jbl gto804 tapped horn/ folded horn

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Jump to Latest
2

2009thread1

Member
Joined 2011
Stuffing will be necessary for reasons other than LF tuning, the stuffing is also used to dampen the resonant modes that occur at the upper end of the range. What do you use for a crossover to filter the high frequencys from the subwoofer? It'll sound like shite if you don't use a filter. Really you should have filtering to remove content on both the high and low ends of the spectrum, filtering off the lows below tuning will help protect against bottoming the drivers.
Click to expand...
looking at other desgins for an 8" subwoofer the box's are massive compared to the one you designed for me ?
 
B

bjorno

R.I.P.
Joined 2005
NEO Dan said:
You are confused, the TL is NOT the design I gave you, what I gave you is much better, better than a 30hz ported box too.
Click to expand...

Hi, Here is an example using your design as a template but with slightly changed dimensions:

b:)
 

Attachments

  • 2xJBL GTO804_T-TQWT_(NEODan).JPG
    2xJBL GTO804_T-TQWT_(NEODan).JPG
    233.6 KB · Views: 398
NEO Dan

NEO Dan

Member
Joined 2008
I think he took the screen shot and then realized that 7 is too short to fit the driver in so he just drew it on. It is impressive that it can be shrunk down so much without loosing much mid-band sensitivity. I do wish we could make this stronger in the bottom end after stuffing.
 
B

bjorno

R.I.P.
Joined 2005
NEO Dan said:
So would you change anything else or redesign, I can redraw.
Click to expand...

Hi Dan,

I redrew your design because of the phase-response at ~75-95 Hz, i.e. the Gldy that show a peak I don't think would be smoothened/attenuated enough by the damping material or folds.

At ~80 Hz I try to keep the Gldy lower than ~9.4 mS a value I used for years allowing the use of a simple sub plate-amp.

No EQ for the sub or signal-delays for the main speaker are expected to be necessary as the off-band ripple is low and the excess phase/Gldy are smooth/low when the speakers are in a row and near a suitable wall.

IME, integration to main speakers with a single sub is then an easy task, in an space like that an ordinary living-room normally provides, of-course.

b:)
 
NEO Dan

NEO Dan

Member
Joined 2008
I think I missed something, I don't see any drawing.
I noticed the GD was a bit lower in the hornresp, it seems a bit optimistic that the very high q notch you got in the MJK worksheets is going to work like that though.
I was surprised by the terminus velocity numbers for such a small cross section.
 
B

bjorno

R.I.P.
Joined 2005
NEO Dan said:
I think I missed something, I don't see any drawing.
Click to expand...

Sorry for writing drawing when I meant simulating as in post @70.


I noticed the GD was a bit lower in the hornresp, it seems a bit optimistic that the very high q notch you got in the MJK worksheets is going to work like that though.
Click to expand...

There are both math artifacts in HR and MJK:s programs: You have to look both at the phase response and the Gldy to estimate if the shown Gldy peak or the change is phase slope are consistent and not forgetting to include the change in Phase/Gldy that for sure will happen when a LPF is introduced to the overall equation.Measuring experience is also of a great value to add...

I was surprised by the terminus velocity numbers for such a small cross section.
Click to expand...

I was not:no:

b:)
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Top Bottom