20 replies to this topic

[Dylby1]

Ok ive just gone into planning stage for my sub boxes, but will need a massive hand designing the port

Firstly the factory spec is for 1.6 cubic feet max for these subs, but ive had alot of people say thats too small so i am going for around 2.2-2.5 tuned to 40 hz
These are the subs: Pioneer TS-W3002D2. http://www.sonicelec...TS-W3002D2.html
But im not buying them from there, just the best specs list i could find

I dont know whether to go a round port, or a slot style port, nor do i know what size i need
This is the basic box design (2.54 cubic feet if made using 16mm MDF, 2.42 if i use 18mm)




Keep in mind i drew these for a sealed box, but wrote the dimensions for this box, so i would offset the sub to the side slightly to allow for the port to come through if it is a slot port.

I can adjust this slightly but not heaps.

Questions are:
Slot port or round port?
If its a round port what size/length and where should it be placed on the box?
If its a slot port, what dimensions should i make it? (maximum is 2 inches wide)

Should i be aiming for a different tune in the box than 40 hZ. I listen to alot of rock/metal aswell as a bit of techno and stuff so i want it to be able to get the higher stuff aswell as the big bass parts of the techno stuff

Sorry if this doesnt make much sense, its got me pretty confused but ive tried to make sense as well as possible.

I used this calculator here to have a play with port sizes but i dont really know what to aim for

http://www.mobileinf...ort lenth 1.htm

For a 2 inch wide slot port, in a 2.5 cubic foot box i got this
35 Hz: 18.47 inches long
40 Hz: 12.90 inches long

For a 4 inch round port i got:
35 Hz: 8.13 inches
40 Hz: 5.54 inches
Thats all i played with because i dont know the advantages of a larger round port over the 4 inches that i decided to put in.

Any help would rule

Edited by Dylby1, 06 April 2012 - 01:34 PM.

[Dylby1]

so after alot of searching on the net, it seems the best tuning for what i want is around 32-35 Hz

I should be able to figure the rest out using the port length calculator above.

I'm inclined to go for a slot port design, at least aesthetically but if round would sound better i will go that way.

[RAD]

The big question: what car is it going into? You're probably looking for a 35hz tune, around 2.2 cubic feet. 32hz at 2.5cubic feet would make a box that would favour low end stuff like dubstep/r&b

[Dylby1]

ok no worries, i will adjust the sizes a bit.
The 2.42 cubic feet is BEFORE adding the sub, so that would take a bit out of it with displacement too

Its going into the boot of a BA falcon sedan

I definitely dont want to favor low end too much as i dont listen to huge amounts of dubstep and r&b.

the 35 Hz @ 2.2 cu. ft. should still be plenty for the lows i would imagine

I've also decided to go for a round port, since i can tune it better with the size/shape of the box

Would 5 inch diameter be too small? according to http://www.carstereo...icles.cfm?id=31 with my specs the smallest port opening is 3.83 inches.

I want to limit port noise without making the port too big as much as i can.

[RAD]

Imma throw a spanner in the works; you won't fit that sub under your rear shelf, so you'll have to concentrate on sub/port orientation. You can build it low & flat so both sub and port can fire up, or have a regular shaped box right near the back of the boot.

[Dylby1]

I've already done the measurements to make sure it fits.

Thats why it is wedge shaped. Ill double check the measurements anyway though

regardless of that though is the 5 inch port ok or do i need a bit larger/smaller?

Im still playing around with slot port designs too, am gunna download a box design program

Edited by Dylby1, 06 April 2012 - 11:03 PM.

[Dylby1]

Just checked it all again, my old box (13 inches high) makes it most of the way to the front before it gets tight.

These boxes will fit fine.

Id go as far as to guarantee that it will fit.

I did measure it, not just chuck the box in though

EDIT: BUT i have modified the box design now too, its an inch lower and an inch shorter than before. to bring it to 2.21 cu ft unloaded.

Need to factor the displacement of my subs though, which apparently is 0.181 cu ft

Edited by Dylby1, 06 April 2012 - 10:04 PM.

[Dylby1]

Edit: post turned out to be irrelevant

Edited by Dylby1, 07 April 2012 - 12:20 AM.

[IamtheSteg]

May I ask a couple of q's?

Are you set on those drivers and why?
What kind of bass are you chasing and how much?
What music do you listen to most of all?

Have you done any modeling to come up with your volume and port requirements? (trying to make a given sub work with a box originally designed for something else and then tuning a port to suit is generally the hard way to get good sound)

Sorry if this is all a bit overbearing but these are pretty important points to get the best sound for you!

