DIY sub - Page 2

I'm glad to hear that. Any word on the IXL-18's?

two boxes or one?

I was thinking you were building two 15s to spread them out and smooth response, If your only building one get the 18" it will make the box easier and will displace slightly more air than two 15s.

maybe go back and read your thread again.

you are asking the same questions all over again.

EQ is always needed. Rooms stink, period. Placement is one of friend and fow.

So far i feel the MiniDSP is a gigantic leap in the world of DIY. I am an idiot when it comes to computers and such, with proper measuring gear the Mini is the bang for the buck king, IMHO. You gotta ground that little sucker though, mine hummed like crazy.....once grounded to the outlet, quiet as a church mouse....

They need to just sell the balanced version, scrap the other one all together....

not sure what you are planning, but a ported/passive radiator 12" gives both of those 18's a push.

the enclosure design is at least important as the driver for performance.

here is a twelve (blue) with 1000 watts in a resonant enclosure and the 18's with 2000 watts in sealed (red and yellow).

pretty much what was shown in the plot. an extra half a cube isn't going to make any material difference.

the way to get maximum spl out of a smallish sub is with lots of power and passive radiators, but that adds to cost and you seem to be looking for the lost cost solution.

roger that, here is 6 cubic feet, one ixl 18.2.2 driver, two of these passives, in a six cubic footer, with 2000 watts.

be sure to high pass them below 20hz or you might get into driver trouble and don't run sine waves through your sub at max power. the amp will be pushing your driver and the p.r.'s to their limits under max conditions.

oh, and build the cab with the woofer on the front and the passives on opposite sides, i.e. the left and the right. this will reduce cab vibration.

If your that size limited for total sub real estate, i would stick to either PR or ported like LTD said. 4.5 just aint big enough for two 18s. The "problem" with PRs is added cost. They usually run approx same as another driver, but they dont require any power or added box size for their added efficiency.

Youll prob find a pair if 15s ported in that size that would perform well. Note either PR or ported WILL require outboard EQ for high pass(normally), so factor that in.

If price aint a factor the LMS-R 15s in 5ft cubed ported might work..... Those are some killer drivers....... Cant model it im on my phone......

Generally I decide on box requirements and then decide on a driver to work well in the alignment needed.

FYI Parts Express ships to Canada too.

Just stretch the dimensions to get a 24" cube (dont forget to increase the bracing dimensions), ignore the amp cutout, and increase the size of the driver cutouts.
http://www.creativesound.ca/pdf/Q12SubMan.pdf



The design LTD posted has some pretty amazing output for a single box that size. The two 12" kits I suggested in post #2 would be capable of 4db less output across the board.

- the ixl 18" driver. not sure what availability is.
- the two passive radiators from ae speakers 18" with no added mass. they are a good value, but i'm not sure what there availability is.
- the enclosure, which can be a little under 24" cube, so that you can use 4x8 plywood.
- that leaves an amp and eq:
if you want two separate devices, the mini dsp is probably the best value for the e.q.
the behringer ep4000 or inuke nu3000 amp will work for the amp.
or you could get an inuke nu3000dsp, which has the eq built in.

i'm not really sure where to point you for a technical read on such a subwoofer. it is pretty straightforward. if you don't have winsid, that might be a good place to start. it is a great tool for learning about how things such as changing enclosure volume affects things like cone excursion and how various types of eq and filters work.

Anyone care to chime in on integrated DSP or MiniDSP.....i can only speak about the Mini....

imtegrated behringer dsp only goes to 20hz, the minidsp goes lower i believe......

the inuke software can be downloaded for free, so you can play with it. while i refer to it as "e.q." it has all the common features (high and low pass filters, various slopes, delay, several bands of highly flexible parametric equalizers, limiters, and so on) and the software is pretty intuitive. the only thing that it doesn't do is allow the "corner" of the filter to be set below 20hz, which sucks if you need a highpass at 10hz or something really low, but there are some tricks than can accomplish pretty much the same thing. for a build tuned to 20hz, such as this one, that won't be a problem.

a big advantage of the mini is that being a separate component, if you add another sub and amp, you don't have to pay for eq twice or three or four or however many upgrades you do. choosing what to buy is confusing as most folks don't know things like what the output voltage is on their receivers, but several folks around here can tell you what to do. i haven't studied this one enough to make a suggestion. the software is pretty good and does all the stuff that you will likely need (high and low pass filters, several bands of parametric equalization, etc.).

while plate amps have their place, both of these solutions are in totally a different league than the "e.q." that you might read about on the plate amp.

for some reason behringer doesn't report the input sensitivity of the inukes (at least the last time that i checked). apparently, it measured relatively low at 0.85v, so if your pre-amp can output that much voltage, you can hit full power with the amp.

http://www.avsforum.com/avs-vb/showp...5&postcount=27

i couldn't find the subwoofer output voltage for the mrx 300, but the 700 was something really high like 7v, so if i had to take a guess, the mrx 300 has more than enough voltage for either the inuke or the 'lower sensitivity' minidsp (2.0v to hit 0db).

Yup, DSP/computer control has lifted us up quite a bit.

Do a Sundown Zv3 18". More displacement and power handling. Verified specs are on Data-Bass, pm me your zip code for a quote.