HELP!!! First DIY Sub and I'm having problem!! Sub Pop!

clip clip...

clipping should sound more like distortion than popping.

speaker wattage is THERMAL not mechanical.

you can bottom out a speaker at 1/10th of a power rating or less depending on enclosure design.

build a new subwoofer ...

I have used that driver in multiple subs over the last few years. In a 1.2cf sealed box, you have to have a 20hz SSF to keep it from bottoming out. In a larger box it takes less power. Factor in your amp with unknown boost and an unknown SSF and there is a very good chance you are bottoming the driver.

-Robert

I have the same woofer in a sealed box, and it's quite easy to bottom it out. I do like the way it sound in the sealed box, but don't like it bottoming out so easily when turned up. I'm in the process of designing and building a ported box. 5.1 cu ft, tuned at 19hz. The port is 4x15. Its a great subwoofer till you start to push it in a sealed box.

subsonic filtering ( equalization ) alone will allow you to make your subwoofer louder. ported enclosure will double the loudness of your subwoofer on top of that.

but ultimately even that may not be enough and then you will simply have to build a bigger subwoofer.


subwoofer can fail in many ways. one way it can fail for example is if you toss it out of the window from the third floor onto solid concrete.

another way is if you play a 600W 1 khz sinewave until it begins to smoke and you burn out all of the glue holding the voice coil together.

another way is you take it out of the box and play a 5 hz sinewave at say a mere 50 watts with the voice coil getting slammed into the back plate until it bends out of shape.

the 600W rating does not apply to the case of throwing the subwoofer out of the window. it also does not apply to the case of 5 hz sinewave running free-air. it only applies to the case of running a subwoofer properly without any frequencies/enclosure combinations that may result in bottoming out.

it makes no sense to have a spec that for the power level that will bottom a subwoofer out because it depends on enclosure and frequency. instead the power spec you see is for the voice coil BURNING out, because that one doesn't depend either on enclosure or frequency but only on available amplifier power.

with proper combination of enclosure and subsonic filter you will be able to use the entire 600 watts. however your low frequency response may not be then as good as you want. ultimately you may simply need to either build a bigger subwoofer or add a second one.

I have one in a 4cf sonotube tuned to 21 hz (4" x 17" PSP flared port) with an older model Parts Express 275w amp. I think the stock SSF is somewhere between 18hz and 20hz. Yes, I can still bottom it out but it is much louder than the sealed box it was in. Good thing this is going to a family member because it wouldn't last a week.

-Robert

Well I have 2 options. One is downfiring, which uses up less foot space and the other is a front firing. The front firing is like this svsound, (http://svsound.com/products-sub-box-pb12nsd.cfm ) only a bit bigger, 20x22x25. The downfiring is 17x17x39, same size ports. WinIsd suggest this woofer ported, and that modeled very well. Those were outside measurements, with .75" sides and 1" front baffle. I prefer downfiring, so that's what I'm leaning towards right now.

You really should learn to do the math to find out what is up. The spreadsheets Linkwitz supplies can help you a lot. Myself, I only do sealed low Q subs, but I calculate were I am going so I know if I can reach the sound level I want the driver/amp/box combination. Personal choice, but I hate ported enclosures.
You would be AMAZED at how much piston area you really need to do 20Hz in a fair sized room even taking advantages of multiple boundaries.
Stay away from down-fire! The drivers are not meant for that kind of offset.
If you want it loud, you need a lot of cone, and a lot of box. Fair size room, 4 12's each with 50L or so and you may still need very low protection. That is unless 100% THD is OK, then just drive the heck out of anything.