Tryin' for a larger/more efficient box... Help

[shredder1 10+ year member]

I'm changing my setup for what seems to be about the umpteenth millionth time. I am going from 2 Skar EVL 12's in a single chamber 4 ft3 ported to 32 hz with 48 in2 vented to a larger box. I'm trying to stay below the window line as much as possible and have 37.5 w x 14.5 h x 26.5 d to use... I am hoping that I see a noticeable increase in bandwith and SPL with this larger box. Could anyone check my numbers as I cannot seen to get Torres working on my computer? I am targeting 5 ft3 net common chamber with 71.5 in2 28" long will this get me to 32hz? Externally will be 37.5 x 14.5 x 26.5 with 300 in3 of bracing displacement and .3 of driver displacement. I'm hoping to brace it well enough to stay with a single baffle if possible. Driver up/ port back will be the configuration. I've always done this myself but after being out and about seeing what other enthusiasts are attaining lately... " I was out of car audio for 15 years"... I was hoping for some help. 5 ft3 net with 71 in2 vented at 28 long, will I see a slight improvement maybe wider bandwith. It plays loud and sounds great now but I've gotten addicted to LOWZ and have re-tuned the small box to 28 hz using an extension on the port but the SPL suffers noticeably. Will the larger box have more extension on the low end over the small box and still SPL? Sorry about the long winded question but I couldn't seem to put it more concisely. I'm at 6.77 ft3 overall and I really don't want to go much larger. I still need to have port clearance unless I build it to the tailgate and port it upwards.

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[BOOMINGRANDPA 5,000+ posts]

those evl look good, told couple pees about the 18 cause it's only $269,, i'd be happy with 1 12, i'd have to get a new box too..

 

[BOOMINGRANDPA 5,000+ posts]

I'm changing my setup for what seems to be about the umpteenth millionth time. I am going from 2 Skar EVL 12's in a single chamber 4 ft3 ported to 32 hz with 48 in2 vented to a larger box. I'm trying to stay below the window line as much as possible and have 37.5 w x 14.5 h x 26.5 d to use... I am hoping that I see a noticeable increase in bandwith and SPL with this larger box. Could anyone check my numbers as I cannot seen to get Torres working on my computer? I am targeting 5 ft3 net common chamber with 71.5 in2 28" long will this get me to 32hz? Externally will be 37.5 x 14.5 x 26.5 with 300 in3 of bracing displacement and .3 of driver displacement. I'm hoping to brace it well enough to stay with a single baffle if possible. Driver up/ port back will be the configuration. I've always done this myself but after being out and about seeing what other enthusiasts are attaining lately... " I was out of car audio for 15 years"... I was hoping for some help. 5 ft3 net with 71 in2 vented at 28 long, will I see a slight improvement maybe wider bandwith. It plays loud and sounds great now but I've gotten addicted to LOWZ and have re-tuned the small box to 28 hz using an extension on the port but the SPL suffers noticeably. Will the larger box have more extension on the low end over the small box and still SPL? Sorry about the long winded question but I couldn't seem to put it more concisely. I'm at 6.77 ft3 overall and I really don't want to go much larger. I still need to have port clearance unless I build it to the tailgate and port it upwards.

if u saying 5cf total ad with 71" sq port 28" long i get just under 32hz., what size is port with of box or just like a square out back or side or what?.. if u tune to 32 bigger box maybe deeper doubt it be louder spl boxes are smaller but may work with huge port, i'd think about tad smaller box tuned to 35hz, others may not agree..

