Jbl GTO 1002d

fussionn

Member
2012-11-20 4:42 pm
Thank you. I'm holding now a sharp sm7700bk home amplifier with recommended preamplifier. I'm thinking to wire this driver in series for now till I can purchase a new amplifier. It is for home. I can do a bandpass enclosure, it is powerful. I need a low pass frequencies filter, right? Sorry for my English.
 
This driver is good for a QWTL (quarterwave transmission line).
Acoustic transmission line - Wikipedia, the free encyclopedia
Transmission Line Speakers
Quarter Wavelength Loudspeaker Design
A 4th order bandpass can give you more ~4dB but is restricted in frequency, good when you crossover at ~80Hz.
In an easy bass-reflex (BR) you can use an ideal 43 L int. volume alignment, with f3 28Hz-ff/20Hz-in room.
JBL GTO 1002D, VB = 43.3 L, FB = 19.7 Hz
(Note: now the problem with this alignment is that for Port you need a 3" internal with length 77.15cm = 30 3⁄8in.)
So if we change to another alignment say (with f3 21Hz in room)
JBL GTO 1002D, VB = 40.0 L, FB = 22.0 Hz
we have a Port 3" int diam and with length 66.2cm = 26 1⁄16in.
As you see (you can simulate your desired alignment with any software, use WinISD or UNIBOX) now the constraint is the length of the port. For that matter another alignment with higher Fb or shorter port length (Vol=50 L f3=20Hz in room).
JBL GTO 1002D, VB = 50.0 L, FB = 23.0 Hz
Port int. diam. 7.62cm = 3in
Port lenght 45.88cm = 18 1⁄16in
I'm sure you would be fine with this type of port size/máx.lenght (FB ~ 23.0 Hz) for the box volume ~50 L.
Precision Port 3" Flared Port Tube Kit 268-350
 

fussionn

Member
2012-11-20 4:42 pm
Got it.Yor are saying that this driver is good for a QWTL enclosure,but i can't design it.Can you?If you can,please design it and write all sizes,I would be grateful.If you can't design it,can i make an enclosure with port made by myself?I mean, someting like this (i can't find the right word for it: /http://194.88.148.41/?mmid=07e3a4a64e18f52d0 .
 
bjorno is very good with those, maybe he can help you. :D

I can only look at his projects and appreciate (from an aesthetic point of view) or do the simulations with other software (like the one linked on post #7). I know bjorno uses very respectful calculations by Martin J. King. I don't have that much experience as I told you but I will help in what I can. After you get the right kind (right size) of measures (wavelength) for your driver/speaker it does not look very difficult, just go with the flow. :eek:
Quarter Wavelength Loudspeaker Design
http://www.quarter-wave.com/TLs/Alignment_Tables.pdf
 
21hz T-TQWT, good for 225 watts @ 1 ohm @ 12.5mm xmax, 29.25" H x 15.25" D x 12" W enclosure.
 

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