2 boxes or 1 big one?

[RoboticCherry-Coke]

Hey guys,

Ok I have a ported sub box at the moment. The box doesn't fit in my boot nicely but I am happy with the results it provides.

I plan on building a new box this time to suit 2 subs. I was going to build 1 big box with a barrier down the middle thus making it two boxes with the same volume as my current box. Then just putting a port in each side with the same dimensions as my current port.

Is this the best way of doing it or should I be leaving it as one big box? How would this effect things?

Cheers

[calais_cruzin]

you can do it either way.

Personally i got for seperate chambers as if one of ur subs blows the other is still in the right size box.

If one did blow and they were in one big chamber it would be too big for the one working woofer.

[RoboticCherry-Coke]

Ok so really there are no disadvantages/advantages to using a big chamber over 2 small chambers other than if one sub blows or I take one sub.

I am happy with the way things sound with my single sub box so I think I will go with 2 chambers each with the same capacity of my single box.

[acarmody]

I have found a few disadvantages to one big box. Depending on size it could A) Not end up fitting in the boot ( I made this mistake, thought I measured it properly), B) would be bloody heavy and will make changing your tyre a lost cause.

[RoboticCherry-Coke]

Well regardless of being 1 chamber or 2 chambers it is still going to be a one big box just with a wall in the middle turning it into 2 boxes. So I will probably still have the problems you outlined but I will just have to measure a few more times first to be sure.

[holdenboy]

If you're going to be making this box as one large box (with the divider internally) then dont bother with the divider.

[RoboticCherry-Coke]

Ah holden boy, I was hoping you would catch wif of this thread. Have seen a few of your other posts and you really seem to know what you are talking about

The only reason I wanted to put the divider in was to keep each camber at the current capacity of my single box, thus keeping ports the same size and length etc.

Why would you leave the divider out, are there any advantages? If I do leave it out how does this effect the port size?

Cheers

[holdenboy]

Theres no real major advantages using a common chamber box, just the obvious things like less work building it etc.
Some people will say that if the subs are receiving the same signal then dont bother with a divider, but if each sub is receiving a stereo signal (left and right respectively) then separate chambers are suitable.


You can just make each box the same volume as your current one, and use the same size / depth port too and it should work out fine.....but if you want more bass from this new box im sure a new design (inc port) would be louder.

[RoboticCherry-Coke]

Well I didn't build the box I have now, one of my mates built it and I bought it off of him. But I did a bit of math and from memory its internal capacity is about 62 liters (will have to double check that, its all saved on my old laptop at work) without taking into account displacement for the port and driver.

I would love to build a box that will get more bass from the system but don't know really where to start when calculating optimal capacity and tuning the port and what not. Any advice? I am sure if I built a sealed enclosure it would make life a hell of a lot easier but want to keep with ported for more SPL.

[acarmody]

Well first, what is the sub? Model number?

And do you want it specially shaped, or can you go with rectangle? And what dimensions are we working with? As in what are the dimension of the available boot space?

[RoboticCherry-Coke]

Sorry, should have thought it provide that earlier. Its a Pioneer TS-W307D4.

I also have a Kenwood sub which I have got off my bother (he crashed his car) which I have been using until I get another matching Pioneer sub.

[acarmody]

Ah good subs, I used to have two. Let me look some stuff up and I might be able to suggest a design and maybe Holdenboy could add some suggestions.

[RoboticCherry-Coke]

Yeah I am really happy with it. I am just having trouble finding a matching one for it now as Pioneer have now released the TS-308 series.

That would be sweet, I would really appreciate any help

[acarmody]

Wow I'm having a bitch of a time finding a manual or something for these subs, but I'll keep trying. How big is the current enclosure? 1cu.ft, 1.5?

[acarmody]

Ok well the TS-W308 seems to be a very similar sub so I'm going to go off those specs, 1.65cu.ft recommended, or 2.05cu.ft maximum. So do you prefer louder/lower with a bit less control, or a good balance?

[RoboticCherry-Coke]

My current enclosure is 2.2 cu.ft. from memory. I need to be on my other computer to tell you for sure as thats were I saved all the calculations.

I just did some google-ing and found a program called WinISD. I am trying to figure that out at the moment so if I make any progress I will let you know. Well I have the manual sitting right next to me so the specs are.