 

[shredder1 10+ year member]

I figured the port at 13 x 5.5 ,I have the car without the re-ported extension currently and it really hits probably 142-144 db or so but I am always looking for more. Unfortunately I became a DJSNT fan and I love those lows... I don't want to set my SSF above 20 hz anymore like I currently am with the small box... I may be asking too much from these subs but I'd like to see what's possible. With the extension I built installed it brought the over-excursion under control... "I thought I was gonna tear a spider before I did"... but I lost at least 2 db in the upper 30's-50 hz range. Yes they are a good small box woofer but shouldn't a larger box be more efficient, have better extension? The way it plays with the extension is great but I'm looking for more hi 30's- mid 50's without losing low to mid 20's very much. check this vid... https://www.youtube.com/watch?v=aFeOskSmcNQ ...

is this too much port at 71 in2? The box extension pic is in my gallery it works great but I like to really open up the volume sometimes and SPL...How much does anyone think the larger box will help? I have about 2000 watts after box rise currently, might this improve?

 

[hispls 5,000+ posts]

Have you even modeled those subs? Depending on specs, they may just wind up more peaky around tuning.

 

[shredder1 10+ year member]

If I do go to a larger box what ratio of port area to box volume does anyone think will work best?

 

[shredder1 10+ year member]

I no way to do this... any help would be great! I'm shooting here in the dark by myself.

 

[BOOMINGRANDPA 5,000+ posts]

5 cf probably ok on those but if u worried about over excursion (or bottoming out) larger box will do that easier.. u could do 4.75 cf ad with big port probably will be deeper tuned low idk about louder (to the ear) my sub got deeper and louder going to slightly smaller lower tuned box but u already at 32, u can still do not quite as big of a box tuned to 35 (after sub/port disp) and set s filter at 28 be fine.. but depends what u want more real deep or real loud..

 

[shredder1 10+ year member]

I guess that's the dilemma isn't it?.. LOL!.. the recommended specs are 2 ft3 per @ 32hz and they're sounding good but I can't get to 25 hz without installing the extension... maybe I should start lookin' at 18's... so much for keeping it under the window line.

 

[shredder1 10+ year member]

Anyways I'm hoping that a larger box will allow me to tune at 32 hz and have a less steep curve below tuning, will this work? Can the port area to volume ratio affect the excursion and the way the woofer extends under tuning? If anyone has any thoughts/advice I'd love to hear it... Even if I'm way off base!

 

[shredder1 10+ year member]

One more question... I see a lot of people discussing whether they have 12 to 18 in2 of port area per cube but not how this affects the output. Is it specific to the driver size or is it an arbitrary # for a certain type of response? Sorry about asking the obvious if it is obvious!

 

[BOOMINGRANDPA 5,000+ posts]

I guess that's the dilemma isn't it?.. LOL!.. the recommended specs are 2 ft3 per @ 32hz and they're sounding good but I can't get to 25 hz without installing the extension... maybe I should start lookin' at 18's... so much for keeping it under the window line.

do 1 18 more cone area

 

[BOOMINGRANDPA 5,000+ posts]

One more question... I see a lot of people discussing whether they have 12 to 18 in2 of port area per cube but not how this affects the output. Is it specific to the driver size or is it an arbitrary # for a certain type of response? Sorry about asking the obvious if it is obvious!

well sub companies list ports like 18-24sq in for most 12's but thats based mostly on box size.. peeps here say 14 sq in per cube so 65-75 be great on 5cf.. btw the 18 only needs 5 cf too lol..

 

[shredder1 10+ year member]

Yeah,but the Skar 12's... are paid for! If i wasn't joking about the 18's... "which I was"... I'd probably just wall it, which will not please the wife. There is this local guy who hits 152 db with 2 12's and it goes low so well ... I'd like to emulate that somewhat! Of course there is one little problem...$$$... He's got 2 DD 9512's on a M4B I think blown thru in a Silverado. It's very impressive but.. very expensive I'm sure.

 

[shredder1 10+ year member]

Thanks for the help, I designed it at about 14 in2 per cube so I just will have to see how they perform in a larger box. They go low really well in a 4 ft3 box so I just will have to try I guess. It's good to know that I'm on the right track, I hope a larger box will help bass extension below tuning. I'm not looking for miracles just an improvement over the 4 cube box. I guess I'm lucky to be under-powering the subs slightly, hopefully I can set the SSF under 27hz... love them lows!