Now that's the proper way to manage it for sure 😀 Way back when I built mine I just imagined how close to the ceiling they probably should have been, and then made them about that far up from the floor by extending the front baffle and sides.. So basically they could now be inverted with the terminus exiting into an non mathematically calculated three sided box open to the back. Not very scientific at all I know lol 😱 They actually sounded pretty good for what they were surprisingly.. The BIB seems to be a fairly forgiving design as long as they can be placed properly. And they're a really easy project for a beginner to have fun and experiment with, that can sound much better than you'd expect it should for some reason.
Last edited:
So a while back I considered some FAST BiB's, but time passed and life happened and they didn't get built. But I am thinking again, so I reread the last 30 pages for review.
Thinking of a full range in a sealed box within the bib and size the bib for the woofer. Using the bib calculator (thanks Godzilla), I got my box dimensions. So assuming I put the full range at preferred listening height and I put the woofer at 2z or 0.434 of line length (which I read as a recommended distance for a sub bib), I would get 28" centerline to centerline between full range at woofer. Which is more important? Holding woofer distance of line length or optimizing the distance between drivers?
Thanks
Thinking of a full range in a sealed box within the bib and size the bib for the woofer. Using the bib calculator (thanks Godzilla), I got my box dimensions. So assuming I put the full range at preferred listening height and I put the woofer at 2z or 0.434 of line length (which I read as a recommended distance for a sub bib), I would get 28" centerline to centerline between full range at woofer. Which is more important? Holding woofer distance of line length or optimizing the distance between drivers?
Thanks
Happy Holidaze and all that jive! 😀
Optimizing distance unless you like your music to bounce up n' down between the two and some piano concertos that are right out of Fantasia if the distance is too extreme for the XO point/slope.
Stuffing solves woofer line misalignment plus more important to place it at a room's vertical odd harmonic.
There's lots of recordings to test this of course, though my fave is Edgar Winter's 'Frankenstein', especially beginning around 3:14. Best to listen with headphones first. Horns really highlight even a little bit off IME: https://www.youtube.com/watch?v=P8f-Qb-bwlU
Anyway, ~13560/4/28 = ~121 Hz and ideally need at least an octave higher to cover the XO BW = ~60.5 Hz XO, though many folks are fine at 1/2 to 1 WL apart, so recommend doing some testing; ditto if there's a S.O. that will be joining you and/or has their own music.
Consider too the listening distance if a large room. IOW if that 28" is at least a 1/3 of an octave shorter to your eyes, then adjust the numbers accordingly: Combining and adding decibels of one-third octave bands to level of octave bands adding dB EQ 1/3 octave band finding number 1/3 octaves between frequencies analysys filter 1/1 octave band filter oct calculator calculation 1/3 octave band to octave b
GM
Optimizing distance unless you like your music to bounce up n' down between the two and some piano concertos that are right out of Fantasia if the distance is too extreme for the XO point/slope.
Stuffing solves woofer line misalignment plus more important to place it at a room's vertical odd harmonic.
There's lots of recordings to test this of course, though my fave is Edgar Winter's 'Frankenstein', especially beginning around 3:14. Best to listen with headphones first. Horns really highlight even a little bit off IME: https://www.youtube.com/watch?v=P8f-Qb-bwlU
Anyway, ~13560/4/28 = ~121 Hz and ideally need at least an octave higher to cover the XO BW = ~60.5 Hz XO, though many folks are fine at 1/2 to 1 WL apart, so recommend doing some testing; ditto if there's a S.O. that will be joining you and/or has their own music.
Consider too the listening distance if a large room. IOW if that 28" is at least a 1/3 of an octave shorter to your eyes, then adjust the numbers accordingly: Combining and adding decibels of one-third octave bands to level of octave bands adding dB EQ 1/3 octave band finding number 1/3 octaves between frequencies analysys filter 1/1 octave band filter oct calculator calculation 1/3 octave band to octave b
GM
Yes Merry Christmas and Happy Holidays!
GM
Good information as always. I will play around with the layout and run some numbers.
So you are saying I should consider placing the woofer at a vertical odd harmonic? So in a room with 9 foot ceilings I should consider 3 foot from the floor for a 3rd harmonic (probably not doable) or at 21.6" from the floor for a fifth harmonic (probably doable)?
I will read your link through several times. Thanks again for the links and all the helpful content.
GM
Good information as always. I will play around with the layout and run some numbers.
So you are saying I should consider placing the woofer at a vertical odd harmonic? So in a room with 9 foot ceilings I should consider 3 foot from the floor for a 3rd harmonic (probably not doable) or at 21.6" from the floor for a fifth harmonic (probably doable)?
I will read your link through several times. Thanks again for the links and all the helpful content.
You're welcome!
Right, 1st/fundamental [floor, ceiling], 3rds, 5ths, 7ths, though beyond 2/5ths doesn't help much.
