LaZyLuke

iTrader: (2)

Hi there, so now I have 8cubes + to play around.. I have two sw 8200 eclipse,

Previously one was in ~2.6 cubes sealed... played quite nice (extended to 7Hz and hummed loud up to 80) now I was thinking getting two in there with separate chambers (2.5 cubes or even 3 cubes each)....

BUT If someone can help me design, or hint of what type of design I can use for these to get them ported or horned I will be very grateful... right now I dont have much time to get through all the designs to pick the best myself... so any thoughts?

Specs:

ECLIPSE Subwoofers SW8200/SW8000 | Fujitsu Ten

I am using ONE 500/1 jl (it was plenty for one 12"- because box was so big the power handling went down significantly- similar will be with ported design.. two should be easy pushed by that amp)

My application:

Pure SQ (with two, SPL should not be the problem as one was enough previously)... I want it to extend pretty LOW as well- definitely below 20Hz

Lord Huggington

iTrader: (1)

I've used two SW8200's extensively in 1.25cf3 each, sharing 750W @ 2 ohms (Visonik V900XD/1500W @ 1 ohm stable), so I assume they were seeing a little less than 300W each with my stock Sunfire GT electrical. 1.25cf3 is enough to cover all the low frequencies in rap - they were retarded on Dipsets' Sippin' Sizzurp intro, I think those lows were louder than when I tried 30-35-40hz tones.

Why were you playing 7hz? That's unnessesarily low.

Eclipse Tech told me (approximately) 1.75cf3 = 30hz, 1.5cf3 = 35hz, 1.25cf3 = 40hz. Even though it's from their tech, I don't trust those numbers without the actual t/s.

I used one in a ported 2.2 cf3 @ 37hz box on 750W (probably seeing 500W) and it was fine, I don't know why Eclipse doesn't recommend ported boxes (besides it being a "long-throw" LMS driver). I don't think it was over-excurting, albeit it was a small box and little power. When I put the gains all the way up it sounded muddy and I don't think it could have handled an actual 750W in 2.5 cubes with the gains at 1/2-3/4.

The sound quality didn't change in the ported box, although it did have the ported tonality sound (sealed to me sounds a little flat everywhere). The frequency response of the sealed box won my tastes because those subs really hammer the lows in 1.25cf3. It was kind of flat up top in the ported box.

If you want it to be louder, I suggest 1.25cf3 each, with 1000W to each, and if that works than go from there, but not past 1.75 cubes because less than 30hz is kind of pointless unless you're bangin' reggae. The point of LMS is to be able to have a high roll-off around the resonant frequency (approx. 40hz) and the lows still be covered, and even in 1.25cubes I found the bottom end acceptably heavy. I think they'd handle an actual 1000W in 1.25cf3 with the gain & EQ at 3/4, but anymore than that you're pushing a 2" voice coil.

Hopefully the 500/1 does rated at 2 ohms because two SVC 4 ohm's wire into 2 ohms, I hated that. For $200 online you can't go wrong with that sub. I'm sure there are smaller subs with better sound quality, but definetly won't get you the desired F3 in a small box + the mad excursion on low power (while having crap efficiency at something like 82dB/1W/1M).

The displacement is .12cf3 (each).

Lord Huggington

iTrader: (1)

Sorry, I missed you wanted SQ.

Definetly shoot for 1.75cf3 each (30hz). -12dB @ 20hz will be nasty, but if you want more you can always get another 500/1 or even better 1500W @ 2 ohms.

What are you listening to that goes below 25hz or even to 7hz?

... and I forgot to add that the difference between 2 sealed & 1 ported is that they equal out in SPL when on the same amp, while the sealed box rocked the lows, the ported @ 37hz had pretty much none. With a ported box, even tuned at 30hz, is still -24db @ 20hz. Definetly use a sealed box.

LaZyLuke

iTrader: (2)

thanks for the insight- I will build a quick 3.5cubes with separate chambers and see

I was aiming at movies in the last setup (no screen this time so just music), also some of the baselines were ridiculous with that 2.6 I had one in... I could easily shake the siding or signs with that- im not aiming for shacking anything off course just saying it was loud....

are you sure we are talking about the same driver? when I calculated the sealed box it 'should' be in with the specs i got from the site I came up with a number around 7-8 cubes....

Lord Huggington

iTrader: (1)

It says SW8200 (670W RMS) on the box ^_^. Eclipse dropped those and started producing the non-LMS SW8210 (750W RMS) because they're cheaper to build, which was a mistake.

You using this?

Sealed Subwoofer Speaker BOX DESIGN - Qtc Calculator

Type in:

Qts .42
Vas 8.27
Fs 16
Vb (box space)

A Q of .707 (flat response) = 4.51 cubic feet @ 26.93 hz.

... which would be ideal for SQ.

In actuality:

1.25 - 44.16 hz
1.5 - 40.83 hz
1.75 - 38.29 hz

See what I mean about not trusting Eclipse Tech guys?

"FS (F3) is the resonant frequency of a speaker in free air (not in an enclosure)".
"FC is the resonant frequency of the driver in a sealed enclosure".

Makes me want to try 4.5 cubes! That's such a huge box for a sealed 12".

Your 2.6 cubes was tuned to 32.72 hz / -12dB @ 22.72 hz. If you make it 4.5 cubes each than you'd be at -12dB @ 17hz, which isn't exactly a huge gain from 22.75 hz, but atleast it's below 20hz before it heavily rolls off, that means you'll be shaking the crap out of things =). Anymore than 4.51 cubes is pointless because it's already below 20hz. -24dB @ 7hz is insane lows. My ported XXX 12" was -24dB @ 27hz and those lows were decent.

I think I'm going to make a 9 cubes net box lol.

LaZyLuke

iTrader: (2)

So at the end of the day I have the same goal as before- make the box as big as possible :]... which wont be that hard with current setup as i don't use up much space with amp mounts...

thanks again for help