*edit* 1 other thing - IME slot vented boxes typically have less port noise than round ports. It's all to do with surface area of the port but the more air you pump thru it the bigger it needs to be to avoid 'chuffing' - if not going slot go the biggest diameter possible to minimize this

Edited by DailyDriver, 07 April 2012 - 09:12 AM.

[IamtheSteg]

Me again!

I just scoped what I could on the Pio driver and apparrently xmax is 12.3mm - plug that into your port calc and it comes back with a minimum round port of about 5.5" - way bigger than the 3.8 you mentioned so be careful to avoid the dreaded chuff chuff!

Also I'd be very hesitant to run the 1000wrms into each driver in a box this size - further specs may prove it a moot point but alarm bells ring when the manufacturer recommends a very small sealed enclosure (where the box creates an air spring helping control the driver and stopping it bottoming out!)... I don't know enough about this sub to give a definitive answer but your box is considerably bigger than Pioneers own recommended max so I would be very careful checking it can handle what you want to put thru it

This may not be the best driver for the box you want to build with the amps you want to run - but it all comes back to what you actually want from the system and where you are happy to compromise...

[Dylby1]

May I ask a couple of q's?
Of course

Are you set on those drivers and why?
Absolutely not. Only chose them because i have used one before and loved it.
Other options i've got floating around in my head are a pair of Alpine type R, or Rockford Fosgate T0

What kind of bass are you chasing and how much?
After pretty big bass, but want it to be best for rock and such, but still be capable for techno/dubstep etc.

What music do you listen to most of all?
Rock/metal but alot of techno and such aswell

Have you done any modeling to come up with your volume and port requirements? (trying to make a given sub work with a box originally designed for something else and then tuning a port to suit is generally the hard way to get good sound)
Only using these, and a few others that i cant remember
http://www.rockfordf.../box_wizard.asp
reaudio.com/box.php
http://www.mobileinf...ort lenth 1.htm

Sorry if this is all a bit overbearing but these are pretty important points to get the best sound for you!

*edit* 1 other thing - IME slot vented boxes typically have less port noise than round ports. It's all to do with surface area of the port but the more air you pump thru it the bigger it needs to be to avoid 'chuffing' - if not going slot go the biggest diameter possible to minimize this

Me again!

I just scoped what I could on the Pio driver and apparrently xmax is 12.3mm - plug that into your port calc and it comes back with a minimum round port of about 5.5" - way bigger than the 3.8 you mentioned so be careful to avoid the dreaded chuff chuff!
Oh ok, i didnt know the xmax so did what it said and used what was already there (6 i think)

Also I'd be very hesitant to run the 1000wrms into each driver in a box this size - further specs may prove it a moot point but alarm bells ring when the manufacturer recommends a very small sealed enclosure (where the box creates an air spring helping control the driver and stopping it bottoming out!)... I don't know enough about this sub to give a definitive answer but your box is considerably bigger than Pioneers own recommended max so I would be very careful checking it can handle what you want to put thru it
The reason i chose to go for a bigger box than the specs say is because people kept telling me to make it bigger, id much rather build it to the specs they supply

This may not be the best driver for the box you want to build with the amps you want to run - but it all comes back to what you actually want from the system and where you are happy to compromise...

Im more than happy for suggestions of subs and amps, im after a mix of good sound quality, but with big booming bass on bassy songs aswell. (i dont want much )

[Dylby1]

Im also toying with the idea of going for a single sub too, alpine type X or the like instead of twin subs

[Dylby1]

Ive come up with a new and better (as far as i can tell) option

I found a way to make a square box instead of a wedge box, which i can run a 2 inch L-Port in

Box dimensions for factory recommended 1.6 cu ft are:
tuned frequency: ~35 Hz
W: 21.5 inch
H: 14.5 inch
D: 15.5 inch
Port Length One: 12.75 inch
Port Length Two: 14 inch
Port Width: 2 inch

Im hoping this wont "chuff"

I dont have bassbox pro or anything so cant model it at all

It will basically look like this: with a sub in it though of course. both firing backwards (I have read in several places that having the port and sub facing the same way is ideal where possible)

 port dimentions.JPG   77.63K   18 downloads

Edited by Dylby1, 08 April 2012 - 02:15 AM.

[IamtheSteg]

Well i found some TS Parameters and managed to run a few models - seems an interesting sub with plenty of output potential

.
The Yellow plot is the ISD preferred enclosure. QTC of .71 and 72 litres or almost exactly 2.5 cubic feet. The exact first box you drew (and sealed too!) SPOOKY ....
The Orange plot is also sealed but volume halved to 35 litres and the response differences would be inaudible both have a -3db point of 34 HZ.

