PDA

View Full Version : Need help with a ported box design



Jayhawkk
10-24-2004, 07:18 PM
I need help with dimensions for building a box. Going to fit two solobaric L7 15" subs with a max width of 40 inches, depth of 25 inches and Height of 20 inches. Using Kickers specs for 3.0 cu.ft. + port; 2.5 x 16.25” port, 19.5” long, per sub.

When making a vented box housing two subs are they seperate with seperate ports or are they combined with one port? If seperate is okay I would prefer building it that way.

Any help with getting the specs I need to help get this box built would be great! :thumbupw:

Scarenius
10-24-2004, 07:58 PM
Talk to JMac, for a small fee he can build you one helluva box design, ported or not.

Jayhawkk
10-24-2004, 09:53 PM
<nod> Thanks.

Apoc
10-24-2004, 10:56 PM
talk to OLD_SCHOOL, he is the man at box designs!

BulldogSr04
10-27-2004, 01:02 AM
Or I will do them for free, just do my iPod link and fill out an offer. PM me when you finish it with your measurements and I will have a plan with dimensions, cut sheet, and assembly instructions asap.

:eek:

mrray13
10-27-2004, 01:29 AM
I need help with dimensions for building a box. Going to fit two solobaric L7 15" subs with a max width of 40 inches, depth of 25 inches and Height of 20 inches. Using Kickers specs for 3.0 cu.ft. + port; 2.5 x 16.25” port, 19.5” long, per sub.

When making a vented box housing two subs are they seperate with seperate ports or are they combined with one port? If seperate is okay I would prefer building it that way.

Any help with getting the specs I need to help get this box built would be great! :thumbupw:


as too answering ur questions....u can build seperate boxes, or one big box with seperate chambers, each with it's own port. and yes, each chamber needs to be 3ft^3 with the port 2.5x16.25x19.5...the 3ft^3 is AFTER port and sub displacement.

the dimensions u list will yield a 11.6ft^3 gross volume, so u have plenty of room.

so each box would be 20"tall x 19" wide x 20.54" deep....assuming 3/4"mdf....each with it's own 2.5 x 16.25 x 19.5 port

one big box could also be made...

20"t x 38.75 w(to allow for the seperating baffle) x 20.54" d..again assuming 3/4" mdf...


the seperate chambered design will also offer a level of protection for ur subs. though it rarely happens in daily drivers, if one sub was to blow in a shared chambered affair, it could possibly cause a "domino" affect, blowing all other subs within that chamber. it can't happen with a seperate chambered box. something to think about.


but yeah, u could also run a shared chamber, box size would be roughly the same as the bottom measurements(including the center brace/baffle)...with a port 4x24x22.08, to achieve the same tuning as above.



hope that helps some.......







wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee :peace:

Apoc
10-27-2004, 09:54 AM
I would do the dual chamber so if you only want to run one at a time, you can. Its a nice conveinience.

mrray13
10-27-2004, 10:16 AM
I'd argue that you'd have to be pretty slow to turn the volume down to blow the other subs ... It's **** near impossible not to tell when one sub blows ...

Also, odds are the subs in a separated enclosure would be getting the same power, so if you continue playing that one at the same levels, you're probably going to blow the other ones within a short period after the first one blew.

In my opinion, it doesn't offer much more protection but rather allows the convience of running one sub ... With a shared enclosure, none of the subwoofers can be blown or else it'll rattle and bang like a mofo ...



u bring up some good points. and i would dare to say in most cases u would be correct. but there are some people who think distortion is music. and if the enclosure is in a trunk, especially a well sealed one, one might not hear the rattle,bang or assume it's just coming from the vehicle.

also, if ya reread what i wrote, i did say "a level of protection for ur subs. though it rarely happens in daily drivers, if one sub was to blow in a shared chambered affair, it could possibly cause a "domino" affect", i didn't say it was a given. :readytog:

in all honesty, i am not sure how one blown sub in a shared chamber would cause the others to go. i was informed of it by a local installer/shop owner whom i respect and is extremely knowledgable. he also told me that it happens more in high power applications (over 1000wrms per sub). which is why most of their bigger installs are of seperate chambers, while lower installs are of a shared design.


and in ur "power being the same" example, what if the power was well within rms, and the first blown sub was just a defective sub? the second sub wouldn't blow anytime soon, unless it was defective as well, correct? unless they are early eD drivers...... :wacky: :wow: :omg: sorry,had too...





besides going seperate throws in a brace without affecting vB...hehe..kinda...




wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee :peace:

Apoc
10-27-2004, 12:01 PM
I say you two should fight to the death...

