amangujral06

Hi guys, here is an attached pic of the box i'll be soon going to get made, Using .75" MDF and .5" mdf for inner port walls. The box shape will remain unchanged, took many hours to decide the slot port for this. And new suggestions opinions are welcome.

already have those , cdt 062i with extended midbass version , getting 200 watt rms @ 80hz 12db .

playing the sub flat from 30-100hz is my main concern ! I can live without the hard hitting punch , but cannot without my upper midbass .

This box is already made now, and this design is finalized as it acts as my rear seat too. . It has a little more than 4.5cu ft volume and 54sq inches of port area . I can change the port length to vary the tuning but i once read it on Hertz subwoofer manual , that if its a slot port box and the port is along the wall then , we have to keep it 30% shorter then calculated to achieve the tuning frequency ! else it gets tuned even lower - well it makes perfect sense ! If i go by hertz audio suggestion - it means my current box is also tuned much lower than what i intended it to be.. I too also wanted to tune it to 35hz but was scared to make my sub bottom out at tracks having below 35hz content . I really dont know what to do ! music was om much simpler to enjoy in 80s-90s . and does the car tuning frequency play a role with a box design , for it to play flat ?

Hi , been a long time since i made up my new box - so here it is ! a revised box , now tuned at 33 hz ! The cad design The box starting to take place Making those angles wouldn't have been easy for the carpenter. the part that will make it all happen ! and there it goes in the box... a channel provided - for future expansion . a panel can be added in the channel though to change the tuning frequency ! an inside view of the magic port .. another view weapons of mass destruction will upload some more pics with the sub in it and the bracing that was added later . Now i decided to tune it at 33 hz and decreased the port length to tune it at 33hz. the box can really move some air , but it lacks the music capability ! its not punchy , a little slow and tends to become boomy . i have tried various different configurations passing it at 80hz at 12db slope, at 63 at 6/12db also at 50 and lower with 6/12db slopes . subsonic s at 25hz and ts being powered by a blaupunkt vpa 1500pro mono amplifier , which delivers 1500rms@ 1 ohms . so here is my next question to you -------- What frequency should i tune the box to , make the sub more snappier and punchier ? also to decrease its boominess .

that will be very difficult

its going in a hatchback. This is for the 15" . In my testing with port placement, i found, i get the loudest output when port is facing horizontally, rather vertically.So i went for this configuration. the sub will face the boot lid and the port will face the front wind shield.

round the port corners, yes that is a good suggestion, i'll def do that. and put 45's in the port - please enlighten me on this. had to use those odd angles, else i wasn't able to achieve this volume or tuning . I just hope odd angles won't effect how the subwoofer response. The worst part was to accommodate the slot port. I had tried over 10 designs for the same.

The port is forward firing. Its going n a hatch back, removed the rear seat and will be cushioning on the port wall so as to keep it look stock.

I'll keep that in mind

Just like the question says, what is the Motor Diameter of havoc 15? couldn't find anywhere, if you guys have it outside the box, please measure and tell . if measuring dia is difficult, just tell me the circumference. thanks

thanks scott !!

Hi there, after trying to build my own ported box , with certain limitations, i came to ask myself that why do we need 12-16 sq inches of port are per cufeet ? The answer was to avoid air shuffing. BUT ! If a box is 3cufeet , the good book says to use minimum of 36 sq inches(minimum) port area for it, now if we use the same sub to play in a 5 cu feet box, port area increases to 12X5 = 60sq niches (minimum) Now i am guessing that the subwoofer will not miraculously start to push more air ,and that we may have to increase the port area to avoid air shuffing. The sub should displace the same amount of air in a 3 cu feet box or 5 cu ft box. So , why not use 36 sq inches port area also for a 5cufeet box? ( you may take FiQ 15" into consideration) Thanks

after explaining a simple fact of science you still don't think that a hotter coil has higher resistance! then there is nothing left to explain anymore . good luck

Have you taken impedance drop due to playing below tuning into consideration? No, No, No. and one more No. What? Impedance rises before and after tuning. Pick up Loud speaker Design cookbook or WinISD and look at some resistance / frequency graphs. Also a speakers impedance is never going to drop below its measured/rated impedance especially with power applied (unless the speaker fails). OP do not count on impedance rise, set gains accordingly, use a different amplifier, or use a different speaker. who said anything about impedence drop ! impedence rise due to box rise dude, box rise! when coil gets hotter , its resistance increases (coil is made of metal isn't it) - Pick up Loud speaker Design cookbook or go meet an electrical engineer ! Just having more no. of posts on one forum doesn't bend the rules of science . Do one thing, buy a good multimeter (or borrow it from that electrical engg. ), set it to measure the resistance, play a decent song with variable low ocatves and see what actually happens outside WinIsd - you'l be surprised what you know till now.

