Terry Cain's BIB -why does it work and does anyone have those Fostex Craft Handbooks?

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#2,861
GM said:
Greets!

Hmm, what part of this did you not understand?: "Well, I recommended a HE 8" as a compromise between LF output and the 'magic' of a smaller driver's mids/HF, so for Fostex there's only the FE206E, FE206ES-R, FE208ES AFAIK.........." I mean I didn't list it because it's not an HE (high efficiency) driver. FWIW, IMO all these require a super tweeter for best performance unless everyone likely to listen to them has age/whatever impaired HF hearing, especially when loaded in a BIB or other horn design. 8" is just too big to do HF with any accuracy over a wide enough 'sweet spot'.

GM
Click to expand...
oh I didn't understand why you didn't list the 207.I thought that it's a HE driver too. Notice that I'm newbie on this :clown:
That's why there are a lot that are using 6" drivers..... 😉
......for the magic of a smaller driver's mids/HF!
I'm not listening music to high levels so maybe the best choice,for me, is the 168Esigma. And maybe if I'd like more bass use a sub!?
What do you say?
A little bit expensive driver but if it worth it I'll buy it. 🙄
 
#2,862
I can't speak for GM, but I can tell you that the 168ESigma is a superb FR driver, and has more excursion than the others, which is useful. In terms of sound quality, it's a step up from the 166/7 & well worth the extra IMO. I don't think you'll need a sub, especially if you're not going for monser SPLs. You'll get 30Hz out of this cabinet / driver combination.

If your room isn't huge, and you want a cheaper driver, then the FF165K is astounding. With that miniscule Xmax, it shouldn't work, but it does. Euphonic distortion? Perhaps. But pipe horns aren't really about clinical accuracy anyway, and this combination is ludicrously musical. In terms of sheer sound per £ / $ / whatever, you won't find much better. Audio alchemy. And the big cabinet doesn't put as much strain on the driver as most other simple boxes would, which is probably why it works so well.

Revised version of the dimensions on the Zilla site for the 168ESigma keeps the Sl area, and increases length to 138in, Zdriver 30in. Goes a bit lower.
 
#2,863
Just to second Scotts comments on the FE168ESig. In particular a couple of points. 1) they do go loud, not headbanging loud, but plenty loud for me (and I do like loud!), 2) you could add a sub but to my mind these equal or better my Adire 12" subs with dedicated amp, bass it tight powerful and low. Adding a sub may get you lower but I think you would lose that awesome power and coherance from a single FR driver.

Its more than worth it!!

Chris
 
#2,864
>>> Revised version of the dimensions on the Zilla site for the 168ESigma keeps the Sl area, and increases length to 138in, Zdriver 30in. Goes a bit lower.

I will post this to the site later this week.

Room treatments: Echo slap has disappeared in most of the room except for the listening position

:bawling:

The sound is no longer bright. Now it's a little dull. LOL. Big changes in the treble... everythings mellow. Maybe i over did things. I will post pics later in the week. All 2x2 ceiling tiles in key places according to the mirror along the side walls. Front and rear walls also have two 2x4 tiles each.

I will build an echo buster soon. Maybe i just need one near the listening position. And a ceiling treatment of some kind. I have an idea that may work.

Fostex 168s and 165k are worthwhile drivers for sure!
 
#2,867
No worries on the generic BIBs... little helpers are too short to hold the mirror up on ceiling. The three of us had a blast screwing in the tiles. First we walked around the room clapping our hands. We all easily heard the echo slap and thought it was fun. Then we hung the tiles and did the same thing. The boys thought it was like magic. But sitting in the listening position the echo slap was still audible. I think it has to do with the ceiling but really have no idea even how the tiles changed the sound of the room.

The room sounds much better now. Not like an echo chamber anymore. Treble energy is reduced (i will not alter the capacitor on the tweeter - but now if i did it would be for more treble not less). Choral passeges are much more listenable and you can make out the voices easier. Things are less confused sounding. Everything tightened up. I suppose its because the room rings less on its own.

We listened to Warren Zevons Warewolves of London and then a few songs on Steely Dans Aja - The original Rocky was on during our air hocky challenge. Fun times with my boys!

I want to build a ceiling treatment next or a bass buster off to the side near the listening position.
 
#2,868
Hello...

the "original" dimensions for a FE207E-BIB are:
L = (Line length) 174"
Zdriver = Driver 35" down from sealed end of cabinet
Sm = 133.875"^2

this dosen't work for me, because a height of more than 50" for the driver is unpractical...I'm lazy, so I prefer to sit when I listen to music 😉 .
Shorter BIB...ok, but I want to have bass!
So...would it realy be SO bad, to take a Zdriver=50" down from sealed end of cabinet?
Of course not the optimum...but maybe still kinda ok! 🙄
 
#2,869
Jeff,

ceiling treatment - YES! ( Of course this will only be possible if your building "donating" the tiles isn't yet completely gutted😀 )
And, as mentioned earlier, try to find a clever way to fix the tiles at odd angles. Thus the wave fronts not getting sucked up by the tiles will be "smeared" enough to stop spoiling the fun.
BTW, isn't it a bit dangerous to involve your offspring? You show what can be done and in no time flat you'll have to optimize the nursery wing as well...


😉 Pit
 
#2,870
Godzilla said:
>>> Revised version of the dimensions on the Zilla site for the 168ESigma keeps the Sl area, and increases length to 138in, Zdriver 30in. Goes a bit lower.