OLD_SCHOOL
10-27-2004, 12:51 PM
my 2 cents.... and thats all i got left is that if i driver "blows" it is usually accompanied by a drop in impedance. thus the reason many of us will tell new people to check the VC's with a DMM. in that event this would greatly increase the working load of the amp supplying more power to the "blown" sub and the working subs i can see possable issue not only with the other subs if kept running but possable amp damage as well. (seperate or not)

however if you can not hear a damaged sub or " blown" one than you need to seriously seek help. because i had never heard a messed up sub until i got one out of the box. when we worked at the shop education of our customers, and quality products along with "smart" installs ensured the least amount of warrenties possable. the kind of noise a blown sub makes is way beyond distortion.

the biggest advantage in a sealed aplication i can see for seperate chambers is that of strength

mrray13
10-27-2004, 12:59 PM
my 2 cents.... and thats all i got left is that if i driver "blows" it is usually accompanied by a drop in impedance. thus the reason many of us will tell new people to check the VC's with a DMM. in that event this would greatly increase the working load of the amp supplying more power to the "blown" sub and the working subs i can see possable issue not only with the other subs if kept running but possable amp damage as well. (seperate or not)





thank u..helps to clear up some things....






I say you two should fight to the death...


but if he won, he might subject this forum to more of his..ummm...arse shots..... :waycrazy: :barf:


'sides i like a good discussion, i might learn something :waycrazy:






wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee e :peace:

OLD_SCHOOL
10-27-2004, 03:57 PM
ok i 2 on 1 you guys against me

my point was if the coils burn and don't disconect ie they become shorted maybe the definition of "blown" is the issue

mrray13
10-27-2004, 08:37 PM
ok i 2 on 1 you guys against me

my point was if the coils burn and don't disconect ie they become shorted maybe the definition of "blown" is the issue


no, no..i'm not against anyone here..


i've always been told that in a shared chamber, if one sub blows, the others could as well. in a seperate chamber, this is less likely.



Thus, if you had two subs wired in parallel (down to 2 ohms let's say) and one blows, the amplifier would power a 4 ohm load instead. Unfortunately, the sub that isn't blown would probably get more (usually only a little more) power because power output typically doesn't halve when the impedance is doubled ...


my point here is if ur already below rated rms of the subs, how would the other sub blow?especially if there isn't much of a power rise? on a system where ur already above the rating, then i could understand the potential problem.



Mrray, if you've ever heard a blown sub in a shared chamber, you'd know that it's going to be noticable even in a well-sealed trunk

never in shared chambers, though i've blown a few in sealed truck boxs(due to stuff pressing in on the subs and me not knowing, not a power issue) and teh thud they made was definitely noticeable.


hell, i'm learning here...

couple questions..

if a dvc sub blows a coil, and one is left, wired in series, what happens to the impedence?

if a sub blows both coils and it becomes an open circuit, why wouldn't the amps full power be directed at the other sub (notwithstanding the halving of impedence, or is that the answer?)?






wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee :peace:

Apoc
10-28-2004, 10:10 AM
hostile..

Apoc
10-28-2004, 05:09 PM
why are you guys fighting about nothing?

mrray13
10-28-2004, 08:21 PM
we aren't fighting...

i'm asking...he's answering......it's called learning...:thumbsup:




3: not necessarlly in series...


yeah, i can't spell..







wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee :peace:

Scarenius
10-29-2004, 12:06 AM
I've been told wiring them in series can lead to really weird distortion in one speaker. Basically, since electricity travels one way, the first sub can **** up the signal which then goes to the second sub, and makes bad stuff happen. This would be heavily dependant on what subs you have.

Jmac is right again. If 2 subs are paralleled, and one blows, as far as the rest of the system is concerned, that sub no longer exists because it has open-circuited. IMO, It's like attaching a hunk a metal to one of the wires going to a sub. Just because it's there doesn't mean the amp is gonna notice.

DBfan187
10-29-2004, 12:21 AM
I've been told wiring them in series can lead to really weird distortion in one speaker. Basically, since electricity travels one way, the first sub can **** up the signal which then goes to the second sub, and makes bad stuff happen. This would be heavily dependant on what subs you have.
music is AC;) It alternates - go in both directions.;)