Matt and all,
I would prefer transiently accurate or transiently coherent to the idea of flat. While a transiently accurate or transiently coherent driver or loudspeaker will test as having a flat frequency response, a flat frequency response driver or loudspeaker will not necessarily be transiently accurate or coherent.
Still, I think I understand what you are asking for and I agree with you. Because of the way the word reference has been used for loudspeakers I believe a reference loudspeaker should be good enough that you can use it to train your ear/brain for what sound reproduction should sound like.
Failing that, you should at least know, with a high degree of confidence, what the acoustical problems are so that you can use the loudspeaker as a reference to find other loudspeakers that might be better. You do not want to acclimate to a sound that would make you turn away from a superior loudspeaker.
Good designing and good building,
Mark
I would prefer transiently accurate or transiently coherent to the idea of flat. While a transiently accurate or transiently coherent driver or loudspeaker will test as having a flat frequency response, a flat frequency response driver or loudspeaker will not necessarily be transiently accurate or coherent.
Still, I think I understand what you are asking for and I agree with you. Because of the way the word reference has been used for loudspeakers I believe a reference loudspeaker should be good enough that you can use it to train your ear/brain for what sound reproduction should sound like.
Failing that, you should at least know, with a high degree of confidence, what the acoustical problems are so that you can use the loudspeaker as a reference to find other loudspeakers that might be better. You do not want to acclimate to a sound that would make you turn away from a superior loudspeaker.
Good designing and good building,
Mark
From the start, given the requirements of the project, my definition was not to produce a "perfect" loudspeaker but a starting point for those wishing to pursue single driver and/or "full-range" projects. Therefore "reference" in my mind was similar to "touchstone" or "benchmark". I agree that we should be aware of what the shortcomings/compromises are of this system.
p.s. Thanks Mark, I'll stay in touch.
p.s. Thanks Mark, I'll stay in touch.
Optical said:
Flat FR is a laudable goal, but it often gets far too much weight when considering the system design. Why? Because it is something that is easy for the advertising guys to present to us & sell us on.
As many a FullRanger has discovered there are other things much more important.
This project is a reference in that it is an affordable, accessible entry project. That even with major pertabations in its FR & its low cost it has the potential to provide audiotory joy to rival projects costing much more.
dave
MarkMcK said:
Hi Mark. When I chose the subject line, I was thinking more along the lines that we could reference other speakers to a standard pair that hopefully several people will build.
I think when companies use reference in the name, it is a marketing ploy.
Aside from the term reference, this should be a fun and rewarding project.
MarkMcK said:
I liked the FE126E a little better mainly due to the extra efficiency and the "published" response. There was a little concern with the low Q of the 126 in a simple T-line. Shielded is a little more versatile and was the pick of the majority. The Q of the 127 seems better suited for a T-line.
MarkMcK said:
You emailed me the responses for the FE103E. I was suprised at the diference in the published response in comparison to what you measured. This is something that most companies seem to do as I assume several people are buying drivers based on the response shown on paper. However, Fostex seems to have a quality of sound several people like. To me, the response of several Lowther drivers on paper looks scary, yet we are familiar with their reputation.
Regards,
Gio.
Dear Mr. Scrooge,
Interesting you should ask because I'm aware of only one person that has actually begun construction and he's not building any of the bipole designs that Dave drew up diagrams for. He's building a bipole TQWT floorstander that I listed dims for several posts back. The rest of us are waiting for drivers. There are three bipole designs on the table; a classic ML-TL, a folded version of that, and the TQWT. I believe the group wanted to stick to straight lines to demonstrate the theory of halving or doubling CSA between single and two driver systems.
Timn8ter said:
dear bob cratchet:
thank you ever so for giving me a clear synopsis of events thus far. you have saved me a great deal of festering time.
i have subscribed to the thread and will try to keep up on my own in the future. super interesting.
should be quite a free for all when you get your drivers.
i myself am waiting on a pair of fe166e's, ft17's and bk-16 backhorns for a little...horny adventure.
Testing....testing....is this thing on?
Season's Greetings, my friends.
Have a listen. (My X-mas card to all)
http://www.npr.org/ramfiles/wesun/20001224.wesun.08.ram
Season's Greetings, my friends.
Have a listen. (My X-mas card to all)
http://www.npr.org/ramfiles/wesun/20001224.wesun.08.ram
If this last post refers to my offer, yes it is on. I have purchased a FE126E and have begun testing the driver. I had an offer from a thread participant to supply a FE127E. I await that driver.
Now, the enclosure designs posted to this thread came after the FE127E decision. So, to those who designed the enclosure, is the massive difference in system performance (Fs/Qts) for the 126 and 127 going to change your enclosures? Will we need a separate design to adequately compare enclosure performance for the 126 and the 127?
Just though I would point out that Fostex recommends a combination backhorn/reflex design for use with the 126. Supposedly cures some problem with the backhorn.
Best,
Mark
Now, the enclosure designs posted to this thread came after the FE127E decision. So, to those who designed the enclosure, is the massive difference in system performance (Fs/Qts) for the 126 and 127 going to change your enclosures? Will we need a separate design to adequately compare enclosure performance for the 126 and the 127?
Just though I would point out that Fostex recommends a combination backhorn/reflex design for use with the 126. Supposedly cures some problem with the backhorn.
Best,
Mark
The rising response of the 126 probably makes it more suitable for a BLH. My usual reaction when I see that in a TL is to tune the cab higher which, in this case, brings the F3 to nearly 80Hz.
Graph courtesy of . Martin King's MathCAD worksheet .
Graph courtesy of . Martin King's MathCAD worksheet .
Attachments
Mark will really help a lot with some accurate data. I am pretty suspicious of the Fostex info- although other makers are equally suspect.
There is no doubt variation between each piece, but measuring one production piece will be a lot closer corrolation to a typical piece than the manufacturers specs. I think the fostex are pretty consistant.
There is no doubt variation between each piece, but measuring one production piece will be a lot closer corrolation to a typical piece than the manufacturers specs. I think the fostex are pretty consistant.
I sort of understand the need to mechanically couple the drivers in a bipole but it´s the first time i saw a monopole speaker coupled to the back-wall. Or am I misinterpreting the drawings in"diya-frref-020.gif" ?
Dave, which program do you use for your drawings?
Still looking for something simple to make sketches with.
Nice project, BTW. (itches already)
Dave, which program do you use for your drawings?
Still looking for something simple to make sketches with.
Nice project, BTW. (itches already)
joensd said:
In the absense of another driver to actively cancel newtonian motion, this scheme ties the driver better to the mass of the cabinet and minimizes it. A more elaborate scheme actually has a tightening mechanism so that you can dial in the amount of pressure on the driver.
VectorWorks. May not fit into your budget, but despite some serious horsepower & feature set, is very simple to use for these kinds of drawings.
Once i have the drawing done, i just get the size i want on the screen, use the OS X built-in screen snap and take the resulting pdf into PhotoShop to tweak it and save out as a gif file.
dave