Looking for Full Range for mid in Open Baffle

[dcathro]

Hi,

I am looking for a full range driver to use as a midrange in a 3 way open baffle.

All the best - most lifelike and dynamic - drivers I have heard have been full ranges like Lowther, Coral, Fostex, etc.

Can anyone suggest a driver that would make a great mid range ( 250 - 2k+) without having to cut of wizzer cones etc?

What are the Supravox and PHY drivers like (never seen or heard these)?

I bought Seas Exotic W8's, hoping that they would do what I want, but so far I am disappointed - they sound quite flat . I will continue to run them in, but I suspect that I need to find an alternative.

Thanks

David



Background information on my project:

I am building a 3 way partially open baffle system. The most important things for me is to have life (energy/dynamics), timing (PRAT), and balance.

I was (for about 7 years) using a pair of reworked Alon Phalanxs, and did really like the openness that the open baffle gave to the midrange and top end. The things that I was less enthusiastic about in these speakers were the complexity of the 4 way design and getting the drivers to integrate, the metal dome tweeter, and the relative inefficiency. I have been listening a lot to light paper cone speakers (Lowthers and Coral Beta 8s) in other setups, and have been very impressed with the life and dynamics.

To that end, I decided to do a high efficiency semi open baffle speaker, with a light paper cone midrange, and tweeter mounted in a panel, and a bass in a vented box underneath, with an average efficiency of 94db.


I have bought the following drivers:

Seas Exotic T35 and W8, tweeter and mid

Seas Exotic T35 Tweeter

Seas Exotic W8 Woofer

Here are a couple of pictures:





Crossovers to be at 250Hz and 2K, very simple first order. The W8 also offered the possibility of running it with no lower filter due to it's high xmax.

The 15' bass drivers that will be in a 140L box will be these:

Kilimanjaro Field Coil 150VWLs





They are essentially JBL K145 field coils.

So far I have been testing, measuring and listening to the the drivers. The T35 sounds fantastic, but I am less impressed with the W8 which does not have the life that I hoped for.

[InclinedPlane]

Well you've already tossed some serious Euros at the project. What do you mean by the Seas driver being 'flat' sounding?

Also, you shouldn't have to cut off any whizzers. If it's cut at 2k, the whizzer will simply not be adding its response. Unless you don't like the look.

I suggest the Fostex F200A for midrange use. It's less efficient, but quite beautiful in sound and appearance!

[c2cthomas]

I want to give this one a go for my next OB project. http://profesional.beyma.com/pdf/8M70E.pdf

I'll be using my AMT1's above 7K and am still undecided on the woofer but will most likely go with a Beta 15

I would love to try a http://profesional.beyma.com/ingles/pdf/6P200Fe.pdf but I can't seem to locate anyone selling them in the US at the moment.

[dcathro]

Originally Posted by InclinedPlane

Well you've already tossed some serious Euros at the project. What do you mean by the Seas driver being 'flat' sounding?

Also, you shouldn't have to cut off any whizzers. If it's cut at 2k, the whizzer will simply not be adding its response. Unless you don't like the look.

I suggest the Fostex F200A for midrange use. It's less efficient, but quite beautiful in sound and appearance!

Yeah, the Seas Exotics were not cheap.

I just find the mid sounds undynamic. The tweeter has lots of life, whereas the W8 is just going through the motions. I am playing music through it constantly to see if it will loosen up.

I had understood that the wizzer will cause interference patterns in the upper mid, and that it was better to lose it.

What do you like about the F200A? At 90db it is a bit inefficient to work in my project.

Cheers

David

[ThorstenL]

Hi,

Originally Posted by dcathro

Can anyone suggest a driver that would make a great mid range ( 250 - 2k+) without having to cut of wizzer cones etc?

If you do not want to throw money around, the Audax PR170M0 is a pretty good choice as OB mid, even in a low efficiency system.

The old SD-Acoustics SD-1 which is probably one of my favourite british 80's/90's speaker used this padded down to around 88dB/W/m (and with lacquered cone) in an open back box, together with a Foster Leaf tweeter and a sealed box 10" Woofer, IIRC (memories are getting more hazy as age creeps up)...



Funny thing, my current speakers seem very much a mixture of 80's/90's british speaker Ideas, kind of like combining the ideas of the Epos ES-25 with the SD-Acoustics SD-1 and a good dash of Acoustic Energy from the Phil Jones days thrown in... Not bad all around, but a little too small to impress the guys who build stonehenge, which is usually my consideration for a "good" speaker.

But, as you are not on a budget, the Supravox 215-2000 EXC OB is probably my choice.