At 2/5ths [~43.2"], it's not that much higher than a typical seated ear height, a good place to put a woofer meant for fairly wide BW over a horn [up to a 1600 Hz XO as proven by many recording studio monitors], so should work well for blending to a 'FR' driver also, especially since this will put them very near/together.
This layout has worked well for me and numerous others with high wall mounted monitors, HT above screen LCR/surround speakers, but far enough beyond the norm for most folks to suggest you cobble together a makeshift baffle to confirm ya'll are OK with it and that moving it up-down a bit puts it near enough in a room mode peak since floors, ceilings can have enough differing reflection coefficients to audibly offset them.
GM
Right, 1st/fundamental [floor, ceiling], 3rds, 5ths, 7ths, though beyond 2/5ths doesn't help much.
At 2/5ths [~43.2"], it's not that much higher than a typical seated ear height, a good place to put a woofer meant for fairly wide BW over a horn [up to a 1600 Hz XO as proven by many recording studio monitors], so should work well for blending to a 'FR' driver also, especially since this will put them very near/together.
This layout has worked well for me and numerous others with high wall mounted monitors, HT above screen LCR/surround speakers, but far enough beyond the norm for most folks to suggest you cobble together a makeshift baffle to confirm ya'll are OK with it and that moving it up-down a bit puts it near enough in a room mode peak since floors, ceilings can have enough differing reflection coefficients to audibly offset them.
GM
There's a pile of wood in the living room... No other place to put it. Great reason to start building ASAP, according to the wife. 😁
I have a few extra days off, so now is the time. My wife thinks it's so funny. This afternoon she snapped a picture of my face today, when I was planning the details. Said I looked manic, happy and a little scared...
I have a few extra days off, so now is the time. My wife thinks it's so funny. This afternoon she snapped a picture of my face today, when I was planning the details. Said I looked manic, happy and a little scared...
I resemble that remark! After almost 14 yrs of nothing approaching HIFI, I've finally been able to afford enough parts, components along with some gifts to [re]assemble a stereo/HT system and after scanning the receiver's 377[!] page owner's manual I'm in so far over my head that other than eventually adding the center, surrounds and hopefully an Atmos system, I'm really wondering if I'll ever be able to use much, if any, of its many 'bells n' whistles'. 🙁
Come Spring, hope to 'burn' some wood to make all the HT speakers; now all I got to do is decide the specifics. No mean task these days, what with all the options available nowadays. I liked it much better way back when choices were few and Altec reigned supreme in cinema sound, making it simple indeed. 😀
Regardless, as always, looking forward to what havoc your endeavors wreak. 😉
GM
Come Spring, hope to 'burn' some wood to make all the HT speakers; now all I got to do is decide the specifics. No mean task these days, what with all the options available nowadays. I liked it much better way back when choices were few and Altec reigned supreme in cinema sound, making it simple indeed. 😀
Regardless, as always, looking forward to what havoc your endeavors wreak. 😉
GM
Good news!
So with you posting this news on the BIB thread does that mean you will be building some BIB's or a variation ?
Regardless, they will be big right?
So with you posting this news on the BIB thread does that mean you will be building some BIB's or a variation ?
Regardless, they will be big right?
Most panels measured out, drill holes pre-marked, it's going quite well.
GM, most of those buttons and options on AV receivers are there for marketing purposes only. Find what you need and don't worry about the rest. It's what everybody does. 🙂
There are frequent discussions on my local diy forum about advancements etc. Some argue that the physics haven't changed and progress is mostly about getting the same performance for less money. So... Get the vintage Altec-like performance for the cheapest price you can find?
GM, most of those buttons and options on AV receivers are there for marketing purposes only. Find what you need and don't worry about the rest. It's what everybody does. 🙂
There are frequent discussions on my local diy forum about advancements etc. Some argue that the physics haven't changed and progress is mostly about getting the same performance for less money. So... Get the vintage Altec-like performance for the cheapest price you can find?
Thanks! Several different BIBs are planned, though none for me at least initially and will be loaded with now vintage decades old RadioShack 'FR' drivers, woofers including the 40-1354 used in TC's BIB, so no plans to post these unless someone should post a box request for the drivers I'll be using.
The HT speakers will initially be cheap DIY MLTL computer monitors with RS drivers to both get it going and be able to sell them in a yard sale for more than I'll have in them, then replace at least the mains with large horn+midbass woofer or preferably [3] way Synergy concept horns [not sure about surrounds/Atmos yet] with Dr. Geddes style multiple sub array to smooth out the room response of an acoustic ~0.5 Qtc IB to cover the ~1-80 Hz BW at THX reference at high SQ.
I auditioned a very expensive HT system at a Magnolia [Best Buy] demo for others today and the potential customers were in awe of its performance, waxing eloquent about its clarity, etc.. Me, I was gritting my teeth so much from all the sibilance, harmonic distortion I had to leave. Later, talking with a worker I've 'bench raced' HT design with, he reminded me that designed in distortion is still what sells same as dialing up a TV to eyeball blistering brilliance. Sad, really sad.