Both sealed boxes will be nicely damped, soak up plenty of power and with the juice you are feeding them get crazy loud (before you add a second sub!) (1 driver in free air at 1000w in these boxes should be good for 120db hypothetically - before you add loading and cabin gain etc - i.e. louder than you should ever listen when driving and enough to damage hearing pretty quickly!). They both model very close to the 'ideal' .707 giving the best combination of power handling, extension and transient response (i.e quite deep, plenty fast, tight punchy bass - ideal for rock thru techno but higher Q's will give boomier bass that some ppl prefer for RnB and HipHop....)

Not to mention they are sooooo easy to build

The Blue plot looks amazing - pretty flat down to 20Hz or so and noticeably (if not massively) more output from 20-50HZ than the sealed configurations... problem is the necessary 5.5" vent needs to be nearly 1.4 metres long (yes metres!). My brain is fried and I can't think of a way around this at 2AM! But maybe some more experienced builders than I can have a shot tomorrow? FWIW the Box is 62l (2.2 Cu Ft) and is tuned to 22Hz. this was the vented enclosure WinIsd put forward but i reckon is unrealistic due to vent issues. (To go shorter you need much smaller diameter and then you will have chuff city )

Maybe there is a way to make that work with a slot vent - i'll investigate more tomorrow...

The pink plot is also a 2.2 cu Ft box, tuned to 32 Hz (35 looked quite similar). The good news is the same diameter port only needs to be 5" (125mm) diameter and 470mm long so would fit your original drawing. You also have Crazy output at the tuning frequency (an 8db gain) so repetitive thumps in the 30-45Hz region will be impressive - but it's peaky as hell and a long long way from being a 'musical' response. If you just want doof doof that may suit you but it could be very very tiring...Also, if going this way you will definitely need a subsonic filter below the tuning frequency or you will kill the subs in no time!

Hopefully the above is of some help... they are only models but can be a good guide to what you can expect from these drivers if Pioneer have been accurate with the TS parameters. The drivers seem the goods, with plenty of clean power and a very reasonable box size you can achieve lots of musical bass that should be fast and tight. Alternatively you can achieve organ liquefying bass in a fairly narrow band...

The one thing i would still check with these drivers though is if you do plan to port them, that they can still handle the power you want to put thru them... If not you will lose most of the SPL gain achieved from that configuration and have far less SQ than sealed as well.

[IamtheSteg]

Just modelled a 1.6 cu ft (45 litre) vented box tuned to 35hz and its plot is very similar to the pink 32 hz tune in a 2.2 cu ft box - only a sharper curve again! Same gain at tuning frequency but a slightly sharper climb getting there!

[Dylby1]

First off, sorry if this makes no sense, there is alot in that post i need to ask questions about haha
Ive broken it into paragraphs, hopefully that helps

The Yellow plot is the ISD preferred enclosure. QTC of .71 and 72 litres or almost exactly 2.5 cubic feet. The exact first box you drew (and sealed too!) SPOOKY ....
The Orange plot is also sealed but volume halved to 35 litres and the response differences would be inaudible both have a -3db point of 34 HZ

So basically, if i go with the sealed box it would make little to no difference if i built it at 35L or 72L?

Both sealed boxes will be nicely damped, soak up plenty of power and with the juice you are feeding them get crazy loud (before you add a second sub!) (1 driver in free air at 1000w in these boxes should be good for 120db hypothetically - before you add loading and cabin gain etc - i.e. louder than you should ever listen when driving and enough to damage hearing pretty quickly!). They both model very close to the 'ideal' .707 giving the best combination of power handling, extension and transient response (i.e quite deep, plenty fast, tight punchy bass - ideal for rock thru techno but higher Q's will give boomier bass that some ppl prefer for RnB and HipHop....)

Not to mention they are sooooo easy to build

This sounds like it would suit me great. 2 of these, based on what youve come up with there will be insane!

All the above (yellow and orange) is with sealed enclosures yeah? (which was, as you mentioned, my first preference anyway)

The Blue plot looks amazing - pretty flat down to 20Hz or so and noticeably (if not massively) more output from 20-50HZ than the sealed configurations... problem is the necessary 5.5" vent needs to be nearly 1.4 metres long (yes metres!). My brain is fried and I can't think of a way around this at 2AM! But maybe some more experienced builders than I can have a shot tomorrow? FWIW the Box is 62l (2.2 Cu Ft) and is tuned to 22Hz. this was the vented enclosure WinIsd put forward but i reckon is unrealistic due to vent issues. (To go shorter you need much smaller diameter and then you will have chuff city )

1.4m ?!?! thats just a bit too long haha

The pink plot is also a 2.2 cu Ft box, tuned to 32 Hz (35 looked quite similar). The good news is the same diameter port only needs to be 5" (125mm) diameter and 470mm long so would fit your original drawing. You also have Crazy output at the tuning frequency (an 8db gain) so repetitive thumps in the 30-45Hz region will be impressive - but it's peaky as hell and a long long way from being a 'musical' response. If you just want doof doof that may suit you but it could be very very tiring...Also, if going this way you will definitely need a subsonic filter below the tuning frequency or you will kill the subs in no time!

