Jeff, the pages are looking great! Many thanks for all your effort, it's much appreciated by everyone, myself in particular.
215? Hm. I'll check, though I'm not 100% confident at this moment in time. That's going to need a hefty enclosure -look at the Vas. As there seems to be some interest in the Supravox drivers, I'll check a couple of others too while I'm doing one or two Lowthers.
Actually, I don't thing the 165LB simulates that badly. The problem Dan in particular had was that the cabinet was optimised for his Fostex ESigma units, so when he tried the Supravox a) the line was too long, tuning them way below their Fs, and b) doesn't have enough volume. There should be some suggested dimensions appearing on Jeff's site for them shortly. Of course, the shorter cabinet means that you won't get the same loading from the corners & ceiling to complete the horn mouth, but I still reckon they'd work OK with some juggling of position. A nice corner-shelf with ornaments a couple of feet above them, anyone? Where there's a will...
Fred -line length has nothing per se to do with where the interior baffle terminates. That's more a question of width & depth. I refered to this a couple of pages back I think. Find the correct terminus area (Sm) for your driver. Divide by however wide you want it to be to get the depth. The baffle will terminate, centred in the enclosure, the same distance from the base as it is from the front and rear walls.
Hey, what's the record for number of pages in a thread? I'm innocent you know -I never expected it to reach these proportions!
Best
Scott
215? Hm. I'll check, though I'm not 100% confident at this moment in time. That's going to need a hefty enclosure -look at the Vas. As there seems to be some interest in the Supravox drivers, I'll check a couple of others too while I'm doing one or two Lowthers.
Actually, I don't thing the 165LB simulates that badly. The problem Dan in particular had was that the cabinet was optimised for his Fostex ESigma units, so when he tried the Supravox a) the line was too long, tuning them way below their Fs, and b) doesn't have enough volume. There should be some suggested dimensions appearing on Jeff's site for them shortly. Of course, the shorter cabinet means that you won't get the same loading from the corners & ceiling to complete the horn mouth, but I still reckon they'd work OK with some juggling of position. A nice corner-shelf with ornaments a couple of feet above them, anyone? Where there's a will...
Fred -line length has nothing per se to do with where the interior baffle terminates. That's more a question of width & depth. I refered to this a couple of pages back I think. Find the correct terminus area (Sm) for your driver. Divide by however wide you want it to be to get the depth. The baffle will terminate, centred in the enclosure, the same distance from the base as it is from the front and rear walls.
Hey, what's the record for number of pages in a thread? I'm innocent you know -I never expected it to reach these proportions!
Best
Scott
Right, just run a few checks. My conclusion: pick of the bunch for a BIB remains the 165LB. Vas on the others is too high; the enclosure volume necessary for the bigger units is too great. I've checked the 3 215 models & that holds good for all of them. They might work better in a mass-loaded type, like the B200: I haven't tried that yet.
Regards
Scott
Regards
Scott
fred76 said:.......did anyone try to sim the 8" non-whizzered 215RTF64 (not the high Qts sig)? It's not really FR but can be augmented with horn tweets for the highs.
BTW, is it okay to use 24mm thick material for all the panels especially for the internal baffle fold? I can only double up 12mm ply, the 18mm that's available here is much lower in quality (lots of voids).
GM,
I learned a lot from our recent email exchange re: altec system. Thanksabunch.
Greets!
You're welcome!
Dunno, my take is it requires a Sm = ~544"^2, so it's close to being a real man's speaker (insert Tim 'The Tool-man' Taylor's grunt here
) and assuming the specs are reasonably close and your room's not a complete acoustic sieve, expect efficiency on the far side of 100 dB/m to at least 30 Hz. Sure! you can't go too thick, only reach a point of diminishing returns. Since stiffness increases at the cube of thickness, you may not need any bracing except around the driver and mouth.
GM
GM,
Would appreciate comments on:
1) What would be the effect of cutting the top at an angle to increase the mouth opening by about 50%?
2) Would turning the BiB upside down for the shorter designs be preferable to the elongated load towards the ceiling?
3) If using BiB as a subwoofer, would big VAS be preferable? Say from <100Hz-150Hz?
Thanks.
Would appreciate comments on:
1) What would be the effect of cutting the top at an angle to increase the mouth opening by about 50%?
2) Would turning the BiB upside down for the shorter designs be preferable to the elongated load towards the ceiling?
3) If using BiB as a subwoofer, would big VAS be preferable? Say from <100Hz-150Hz?
Thanks.
The 113" line length seems shorter compared to some 6"rs... Thanks!
giantstairs said:
Greets!
Looks like this one got lost in the heap, so to speak........
L = 64.58"
Sm = 220"^2
driver down 14" from the top (pointed end)
With a ~53 Hz cut-off , wider BW nulls due to the fast taper and too high a driver position without a third fold, you may not be happy with the results. Only one way to know for sure though.
GM
ultrakaz said:
Greets!
Frankly, even though I've posted some scaled down BIB designs, I would prefer a separate webpage distinct from the BIB one for a bottom firing configuration since they require virtually completely different designs for best performance due to being mass loaded, otherwise it needs to be spaced up too far to qualify as a BIB horn, requiring a more robust base than a mass loaded one to get the center of gravity (CG) down.
GM
fred76 said:
Greets!
Yes, see my previous post.