HIFI will remain huge, 'old school' high efficiency, since all of my preferred music was recorded, voiced, played back on them and will continue to do so as long as I've room for them.
GM
Cool! Wish I was at that point, but I've a lot to do before I can use the shop.
Thanks, this is what I was told today at Magnolia [Best Buy] since I don't stream or have a smartphone to program/use as a remote nor WIFI, etc..
Unfortunately, HE/prosound components are expensive, though if I go Synergy concept it can be done with cheap drivers except for the HF driver.
The HIFI will remain Altec/GPA based though.
GM
So GM I have looked at this several ways. I would like to keep my fr/wr driver at ~39" and that puts it kinda in the way if I go with placing the woofer at 1/3 or 2/5 harmonic from the floor based on 9 ft ceilings. And I have not decided how I want to do the sealed box within the bib. So I am strongly considering just making a bass bib and have the fr/wr outboard. It would give me more flexibility down the road.
So I'm thinking bass bib with driver at the 1/3 vertical harmonic, 36" from the floor. Assuming a woofer with a Fs of 39hz I get a folded height of 86" and the woofer is at 0.29L of pipe length. I could also size the box for a Fs of 35Hz with a folded length of 96" and the woofer at 0.31L of pipe length. Is there any noticeable benefit to going with the latter over the former? I will make the box 96" tall regardless, but just locate the inner baffle accordingly.
Thanks as always
GM
Also I have been going through this bib thread again from start to finish. Scanning.
And I think GM is short for Gold Mine. A lot of helpful information for those that take the time to do the digging.
Thanks again
Also I have been going through this bib thread again from start to finish. Scanning.
And I think GM is short for Gold Mine. A lot of helpful information for those that take the time to do the digging.
Thanks again
That's what I've done, though with compression radial horns turned sideways. Note that if you put them to the outside, then you can add a bit of physical delay due to the increased distance to your ears Vs the bass and maybe not need any electrical delay if within a 1/4 WL of the XO point/slope. I meant to mention this earlier, but forgot.
Unless you're driving the woofer with a high output impedance amp that ideally needs to be tuned to Fs, just ignore what the Fs is and make the pipe's dims as close to ideal as practical. Note that if the floor or ceiling has an obviously different construction, then the ideal harmonic locations can be offset towards the more absorptive one, so a little bit of testing will need to be done to find where the modes make the strongest bass above the first vertical dip = ~13560''/2/108" = ~62.78 Hz. Note too that the speed of sound [SoS] can vary a bit, so can be off a Hz or three.
GM
You're welcome!
Note you can search the thread or forum or entire DIYaudio for that matter, though I usually do google searches to get what's been posted here and elsewhere.
Yeah, the various women in my life certainly 'mine[d]' me. 🙁
GM
Long afternoon of sawing behind me and it's basically finished. It's not a complex enclosure, thankfully. Next up: holes for dowels.
Been wanting to improve on my upward firing fe108es BIBs for a while and finally got some wood cut. My biggest issues are the low driver placement and the lack of coupling with the ceiling.
GM, how do these proposed cabs look? My original cab using the BIB calculator has a line length of 224cm. I have kept the width and depth and just extended the height to 122cm. Will it help to cut the sides as shown or scalloped? I'm not sure where exactly to place the drivers as the new line length is unclear to me, especially in the drawing on the left.
All panels have been cut to 122cm, material is OSB -- if the cabs work out I plan to do a more definitive build in Birch ply.
GM, how do these proposed cabs look? My original cab using the BIB calculator has a line length of 224cm. I have kept the width and depth and just extended the height to 122cm. Will it help to cut the sides as shown or scalloped? I'm not sure where exactly to place the drivers as the new line length is unclear to me, especially in the drawing on the left.
An externally hosted image should be here but it was not working when we last tested it.
All panels have been cut to 122cm, material is OSB -- if the cabs work out I plan to do a more definitive build in Birch ply.
Looks good to me giantstairs. I'd imagine room placement will be critical with the bass being reinforced coupled to the floor. This BIB might like to be pulled out into the room a bit more than usual. I've always wondered how moving the driver up or down the front baffle would change the sound - and if this would make a drastic or benign difference.
BIBs are so simple it almost insults complicated horn builds.
BIBs are so simple it almost insults complicated horn builds.
Thanks Zilla!
Yeah, room interaction is key. I'm asking because when I tried flipping my original BIBs upside down with a 20cm base (three sided, back open to the wall) I got better bass, but with noticeably less extension and a lack of "openness" compared to firing up. And of course the driver was WAY too low.
I'm hoping by making the enclosure longer, cutting out the sides, and changing driver position I will mitigate these problems to some extent. Or not?
Yeah, room interaction is key. I'm asking because when I tried flipping my original BIBs upside down with a 20cm base (three sided, back open to the wall) I got better bass, but with noticeably less extension and a lack of "openness" compared to firing up. And of course the driver was WAY too low.
I'm hoping by making the enclosure longer, cutting out the sides, and changing driver position I will mitigate these problems to some extent. Or not?