Tapatalk

[pwmin]

looks like the dimensions will work. It won't be able to find under the stb, but I can just move it back. If I make it shorter, I'll have to make it longer and it's already long enough. I just hope I can still get a larger bin in the trunk, but I'm pretty sure I still would be able to.

[xtremerevolution]

looks like the dimensions will work. It won't be able to find under the stb, but I can just move it back. If I make it shorter, I'll have to make it longer and it's already long enough. I just hope I can still get a larger bin in the trunk, but I'm pretty sure I still would be able to.

 

Well, being a 12" sub, it needs to be a tad bit taller anyway. Looking forward to seeing this box built.

[pwmin]

Well, being a 12" sub, it needs to be a tad bit taller anyway. Looking forward to seeing this box built.

It's a 10" sub...the 12 is going bad

[xtremerevolution]

It's a 10" sub...the 12 is going bad

 

Lol, nevermind. Confused myself for a second. The model was done with the 10" though.

[pwmin]

Lol, nevermind. Confused myself for a second. The model was done with the 10" though.

lol, ok, thought i was clear, but just wanted to make sure

 

Those measurements are OD, right?

[xtremerevolution]

lol, ok, thought i was clear, but just wanted to make sure

 

Those measurements are OD, right?

 

Yep.

[pwmin]

well, i fucked up, lol and made the hole for the sub on the long side of the box....offset to the left. I think I want to orient the box the other way, anyway as it looks like it will fit in the trunk better that way. Should the port be behind the sub then or still where you said to put it? I did add one 1" dowel longways and did a double baffle.

[white4d96]

I think you could do port off to the side of the sub and still be good. Not 100% on what you mean by on the long side to the left, but if it's what I think you mean you'll be good.

 

And uh, Andrei, about the sealed boxes bottoming on low notes, I'm not 100% that that's correct. I know ported boxes will unload and bottom out below tuning (unless you use tiny ports) but if memory serves on lower notes the sealed boxes just have rolloff from the cone having to push through higher pressure air the further it moves. Then again I haven't looked into it in awhile, I haven't gone sealed in 4 years

[xtremerevolution]

well, i fucked up, lol and made the hole for the sub on the long side of the box....offset to the left. I think I want to orient the box the other way, anyway as it looks like it will fit in the trunk better that way. Should the port be behind the sub then or still where you said to put it? I did add one 1" dowel longways and did a double baffle.

 

You can put the port anywhere really as long as it fits inside the box and clears the sub.

 

I think you could do port off to the side of the sub and still be good. Not 100% on what you mean by on the long side to the left, but if it's what I think you mean you'll be good.

 

And uh, Andrei, about the sealed boxes bottoming on low notes, I'm not 100% that that's correct. I know ported boxes will unload and bottom out below tuning (unless you use tiny ports) but if memory serves on lower notes the sealed boxes just have rolloff from the cone having to push through higher pressure air the further it moves. Then again I haven't looked into it in awhile, I haven't gone sealed in 4 years

 

It depends on the sub and how the sub is made. You should try modeling a variety of subs and see how it works. If you tune a box low enough (such as this one), you won't have a problem with the sub unloading. You'll notice from the excursion plot that we're within xmax till down to 26hz. That's 25hz of distortion-free output. We can probably get down to 24hz or 23hz before we hit xlim, which is the maximum mechanical excursion. What music do you know of that plays that low? I don't know of any except for organ music. The whole "sub unloading" deal is a non-issue with a correctly designed box that's tuned low for SQ.

 

Looking at the excursion plot again, you'll see that the excursion is severely controlled near the tuning frequency. The port creates the output at that point.

 

Try modeling this same sub box in WinISD Pro and checking the excursion at rated power. What you'll find is that it bottoms out very, very quickly under rated power, and to fix that, you'd have to give it considerably less power to keep it within excursion limits. Alternately, you have to make the box significantly smaller, which in turn raises your Qts and eliminates your bottom end output, making your sub sound boomy, uncontrolled, and just plain bad.

 

Few subs are suitable for both ported and sealed duty. Most subs are ideal for only one or the other. This particular sub did not model well in a sealed alignment.

[pwmin]

yeah, so I got the box built (minus the carpet) and hooked it up and I'm getting feedback wherever the volume is. Obviously, if I turn it up i can't hear it, just bass, but that's not cool. So I messed w/ the RCA's and I can wiggle them and the sound goes away and comes back depending on the position. Of course it's the amp and not the sub. I hooked another set of RCA's up to the ones that were already ran and wiggle the connection and it doesn't change anything, but w/ the new RCA's if I wiggle them at the amp, it comes on and off. Guess I'll just have to deal with it. I'm going to put the 12" back in and just run it until I can afford an amp. Not sure why I get feedback with this amp/box and not with the other one, but the other one is not air tight

[pwmin]

thinking about getting this amp...http://www.sonicelectronix.com/item_33117_Crunch-PZA700.2.html

 

I want something that I could possibly use to run the fronts later on (and cheap). For cheap amps, Crunch have always seemed decent in my experience.

[xtremerevolution]

thinking about getting this amp...http://www.sonicelectronix.com/item_33117_Crunch-PZA700.2.html

 

I want something that I could possibly use to run the fronts later on (and cheap). For cheap amps, Crunch have always seemed decent in my experience.

 

I have no experience with that brand. In my experience, you get what you pay for. Those ratings are not RMS by the way.

Edited November 23, 2011 by xtremerevolution

[pwmin]

I have no experience with that brand. In my experience, you get what you pay for. Those ratings are not RMS by the way.

shit, didn't notice that, lol. All the others I looked at had RMS first and I just assumed....ass out of me