Except, I personally would probably double them up in series and dump that dome tweeter for a nice HE ribbon/planar/amt (many options) and set things up in MTM and I would use a somewhat a little larger bass driver (think 24", I always think of 15" drivers as lower midrange devices... :-P) also doubled up, with the lower one sealed and the upper one dipole.

Basically:

24" W (dipole-passive)
9" M (dipole-passive)
T (dipole-passive)
9" M (dipole-passive)
24" W (sealed-active)

This forms my current "modest proposal" - an ongoing speaker concept that takes it's name of Swift's satirical "Modest Proposal" which has yet to be financed and build... :-(

Ciao T

[dcathro]

Thanks Thorsten!

I suspect the Supravox's are more my cup of tea.

Any impressions on what they sound like? Do they have the life of a Fostex or Lowther?

Cheers

David

[ThorstenL]

Hi,

Originally Posted by dcathro

Any impressions on what they sound like?

I had the first ever pair of 215-2000 EXC OB (open baffle variant), as they where originally intended as the "special edition" drivers for a somewhat abortive commercial open Baffle Speaker:

Noteworthy Audio Loudspeakers 2

I listened to them for about two years. They are very evenhanded sounded with no obvious single outstanding strenth or weaknesses, just good music all across the board, for the range they cover. Mine where C37 lacquered of course.

Their dynamic range falls a little short of a pair of 15" corner horn loaded Tannoys (hardly a surprise). They convey microdynamics and immediacy much better, I'd say nearly level with a Goodmans Axiom 80 (but without the Goodmans drawbacks).

For really low and deep bass a (sub)woofer is needed, but depending on bafflesize a solid 100Hz resonse without EQ with -6dB in room at around 50Hz with a sufficiently large baffle.

I used a dual 12" Pro Driver sealed active Sub and Visaton TL-16H Horn supertweeters at around 60Hz (3rd order) and 15KHz (1st order) to extend the bandwidth of the Baffles shown.

Originally Posted by dcathro

Do they have the life of a Fostex or Lowther?

If you mean with "life" the agressive and forward edge of especially the Lowthers and the Whizzered Fostex, no that is completely absent. If you mean that directness and immedacy that gets you very involved in the music - I'd say it is much more in the class of the Feastres Drivers and the Goodmans Axio 80 (and similar also to the Phy HP) and as low down as Lowthers and especially Fostex (I find the Fostex that do not take my ears off sound like dead feet).

You can read what Troels Gravensen has to say about them (he did not have the 2000's which are a distinct step up from the lower ranking cheaper stuff).

The only fly (make that monster Mothra) in the ointment is the not insubstantial amount of Euros per pair...

Ciao T

[pjanda1]

It's good to see you back, Thorsten.

Paul
Wild Burro Audio Labs - DIY Full Range Speakers

[nicoch58]

Originally Posted by pjanda1

It's good to see you back, Thorsten.

Paul
Wild Burro Audio Labs - DIY Full Range Speakers

[dcathro]

Hi thorsten,

Thanks for that info. I picked up a pair second hand. They are exactly what I am looking for!!

The photos online do not do these justice. The motor is an absolute monster. I am listening to one on the bench (no baffle) now, and it has phenominal dynamic grip! Really beautiful.

Originally Posted by ThorstenL

I listened to them for about two years. They are very evenhanded sounded with no obvious single outstanding strenth or weaknesses, just good music all across the board, for the range they cover. Mine where C37 lacquered of course.

Never tried this (C37), did it make a difference?

Their dynamic range falls a little short of a pair of 15" corner horn loaded Tannoys (hardly a surprise). They convey microdynamics and immediacy much better, I'd say nearly level with a Goodmans Axiom 80 (but without the Goodmans drawbacks).

I have heard a speaker system that had dual Axiom 80's - it was amazing! I think that comment was the clincher for me to buy!

If you mean with "life" the agressive and forward edge of especially the Lowthers and the Whizzered Fostex, no that is completely absent. If you mean that directness and immedacy that gets you very involved in the music - I'd say it is much more in the class of the Feastres Drivers and the Goodmans Axio 80 (and similar also to the Phy HP) and as low down as Lowthers and especially Fostex (I find the Fostex that do not take my ears off sound like dead feet).

Yes, they sound very even handed. At what frequency would you suggest crossing them over to a tweeter. I am thinking of around 4KHz which I hope will avoid the worst beaming.

The only fly (make that monster Mothra) in the ointment is the not insubstantial amount of Euros per pair...

Ciao T

I would say that they are worth it.