Ive currently got a DD9512 on an eAudio3000D @ 1 ohm.

Problem is that it doesnt play the lows all that well. Its in a 2.5 cube box tuned to 40Hz (design from DD Phil). Has anybody tuned this sub to lower than 40Hz? What about making a bigger box? Will that help with the lows? Dont get me wrong, the sub is very loud, but its just annoying that it struggles so much with the lows...

Any ideas or suggestions?

Thanks.

I think i found the reason for the poor low end. My ss filter was set a bit high.... I hate when I overlook simple things like this

Anyway im still curious, has anybody tuned this sub to lower than 40Hz and also what effect would it have if I build a bigger box?

i wouldnt go much bigger then the 2.5cube. just add more length to the port or redo the port. thats my suggestion.

They're not a sub for lows, they kick ass at their 40-55hz peak. Tune lower, and you'll lose the energy in those frequencies. A bigger box does'nt seem to help either. I tuned my old one at 37-38hz for a small advantage at the low end, without sacrificing things past 40hz. It worked to the mid 30's, but fell off quickly from there.
You could try reducing your port area, but you might get some chuffing.

2.5 cubes is good... you can always just try tuning that box to 35hz ish

I was gonna suggest you check your filters... That should play pretty damn low anyway - what are you listening to?

My friend has his 9915s in a big box tuned way low. Peaks at 30Hz so I guess it must be tuned at 25Hz. Kicks lots of low end but has a loss at high frequencies which I suspect could be box volume. Did 147+ off just one M3.

When I ran my single 9915 I tuned it to around 33Hz. Gave plenty of low end all the way down to 30Hz and had quite a bit of control. They have a very strong spider setup. My 9915 peaked at 40Hz and it was my favorite combo, in a box that was around 3.2ft^3 net.

Hope that helped.

I know I keep asking, but no one has yet to answer, what are you trying to play below 30Hz?

Are you a pipe organ fan?

It's very easy to design a box to play to 20Hz (or under), but given there is no music down there, why bother and lose all that energy where you really want it?

Phil

pipe organs go down to 16Hz.

40hz is generally low enough for most music, but low 30's is often better.

am I the only one that drives around listening to "bass testers"?

Which is below 30Hz, exactly what I said above.

Phil

yeah, exactly what you said above

Some hip hop have beats in the 25-30Hz range from what I've read... USDA - White Girls is usually given as an example.
I wonder if this is true? Anyone know?

There are alot of songs that play below 40Hz...

Anyway like i said above, the ss filter was set too high. Plays much better now but still not as low as my cvr. Im still happy with it though. I was just curious...

Thats 32hz... There isn't a great deal of music below 30hz. Tuning at 40hz gives you more of a peak around the 45hz mark usually - of course this is a generalisation, there are more variables than just the tuning freq.

Me personally I prefer to tune lower. The benefits are you can play lower if and when you need to. Also you dont get the peak that you would get if you tune higher, I prefer a flatter response - but thats just me.

Lower the tuning then, but you'll lose output where it's actually worth while.

Phil

No need to lower the tuning if im happy with it...

It wouldn't hurt to plug your port down to reduce area and lower the tuning. You can use wood, or even heavy foam.

The exact tuning of an enclosure depends on the location of the woofer and port in the car, the direction they face etc. Often a little fine tuning, in vehicle, is the best way to arrive at the eact result you're looking for.

Phil

Thanks for your help. For now i will keep it as is. It sounds good