I've got quite a lot going on right now if you cant tell, I've got a client's SQ truck and my personal SPL build going at the same time. I've got some great info from you guys on the SQ build so lets try some on my SPL build. Last year we took state records in USACi in Stock 1801-3001, since then we've been addicted to going bigger and louder. We want to be able to still play music so, no pure tones/burp set up. We've got the durango ripped to down to having nothing but a dash, being completely deadened up.

The idea sits at building a wall behind the B pillars for 4 18" BTLs. Haven't decided on what to do to power them yet.

We have more than enough room to give them all the airspace in the world and want to get as as high of a number as possible.

My main questions:

Does it make any difference to have all 4 sitting in the same airspace, say 30-ish cubes. Or to have them paired or separated individually? Which ever puts the highest numbers up is really what matters. We can easily give all four 32 cubes giving the full maximum of 8 cubes per. I'm just curious if this may be overkill, I may simply feel this way because I've no experience with woofers of this size and power handling.

I plan to build the box to be extremely strong, Double plying 3/4 MDF all around maybe triple on the baffle, fiberglass rounded edges all around, and 2 steel threaded rods for center bracing.

We've only found 170amp alternators for mopars so we were thinking of running dual 170's. I was tossing the idea around of running the stock alternator and separate 170 set to run 16V to 16V batteries to push 8 sundown 1500Ds. I don't know which would be better.

Just looking for ideas and insight.

Thanks,

Scott

Edited February 15, 200817 yr by Erotomania

As I can only be considered a casual competitor, I see it as there are a few different ways to approach the internal design. I have noticed a good number of competitors going with smaller inner air spaces and separate chambers with external ports in hopes to fight impedance rise. While on the other end some guy are going in the other direction with one huge air space and a single massive short port for the most efficient set up, almost to the point of free-air. Both ways are effective, and both have their obstacles.

I see a lot of comp guys tuning their ports up. We really want to catch lows and want to tune for maybe 30 or lower. I may make a removable port so we can play with port tunings but as it stands now we'll be feeding 4x18" BTLs 32 cubes ported at whatever we tune to in shared space walled off behind the b pilar powered by rather 4 rockford t20001bds or 4 memphis MCD2500's. I think the Rockfords are higher quality amps but the memphis atleast claims more power. We're also looking at running atleast 3 batteries and 2x200A powermaster alts.

Opinions welcome

well figure out your 1/4 wave frequency... then cut that in half and tune to that frequency( ie: if 1/4 frequency is 70Hz tune wall to 35Hz ... a durango I believe to be in low 70 for 1/4 wave)... it will still yield good SPL numbers while sounding really good on the looooooooow notes... plus it will do really nice hair shows

btw... tuned low with only 2 x 3/4 ply is too too weak.. try building a steel cage in the truck first then attach the MDF to that if u dont want to use steel..try basically building a frame like in a house that gets pretty strong too

also if u want to do this u might be best building 4 boxes altogether for strength

like said earlier there are many many ways to tackle this..the best way is to build the biggest box and start from there

well figure out your 1/4 wave frequency... then cut that in half and tune to that frequency( ie: if 1/4 frequency is 70Hz tune wall to 35Hz ... a durango I believe to be in low 70 for 1/4 wave)... it will still yield good SPL numbers while sounding really good on the looooooooow notes... plus it will do really nice hair shows

btw... tuned low with only 2 x 3/4 ply is too too weak.. try building a steel cage in the truck first then attach the MDF to that if u dont want to use steel..try basically building a frame like in a house that gets pretty strong too

also if u want to do this u might be best building 4 boxes altogether for strength

like said earlier there are many many ways to tackle this..the best way is to build the biggest box and start from there

Yeah we've been thinking of layering up some more, we have a lot more space than we know what to do with so the box can be big enough to compensate for being layered up even 4 layers thick with mdf. I was told it was a good idea to build a wall where the box will sit, just fit a woofer of some kind in there and RTA it to find the trucks resonate frequency with the wall in place and tune the port for that to get the most out of the set up. That would probably sound like chit but makes sense to put down the highest number possible within reason. Ideally we'd be able to swap ports between an SPL comp only port and ground shaking fun low tune.

I'm all for doing whatever we can to built the strongest box possible, metal work just isn't exactly our thing. So maybe more plys of mdf and good bracing +steel rod reinforcement in the center should do the trick.

well figure out your 1/4 wave frequency... then cut that in half and tune to that frequency( ie: if 1/4 frequency is 70Hz tune wall to 35Hz ... a durango I believe to be in low 70 for 1/4 wave)... it will still yield good SPL numbers while sounding really good on the looooooooow notes... plus it will do really nice hair shows

btw... tuned low with only 2 x 3/4 ply is too too weak.. try building a steel cage in the truck first then attach the MDF to that if u dont want to use steel..try basically building a frame like in a house that gets pretty strong too

also if u want to do this u might be best building 4 boxes altogether for strength

like said earlier there are many many ways to tackle this..the best way is to build the biggest box and start from there

Yeah we've been thinking of layering up some more, we have a lot more space than we know what to do with so the box can be big enough to compensate for being layered up even 4 layers thick with mdf. I was told it was a good idea to build a wall where the box will sit, just fit a woofer of some kind in there and RTA it to find the trucks resonate frequency with the wall in place and tune the port for that to get the most out of the set up. That would probably sound like chit but makes sense to put down the highest number possible within reason. Ideally we'd be able to swap ports between an SPL comp only port and ground shaking fun low tune.

I'm all for doing whatever we can to built the strongest box possible, metal work just isn't exactly our thing. So maybe more plys of mdf and good bracing +steel rod reinforcement in the center should do the trick.

if ur not into welding build urself a nice frame to work with..maybe 2x4's or even 4x4's for extra strength... I did it in an S10 cut-through... ill see if I can find some build pics ... but its very solid with only 1" thick walls and the 2x4 frame... the complete enclosure is internally 48"wide x 31"high x 44"deep and it holds 4 15" subs( at the moment the old DB drive platinum subs) the Fi BTL's are laying on the floor with no time to try them... so far did 153.62 on TL with only a single Powerbass XA3000d

also my best friend besides deck screws is PL Premium construction adhesive

I think I went through about 24 tubes of the stuff..but anywhere the 2x4's touch the body or frame I put on an extra thick bead to make sure no rattles of wood against metal and also where I could I screwed into the metal frame of teh truck( ofcourse I had permission from the owner)

heres a few pics I found ... the almost finished product is still in my camera

as u can see tehre is still lots of work to be done... bondo all the corners and such..there have been angle added into the back corners since these pics

hope this helps give u some ideas for your build