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Discussion Starter #1
This is my 1st sub so I just wanted to get a reality check and see if I'm not doing something wacky. I ordered parts, they will arrive in 2 days. Plan to start cutting MDF tomorrow.

Here is the plan

Ported 10.5 ft^3 :eek:
Tune 19 Hz
Driver 15" RSS390HF-4 Dayton
Amp modded BASH 300W (sub sonic filter modded from 17.7 to 11.5 hz)

software WINISD
 

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Discussion Starter #5
why so big?
It keeps the response totally flat down to 20hz... in simulations. The footprint of the sub is 2x1.8 ft which is pretty standard, it's just taller than most (3.8ft). I have an "off the shelf" sub cps12wi which is rated at 25-120hz +/-3db. So the whole point is to have something to differentiate my home built sub. The difference will be it starts rolling off at 20hz rather than 30hz.

If I build a smaller box, I will just duplicate the response of my existing sub.
 

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There is no 11.5 hz HPF in the boost tables unless you're doing a custom one. 10 cu.ft. tuned to 17 hz with the HPF modified to 13.9 hz with 1 db of boost in the 20 - 24 hz range would give you a smoother response and about the most low end extension you can get with a 12 mm Xmax sub.
 

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Discussion Starter #7 (Edited)
There is no 11.5 hz HPF in the boost tables unless you're doing a custom one. 10 cu.ft. tuned to 17 hz with the HPF modified to 13.9 hz with 1 db of boost in the 20 - 24 hz range would give you a smoother response and about the most low end extension you can get with a 12 mm Xmax sub.
I know there is no 11.5hz in the tables. If I'm going to the trouble of soldering I'm going to drop it down below 13.9. You can reverse engineer the table and figure out fc=constant/sqrt(r1*r2) so I'm going with slightly larger resistances to hit 11.5. (also r1/r2=constant*Q). Once you have the constants calculated you can toss the table in the trash.

I'll take a look at 10ft with 17 hz when I get home tonight to see what I think, thanks for the suggestion. I have a feeling that would require me to place my ports on the side rather front so visually I'd like to see the ports in front, so that's a deterrant.

The advertised xmax is 14mm rather than 12mm. I'll have to check the file I imported into winisd I suppose, I never looked at it vs the online specs. If they are different, I guess I'd have to trust the online specs more.

QUESTION: Is the excursion shown in winisd one direction or the sum of both directions? in other words should it be compared to xmax or 2*xmax?

Thanks
 

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Discussion Starter #10 (Edited)


OK I learned the hard way never build a sub in 1 weekend. My butt is officially busted.

This thing has a "swappable" port plate set to 19 hz. I'm going to build 2-3 more plates I think and try them out (one at a a time). I have plenty of 3" pipe to play with.

Dont worry about the paint, sill have to do some coats.

It has built in handles, you can see one on the right.

How does it sound? I would describe it as accurate, environmental, and even tame. Sure it shakes the house, but, with a 19hz port it's not going to shake things up like a 37hz port. I've only tried music so far and music doesnt have much going on around 19hz.

This is my 1st sub so I'm pretty pleased it even works at all. There is a slight leak at the driver, should be an easy fix.
 

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Discussion Starter #11
Last night I plugged it in into the 5.1 system in the basement and watched the 1st scene of Transformers 2. Very impressive sound for a $159 driver and $149 amp. Better than the cps12wi I have which is $400 online. Also 4x heavier lol. It sounds less localized and more environmental, like you dont know where the sub is when the lights are out. It also sounds "big" like you hear it less and feel it more. I did push it to distortion (for a test), I'm assuming the driver distorted before the power supply. 300w rms should put out well over 300w peak.

My next tuning plate will be 26hz. I suspect it will get really loud based on winisd simulations compared to the 19hz plate. It will also lose "flatness" and peak up at 26hz. I'm curious to see what that does for movies.

I wanted to see how loud it was outside the house during transformers so I walked outside. Keep in mind the sub is now in the basement. It sounded really cool from outside, but not so much to "tick" the neighbors off I think.
 

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ISLAND1000 said:
SEE?? DIY is easy, cheap, and good for your soul.
I'm gunna second that. I love building new boxes now. Haha. Every time I hear my sub on low bass drops in hard hitting rock songs, it simply puts a smile on my face hearing the sub 20hz extension, while maintaining that "hard hitting" bass. I did a little demo on my new horn a few weeks ago for a friend of mine. He listens to song that have hard hitting double bass in them (I mostly demoed Of Mice & Men and "Of Mice & Men" album from them) and after about four songs at nearly full volume, he had me turn it down. The constant double bass was making him (and me frankly) feel sick to our stomachs. Pretty crazy. Then I turned on some bass testers that had heavy 20hz content in them, and he was amazed. I thought my windows were going to break :hsd: The steel panes between the glass was slapping back and forth on the glass. I immediately turned it down. Can't have that happening ! I'm much to poor to buy a new window ! Haha.

@hanzblinx

That plate port thing is very interesting. I'm curious to see how you think the different port tunings sound.
 

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Discussion Starter #15
I tried the 26hz plate (actually went with 27hz). Tested it on music so far, no movies yet. Conclusion, much louder, but not my style. I miss the more flattened response.

The 27hz plate has 4 tubes. If I plug one it will drop the tune to 22.8hz. I forgot to try that, will give it a shot. The new plate also looks better, I kinda goofed the 1st (19hz) one. The new plate also has 3" tube couplings from Lowes so I can swap the tubes without making a new plate.

So I suppose I will end up lower than 27hz (as I expected) but if I feel like annoying the neighborhood, it will be useful.
 
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