Custom MDF enclosures : Install / Cost info needed (pics enclosed)

[s0uljah]

Nice, I stirred up a little intellectual debate here amongst all the uncles, bacha's and anyone inbetween

Originally Posted by jkdas

sealed saves space too! 113lt in the boot! phew!
and so whats his amp and whats your recommendation?

Originally Posted by Sam Kapasi

Frankly, I would have recommended a sealed box anyways, but i fear your amplifier may not have juice enough to drive a 15" sub in a sealed enclosure.

From what I have read... and from the 'effect' of the ported boston subbie in the santro I posted...
seemed like Sealed is more suited to my listening.

Regarding the amplifier in question... its not a name brand amp, roughly 150 watts RMS if im not mistaken.
Heard this amp in a setup, but only front comps and rear 6x9"... there was no subbie. Specs :

1 x 1200 watts bridged
2 x 600 watts
2 x 300 watts @ 4 ohms 0.03% THD
Sensitivity (signal to noise) 102 db
Frequency response 10Hz - 35KHz (+1db)

Regarding building the box : I went by the place again but couldnt speak to the concerned guy...
Wanted to run the measurements by him and also ask for the pin-connectors instead of the older wire type switches.

my dad says lining the insides of the mdf box with glasswool would be a good option... as a cheap replacement for fibreglass...
I think I read this somewhere else on the forum too... gunbir/navinji, is this feasible ?

What specs should I ask for regarding MDF... Navin you mentioned 25mm, is this a good thickness ?
The reason I ask is because the guy was saying the mass produced boxes used these days are usually ply
and they make MDF only when accessory walla's request it. Since I have been able to catch the source
directly I can make sure I get what I want !!

[navin]

glass wool is good. it is cheap too but it can cause a rash. so be very careful handling it.

25mm MDF is good. If you are using ply get marine ply as it is void free. I find a good void free marine play makes even better boxes than MDF.

[low_bass_makker]

19mm is also good but u have to add some braces inside to make it vibration free also to seal the enclousre u can use silicon used to fix windscreen it is the cheap and best to do the job......

[s0uljah]

Originally Posted by navin

...can cause a rash. so be very careful handling it.
........25mm MDF is good. If you are using ply get marine ply

hehe... was just discussing all this with friends at college and this guy was sayign how he took apart his dads oooooooold speaker boxed in teak wood & played with the 'creamy' stuff inside... he actually rubbed it on his hands and ended up with a horrible allergy!!!

marine ply : I will check with these guys what sort of ply they can source for the enclosure... What about thickness for ply?

LBM thanks for the input... will keep it in mind...

Also regarding volume would 14" x 14" x 18" be an ok spec for the enclosure ? This is considering someone mentioned I need to allow for the volume of the subbie as well ?

[low_bass_makker]

the above are the enclousre outside dimension and if a 19mm mdf wood is used inside volume is 42 liters......this is not a benchmark for the sub the volume can be reduced and increased as per listening tastes. If the box is made smaller it will sound puchy and the low end will be absent but if the box made larger then the lowend will be there but the puchy sound will be a liitle less.

so if u listen to rap and hip hop then go for big box but if u like rock or techno then go for small box......
also dont forget to stuff the box to about 60-70% with stuff glass wool ....

for more freq response of the driver do a plot on winisd and see the results.....

[s0uljah]

thanks again LBM, now thats something I need to consider really !!

Prob is I listen to most types of music, can be called a heavy trance head and the breakdowns and smooth basslines really appeal to me. At the same time I also listen to very slow psychedelic ambient stuff which have very deep bass at times but not a constant thud. To top that off I sometimes remember my school days and I throw in some busta rhymes, tupac, warren g,,, you get the picture !!! So its all a bit confusing...... I dont know how to express the kind of bass that plays in the ambient/downbeat music that really makes me smile... maybe I should post links to a few tracks !!!

glasswool - If you hadnt mentioned that I would have thought that just a thin layer of glasswool on the insides would be sufficient !!

note :example of chill/ambient -
Vibrasphere - Selected Downbeats Vol.1
Entheogenic - Golden Cap

The trance mostly ranges from 144 - 146 BPM (+/- a little)

[gunbir]

Originally Posted by s0uljah

thanks again LBM, now thats something I need to consider really !!

Prob is I listen to most types of music, can be called a heavy trance head and the breakdowns and smooth basslines really appeal to me. At the same time I also listen to very slow psychedelic ambient stuff which have very deep bass at times but not a constant thud. To top that off I sometimes remember my school days and I throw in some busta rhymes, tupac, warren g,,, you get the picture !!! So its all a bit confusing...... I dont know how to express the kind of bass that plays in the ambient/downbeat music that really makes me smile... maybe I should post links to a few tracks !!!

glasswool - If you hadnt mentioned that I would have thought that just a thin layer of glasswool on the insides would be sufficient !!

note :example of chill/ambient -
Vibrasphere - Selected Downbeats Vol.1
Entheogenic - Golden Cap

The trance mostly ranges from 144 - 146 BPM (+/- a little)

Ani, I know what your dillema is... what sub have you finalised. Please post a link to model and tech specs... if you have already posted that earlier in this thread forgive me for being lazy...

