Newbie Question: How to calculate Cu.ft Enclosure?

[mengz]

hey guys, i just went to mega sound yesterday and got my new box edi :) its a 1.3 cuft box with 42Hz porting frequency, but not round ports, its square port :) and i must tell you, it sound a whole lot better compared to my old paria box. My bass is so much more tighter. i lied to my gf that i change to new woofer and she beliffed :P

anyways i like the ppl there, their very knowledgable and the thing i like most is, they nvr like preassure u to buy stuffs from them. he even offer to let me test the box 1st, if i like it i take, if not, i return :) ahhHhh nice !!!

p/s: the new enclosure only cost me rm130, i bought tat paria box of mine for rm170 at some accesorry shop!! !@#@!#@!##!@!#

 

[Bert]

yeah.. megasound makes good boxes for reasonable prices to the specs you want.

 

[icecube]

Originally posted by mengz@Feb 17 2005, 16:09
hey guys, i just went to mega sound yesterday and got my new box edi :) its a 1.3 cuft box with 42Hz porting frequency, but not round ports, its square port :) and i must tell you, it sound a whole lot better compared to my old paria box. My bass is so much more tighter. i lied to my gf that i change to new woofer and she beliffed :P

anyways i like the ppl there, their very knowledgable and the thing i like most is, they nvr like preassure u to buy stuffs from them. he even offer to let me test the box 1st, if i like it i take, if not, i return :) ahhHhh nice !!!

p/s: the new enclosure only cost me rm130, i bought tat paria box of mine for rm170 at some accesorry shop!! !@#@!#@!##!@!#

wah only RM130 for a custom enclosure? got wrap with carpet one ar?
aiyo must pay a visit to mega sound already.... anyone have their address??
not familiar with PJ area.... always sesat ...... :( :(

 

[Yong_5290]

megasound...

no..21...jln SP 4/2 Taman Subang Perdana,Sec 4,40150, Shah Alam,Selangor

Mengz...
glad 2 hear u got ur self a good enclosure at a good price(reasonable)..
the worker there r quiet n looks serious in their work...especially the boss Ah Siang..they might look very 'lan si' when they got lotsa work...
but later on...when they r free...they can xplain 2 u lots of stuff bout ice n eventually promoting u some stuff(of coz...all the acc shop will)but the way they promote wont b pushy...they will tell u its good n up 2 u 2 blif it

 

[appleyard]

icecube

i no sifu lah. if you look throughout my post i still ask some noob qoestion (still learning here).

i talked with lots of US forrumer, that way i learn more and faster because they are pro installer and some of them are those ppl who did the amp or speakers you are using.

you can find my noob post here.

http://www.carsound.com/cgi-bin/UBB_CGI/ultimatebb.cgi

sorry not familiar with ICE scene over there in KL (envy you guys).

 

[icecube]

Originally posted by Yong_5290@Feb 17 2005, 19:50
megasound...

no..21...jln SP 4/2 Taman Subang Perdana,Sec 4,40150, Shah Alam,Selangor

thank yong.. :D

appleyard, thanks for sharing the knowledge...

 

[mengz]

yeah yong ur right.... coz at 1st i reach there the workers quite busy. nobody layan me at 1st....i was like...wtf?!!! then eventually one worker, which i think is one of the seniors there, wear specs one abit 'sou ngah' he layan me la. ask me wat i need etc. then as we speak he seems kinda frenly, explaining everything i ask and giving me oppinions. then he gave me a brief introduction to their competition car, which was this old yellow toyota. then later the boss came back then he got explain to me also lor. and he was the one who suggest me to try the box 1st instead of buying a new woofer straight...hehhee

anyways icecube, mega sound although its stated shah alam, but its not really at shah alam. its at kampung subang, after terminal 3. if u really wanna know the way there, pm me and i'll give u my number so u can call me. i'll give u the directions ba. coz at 1st when i went also i couldnt really find it :) i had to ask another accessory shop which was quite reluctant to tell me hahahhaa :P

 

[Yong_5290]

oh...tat guy kah...he's the 1 who customize my whole floor board 1...
the taukeh got take u into his office n show u the software 2 calculate enclosure ar...u can ask him all type of woofer n then he will show u wats the best size(enclosure) 4 the sub...they r using the blaupunkt software if not mistaken...