who said anything about impedence drop ! impedence rise due to box rise dude, box rise! when coil gets hotter , its resistance increases (coil is made of metal isn't it) - Pick up Loud speaker Design cookbook or go meet an electrical engineer ! Just having more no. of posts on one forum doesn't bend the rules of science . Do one thing, buy a good multimeter (or borrow it from that electrical engg. ), set it to measure the resistance, play a decent song with variable low ocatves and see what actually happens outside WinIsd - you'l be surprised what you know till now.

Have you taken impedance drop due to playing below tuning into consideration? No, No, No. and one more No. the Fi Q was playing n a sealed encloser and ofcourse the plutonium wasn't playing below tuning frequency , coz that will make any1 pretty stupid for a person who bought a 2000$ subwoofer

Subwoofers always suffer from box rise, Even after pairing a sub with matched rms amplifier, the subs never ever get the rated power. some subwoofers like groundzero plutonium can go upto 10ohms impedance ! my fiQ even after wring at 1ohms rises upto 2.5 ohms. even if you give both of your subs 350rms each, your subs will play cool. so , don't worry and enjoy

I totally agree that these are the guidelines, BUT, can 36 Sq inches port area on 5 Cu feet box drastically changes the performance Vs 60sq nch port area ? Again when we know that the sub is going to displace the same voulume of air ! Its a big question for me as this factor is affection my box design By using a lot of volume on port itself ! Any guys out there , who had already experimented with the same ?

Hi guys, got a Q15" with flat wind coil and extra spider. Now need to built a box for the same. Can only make a ported box with internal volume as maximum of 3.7 cufeet.. It will be a rectangula ported box with no bracing inside.. using 3/4" MDF Box external dim - 11.25 X 36.5 X 19" - internal volume come to be 3.7 cu feet. i still have too account sub volume displacement, port displacement and is there something left to account in? now come my queries - What is the mounting depth of Fi Q 15" ? What is the cut hole Dia for 15" Q ? How much diameter using round port will be needed - minimum and maximum ? How much more power handling the sub gets with flat wind coil alone ? Does flat wind coil gives the sub some extra oomph, or its just a coil ? Actually i have many more questions, i don't want to seem rude by asking all at once. Nick , Scott , i'll be grateful if you help too, i understand how busy you guys are regards.

some one here who can help?

thanks for the reply. I looked into the tech section. but there is still no answer to my questions like.. How much more power handling the sub gets with flat wind coil alone ? Does flat wind coil gives the sub some extra oomph, or its just a coil ? few more queries... what material port pipe should i use for best results ... PVC , alumnium or steel ? Should i have to brace the box even if using 3/4 mdf ? won't be running more than 600rms to the sub. can i tune the box to 26hz or maybe lower and still expect a good frequency response?

Hi all, one of my friend just bought a new 18"ssd with Flat wind and Bp power. he wanted to achieve maximum spl with minimum power so a bigger sub was chosen. Now, he has a blaupunkt vpa1500pro amplifier which puts out 950 Rms @ 2ohms and 1500@ 1 ohms. As the sub is dual 1ohms, he will be wiring it at 2ohms for a clean 950rms output. Now the problem starts, the car boot is limited to 4.5cufeet of space at maximum, the idea was to go for a ported box but as recommended by FI on this forum first few topics, atleast 6cufeet is needed for a SSD . And that's true due to its lesser powerful motor compared to Btl's or SMD's which can be used in 4.5 cufeet ported boxes. Round port is to be used - 4" or 5" , whatever the 18"SSd owners recommend. plan was to achieve loudness for street bass. so guys what would you recommend the tuning frequency ? I had in mind a target of 32-33hz but it seems outta range now. Now we all know of a magical stuff - poly-fill !! But i don't know if poly-fill works in ported enclosers or not. again plz answer this too. So what say guys, 4.5cufeet , target ported box only. ANY SUGGESTIONS?

Is really that difficult for you to visit ficaraudio.com and look it up...Sealed box: 3.5-5 cuft well the topic reads some goals that need to be achieved so its better to ask SSD users for realistic and experienced recommendations.. why so much anger? i am here for some help on behalf of my friend , if you can't , atleast don't spoil it too.

so how much volume is recommended for a sealed box?