SPL & SQ / Fabrication

I have a great interest in the science of box design and I've seen several examples around the 'net of folks building high-power series-tuned 6th order bandpass boxes for SPL purposes. One common design theme seems to be to purposefully undersize the rear port, the reason given is for "cone control". This appears counter-productive to me because the frequency where port velocity will be the highest, and thus having an undersized port will have the most effect (whatever that effect may be), is at the tuning frequency when cone excursion is at a minimum anyway. It seems to me all these guys are doing is making a 6th order bandpass that becomes a 4th order basspass with a…

Sorry for the long post. I just bought a pair of Beals Bros 8" midbass drivers. I have no specs on them. I know you are probably saying to yourself, why would he buy them if he doesnt know anything about them. Well they were cheap and in great shape. Now on the the questions. As many of you know I am currently running a set of CDT HD-62 pushed by a Memphis 16-mc300 ~150x2@4ohm (depending on voltage) ~240x2@2ohm ( " " " ) Here is where the questions start. The Beals is 2 ohm nominal and the HDs are 4ohm. that would make the final load 6ohm for series ( not enough) or 1.3ohm for parallel ( too low). I have heard that lower impedance=more distorti…

Port around 1cubes per chamber. Tuned around 33hz Sealed around .75cubes per chamber Thanks! For 10"

Im pretty sure Ive seen this before. wondering how the port length is calculated. say the port opening is 3.75x13, Id assume when it splits Id make each continuance of the port 1.875x13. do I measure the length of the first part before it splits, and add to it the length of the part after the split to get the overall length. do I calculate the length as if I were running 2 1.875x13 ports, or a single 3.75x13 port. with the box volume and tuning I was using, they were very similar, 29.6 for one and 28.92 for the other scenario, so either one would end up close enough, but Id like the know the correct way. if either of these are correct.

http://www.power-sonic.com/index.php?id=31&gr_id=40 They use the same glass mat technology as Kinetik. I'm thinking about putting three of these in the back of my car. What do you think? Nominal Voltage........................................................ 12 volts (6 cells in series) Nominal Capacity 20 hour rate (5.5A to 10.50 volts) ................................................... 110.0 A.H. 10 hour rate (10.3A to 10.50 volts) .................................................. 103.0 A.H. 5 hour rate (17.7A to 10.20 volts) .................................... 88.5 A.H. 1 hour rate (61.8A to 09.00 volts) ............................................... 61.8 A.H…

Alright. Here is what I have to work with. The box will be for a 12" ICON. I want it ported to play low and deep. As you can see from the picture, the only dimensions I have play on are X and Y. I know nothing about round ports so help me out here. The ports coming out the top will be placed directly beneath my open 6x8 reardeck holes.

I have 2 sa15s and i'm designing a new box. It's a daily driver but i want it to be a very loud daily driver. i currently have a hifonics hfi1500 (pending upgrade) big 3 done, XS Power D925 on the way along with second skin coming. I'm probably going to go around 7.5-8 cubes after displacement and wondering which one will get louder to. If i go aeroport how big and long should i go. Any input is appreciated! Thanks

Hey guys i'm building my first my box for three fi bl 12's and want to tune it to 31-33 and was wondering which would be better? Sealed,ported, or banpass?? Any suggestions would be helpful

so i just wired down my fi q 15 to 1 ohm.. and it hits every note really hard.. and i mean really hard.. but it doesnt sound to clean.. its in a sealed box 2.3 cf could it be because the ohm is set to low? should i have left it at 4 ohms?

Alright guys here it goes... Trial 2! for my woofer box.... My current design is 31.5w, 22d and 16.5t. I don't remember the wood thickness but I found a scratch paper and I only made my box 3.5cuFt... Which is the smallest they recommend for a level 5 15". Why I did that? I have no bloody idea.... Anyway I re measured and I can add a little more to the box -- roughly 2.25 inches on top, and 7.5 inches on width. I would like to try and reduce the dept the most I can because as of right now I cannot fit more than one battery back there. I would like to be able to lay my amp down nice and neat and have the bat next to it. I will be trying to design my own again but I woul…

Horns and i want to know of were to start... maybe links to some sites and what not.. anything is helpful thanks everyone

i got a bigger amp for my 10's and now my back wall of my truck flex's way to much ...it has a knocking sound i can make it stop buy pushing as hard as i can on the consol ...what would be the best way to stiffen the wall...the box is bolted to it but only at the bottom ..i could put some more bolts into the top but im not sure it would end it ...another idea i have is to weld some tubing to the back of the wall inbetween the cab and bed ..well here is the only pic i have to show where the consol meats the wall

Hey guys! I did a bit of reasearch but couldn't find a good topic about this. What do you guys reccomend for some good box building tips for the best box possible? Not like designs so much (Although if you wanted to post set-ups such as like...Explorer, sub up port back (as an example) that might be helpful to some), but things to do in the box. Things like: Rounding the port edges to flairs 45 degree angles in the corners for standing waves placing the subwoofer so its at the back of the port length where to add braces so that turbulence is minimized (or using rod threads or your favorites) those were a few I could think of as example and I'm not even sure if they're al…

I understand that if you have the same setup you need to double your wattage each time to get 3 db louder. My question is when you get up to say 4kw and you have to double it to 8kw to get 3 db louder is there a significant difference in loudness? Is it the same audible difference than say the same setup at 200 rms is doubled to 400 rms.