 

[xtorm]

o.........the blaupunkt 1....hehehehehe.....

nvr when there yet.... will call up jumat to send my HU masuk hospitallahh

 

[icecube]

Originally posted by mengz@Feb 19 2005, 16:48
yeah yong ur right.... coz at 1st i reach there the workers quite busy. nobody layan me at 1st....i was like...wtf?!!! then eventually one worker, which i think is one of the seniors there, wear specs one abit 'sou ngah' he layan me la. ask me wat i need etc. then as we speak he seems kinda frenly, explaining everything i ask and giving me oppinions. then he gave me a brief introduction to their competition car, which was this old yellow toyota. then later the boss came back then he got explain to me also lor. and he was the one who suggest me to try the box 1st instead of buying a new woofer straight...hehhee

anyways icecube, mega sound although its stated shah alam, but its not really at shah alam. its at kampung subang, after terminal 3. if u really wanna know the way there, pm me and i'll give u my number so u can call me. i'll give u the directions ba. coz at 1st when i went also i couldnt really find it :) i had to ask another accessory shop which was quite reluctant to tell me hahahhaa :P

thanks, i tot shah alam is like.... really shah alam leh... oh its actually near subang airport is it ?? hmm.... not really free yet to go visit them... will try to find or ask around when i get there... paiseh to bother u :D maybe u can roughly describe the way to get there .. :D
cheers!

 

[mengz]

heheh yeah yong...tat guy ler....i will be going back there to do my floor board also ler...very nice work ler i saw them doing for this one car when i was there.....hmmmm...i nvr went into the comp room to use the software wor....coz i gave him the specs liow and he said its correct coz around there also the figure.....but when the boss came back he ask me need to use or not i didnt ler...coz sudah pasang and i was dam happy and impress edi....got the kinda bass i wanted...hehehe

icecube hmmm...okies...u use the old airport way to go to terminal 3. u pass terminal 3 continue going summore....then u will pass this long straight road which has lotsa restaurants on the right..one of the restaurant has an airplane cockpit at their main entrance....continue going straight and follow the road.....u will then reach a small bridge....after u pass the bridge...theres one traffic light. turn left at the traffic light and u can see a row of shops on ur left....alot of workshops etc...then u can see megasound there...its facing the main road....one of the last shops at tat stretch....hope my direction is clear...

cheers

 

[gogsard]

can they do a bonet speaker board for a kenari ?

 

[Yong_5290]

can...they can customize it 4 u using mdf wood...

 

[appleyard]

Originally posted by Bert@Feb 17 2005, 09:26
The main reason why most people go for sealed boxes are very simple... It's much smaller!

Can you afford to have a 2 cuft box in your boot? How about 3-4 cuft? If you can then its good and you will need to port cuz ur car is big and need more bass but for a normal car (wira/waja sized) 1 sealed 12" will be enough bass for most people.

reason for using sealed box is not because you can run away with small box. Not many subs can give more bottom end in 1 cu.ft or less sealed box. Most ppl will end up having Qtc of 0.9 and above which is in boomy zone. Transfer function of the car may help a bit on the low end but the roll off is early.
You want the sub-woofer to play sub-bass well into the low region at reasonable SPL level. But somehow ppl like the boomy bass ..... maybe they have yet to listen to sub-bass down low... B)

one thing if you want small box ....... get a sub which can play low in small box and plenty of power due to efficiency trade off (Hoffman's Iron law).

on the small sealed vs. ported box ...... well i fired up WinISD & here's what i got.

Shiva in 1 cu.ft sealed will have F3 at roughly 44Hz.

Shiva in 1 cu.ft ported box tuned at 26hz will have F3 roughly at 40 Hz. It has the same roll-off slope (approx.) as in that 1 cu.ft sealed box but louder by at least 2dB.

well? reason for porting is to extend the freq. lower (as shown above) and the main part is to make it louder.
Big ported box with big port area is meant to be loud which is why it is chosen to be done in the first place.
You can make small ported box but why bother to do complicated box when what you want is more loudness?

 

[icecube]

wah, nice explaination... does that mean the larger the box and port, the louder it get ? (just a conclusion) .... does that apply to all type of subwoofer? thanks, i cant understand the winisd software ler... noob here.