Nominal Power: 400W
Max Power: 1200W
Nominal Impedance: dual 4 ohm
Sensitivity: 89dB
Frequency Response: 18Hz to 500Hz
Displacement: 0.076 cu.ft (2.16 liters)
Revc: dual 3 ohm
Levc: 3.55mH (8 ohm) / 1.04 (2 ohm)
Fs: 34.8 Hz
Qms: 13.99
Qes: 0.54
Qts: 0.52
Vas: 1.444 cu.ft (40.865 liters)
Rms: 2.561 N.S/m
Mms: 164.05 g
Cms: 1.3 x 10^-4 m/N
Diam: 9.5" (242 mm)
BL: 20.54 (8 ohm) / 10.27 (2 ohm)
Xmax: 0.37" (9.4 mm)

That's everything from the manual so hopefully that helps. Also I am currently running the sub at 2 Ohms

[RoboticCherry-Coke]

So do you prefer louder/lower with a bit less control, or a good balance?

I am not sure I know what you mean by less control, can you explain? But what I am aiming for is a box to give me max SPL so low and loud it is a I guess :P

[acarmody]

I probably wouldn't go over the 2cu.ft recommended by Pioneer, I mean nothing says you can't, but I'm sure Pioneer spent a decent amount of time and money researching their designs.

[RoboticCherry-Coke]

Yeah well looking at the manual the maximum recommended is 2.05 cu.ft for my sub. However my current box is 2.2 cu.ft and that does a real decent job but if I can get more from of a different sized box I am willing to give it a shot.

After playing with WinISD for a bit its saying that I should be aiming for 94.5 liters (3.33 cu.ft) so that is a hell of a lot bigger than both my current box and the max recommended by Pioneer. Surely I have done something wrong in the application for it to recommend a box that large.

[acarmody]

Well one design is, 900mm wide, 400mm tall, 425mm deep, with two 4" PVC ports 400mm long (or 420mm with 20mm flares on each end). This is a 30hz tuning frequency, and a Vb of 4.055cu.ft.



Remember you can build it larger but it will be a bitch to get in/out of your boot.

[RoboticCherry-Coke]

Ok cool, So just so we are on the same page that is for 2 drivers?

When it comes to the shape of the box I am assuming that isn't overly important as long as I meet the required volume as I am wanting to build it so that part of the box will sit on the diff hump so I can utilize as much of the boot as possible.

[acarmody]

Yep volume rules over shape.

[RoboticCherry-Coke]

Remember you can build it larger but it will be a bitch to get in/out of your boot.

Yeah I am more concerned about access to my spare than the pain of getting it in and out :P

[holdenboy]

How much power do you have?
I did a similar style box in my wagon before going to 15s, 2 x Jaycar 12s and my Schneider amp.....from memory 144s at 40hz on my meter at the time (so 140-141db on Termlab) but sounded great on most types of music, 1 x 6" port meant i could safely give each sub around 5x their rated wattage for extended periods.
If i were you i'd go with a single 6" port, just make the box abit wider than i did (another thing i was testing). Use a minimum of 18mm MDF too, the larger panels will flex with a fair amount of power and can cause leaks in anything thinner (16mm included), leaks arent good for those Pioneers



I know, i know.....its a poor example of a box but i think it was in the car for 3 maybe 4 days and ended up in the box cemetary

[RoboticCherry-Coke]

Thanks for the input holdenboy, so are you saying I should go with a box bigger than the maximum recommended by Pioneer. As mentioned before Pioneer say a max of 2.05 cu.ft (58 liters) where as WinISD is telling me 3.33 cu.ft (94.5 liters) for a single sub situation.

I was planning on using 18mm MDF as I have been warned about using anything smaller. As for the port what are the advantages of using such a huge port? Would you get the same result with two 3" ports?

As for power I am running two mono blocks. One for each sub. One is a Kenwood KAC-8105D, that is 1000w max and 500w RMS @ 2 ohms. The other is a cheap 900w Jensen I bought when I first started doing my car audio and that is around 450w RMS @ 2 ohms from memory. I hope to replace the Jensen sometime down the track and get another Kenwood so as to keep the amps the same.