After trying some homebrewed backhorns which I couldn't get balanced and some open baffles that just didn't work, I'm keen to harness the full potential of my FE168 Sigmas.
The flashes of brilliance I have had from these drivers from time to time have shown me that they can be truly stunning.
The BiB looks like a relatively straightforward build and in theory, the maths has already been done so it'll be a good match.
Any of you folks reckon something else will give a better result?
I really want to get these puppies off my work in progress list and into use.
TIA,
Drew
The flashes of brilliance I have had from these drivers from time to time have shown me that they can be truly stunning.
The BiB looks like a relatively straightforward build and in theory, the maths has already been done so it'll be a good match.
Any of you folks reckon something else will give a better result?
I really want to get these puppies off my work in progress list and into use.
TIA,
Drew
Hey Drew
I assume you've checked out the Frugelhorn and Spawn of Frugelhorn threads?
Can you expand on "open baffles...just didn't work". I'm kind-of (read: slowly, lazily) working on two simultaneous projects: a spawnoffrugel for my FE108s, and an open baffle for multiple drivers, and am interested in any experiences pro or con with open baffles.
Regards.
Aengus
I assume you've checked out the Frugelhorn and Spawn of Frugelhorn threads?
Can you expand on "open baffles...just didn't work". I'm kind-of (read: slowly, lazily) working on two simultaneous projects: a spawnoffrugel for my FE108s, and an open baffle for multiple drivers, and am interested in any experiences pro or con with open baffles.
Regards.
Aengus
I have had a pair of professionally built BIB cabinets for going on two years now, and mules for months before that, and can tell you that your FE168's will flat out RIP in the BIB alignment. It is a very musically honest speaker, with honest sub 30Hz response, a driver with an honest 94db SPL rating, and with some digital EQ, to shelve up the treble and flatten the notch in the midband, no tweeter is needed, and if one is, it very easy to implement.
One of the best alignments I can think of, assuming you've room to experiment with room-positioning. Airy through th emidband and vocal regions, massive bass extension and a dipole feel to the LF -ever wondered what stereo bass sounds like? You'll know after hearing a pair of these things.
Are we talking about the FE168Sigma or the more recent FE168ESigma here? They're very different drivers and need slightly different treatments -I've modified some of my ideas on this since some of the ones emerged on Zillaspeak.
Are we talking about the FE168Sigma or the more recent FE168ESigma here? They're very different drivers and need slightly different treatments -I've modified some of my ideas on this since some of the ones emerged on Zillaspeak.
Excellent. Lovely unit. Revised dimensions for the non 'E' model 168Sigma:
Line length 128in
Zdriver 27.75in
Sl=75in^2.
You should get solid performance to the low 30Hz regions. Not bad for a driver with an Fs of 60Hz.
Get a pair of Dave's phase plugs into them while you're at it, if you haven't already.
Line length 128in
Zdriver 27.75in
Sl=75in^2.
You should get solid performance to the low 30Hz regions. Not bad for a driver with an Fs of 60Hz.
Get a pair of Dave's phase plugs into them while you're at it, if you haven't already.
Never heard the BIB, but i designed this for the 168.
ron
http://fullrangedriver.com/gallery/albums/userpics/10015/rons-a2-pair.jpg
ron
http://fullrangedriver.com/gallery/albums/userpics/10015/rons-a2-pair.jpg
Yep on the Austin principal. I designed those for Tony (layertone), he built them on a CNC out of layers.
ron
http://fullrangedriver.com/gallery/albums/userpics/10015/thumb_Austin_II_twins.jpg
ron
http://fullrangedriver.com/gallery/albums/userpics/10015/thumb_Austin_II_twins.jpg
Scottmoose,
Headed to the local hardware today and they had pre cut MDF panels that looked good for a BiB build but they were only 16mm thick.
Is this going to be too thin and flexy? My previous horn build for the FE168 had a fair wad of panel honk and that was built in 25mm MDF with lots of internal bracing and panels so I"m concerned that 16mm will sound terrible.
Can do chipboard too if folks think that would sound better than mdf...
Suggestions?
Headed to the local hardware today and they had pre cut MDF panels that looked good for a BiB build but they were only 16mm thick.
