custom sub enclosure

mhmacw

so ive been thinking and calculating and i think i have this thing firure out. it will be similar to a 8th order bandpass with one difference. the speaker will be on a 45 degree angle facing up and out inside the main body of the box. that box will have a chanber on both sides. so three chambers total. the rear of the speaker will be ported to the side chambers by 1 3 inch port. the front of the speaker will be ported to the room with 4 1 1/2 inc ports. the side boxes will be ported to the sides with 2 1/2 in ports each. make any sence. any design suggestions?

rallyshark

See response in subwoofer section.....:D

mhmacw

ok rally im no artist but i can build anything. does this match the description in my post?haha the sub is a ma151xq and i was leaning toward a 500 wrms 8 ohm plate. its a dvc so i can bridge i guess but id like to just use raw power. actually if you get technical its 4 chambers i guess

ben62670

Still not buying your tape deck.

mhmacw

it can be no higher than 25 3/4 high outside dim and no more 24 deep. width is unlimited i intend to use it for listening while mowing the field. as it is i have to open a window to hear behind the barn over the 870 johndeere. id like to put some garden speakers in and not have to install an outdoor sub for the deck. im not sure i want to sell it now haha

ben62670

I like Fords.

mhmacw

i like hunting

ben62670

I like old MF's too:)

mhmacw

i like old HD's too

ben62670

How many rpms does a PTO spin at?

tonyb

ben62670 wrote: »

I like old MF's too:)

You forgot the "I" and the "L" in the middle of the M and F, Ben.

ben62670

Lol.

mhmacw

well that would depend on the gear ratios between it and the driving source. What doe PTO stand for?

ben62670

You anit no farmer. PTO= power take off. Where you from?

mhmacw

im in central illinois north peoria county

ben62670

A sub unless corner loaded like an end table doesn't work. If you are thinking coffee table forget it. Welcome to Club Polk.
Ben

mhmacw

i was thinking at the far end of the room in inthe center along the wall under a window. the room is 36 long and 16 wide. the focal center for critics is 14 ft from the sub and to the side between 2 rta 11t for the left channels and 2 dcm timewindows for the right. for theater i willcompromise sub placement by about 4 ft. shifting the sound center 90 degrees .the 11t then turns to front l&r and the timewindows are surround L&r a cs350 fills in the middle. i was thinking a plant stand if i can keep the plants on it lol

rallyshark

Listen to what Ben says, he knows MUCH more about this than I:o FWI, I would lose a couple of chambers and just build a standard bandpass enclosure if I were you. I looked up the sub and it says it's 4 ohms, and single VC? So a 500watt at 4ohm plate amp is what you would want I guess. If you really want to keep it simple, but still get high output, just build a big **** ported enclosure and move on..A 3 cubic ft ported enclosure tuned to around 25hz would blow your socks off with that thing probably. Maybe Ben would be nice enough to plug in the numbers and give you some specific port/ enclosure dimensions:D If not, then I will see if I can install the software and come up with something tomorrow maybe:)

mhmacw

hey thanks. i appreciate the work however i do have the thing in my hand and its a dvc. 4 ohm so i guess 8 ohm or 2 depending on how you choose to wire it. thats why i thought high current plate at 8 ohm. relatively small amp for the amount of power you get. your point on the big box is kind of eher it started to be honest hah. as i was onlythinking of a box in a box due to the necessary air required would have made a rather small box compared to what i have in mind. if its ok to make a huge box im all for simple!. see the pics... its a dvc

rallyshark

Ok, I don't know how this is as I've never tested the program, but here ya go...
I did this on Winspeakerz, and here's your best bet since you said width wouldn't be an issue:eek:
10 cubic foot ported enclosure with two 6" x 10.8" ports with a tuning frequency of 30hz.
It will give you a real kick in the arse around 40hz, but will start crash below 30hz. You said you wanted LOUD:D This should be good for around 120db in the 40hz range....That's an awful lot of MDF and bracing, LOL!
I played with a bandpass enclosure that could give an extra 2-3db, but that's only from about 40-70hz, and everywhere else in downhill:D
Once again, I emphasize, I have never tested this program, so I'm not sure of it's accuracy:D

mhmacw

hey thanks rally... check this out! its 30x18x18. unfoutunatly i dont think itll be a plant stand due to the fact that it ROCKS and nothing will stay on it with only 35 wrms lol. now i need feet and some of that black wood grain stuff on the 11ts. also a grille but i thoght about 4 steel bars powdercoated black across the front cause it throws like a major league pitcher haha. and i dont think a grille would look good sticking out 3 inches.

rallyshark

OK, since you're into experimenting and having fun with this. Put a 6" diameter port that is 15" long in the enclosure you built, and we'll see how good this software works:D That SHOULD knock your socks off if you think it sounds good now:eek: Report back please...

EDIT:
Make that 16" long port.
This should give you a good gain while still giving decent lowend extension. You will actually LOSE output and gain very little extension if you tune it any lower. At least, that's what the software is telling me.

mhmacw

ok heres me thought ... i hhave a closet flange(toilet type flange right) ill install that flange that way we can changge the port length to what ever when ever. ill do the deed tomorrow and see what we get. i havent gotten the amp yet but i have 35 true to each coil so it aught to talk enough to get an idea. also i have to make a trip to home depot for the 10 ft stick of 4' pvc. also what does your thing say about a port like the blue man group? i mean on the outside of the box. it would sure change the vented volume and if the port is the same length the freq should be too right?!


i just saw the 6 inch thing ...ill get one of thse tomorrow too!

rallyshark

Awesome! I can't wait to hear your findings:)

mhmacw

crap! the 6 inch closet flange doesnt exist other than cast iron so it seems. do you have a knock your socks off length for 4 inch port. or two or three...

also ...ill be in the cabin hunting this weekend so ill post on tues about it i think just a heads up. mabe sunday but im not sure

rallyshark

Try this: 3 ports with 4" diameter and 17.75" length.
I'm not sure about the external ports vs internal. I assume the results would be similar, but I don't know.

mhmacw

Actual ID of the box is 28.5x 17.75x 17.75. I wonder how much clearance between the end of the port and the back of the box is going to need to be maintained. Clearly the 17.75 won't work. But the 4" closet is the biggest I can find online anyway, so we're kina stuck.

rallyshark

I'll see what I can come up with tonight after work:) FWIW, the ports don't have to be straight, and you need at least 2-3" clearance I think.

mhmacw

i think it would look really cool if they were 90 degree elbow in line under the box.

mhmacw

ok the elbow wont work unless i lift to enclosure 10 inches off the floor. so now i guess the question has evolved to which way should the port exit? the speakers in the front so do i port out the front, back or bottom. my calculator reads 2) 4 inch ports7.66 (75/8) long 40 (Hz). do you get the same?

rallyshark

mhmacw wrote: »

Actual ID of the box is 28.5x 17.75x 17.75. I wonder how much clearance between the end of the port and the back of the box is going to need to be maintained. Clearly the 17.75 won't work. But the 4" closet is the biggest I can find online anyway, so we're kina stuck.

So THIS is the final size?? If so, then I need to recalculate with the different size. I was figuring with about a 4 cubic ft, but this will end up being just a little under 5 after you subtract for the woofer/bracing etc.
Also, what is your major use going to be. If you tune it to 40hz, then you're going to loose a lot of the lower bass. It's response is going to fall like a rock below 50hz! Granted, it will be louder and peak around 50hz, but I don't know that it's worth the trade off.