diyAudio Full Range Reference Project

[MarkMcK]

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

[Timn8ter]

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 .

[planet10]

Originally posted by Timn8ter
brings the F3 to nearly 80Hz.

that's not all that bad... a loss of 10 Hz to gain 2 dB more efficiency -- maybe some other gains too?

What dimensions?

it will be interesting to see Mark's comparitive data.

dave

[Timn8ter]

What dimensions?

Single driver TQWT
L = 26"
So = 4.5"
SL = 31.5
port 1.5" dia, 1" L
zDriver = 13"
zPort = 25"

[Variac]

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.

[planet10]

Something like this? I choose xSection breakdown based on minWidth and added a bit of a base... driver mounted on slantSide to keep minimum height....

dave

[planet10]

Originally posted by Variac
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.

One of the reasons all the version numbers on the drawings are still WAY less than 1.

dave

[planet10]

And this pic which illustrates why you might want to put the driver on the slantSide.

dave

[joensd]

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)

[planet10]

Originally posted by joensd
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" ?

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.

which program do you use for your drawings?
Still looking for something simple to make sketches with.

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