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wanna see what yall think of this setup. the fosgate 8's sound really good on some songs but absolute crap at others...its my first attempt at a ported box so feel free to comment on the overall design
http://i1157.photobucket.com/albums/...0d5/photo2.jpg
http://i1157.photobucket.com/albums/...0d5/photo4.jpg
http://i1157.photobucket.com/albums/...0d5/photo5.jpg
A couple questions:
1. how are you coming up with the shape of your boxes? Are you keeping track of your port dimensions? The two side boxes seem to be different in the port areas. If that's not done correctly, your sound will suffer.
2. Why so many screws? Believe it or not, but wood glue is better for boxes. Screws can vibe loose, wood glue tends to stay.
3. Are there any reasons why you want to have them fire differently? One is front-firing while the other two are rear firing (If I'm imagining the placement correctly). I find in the trunk, rear-firing produces more output but my ports are on the same baffle as the sub. So your most powerful sub isn't in its most efficient placement (though with three subs it may not matter).
4. How's it all wired?
A couple questions:
1. how are you coming up with the shape of your boxes? Are you keeping track of your port dimensions? The two side boxes seem to be different in the port areas. If that's not done correctly, your sound will suffer.
I made the w7 box to fit dead center in the trunk, front facing so that nothing in the trunk could possibly damage a $1,300 sub with no warranty ^.^ the side boxes are simply the biggest I could make while keeping a little bit of trunk space. I want to fiberglass the back side of them to fit right on the wheel wells but didn't even think of that initially. yes, the ports are the same (can't remember right now) but are 1" wide and some odd 30" long and maybe 12" tall (I think I was going for like 30 hz and have no idea why now, that could explain the crappy sound)
2. Why so many screws? Believe it or not, but wood glue is better for boxes. Screws can vibe loose, wood glue tends to stay.
it is all put together with glue too, jut used the screw as added benefit
3. Are there any reasons why you want to have them fire differently? One is front-firing while the other two are rear firing (If I'm imagining the placement correctly). I find in the trunk, rear-firing produces more output but my ports are on the same baffle as the sub. So your most powerful sub isn't in its most efficient placement (though with three subs it may not matter).
I think I was trying for some sort of band-pass type thing IDK
I thought that ported boxes sound came from the ports, not the subs?
and yeah the w7 is facing the seats because that is basically an impossible spot to take any impact damage ya know
4. How's it all wired?
2 amps,
1 sony 1000w for the fosgates wired in parallel to a bridged (mono) output
1 4000w mono (maybe 3000w would have to check) for the w7 with like 8g wire lol
it was really my first experience using ports so feel free to criticize and offer improvements, as far as the w7 box im not concerned about it.
Okay, since you know port dimensions and tuning frequency I think you know what's going on :thumbup: but yeah I would think unless they have some awesome TS parameters those small joints aren't going to do 30 hz very well. Also, only right around tuned frequency will sound only or mainly come from the port. The sub will always be the main sound producer; port sound adds to the output.
A neat experiment is to use a test tone (or tone generator app on your phone and play that thru your system) that is the same as whatever you ported box is tuned for. You will notice the sub hardly moving but sound is loud and pumping. Start playing tones under the tuned frequency and output dramatically drops off. Start playing above the frequency and you'll see the sub moving more and more. It's basically using the back waves from the back of the sub to augment the sound, where a sealed box doesn't do that.
Also, band pass is a tricky setup, it's basically using one sub with dual chambers to create an enclosure that has great sound in a very limited band of frequencies. UNless you compete in SPL or have music with a very limited sound, I'd stay away from bandpass setups (which technically you don't have anyway since you have multiple freestanding enclosures with their own subs).
So far though, not bad. I'd try to find some specs and see where the limits of the small subs are and tune to just above that. Good luck, keep posting progress!
TS parameters?
and ok that makes a lot of sense about the port vs sub output...when I was looking up stuff that never came up on the internet :flaming:
that is an awesome idea! I will certainly be doing that once I get them back in the G
right I know its not a real band-pass or anything but some reason I was thinking that the port sound would mix with the w7 and be louder or something I don't remember? no clue where I got that idea but I think that's what the logic was...plus that shape is really the best I could get to fit in the back of a G with trunk space:http://i1157.photobucket.com/albums/...ond0d5/252.jpg
I left the room on the sides so that the trunk can close (I don't want those damn vertical hinge things) and that leaves room for my air compressors...I could also add a battery on each side if I really wanted too ^.^ considering moving mine to the trunk when I go FI, haven't decided yet
I know the specs on are on RF website and I think are like 40/45 somewhere in there but I was a bit less informed last year when I made the boxes. was trying to get into the "sub-bass" area but oh well XD been needing to rebuild those boxes anyway...
Thiele-Small parameters (TS parameters) are bits of information about a driver that tell you everything you need to know about their specifications as far as what type of box to use, what volume of air they should be in for each type of box, what their resonant frequency is, their excursion limit, power handling limits, etc. They're very technical, but there are parameters that let you know if your sub will in fact get down that low, if they will work in an infinite baffle setup (the kind with no box), and many more. They're for sound nerds basically.
The finished product looks much better than the work in progress :thumb_rsvd:
oh ok I gotcha so it would be like this stuff:
http://i1157.photobucket.com/albums/...rior/Subs9.png
I looked at all that stuff when picking the sub and designing the box, that's how I got my box dimensions (also have a page with volume specs) and I used the12volt to determine port volume for whatever freq. I was tuning for...thinking it was like 30 but idr. I see on the page I listed ^ that the Fs (Hz) is 39.6 so does that mean that they can't go any lower than 40Hz or that's just there best?
Along with other factors, i would say that 40hz is ok, but 30 isn't looking at those specs.
yeah that's sorta what I've been figuring out over the last couple days, will end up redoing them before long.
oh here is a sample pic of what the end result is in my mind. after I find a way to not need to keep a donut, have a bit of camber and blew 3 tires due to wearing out, I am going to completely build them in and make it look like 1 piece
http://i1157.photobucket.com/albums/...rior/subs8.jpg
redoing the board/leather stuff around the tank (may get a new tank too) and running the compressors through the wall. gonna have a "window" under the w7 and infront of the compressor showing the w7 amp, may throw some neon lighting down in there too to match the rest of the trunk, or a different color or something. the amp for the 8s will be on top of the box out of sight starting once I put the subs back in
I am also thinking about making a side window thing where you could see the compressors too but haven't decided yet