Is this going to be too thin and flexy? My previous horn build for the FE168 had a fair wad of panel honk and that was built in 25mm MDF with lots of internal bracing and panels so I"m concerned that 16mm will sound terrible.
Can do chipboard too if folks think that would sound better than mdf...
Suggestions?
DrewP said:
Got access to 19 mm or thicker marine grade plywood? Since the 'FRD' website got hacked, I can't view RC's design, but I imagine it generates much more acoustic pressure than a BIB due to a higher compression ratio/low flare factor, so won't tend to 'sing along' nearly as much.
Another option is well braced HDF.
WRT MDF or similar, its MOE (modulus of elasticity, i.e. its stiffness spec) varies quite a bit around the world and often between factories within a company and even batches for various reasons whereas plywood was fairly consistent for a given grade/thickness/number of lams (or at least this was still the case last I checked with Georgia-Pacific back 6-7? years ago), so by increasing the thickness of lower MOE materials we can arrive at a ~equivalent to BB ply if you're willing to build a box around a box.
For example, the last MOE specs I have for 3/4" MDF and marine grade ply were 527k and 1.8 m psi and since stiffness increases at the cube of thickness, the MDF needs to be at least:
t2 = t1*(m1/m2)^0.33 = (0.75*(1800 k/527 k))^0.33 = ~1.125" thick
where:
t1 = reference thickness
t2 = equivalent thickness
m1 = MOE of t1
m2 = MOE of t2
In this scenario though, it's better IMO to do the outer box in a furniture grade hardwood if the budget allows and/or there's any potential WAF issues with monolithic structures in her 'space' and in each of these cases, bracing requirements will in theory be limited to one below the driver and cross bracing on the mouth side to tie all four walls together to keep them from potentially 'breathing'.
BTW, there's been some minor advances in BIB design, so FWIW I recommend going ahead and using T.C.'s original line length/folded height and adjust the dims per either the formulas or one of the provided spreadsheets, adjusting Qts as required for any added series resistance in the signal chain such as a high output impedance amp, etc.: http://www.zillaspeak.com/bib-howtobuild.asp
GM
Thanks for keeping things fresh Scott! I will try to post these newer, modified dims for these two great Fostex drivers on the the BIB site.
Overall performance between the older 168s and the 165k is a matter of personal taste. They each have a slightly different midrange presentation. 168s handles more power and stays together (less congested) at higher volumes. But the 165k has a different enough sound that some people may prefer it overall at lower and medium volume levels. Both AMAZING drivers imo!
--
Excellent. Lovely unit. Revised dimensions for the non 'E' model 168Sigma - old style with wizzer:
Line length 128in
Zdriver 27.75in
Sl=75in^2.
--
Just for you mate: a Godzilla shortened BIB for the FF225K. 136in line for a 68in tall box. W = 10in, D = 14.5in (including a 0.75in thick internal baffle). Zdriver 29.5in.
Overall performance between the older 168s and the 165k is a matter of personal taste. They each have a slightly different midrange presentation. 168s handles more power and stays together (less congested) at higher volumes. But the 165k has a different enough sound that some people may prefer it overall at lower and medium volume levels. Both AMAZING drivers imo!
--
Excellent. Lovely unit. Revised dimensions for the non 'E' model 168Sigma - old style with wizzer:
Line length 128in
Zdriver 27.75in
Sl=75in^2.
--
Just for you mate: a Godzilla shortened BIB for the FF225K. 136in line for a 68in tall box. W = 10in, D = 14.5in (including a 0.75in thick internal baffle). Zdriver 29.5in.
Many thanks all for the input.
I'm afraid the early arrival/presence of a little one in the house 2 and a half years ago threw a spanner in the works with regard to audio projects but lately I've got to and got the Garrard 401 up and running and I'm keen to set up a single source vinyl rig in the living room so the FE168 Sigmas will be coming off the open baffles that they've been sitting on for the last half a decade and into some proper enclosures at last.
I'm afraid the early arrival/presence of a little one in the house 2 and a half years ago threw a spanner in the works with regard to audio projects but lately I've got to and got the Garrard 401 up and running and I'm keen to set up a single source vinyl rig in the living room so the FE168 Sigmas will be coming off the open baffles that they've been sitting on for the last half a decade and into some proper enclosures at last.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.