Who says they sim bad? Anyway, the only difference between them in this BIB is that the 165LB rolls off down low similar to the original's 40-1354 while the 165 GMF stays ~flat to cut-off:
L = 105.93"
Sm = 220"^2
driver down 23.03" from the top.
GM
>>> Frankly, even though I've posted some scaled down BIB designs, I would prefer a separate webpage distinct from the BIB one for a bottom firing configuration...
What do you envision here GM? Perhaps I can create another site dedicated to these other types of designs? It can all be linked together with the BIB site... sortof a sister page.
Soon the BIB site will be finished for all the data i have from Scott will be posted. Tho i would like to post pics from individuals that build future BIBs... and anyone that wants to offer an essay or article regarding BIBs i will post.
I would also like to further build the BIB site as designs continue to come my way.
Peace,
Godzilla
What do you envision here GM? Perhaps I can create another site dedicated to these other types of designs? It can all be linked together with the BIB site... sortof a sister page.
Soon the BIB site will be finished for all the data i have from Scott will be posted. Tho i would like to post pics from individuals that build future BIBs... and anyone that wants to offer an essay or article regarding BIBs i will post.
I would also like to further build the BIB site as designs continue to come my way.
Peace,
Godzilla
ultrakaz said:
Greets!
1) It will shorten the effective line length and create a 'faster' flare rate, ergo will be tuned higher and shift its harmonics somewhat.
2) It is to me.
3) High Vas is preferable in a wide BW compression loaded horn. For TL variations, a moderate Vas combined with a medium Qts is best to keep size semi-reasonable. The main thing is to not use very stiffly sprung units that work well in tiny cabs with PRs. These are more suited to ~high compression LF/midbass horns.
For sub duty, low Fs, medium Vas, Qts, is the goal. Regardless, a BIB isn't a good idea unless you map your room's modes and design one with an inverse FR to ~match it. Better to mass load it to keep size semi-reasonable and reduce the ripple in its passband.
GM
Godzilla said:
Greets!
Yeah, a link to another page for drivers that don't make the BIB 'cut' would be nice, which means I need to re-do the designs for the ones I've already posted as time permits. I'll send you a pm when I have time to pursue it.
Anyway, thanks for all your's and Scott's efforts!
GM
GM said:
Hi GM,
Thanks for the 165GMF sim!
I think it was you who gave the impression that the 165LB was 'bad' on sim on Post #135 hehe. But I most likely read it 'out of context':http://www.diyaudio.com/forums/showthread.php?postid=867208#post867208
Anyways, maybe Godzilla could revise the Line length diagram in the "How To" page by emulating the diagram expample attached by Scottmoose some pages back:
http://www.diyaudio.com/forums/attachment.php?s=&postid=760327&stamp=1131273009
I mean use the flare ('start' to 'end' captioned) = Line ???
Then use the length from where the flare starts to where the internal baffle terminates (center) + distance from front/base/back to internal baffle center = Baffle Height ???
A big thanks to GM, Scottmoose, Godzilla, and TC...
Greets!
You're welcome!
No, you read it right, it really sucked, and explains why when I tried to save the current sim after I had already posted, it asked if I wanted to overwrite the existing one, which turned out to be the one I did using TC's pipe. At that point in the thread, I was just plugging specs into it since that's what ya'll were asking for. Shows you how good (not!) my short term memory is.
I'm going to get with him on some changes, including the dims, drawings.
GM
You're welcome!
No, you read it right, it really sucked, and explains why when I tried to save the current sim after I had already posted, it asked if I wanted to overwrite the existing one, which turned out to be the one I did using TC's pipe. At that point in the thread, I was just plugging specs into it since that's what ya'll were asking for.
Shows you how good (not!) my short term memory is. I'm going to get with him on some changes, including the dims, drawings.
GM
http://www.zillaspeak.com/bib.asp
More designs up... Supravox and Monacor... and a lovely intro from Scott.
Peace,
Godzilla
More designs up... Supravox and Monacor... and a lovely intro from Scott.
Peace,
Godzilla
http://www.zillaspeak.com/bib-howtobuild.asp
Thank you lovechild! I included your 'to scale' drawing. Which driver was that again? I'd like to note it on the site.
Peace,
Godzilla
Thank you lovechild! I included your 'to scale' drawing. Which driver was that again? I'd like to note it on the site.
Peace,
Godzilla
Hi there!
Scott, you made some dims for me a while back for the Monacor SPH60X, which were smaller than the posted on zilla's BIB page.
These are to be assembled in the near future....
Thanks again/Peter
7" wide, 14" deep, and 60" tall. 1" material is preferable. The internal sloping baffle will terminate 5 1/2" from the front and rear internal cabinet walls and 5 1/2" from the floor. The point above the driver needs a light layer of stuffing, and perhaps a 1/2" or so layer on the base of the cabinet
Scott, you made some dims for me a while back for the Monacor SPH60X, which were smaller than the posted on zilla's BIB page.
These are to be assembled in the near future....
Thanks again/Peter
7" wide, 14" deep, and 60" tall. 1" material is preferable. The internal sloping baffle will terminate 5 1/2" from the front and rear internal cabinet walls and 5 1/2" from the floor. The point above the driver needs a light layer of stuffing, and perhaps a 1/2" or so layer on the base of the cabinet