[low_bass_makker]

jbl sub general Specs of JBL GT4-15

Frequency Response 20Hz - 400Hz
Sensitivity 91dB
Impedance 4 Ohms
Voice-Coil Diameter 50mm
Cut-Out Diameter 362mm
Mounting Depth 172mm
Overall Diameter 385mm
Vas 133 liter
Qts 0.44
Fs 28.36Hz
Qes 0.47
Qms 7.35
Sealed Enclosure (vol)43L
Vented Enclosure (vol)113L

[s0uljah]

arrreeeey gunbir bhaiya,

what is this forgive talk??? Your inputs on the forum are extremely helpful.
If anyones lazy its me askign all these basic questiosn when I can actually do some reading of old threads and figure out stuff myself...but then instead Im making use of some of india's finest grey matter here at t-bhp Lol

Manufacturers Page for JBL GT4 - 15"

LBM's given you the specs right there though...

Powering it with an amp thats 2 channel, bridged it puts out about 150 rms if im not mistaken...

Thanks guys!!

[gunbir]

Originally Posted by low_bass_makker

jbl sub general Specs of JBL GT4-15

Thanks LBM, do you happen to have the response plot for this sub?

[low_bass_makker]

Originally Posted by s0uljah

sorry to bother you again !!! can you just point out in the pic below which is to be 14.. 14 and which side is 18. I think I have an idea of this.. but its bothering me just wanna be sure.

and by the way 14 + 14 + 18 = 46 ltrs
so is it 42 ltrs and + 4 extra for the sub volume??

man man what are u doing man this is wrong

this like this

14 inch X 14 inch X 18 inch
or
34.3 cm X 34.3 cm x 45.7 cm

this comes to 34.3X34.3X45.7 these are outside dimensions so we need to deduct 19+19 mm from each side (two sides)

so it comes to
30.5 cm X 30.5cm X 41.9cm
now the internal volume comes to nealry 39 liters

this is how it comes this is close to 42 liter for which we can use this box volume calculater....

http://www.the12volt.com/caraudio/boxcalcs.asp


the driver volume is not a big issue in making of a encloure so u can leave it and go the sam bhai way not navin ji way....in navin ji u will get lost

[s0uljah]

yeah dude i went way off track at the time I PM'd you.. thats how i ended up starting the thread.

i had tried the 12volt site earlier...was just blinking
cant believe i have gone this rusty to handle such simple math :(

[low_bass_makker]

Originally Posted by gunbir

Thanks LBM, do you happen to have the response plot for this sub?

download winisd from here
http://www.linearteam.dk/default.aspx?pageid=winisd

punch in the specs there u go u get the plot......

[gunbir]

Originally Posted by low_bass_makker

download winisd from here
http://www.linearteam.dk/default.aspx?pageid=winisd

punch in the specs there u go u get the plot......

Thanks LBM... but dont you think I would already know this... We dont use WinISD as it isnt always accurate.

I was asking for the plot from the JBL user manual... as I couldnt access it (actually I couldnt find it) on the JBL website. If you dont have it either its fine...

[Bass&Trouble]

Originally Posted by s0uljah

Prob is I listen to most types of music, can be called a heavy trance head and the breakdowns and smooth basslines really appeal to me. At the same time I also listen to very slow psychedelic ambient stuff which have very deep bass at times but not a constant thud. To top that off I sometimes remember my school days and I throw in some busta rhymes, tupac, warren g,,, you get the picture !!! So its all a bit confusing...... I dont know how to express the kind of bass that plays in the ambient/downbeat music that really makes me smile... maybe I should post links to a few tracks !!!

note :example of chill/ambient -
Vibrasphere - Selected Downbeats Vol.1
Entheogenic - Golden Cap

The trance mostly ranges from 144 - 146 BPM (+/- a little)

Souljah, I've had this general observation. Anyone who likes electronic music with a 120+ bpm (includes me, I moonlight as a DJ, and I can pretty much hump House music all night long), so that includes upbeat Lounge, all kinds of House/ Trance, Techno, DnB, Garage, Hardcore (not XXX, Sam, you wicked mind ) enjoys it best with a really attacking midbass and HF. The subs have to be kept to the bare minmum. Not overpowering the rest of the band, and yet strongly there when that bassline comes along.

In fact (if you agree), this sounds damn good on pro audio stuff, like in Discos and all ya know? Bloody electrifyingly trippy! And the subs in clubs don't even mostly play under 40Hz! But you have massive mid-bass drivers pulverising everything between 100 to 500 Hz, and horn-loaded compression drivers to take care of the rest. I don't regard this as SQ, and I had tried to bring this up once, but everyone told me that club sound is crap (Boo hoo! I love JBL, Turbo-Sound and Meyer pro setups).

So what I'm trying to say (which I think I've partly forgotten thanks to some Grey Goose), is that you should focus on some really spanking component speakers, and make sure that you provide them the right environment. The subs are well, simply mandatory.