open baffled all over again

[Rudolf]

Originally posted by GeorgeBoles
I am still unclear about "distance rear wall" and "distance side wall". Do these distances relate to the DRIVER or the EDGE OF THE BAFFLE from the adjacent walls?
4. To work out the effective baffle length in the arrangement in the Orion, do you just add up all the wall lengths, and is the width just the height of the box, or is there a little bit extra for the depth that the drivers are placed into the box, or is it more complicated than that?? (Is this a "W" design?

George,

"distance rear wall" and "distance side wall" relate to the DRIVER center. If the wavelength of a frequency is four times the "distance rear wall" or "distance side wall" these frequencies are attenuated. If the wavelength is double the distance these frequencies are amplfied. XLbaffle takes care of that.

XLbaffle is not particularly suited to calculate a H or W baffle like in the Orion. The most (and only?) important dimension of a H or W baffle is the depth. You should look up the how-abouts at http://www.linkwitzlab.com/models.htm#B and #C

Rudolf

[ThorstenL]

Konnichiwa,

Originally posted by GeorgeBoles
2. "Measurment" of sound level was done with a "Mark I Tympano-Cochleometer" (much like a Mark I Optico-Retinometer in the visual realm.)

A potentially quite useful device, but not in order to generate a curve that can be compared to simulations.

Originally posted by GeorgeBoles
3. I am still unclear about "distance rear wall" and "distance side wall". Do these distances relate to the DRIVER or the EDGE OF THE BAFFLE from the adjacent walls?

In all my various spreadsheet calculators I always assume the distances to the center of the sound source (driver center), as was also remarked by Rudolph.

Originally posted by GeorgeBoles
4. To work out the effective baffle length in the arrangement in the Orion, do you just add up all the wall lengths, and is the width just the height of the box, or is there a little bit extra for the depth that the drivers are placed into the box, or is it more complicated than that?? (Is this a "W" design?)

You cannot even get a good approximation of M/W/H baffles using my calaculator. They are complex resonant systems not ameanable to easy analysis using my spreadsheets and even the Formulas Linkwitz provides are not terribly accurate.

Originally posted by GeorgeBoles
a.) Is the SEAS Millennium in the Orions capable of performing as well as a 12 year old magnetic planar driver?

No.

Originally posted by GeorgeBoles
b.) Is it the tweeter/mid-range driver itself or the open baffle of these designs which provides the magic? (Don't you just love questions like that?)

It is both.

Sayonara

[GeorgeBoles]

a.) Is the SEAS Millennium in the Orions capable of performing as well as a 12 year old magnetic planar driver?

No

GLONG! All of a sudden, I am less happy. Kuei Yang Wang, have you heard either the Orions or the Millennium tweeter in a quality enclosure? I thought that I had things nearly, finally sorted out in my mind.

Perhaps then, I should be making something with one of the long ribbon tweeter/midranges. Likely contenders would be: B&G, Newform, DHenryP's DIY design ... any thoughts?

Are there any others out there who have experience in this specific area who either agree or disagree with Kuei Yang Wang's thoughts. Kuei Yang Wang, is there anything to elaborate on with regards this quetion?

Thanks again to Rudolph and Kuei Yang Wang for your thoughts.

Best regards,
George

[ThorstenL]

Konnichiwa,

Originally posted by GeorgeBoles
Kuei Yang Wang, have you heard either the Orions or the Millennium tweeter in a quality enclosure?

I heard them in a number of DIY and commercial speakers. I have also heard the various assorted other Dome tweeters, the best of this rather bad lot are the Focal inverted domes or the Thiel inverted ceramic domes. Conventional domes are not suited to use in high fidelity speakers, inverted domes are only a little better. Try spherical wave horns with low compression ratio drivers or ribbons with a modest horizontal waveguide.

I'm non too hot on magnetic planars (or any other full range dipole) either, but Quad ESL's and other sensible fullrange ESL's (can be DIY'ed) are the best solution if you like the presentation given by planars (or in other words full range dipoles).

For something more conventional you could look at the Audax PR170M0 in an open back or apperiodic enclosure combined with Aurum Cantus or Fountek Ribbon and then add an active dipole section (like 4 x 8") for the bass. That would likely be one of the best compromise solution using conventional, compact and affordable Speaker that combines the good sides of ESL's/Ribbons/Planars and of Electrodynamic systems.

Sayonara

[Nuuk]

For something more conventional you could look at the Audax PR170M0

Correct me if I am wrong but I though that Audax had stopped supplying drive units for DIY.

[ThorstenL]

Konnichiwa,

Originally posted by Nuuk
Correct me if I am wrong but I though that Audax had stopped supplying drive units for DIY.

They have. Madisound bought a very large batch and are still supplying them. For after that, Sammi Sound Korea have a passable substitute, the SR165A50 (yes, I have used these too) though I liked the Audax a little better.

Sayonara

[ultrachrome]

Kuei wrote: Audax PR170M0 in an open back or apperiodic enclosure combined with Aurum Cantus or Fountek Ribbon and then add an active dipole section (like 4 x 8") for the bass.

This sounds like what I might looking for. Something quite the opposite of my Ellis 1801 (SEAS Excel in BR and dome tweeter) but able to be powered to movie levels with a low powered amp, powered bass section aside.

When you say open-back, how is that different than dipole?

Would you arrange the bass drivers in a line or something like an H configuration? Four 8's instead of a pair of 12's?

[ThorstenL]

Konnichiwa,

Originally posted by ultrachrome
This sounds like what I might looking for. Something quite the opposite of my Ellis 1801 (SEAS Excel in BR and dome tweeter) but able to be powered to movie levels with a low powered amp, powered bass section aside.

For movies and some REAL SPL handeling consider the big Neotek ribbon and a d'Appolito Array with two PR170M0. That should easily exceed 100db/W/m.

Originally posted by ultrachrome
When you say open-back, how is that different than dipole?

Open back with some flowresistance will be more of cardiode than a dipole.

Originally posted by ultrachrome
Would you arrange the bass drivers in a line or something like an H configuration?

More a kinda "M" or "W" configuration, 2 High. This is for a compact and affordable LF array, around 20" tall & 10" or less wide, upon which could be seated our MF/HF Box with PR170M and one of the smaller ribbons.

I would normally recommend a suitable set of bigger woofers, up to 4 X 15" per side in a "M" arrangement.

Originally posted by ultrachrome
Four 8's instead of a pair of 12's?

No, more like a pair of 10" or a single 12".

Sayonara

[ultrachrome]

Thanks for the clarification.

My Ellis 1801s are about 83dB. 95dB would seem to be enough especially if I powered the subs with separate amp.

I just found the JP2.0 Project Part 3 A.K.A PR170s sound amazing.. And a few questions! thread so I'll begin following that.