I will post this to the site later this week.

Room treatments: Echo slap has disappeared in most of the room except for the listening position

:bawling:

The sound is no longer bright. Now it's a little dull. LOL. Big changes in the treble... everythings mellow. Maybe i over did things. I will post pics later in the week. All 2x2 ceiling tiles in key places according to the mirror along the side walls. Front and rear walls also have two 2x4 tiles each.

I will build an echo buster soon. Maybe i just need one near the listening position. And a ceiling treatment of some kind. I have an idea that may work.

Fostex 168s and 165k are worthwhile drivers for sure!
Click to expand...


I was thinking on my commute home the other night, and may have a strage sollution for you. This came about thinking about the s. tweeter problem, actually. Instead of the acoustic time, this may or may not work-worth the effort nontheless, a section of thick rubber may help dampen the sound a bit. The rubber like they use for mats, ussually weight lifting, or for standing at work benches. Another take on this may be the kind of mat used in wet locations, with the holes in them. The chain configuration may trap and dampen if used correctly. Also, someone a while back in this thread was using bubble wrap for a terminus lining. The foil sided bubble wrap may be something fun to play with. As for the ceiling, I saw a listening room where they draped a large piece of fabric, maybe called a sconce - not sure- I am still a guy, along the cieling. The material was draped across rods running widthwise through the room. That may filter a bit of the echo.
 
#2,871
Scottmoose said:
I can't speak for GM, but I can tell you that the 168ESigma is a superb FR driver, and has more excursion than the others, which is useful.
Click to expand...

I have been using my 168Bibs for about a month now and they really are very nice 🙂 They are also very sensitive. Sensitive about placement but especially about damping.
Initially I glued heavy carpet tiles from the top to a little below the driver (on the back of the baffle, the front of separation panel and on both sides but only directly beside the speaker) and on the bottom. This made them sound dull and thick. I have bit by bit removed a lot of the carpet (it was hell to get it out of the point :devilr: ) Each bit of tile I took out improved things, made them sound more alive. What is left is on the separation panel and the bottom, partly because it is just impossible to get out but I guess I am near optimum now.
The consequence has been too much midrange energy coming out of the top. I have tackled this by putting in some Baf around the mouth to about 60cm down (its main effect being much better imaging). Also putting tiny bits of Baf on both sides of the driver was a big improvement.
Anyway because this is my first fullrange project I don't know if this is a general issue or just a 168eS thing but I urge anyone who is not completely happy with his Bib to experiment with damping. In my case this has made a much bigger difference than I expect changing to another driver would have made and without the cost.
 
#2,872
>>> BTW, isn't it a bit dangerous to involve your offspring? You show what can be done and in no time flat you'll have to optimize the nursery wing as well...

LOL Pit! My kids are 7 and 9 and have no trouble at all listening to music. Often you will hear them both singing along to Let it Be in the car or Eye of the Tiger in the playroom. I was shocked when they listened to Deacon Blues with me yesterday after putting up the tiles. They actually sang – learn to work the saxophone, I, I play just what I feel… It was really awesome!

Btw, the sax on that song always sounds like a kazoo but not thru the BIBs. It sounds like a dirty sax.

Ceiling tile certainly helped reduce the –confusion- in the room. I see how treating the room can eliminate it as a variable. Pretty cool.
 
#2,873
Scottmoose said:
I can't speak for GM, but I can tell you that the 168ESigma is a superb FR driver, and has more excursion than the others, which is useful. In terms of sound quality, it's a step up from the 166/7 & well worth the extra IMO. I don't think you'll need a sub, especially if you're not going for monser SPLs. You'll get 30Hz out of this cabinet / driver combination.

If your room isn't huge, and you want a cheaper driver, then the FF165K is astounding. With that miniscule Xmax, it shouldn't work, but it does. Euphonic distortion? Perhaps. But pipe horns aren't really about clinical accuracy anyway, and this combination is ludicrously musical. In terms of sheer sound per £ / $ / whatever, you won't find much better. Audio alchemy. And the big cabinet doesn't put as much strain on the driver as most other simple boxes would, which is probably why it works so well.

Revised version of the dimensions on the Zilla site for the 168ESigma keeps the Sl area, and increases length to 138in, Zdriver 30in. Goes a bit lower.
Click to expand...
So let's do it! :smash:
I'll order the drivers asap...................

Now I need help with the cabinet :clown:
Which is the best width for the front baffle?
 
#2,874
Peterr,
I totally agree with the damping of these things! They are super sensitive! I reckon very thin felt of 1mm would be ideal and surrounding the driver to about 15cm each side and the back, even the hole for the driver! Of course it needs to routered out (flared) to let the driver breathe too.

Stroop
 
#2,876
7.25in wide, 10.25in deep, internal, not including the depth of the internal baffle. So, assuming 3/4in material, 8.75in wide, 12.5in deep, external.

I'd probably use a suprabaffle with a 14in diameter. The SB dimensions are approximate as the response of a pipe-horn will tend to vary depending on the room it finds itself in. 7in over the driver diameter is what TC appeared to find best in his experimenting.
 
#2,877
Scott, or anyone else.

I had mentioned earlier working on an in wall BIB. I wanted to check, since I can not use the 1:14142 ratio, would there be any negative effects of using a 6.5x13.5 for a SD of 87.75 (88.125 recommended) on the FF165K BIB? If so, should there be any other consideration put into place for the pipe?
 
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