 

[Yong_5290]

Originally posted by appleyard+Feb 20 2005, 21:02 -->

QUOTE (appleyard @ Feb 20 2005, 21:02 )

--QuoteBegin-Bert

@Feb 17 2005, 09:26 The main reason why most people go for sealed boxes are very simple... It's much smaller! Can you afford to have a 2 cuft box in your boot? How about 3-4 cuft? If you can then its good and you will need to port cuz ur car is big and need more bass but for a normal car (wira/waja sized) 1 sealed 12" will be enough bass for most people.

reason for using sealed box is not because you can run away with small box. Not many subs can give more bottom end in 1 cu.ft or less sealed box. Most ppl will end up having Qtc of 0.9 and above which is in boomy zone. Transfer function of the car may help a bit on the low end but the roll off is early. You want the sub-woofer to play sub-bass well into the low region at reasonable SPL level. But somehow ppl like the boomy bass ..... maybe they have yet to listen to sub-bass down low... B) one thing if you want small box ....... get a sub which can play low in small box and plenty of power due to efficiency trade off (Hoffman's Iron law). on the small sealed vs. ported box ...... well i fired up WinISD & here's what i got. Shiva in 1 cu.ft sealed will have F3 at roughly 44Hz. Shiva in 1 cu.ft ported box tuned at 26hz will have F3 roughly at 40 Hz. It has the same roll-off slope (approx.) as in that 1 cu.ft sealed box but louder by at least 2dB. well? reason for porting is to extend the freq. lower (as shown above) and the main part is to make it louder. Big ported box with big port area is meant to be loud which is why it is chosen to be done in the first place. You can make small ported box but why bother to do complicated box when what you want is more loudness? [/b][/quote] it will b good if u can show us how good is ur ported enclosure performing... tok onli is useless.... y dun join us in TT n show it 2 us :D

 

[appleyard]

Originally posted by icecube@Feb 20 2005, 21:47
wah, nice explaination... does that mean the larger the box and port, the louder it get ? (just a conclusion) .... does that apply to all type of subwoofer? thanks, i cant understand the winisd software ler... noob here.

the larger the box, the more efficient the sub gets which translate to lower power requirement to reach max. linear excursion (Xmax). So if you have small power amp and plenty of boot space, go with big box. Otherwise if space is premium, you need bigger power amp.
Remember SPL is all about moving the air & not power.

A port is a resonator (helmholtz) which is the same as passive radiator (sub) when coupled to a sub. So the bigger the port area, the louder it is going to be. Just imagine bigger port area as 'bigger speaker/driver'. It is the port AREA that is important and don't confuse it with port size or volume.

yep, applicable to all subs.

How to use WinISD? Read the Help section.

point to note ... if you are not familiar with ported box design, don't do it. You will end up making the sub sound worse. Plus the damage to the sub when it unloads at lower than port tuning freq.

 

[appleyard]

Originally posted by Yong_5290@Feb 20 2005, 22:04
it will b good if u can show us how good is ur ported enclosure performing...

tok onli is useless....

y dun join us in TT n show it 2 us :D

sure i want to but unless you are willing to pay the shipment of my vehicle to your place. To & back please ... :)

if you don't understand my earlier explanation, please ask which one you need me to elaborate.

 

[Yong_5290]

oh ya...u r in the the other side of m'sia...4gotten...

nah...juz tat normally i c most ppl play sq also using sealed enclosure...even those go 4 competition also using sealed....n u noe hoe small i c sub enclosure 2 enter the iasca m'sia competition...0.6 cu.ft

 

[appleyard]

Originally posted by Yong_5290@Feb 20 2005, 22:23
oh ya...u r in the the other side of m'sia...4gotten...

nah...juz tat normally i c most ppl play sq also using sealed enclosure...even those go 4 competition also using sealed....n u noe hoe small i c sub enclosure 2 enter the iasca m'sia competition...0.6 cu.ft

1. Sealed box easy to do. You can't simply do any shape you want on ported box as the port will get into the way.

2. Ported box if not done properly will have peaky response in a freq. band which needs to be tamed. Same with sealed box. Too small will get ya in the boomy zone (high Qtc)

3. It is not how small the sealed enclosure that you want. It is what freq. response that you want the sub to give. Too small of a sealed box will make the sub to have peaky response and roll-off early hence losing precious low end.

4. Reason to choose ported box is :
- you want the bass to extend even lower without getting the box too big.
- extra dB output due to increased efficiency (+3dB near port tuning freq.)
- you can meet the min. bass SPL requirement in IASCA SQ competition with lower sub amp power. So can join lower class. Good for those with small budget.
- well ..... loud or low or both.