Help Please. I want to build a ported box for 4 FI 15" BTL's Currently I have a 9 Cuft box with 2 FI 15" BTL's. Each sub in it's own enclosure. FI suggests 3-5 Cuft per sub. Can I make just one box for all 4 with one port? Or do I make a box that seperates all 4 or two? I like the sound with 4.5 Cuft per sub. I am also lost on the port area if I make one 18 Cuft box for all 4. Really appreciate your suggestions here. Thanks, JR

This will be my first show in over 2 years by this time! Last event I was in was the 2002 SLAP Finals where I was 4th. My system isn't designed for dB Drag so I will be outclassed a bit, but it will be fun to get into the lanes again. Here is the link to the show if anyone cares:) http://www.termpro.com/asp/members2.asp?Who=13&MemberID=6498

As per title lads, with my equipment coming soon I wanna go with the loudest design possible, will be using 2 AA Mayhems with 2 Hifonics 2607D's to power them, have a nice bit of room to play around with (say a max of 25-30cuftexternal) Will I go flat wall Port up top?? Flat wall port drivers wide?? Clam?? Small Tunnel?? I'm not really pushed about numbers as I want this to rattle people (will tune to maybe 30-32hz) All suggestions welcome guys

ok, so i have the dimensions for everything, but i want to make sure if its all good, also if someone could do a sketch of it? 2 - 15" nightshades 1 saz-3500D 99 s10 ext cab subs forward, port in the middle firing up but along the back wall of the box. box height - 27 depth - 14.5 Length - 46.5 Port height - 6 width - 16 length - 26.25 net air space 6.68ft3. port area 96.00 in2. @32.19

ALright so i want to do a kerfed port on my next box... i read a thread and i am almost ready to give it a shot. However i have one question. when you do the kerf, do you use the port piece to kerf and then attach it to the front piece on the box or is the port piece and front piece one seemless piece with the kerf in it? if this doesnt make sence i will try to expalin better.

this is my first time tooling around with winisd. my fi sp4 should be here any day and i'd like to make sure my box design is okay or if i should tweak it. ive seen port velocity used frequently around here and i was wondering how i can determine port velocity. is it for aeroports only or can port velocity be determined in a L slot port? can someone explain how to find out the port velocity for a L port. and before people start saying, yes i did search around a while on the forum and google and couldnt come up with the answer. thanks!

Ok guys, I was looking into a few stats on bench testing, and noticed that amps wired to ".5 ohms nominal" could see up to 1.5 ohms in reality. So, with that in mind, I read into box rise and all that good stuffs. I was just wondering, If I skip terminals on the box altogether and run wires through a small hole (that would be sealed up after of course) or out through a port would this help at all? Or would the longer length of wire just defeat the purpose? Thanks in advance, as always.

ok my friend will build me a box in his wood shop but i need to get him plans. SI 15 MAG, ported. what do you think of the aeroports? is it worth it for only $25 extra? most people use 2 of them at $12 each. power will be a hifonics ZEUS 1000D 1000@1ohm it is a lexus 2002 es300. should be the same as the new camrey. people have put 2 15 in there before with a almsot bent box. i only need 1. the red strap is what i will be using to hold the sub in place, i would also love there to be ehough room to put my trunk battey next to the box. it is 6.5 inches wide demetions are THANKS FOR ALL THE HELP I AM FINALLY BUYING A SUB TO FINISH MY AUDIO SYSTEM AFTER 2 YEARS!!!!!

I have a recording studio and have folded horn pa subs and is the loudest and cleanest of all the pa designs. I was wondering if anyone has made a folded horn sub for a car (I've never seen one but maybe I'm ignorant) and the pros and cons. Thanks

I have been looking in to these two subs for months now reading everything I can. I am still stuck maybe some smart people can help me out. ok I am looking for high quality, clarity, accurate, punchy sound not so much loud. mainly SQ. I had two Pioneer TS-W309D4 in a sealed box at 1.15 Cu. Ft. Air Space per sub. powered by a Pyle PLA2678. I liked this sound it sounded nice punchy. but I wanted something better so this guy told me about FI and Audio Pipe amps . so then I got a FI SSD 12 with only interior leads. powered by a AUDIOPIPE APSM-1500 and in 2cu ft. of air space. tuned to 32hz ported. it got so loud my nose flap would shake and it was awesome and still …

I recently got a great custom box by Audibel Customs for free but I was thinking about building my own fiberglass/mdf enclosure. The only reason I went with Audibel Customs was for the free enclosure if not I would have gotten the Mach5 IXL's. But the Custom box Quentin built is great and hits hard. I just need more space. What I plan on doing is making everthing mdf except for the base/feet of the box. The reason is because my truck has a lot of bumps/curves on the bottom behind the seats and I can gain some airspace in order to do 2 SSA Icon 10's in the future once money comes. I have learned/researched alot of other build logs on fiberglassing and think I have the capa…