• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Open Baffle Epiphany!

Yeah, found a solution for the missing highs and muffled upper mids.
Version 2.3 has now has now the FHT8 horns that I used before for the mid range as tweeter and it's whole new world. Highs are present and finally the upper part of hi-hats and cymbals can be heard!

Version 2.3 also has a different crossover setup. I had to make a mix of two crossover boards with disabled paths on one that are not needed.

15" CTS driver at the bottom runs up to 300Hz with 12dB
15" Eminence runs up to 800Hz with 12dB
8" Electro Voice MC8 runs 800 to 5000Hz with 12dB
FHT8 horn goes 5000Hz and up

attachment.php


Now I just need to get this in a nicer package! Design ideas would be helpful :-)

I'm just happy that I build it kind like a modular way so that old parts are still usable. Ugly but it's a beginning.


image.jpg
 
Those things should love a nice SET moniblock. Biggest mistake I ever made was selling my Bottlehead Paramours.


Sent from my TARDIS at the restaurant at the end of the universe while eating Phil.
 
I have a new OB project working.....Got some drivers today that I think will be a good fit.:D

These are 8x12 full range. My question, to orient them vertically or horizontally?
Or does it make much difference?

I was thinking it might make a bit of difference with dispersion etc.

Cheers :beerchug::beerchug::banana:
 
Personal preference is horizontal, due to dispersion. Though I have seen them mounted vertical.


Sent from my iPhone using Tapatalk
 
PioneerGuy75 said:
I have a new OB project working.....Got some drivers today that I think will be a good fit.:D

These are 8x12 full range. My question, to orient them vertically or horizontally?
Or does it make much difference?

I was thinking it might make a bit of difference with dispersion etc.

Cheers :beerchug::beerchug::banana:
Click to expand...

Isophon?
If so I believe they are meant to be mounted vertically.
I could be wrong though.

Art

Edit : I am wrong. Just looked at an Isophon spec sheet for the 2132/25/11 and it shows the driver mounted horizontally
 
Last edited:
PioneerGuy75 said:
I have a new OB project working.....Got some drivers today that I think will be a good fit.:D

These are 8x12 full range. My question, to orient them vertically or horizontally?
Or does it make much difference?

I was thinking it might make a bit of difference with dispersion etc.

Cheers :beerchug::beerchug::banana:
Click to expand...

Apparently I am missing something....I can't find the magic :no:

I have tried several drivers and nothing sounds good to me.:no:
 
I think it's not so much magic than having the right driver combo.
My first test with a 15A, horn mid and horn tweeter was also not convincing to me. I switched the 15A against an old CTS driver it makes a hell of a difference for the bass.
The 15a runs still in parallel to 800Hz, the rest above is for a MC8 and a horn tweeter.
Experimenting right now with a Heathkit AS183 with the CTS in parallel for the bass but the Heathkit lacks luster in the tweeter range.
It's not all one shot, sometimes you need to experiment to find the right way.
 
darg said:
I think it's not so much magic than having the right driver combo.
It's not all one shot, sometimes you need to experiment to find the right way.
Click to expand...
I'm definitely no OB expert but when I was mesiin' around with some 8" speakers here I found an old alnico organ speaker (Rola) that sounded REALLY good while another high quality speaker (JBL) intended for a ported cabinet sounded REALLY lame, totally lifeless and just plain wrong.
 
Exactly, not all speaker will be a success in OBs.
I also figured, they sound different than a boxed speaker. Can't really grasp it but it might be that our ears are so trained to the sound of boxed speaker that the representation of instruments with an OB needs some training. At first I was also a little bit disappointed but after listening to very different music over a couple of days I discovered that compared to a life instrument without any audio processing behind it instruments in certain music are much better refined and more sounding more like the real thing.
Also not every music might be suitable for OBs, I listen to a lot of electronic music and some of that is better on my Atlas than on the OB but most of the older 80ies and 70ies stuff and all of the Bluegrass material I have sounds so much better!
What fascinates me on the OB is that room filling sound. With my boxed speakers the sound is best at my listening position, with the OBs it's much more distributed in the room and I can listen to stuff not only for the couch but also in the kitchen and dining area in my great room.
Experiment maybe also with the speaker position. OBs need to be right positioned. I haven't really taken that on since I need to find the final design for them. The ones up here in the thread are pretty rough but flexible with that modular build in upper baffle.
Need to find a wood shop with a CNC to get good design cut.
 
valvenator said:
I'm definitely no OB expert but when I was mesiin' around with some 8" speakers here I found an old alnico organ speaker (Rola) that sounded REALLY good while another high quality speaker (JBL) intended for a ported cabinet sounded REALLY lame, totally lifeless and just plain wrong.
Click to expand...

That is what I have been doing....Tinkering with various old drivers out of open back setups.....

I understand that anything designed for box use will not sound good....

These latest are 8" x 12" full range drivers from old console, they looked decent so I thought I would try it. They just don't have any oomph....:no:
 
Might have chance with the University drivers.
I think the key is to have a paper or cloth surround and not a rubber or foam since these are softer and have more give like it is needed for boxed speaker.
I made a test with two 15" drivers for bass. One set is the massive CTS and the others I got a week ago which are 15" Magnavox driver with a much smaller magnet. The smaller Magnavox magnet drives the bass just marginal less so I think the main thing is size and the surround material. The CTS was from a Magnavox tube console while the Magnavox driver was from an Astro Sonic solid state console.
 
@PG75: You could also dish out some cash and go with some tried and true speakers but I'm thinking you're either trying to use the speakers you have on hand or at the least 'hear the magic' before investing into something you might not be too crazy about in the end.
 
I harvested these 16" woofers from some Sansui speakers left on the curb and was surprised at how well they work in open baffles. Those old Kabuki speakers if you recall featured huge woofers and multiple drivers stuffed into relatively small enclosures.

picture.php
 
PioneerGuy75 said:
I do have an old pair of University 3-ways...Would these be appropriate for OB use?
Thanks :banana::banana:
Click to expand...

Those sound very promising.

The best thing I did was follow poultrygeist's bi-amp recommendation,with active crossover. My motley assortment of drivers runs from Foster bullet tweeters, Richard Allan CG10T "full range" with whizzer cones (and doped fabric accordion pleated surrounds) to B&W 13" woofers with foam surround. The woofers were designed for huge "infinite baffle" enclosures (B&W DM70).

My Richard Allans are the star of the show, but the little foster tweets add sparkle, and the woofers handle below 350Hz, with about 6dB boost above the RAs. The tweets are dialled (further) back with an L-pad.

None of this should work maybe, but it does!

Try those Uni's and let us know!!
 
You must log in or register to reply here.
Back
Top Bottom