mjking57

Responses from mjking57

Open Baffles with Subwoofers
If you size the baffle correctly, you can electrically high pass the Fostex at between 400 and 500 Hz and use the dipole hump to extend the acoustic response down to 200 to 300 Hz. The baffle does not need to be huge, probably about 20 inches wide... 
Just wave!
You have it correct. And in theory, yes a notch could be produced. But the minute you add back in the damping produced by the acoustic impedance of the terminus, add fiber or foam damping in the line, place the driver along the line instead of at ... 
Just wave!
Assume we have a driver with an fs of 50 Hz and it is installed at the closed end of a straight TL tuned to 50 Hz, the simplest form of TL design. The TL will produce standing waves at the 1/4, 3/4, 5/4, … frequencies of 50 Hz, 150 Hz, 250 Hz, … a... 
Just wave!
I don't know anything about the speaker measured or the measurement set-up, so my response is speculation. I have seen a similar notch in some of my measurements and have investigated the cause.I don't believe any of the measurements that you have... 
Just wave!
A TL that is closed at one end and open at the other always produces a quarter wave standing wave resonance. It does not matter where the driver is along the length or if the geometry is tapered, straight, or expanding. Always a quarter wave. This... 
Reasons
Yes, that is what I am saying. I am talking about small changes to the tuning and sound, not transforming a poor performing speaker design to a world beater. The trade-offs may have improvements in one area but degradation in another. No magic, no... 
Reasons
Bob Brines, Jim Salk, and Dennis Murphy to name a few have all used my software (Paul Kittinger did the actual TL design work for the later two) to design the TL portions of their speakers. Bob Brines was a very early supporter of the software and... 
Reasons
"One thing I learned was, respect for those who had mastered the art of transmission line design."Art is the right word to describe those older designs. By intuitive feel and a lot of trial and error a few people could build very good TLs. But the... 
Reasons
"back in the 70's"The music was sooooo much better. Big cars, big hair, big LP jackets that I could look for hidden pictures and read without a magnifying glass, big amps and speakers producing huge sound. No earbuds or blue-tooth speakers playing... 
Reasons
(MJK) Some answers.What are the attempted advantages of a TL speaker cabinet with equal sizes channels all the way to the port, as opposed to each channel being wider than the last? (MJK) A constant area TL with need to be L = c / (4 x f) long to ... 
Reasons
Of the links mentioned, the Philharmonic Audio page is the only one that accurately describes how a TL works. The first article linked is full of inaccuracies and just plain wrong information, the fact it was written in 2016 is very surprising. Th... 
DIY ?uestion
For TL theory that is backed up by measurements consider looking at the articles on my site.www.quarter-wave.comThere is more bad information about TL's on the Internet than accurate information. The methods on my site have been used to design man... 
Albany NY "Capital District"
I am in Clifton Park. I am primarily a DIY speaker builder and not so much into high end audio gear. 
Transmission line speakers
You are better off designing and building a TL yourself then buying a commercial version. Most commercial TL's are undersized.