Sub lacking above 50hz

[acdcrocks0323]

Hi everyone. I purchased a Soubdqubed hds212 about a month ago. I built a vented box tuned to 30 hz and was about 2.5 cu ft which was recommended by WinISD based on its T/S parameters. I've been bumping it for a few weeks trying to get it dialed in and broken in (since I have read that the SQ suspensions are pretty stiff). I'm currently using a 4 channel amp with the rear 2 channels bridged. I have it crossed over at 80 hz. It's only pushing about 200 watts but I am upgrading my setup to have a dedicated sub amp.

Anyways, I am happy with how loud and low it can get, especially considering the low power it has been receiving. The problem is that there is a gap in between my components and the sub (btw I'm running JBL p660c with passive crossover). I know a sub shouldn't be responsible for too much of a frequency range, but it should surely be able to extend more than 30 hz-50hz before the output really diminishes. So what gives? Any suggestions or ideas of what I could do? Is this sub just not made to extend into low midbass territory? Thanks

Click to read more...

 

[hispls 5,000+ posts]

Tune at 30hz and that's pretty much what you'll get with a sub like that. Considering they're essentially a DD 95 knockoff I'd suggest playing them in the "DD box" for best results.

 

[acdcrocks0323]

Ok so I looked up the "DD box" The DD Box | DD Audio and the chart of guidlines is the same that the SQ website provides for its subs Box Sizes and Tuning . That is pretty much exactly what kind of specs that I'm using, 2.5 cu ft and that size port.

So what you're saying is since its tuned that low, I won't get any extension higher than 50? So how can I get a more flat response at least into 80? Just tune it higher?

 

[murph 10+ year member]

2 cubes 36hz

 

[NASTY08IMPALA 5,000+ posts]

Playing 20htz over box tuning with any kind of authority is askin for alot what kinda music do u listen to?

 

[mlstrass 5,000+ posts]

Try raising LPF on sub to 100/120Hz and see if that helps. Usually with AQ/DD subs tuning very low like that will cause them to roll off faster on the top end...

 

[Rich B 5,000+ posts]

Try reversing the + & - wires to the sub, you might have phase cancellation with the mids.

 

[Jeffdachef 5,000+ posts]

Pretty sure more power isnt going to solve this problem. You have a box that kills the lows but it might not necessarily be a flat response box. Download Winisd pro and look up a tutorial on how to use it on youtube. Car audio Fabrication (CAF) has a good beginners tutorial on YT. It'll show you the frequency response chart and you can plug in many tuning options and compare the differences in how the sub will sound with each tuning/box size.