jbl gto804 tapped horn/ folded horn

[2009thread1]

It's always good to know where you are starting 009.
Is your name really Doug?

me ? lol

 

[2009thread1]

is there a chance of getting a design for my jbl gto804 in a tapped horn ?

 

[NEO Dan]

Looking at it now it seems that you would not be able to build for just one driver, two is possible. How much power do you have?

 

[2009thread1]

How much power do you have?

i'd say plenty, i give them 250 watts rms each, i was hoping for a single driver so i dont have to have a massive box

 

[NEO Dan]

Well there is no free lunch. I think 2 in ~71l is OK considering you have a 50l box?

ID=28.80
Ang=2.0 x Pi
Eg=2.83
Rg=0.00
Fta=-0.29
S1=275.00
S2=270.13
Par=19.50
F12=0.00
S2=270.13
S3=205.24
Par=260.00
F23=0.00
S3=205.24
S4=200.00
Par=21.00
F34=0.00
S4=0.00
S5=0.00
L45=0.00
F45=0.00
Sd=214.00
Bl=12.89
Cms=2.51E-04
Rms=3.36
Mmd=113.38
Le=1.64
Re=3.49
TH=2S
Vrc=0.00
Lrc=0.00
Ap1=0.00
Lpt=0.00
Vtc=0.00
Atc=0.00
Pmax=100
Xmax=5.0
Comment=NEW RECORD - JBL GTO804

 

[2009thread1]

the current box for the two jbl's in 1.33 cubes, slot ported at 35hertz, but i had to stuff it and i still get port noise, and it isnt loud on the lows
what do you mean "no free lunch" lol ?

 

[2009thread1]

ive just recieved this from a youtube subscriber, jbl gto804 t-line by 2009thread1 - Google 3D Warehouse
he designed it to the specs of the jbl, but still i'd prefer a tapped horn or should i try and stear onto something different for this subwoofer ?

 

[Brian Steele]

I would NOT design for ED drivers, they are not the specs they claim; I have measured TSP's for both versions of the 18" and they are not even close. When I contacted ED the excuse they gave me was they don't have the ability to measure drivers...

+1 on that. I've measured the 13kv and the 13Ov - nowhere near measured specs. Looks like they gave you a different excuse than they gave me. See http://forum.edesignaudio.com/showthread.php/13kv-2-d4-questions-55280p2.html

 

[ODougbo]

Compact - Lower - High Power

I always liked the sound of a good 8"; compact is nice also. As far as goals: lower; I don't need to play it loud, although HT action scenes (explosions)can bottom-out, ruin a driver, so want to keep that in mind.

Yes, Doug here.

Hi Doug,
What direction do you want to go - lower, louder, fatter response???
I've made room in my inbox

 

[2009thread1]

when i play movies, i run 2.1 stereo
i have a denon pma710ae stereo amplifier with q acoustics 2020 speaker in gloss black and my 500 watt power amplifier, i never bottom the subs out even in movie scenes, but i mainly listen to dubstep, drum and bass with lots of lows and a sinle 8" in a room my size is ample, two just rumbles the floor and everything else around me

 

[tb46]

Hi 2009thread1,

Do you have any idea on a preferred size? When I simulate a TH (for a single JBL GTO804D) in Hornresp I get something around 95/110 L_net. For a tapped horn with a long folded horn path that may mean 125/130 L_gross. Your preferred external size will determine the folding.

Regards,

 

[2009thread1]

if i can get it out of one sheet of mdf that would do, if it needs to be big for the sound i should be able to fit in somewhere
if you can sketch it up and email it to me on google sketchup i'd really appreciate it

 

[tb46]

Hi 2009thread1,

I haven't found time (or reason, I use ACAD) to learn Google sketchup, maybe NEO Dan can help. I'll attach a first try Hornresp input and spl window:

Regards,

 

[2009thread1]

thanks, if the tapped horn idea is going to be really big i'll go with the t-line enclosure

 

[ODougbo]

P2D28 8"

Just had thought, I have a couple of these unused.

Rockford Fosgate

Fs (Hz): 40.0
Re (Ohms): 3.50
Le (mH): 2.5
Qts: 0.45
Qes: 0.48
Qms: 6.00
Cms (m/N): 0.18
Vas (L): 10.0
Mms (g): 88.5
Mmd (g): 86.9
Rms (kg/s): 3.7
Airload (g): 1.6

SPL (dB - 1W/1M): 84.0
BL (T*M): 13.0

Woofer Displacement: 0.85 0.030 liters | cubic ft
Power Rating: 200 400 RMS | Peak
Linear Excursion, pk-pk (Xmax): 0.315 8.0 inches | mm
Sd (cm2): 200

 

[tb46]

Hi 2009thread1,

The sketchup TL looks like 72.38 L_gross, that is a lot smaller. But which one is better?

Regards,

 

[tb46]

And for what it's worth the SPL response of the sketchup TL:

Regards,

 

[2009thread1]

Just had thought, I have a couple of these unused.

Rockford Fosgate

i live in the uk so buying from america will be expensive, how would the rockford fosgates hold out on 250 watts rms ?

The sketchup TL looks like 72.38 L_gross, that is a lot smaller. But which one is better?

ive never heard a t-line before, but from videos they're really loud on the lows, but ive never heard an 8" tapped horn before

 

[NEO Dan]

Hi 2009thread1,

I haven't found time (or reason, I use ACAD) to learn Google sketchup, maybe NEO Dan can help. I'll attach a first try Hornresp input and spl window:

Regards,

Don't be looking at me - your the one with AutoCAD

It's not like you need AutoCAD to get good looking output either:

An externally hosted image should be here but it was not working when we last tested it.

Go have a look and VOTE

 

[ODougbo]

Amen Brother Neo.