I definitely dont want it too peaky, which was one of my concerns at the start (which i didnt mention i dont think but should have)
Id be after a more musical response than peaky for sure

The one thing i would still check with these drivers though is if you do plan to port them, that they can still handle the power you want to put thru them... If not you will lose most of the SPL gain achieved from that configuration and have far less SQ than sealed as well.

well i think based on all that, a sealed enclosure will suit me better (as i originally said lol)

But just for reference, how would i go about checking what they could handle ported vs sealed?

Just modelled a 1.6 cu ft (45 litre) vented box tuned to 35hz and its plot is very similar to the pink 32 hz tune in a 2.2 cu ft box - only a sharper curve again! Same gain at tuning frequency but a slightly sharper climb getting there!

So this would be even more peaky over the original pink tune?

[IamtheSteg]

First off, sorry if this makes no sense, there is alot in that post i need to ask questions about haha
Ive broken it into paragraphs, hopefully that helps Good idea

So basically, if i go with the sealed box it would make little to no difference if i built it at 35L or 72L? - Pretty much, 'tis the beauty of this driver in a sealed box. You could even go as small as the 25 litres or so Pio recommend with bugger all difference in sound...


This sounds like it would suit me great. 2 of these, based on what youve come up with there will be insane! I agree

All the above (yellow and orange) is with sealed enclosures yeah? (which was, as you mentioned, my first preference anyway) Got It

I definitely dont want it too peaky, which was one of my concerns at the start (which i didnt mention i dont think but should have)
Id be after a more musical response than peaky for sure

well i think based on all that, a sealed enclosure will suit me better (as i originally said lol)Agreed, I can't see a way to get a smooth alignment for these subs with a vented enclosure that will fit with the box dimensions you have (unless you want PVC stormwater pipe running all around your boot )

But just for reference, how would i go about checking what they could handle ported vs sealed?Other than speaking to Pio/their rep/sales people etc, I can't tell you. My major concern is the massively steep roll off below the tuning frequency, making it very easy exceed Xmax with little actual output. Subsonic filters will probably take care of this and above that the port is doing the work that gives all the gain. Still personally i would check and double check, as much as possible before throwing any driver but particularly one designed for use in a sealed enclosure, into a vented box that peaks and troughs so sharply.

TBH there will be others around here far more versed than me in the dark arts of vented boxes who can give much better advice. I personally have a pretty heavy bias towards quality drivers in sealed boxes in the car environment (could you have guessed?). I have always been able to achieve my goals with nice subs in easily constructed sealed boxes
Of course there are plenty of drivers that suit vented enclosures and can maintain a flat response...

So this would be even more peaky over the original pink tune? Yuppers!

Edited by DailyDriver, 08 April 2012 - 11:51 AM.

[Dylby1]

Sweet thanks mate, thats been a huge help.

I've gotta be better off going for a good sealed design over a ported design that has been compromised to suit the car it is going into.

I definitely dont want my boot to look like a plumber built the sound system haha

[Dylby1]

Ok hopefully last question

The displacement of my sub is 0.181 cu ft. so ideally i would want to build the box so that it is the 35L (or whatever i choose to go) after displacement, not before right?
so i would build it 0.181 cu ft larger than the size box i want?

[IamtheSteg]

Technically, but you have seen the difference taking 37 litres out of the box did (sweet FA) so, at least in a sealed box of this size you shouldn't sweat too much about Driver displacement... I'm still impressed that the first sub you drew turned out to be the optimal enclosure

Are you still thinking one driver in each side of the boot? I reckon you should be fine if you aim for your box to be anywhere from 40 litres up and you should have a killer Sub Bass setup.

[Dylby1]

Technically, but you have seen the difference taking 37 litres out of the box did (sweet FA) so, at least in a sealed box of this size you shouldn't sweat too much about Driver displacement... I'm still impressed that the first sub you drew turned out to be the optimal enclosure
So am I, bit pissed that all the effort put into designing 11ty other boxes was kinda pointless. BUT i have learned a fair bit from it so i guess its not entirely wasted

Are you still thinking one driver in each side of the boot? I reckon you should be fine if you aim for your box to be anywhere from 40 litres up and you should have a killer Sub Bass setup.
Pretty much thinking have the 2 subs facing straight back side by side, same as a prefab box would, except my subs will actually fit properly
Something along these lines basically: