In Reply to: RE: You are not building a MLTL posted by gortnipper on June 28, 2012 at 20:05:31:
"Where would you recommend the driver height in these type of 10ft3 designs? "
If the driver is offset at approximately 1/3 the length of the straight transmission line, the 3/4 wavelength standing wave can be totally suppressed, and in addition the impact from every other quarter wavelength mode (3/4, 7/4, 11/4, …) will also be essentially removed from the system SPL response. Using this 1::2 ratio, a 39” ear level driver position would require a ~58.5" line height with the driver center 19.5" down from the line top. Total internal line volume of 11 cu_Ft with a 419 sq_in line section area, short 6" port 7" above the line bottom. …. a normal tall MLTL.
' I am sorry, but I am not quite sure what you mean by, "The GPA 604 deserves a freeware in-room MLTL and in-corner design"? '
A custom speaker design uses the owner's actual room dimensions including proposed speaker positions and listener position, as well as the owners personal preferences like "I want BASS". The designer uses simulations which include: room modes; corner gain; rear wall gain; absorption from carpets, drapes, furniture; room absorber/diffuser panels; cabinet edge diffraction optimizations; custom crossover circuits; baffle step compensation circuits; custom T-Line stuffing options; etc... Design experts with CAD software required.
I used the term "freeware design" to mean complete design drawings not requiring additional expert CAD software help for a common up against the wall Big-speaker placement. The GPA 604 III has unique T/S parameters, SPL/frequency response, and polar horn response that would model a slightly different cabinet from the classic Altecs.
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Follow Ups
- A more typical tall, high driver MLTL - scooter 21:05:19 06/30/12 (2)
- RE: A more typical tall, high driver MLTL - RC Daniel 01:50:33 07/01/12 (1)
- RC ... what T/S parameters for GPA 604 III are you using? - scooter 13:02:18 07/16/12 (0)