jbl gto804 tapped horn/ folded horn

[NEO Dan]

I think I see what you mean by artifact now that you point it out.

 

[2009thread1]

i had some issues of thinking and finding somewhere to put it lol

 

[2009thread1]

I think I see what you mean by artifact now that you point it out.

I think I see what you mean by artifact now that you point it out.
jbl gto804 6th order bandpass by 2009thread1 - Google 3D Warehouse
what do you think ? its tuned to 30hz

 

[panjilaras]

hi there any update for GTO804?

 

[Zubs]

Strange that this popped up, I did a bit of hornsrep work with this sub a while ago, and came up with this.

Its tiny. 24.7 Liters, with a terminus are of 40 square cm. I'm not even sure if its possible , or plausible to build something like this (I,m still new)

Just thought Id share.

 

[2009thread1]

Strange that this popped up, I did a bit of hornsrep work with this sub a while ago, and came up with this.

that looks quite good ? im not using the jbl gto804 anymore ive just bought a q acoustics 2070 subwoofer, and i have another tapped horn.

 

[2009thread1]

hi there any update for GTO804?

what were you after ? ive been sent a box for them but i dont use them now

 

[bjorno]

Strange that this popped up, I did a bit of hornsrep work with this sub a while ago, and came up with this...Its tiny. 24.7 Liters, with a terminus are of 40 square cm. I'm not even sure if its possible , or plausible to build something like this (I,m still new)

Hi Zubs,all

Your design will work but you have to restrict input power at max to 40 W because of the otherwise high terminus air velocity:Here = 10 m/s.

The f-3dB would be about 29Hz together with a smooth roll-off if using a density of wool=0.25 x lb/f^-3(~4 x kg/m^3):Weight= 0.2 lb (~0.92kg).

b

 

[Zubs]

Hi Zubs,all

Your design will work but you have to restrict input power at max to 40 W because of the otherwise high terminus air velocity:Here = 10 m/s.

The f-3dB would be about 29Hz together with a smooth roll-off if using a density of wool=0.25 x lb/f^-3(~4 x kg/m^3):Weight= 0.2 lb (~0.92kg).

b

Hi b

I thought the 40 square cm terminus area would be to small. increasing the area exaggerates the bump at about 30Hz pretty quickly.

 

[bjorno]

b wrote:density of wool=0.25 x lb/f^-3(~4 x kg/m^3):Weight= 0.2 lb (~0.92kg).

Should be: Weight= 0.2lb(~0.092kg)

Zubs:

I thought the 40 square cm terminus area would be to small. increasing the area exaggerates the bump at about 30Hz pretty quickly

A TL usually uses more damping material than a T-TQWT==> (IMO,In HR:2-3 dB peak allowed;stuffed max half-ways).
In HR You can allow to have a ~ 4-5 dB peak for a TL but you have to stuff using correct density and weight of damping material using at least 2/3 of the total length counted from the closed end.

b

 

[emilime75]

Hey folks, I came across this thread trying to find more info on tapped horns and for a suitable design to build. I'll admit, I'm a complete newb when it comes to both tapped horns and sketchup, but I was looking at this design and wondered about the rest of the dimensions needed to build it and if it is suitable for my woofers which are the Infinity versions of the JBL GTO804. My woofers are the REF860W, here are the specs http://manuals.harman.com/INF/CAR/Boxes and Parameters/860W_final.pdf

Would the design from NEO Dan below(page 5 post 45) work with these drivers? How can I get the rest of the dimensions needed to build it? Many thanks in advance.

By the way, this is intended to go in my car. For power, I have about 200 rms per woofer available, subsonic filter is adjustable between 20-50Hz at up to 24dB slope. It will be low-passed somewhere around 60-80Hz. My main goal is excellent sound quality, extension and output, in that order.

Do you think this is small enough?

 

[bjorno]

Infinity-Ref-860w

Hey folks, I came across this thread trying to find more info on tapped horns and for a suitable design to build. I'll admit, I'm a complete newb when it comes to both tapped horns and sketchup, but I was looking at this design and wondered about the rest of the dimensions needed to build it and if it is suitable for my woofers which are the Infinity versions of the JBL GTO804. My woofers are the REF860W, here are the specs http://manuals.harman.com/INF/CAR/Boxes and Parameters/860W_final.pdf

Would the design from NEO Dan below(page 5 post 45) work with these drivers? How can I get the rest of the dimensions needed to build it? Many thanks in advance.

By the way, this is intended to go in my car. For power, I have about 200 rms per woofer available, subsonic filter is adjustable between 20-50Hz at up to 24dB slope. It will be low-passed somewhere around 60-80Hz. My main goal is excellent sound quality, extension and output, in that order.

Hi,

Here is an HR example of using a Infinity Ref-860w driver in a 65 L T-TQWT:

Note: the port of this design should point the same direction as the driver fronts where the distance from the midpoint between the drivers to the port is~8 cm.

b

 

[emilime75]

Hello bjorno, thank you for the reply. Have you built this or used the Infinity REF860W? If so, what was your opinion of it? It appears to me, according to the plots, that it will work well in my intended pass band of 25 to about 70 Hz. Sadly, I don't really know what to make of the rest of the plots. Is this a good choice of woofer for a tapped horn? How can I use the info you have provided to design/build an enclosure? Many thanks.

 

[2009thread1]

Hello bjorno, thank you for the reply. Have you built this or used the Infinity REF860W? If so, what was your opinion of it? It appears to me, according to the plots, that it will work well in my intended pass band of 25 to about 70 Hz. Sadly, I don't really know what to make of the rest of the plots. Is this a good choice of woofer for a tapped horn? How can I use the info you have provided to design/build an enclosure? Many thanks

the design done for the jbl gto804 was for me, but sadly i still havent built it, as ive stupidly bough the q acoustics 2070 subwoofer, and they forgot to mention the rediculous amounts of port noise ! so thats my next plan, build a new box for the 6.5" subs that come out of it

 

[cyro99]

Hi Dan,
I 'm about to use a GTO-804 on my first project and from searching on Google, I found this interesting thread.
If I only want to use a single GTO-804, which parts should I modify?
(Assuming the parameters are similar to what 2009thread1 wanted.)

 

[bjorno]

FYI:

A ~1 cu.ft T-QWP suggestion using a single JBL GTP-804:

b

 

[cyro99]

Hi, bjorno.

That is real nice ...
I will look into it.

P.S.: Sorry for the late reply .. been busy preparing for the holiday ...

 

[cyro99]

Hi bjorno,

Thank you for the calculation.
That is nice.
I will look into it ...

P.S.: sorry for the late reply .. been busy preparing for the holiday ...

 

[zobsky]

You wanted a compact TH, here it is (about 60 liters as is). Adjust the L23 and L34 sliders to modify your desired low end extension and roll off on the low end respectively.

Note that I've choked the horn off at point S2 to clean up the SPL response.

You really should try to learn hornresp., if at all possible. Plenty of folks on this DIY forum to help you along. Note that I had a small error in the input screen (didn't account for the fact that that this is a 4 ohm driver, so real word SPL will be somewhat higher).

Also note that these curves are in free space i.e. suspended in mid air in the middle of a corn field. If you can tuck the cabinet into a corner, efficiency will go up dramatically.

 

[NEO Dan]

You mean SPL will be lower because you are showing 2w nominal.