Thanks Dmason
I start to understand.... so "high grade etc.." is a kind of noise absorber for undercarpeting.
Think wuold be hard to find it in Italy. It's usual for that purpose to use a rubber carpet or other materials...I'll try to look after anyway.
Dmason, as owner of Omega Speaker, does your pair have the hole in the dustcup? How is it protected... In the same article Lou said "The driver (Fostex) has a hole in the center etc...., [b]this is covered by a protective screen to repel dust"....[/b]
Any thought?
Ciao. Fab.
I start to understand.... so "high grade etc.." is a kind of noise absorber for undercarpeting.
Think wuold be hard to find it in Italy. It's usual for that purpose to use a rubber carpet or other materials...I'll try to look after anyway.
Dmason, as owner of Omega Speaker, does your pair have the hole in the dustcup? How is it protected... In the same article Lou said "The driver (Fostex) has a hole in the center etc...., [b]this is covered by a protective screen to repel dust"....[/b]
Any thought?
Ciao. Fab.
McFaBs said:
Greets!
You're welcome!
YMMV = 'your mileage may vary': http://en.wikipedia.org/wiki/YMMV
Carpet underlayment (aka 'padding' or felt) comes in three basic grades and each has a range based on various company's marketing strategies, though I've noticed in recent decades that the lower grades are probably all made by just a few companies around the world since they are apparently now only made from scrap foam (aka 'rebond' or 'junk bond') at least WRT what's available in the USA.
When I was young, jute was the norm and how dense/thick it was determined it's grade, being able to quickly assess its quality by its color until unscrupulous folks started dying cheaper grades to fool the casual consumer. You want some serious noise attenuation, then 3/4" - 1" of the best grade will get the job done and under an equivalent quality carpet you don't so much as walk on it as float, but if you have to ask for a quote to do your home you probably can't afford it. http://en.wikipedia.org/wiki/Jute
My last 'update' on this subject was in '94 though, so doing a quick search to see what the 'latest n' greatest' is, it appears that in the never ending search to get more from less, the industry hasn't been 'asleep at the wheel': http://www.acousticalsolutions.com/products/floor_underlayments/superfloor.asp
Then there's the 'explosion' of engineered foam products.............
Anyway, IMO if you need to use such serious (wide BW) damping on a cab, then the cab's design and/or construction is fundamentally wrong for its intended BW, which sadly is the norm in the consumer speaker industry. That said, if you can beg/buy at a reasonable price some being removed from a commercial or private mansion renovation, it's great for damping anything made from metal, ceramic, etc.. Ditto for damping small machines, 3/4" pads of it were used under typewriters, mechanical calculating machines, etc., so works well damping TTs, CD players, etc.. WRT using it in a FR speaker app, lining a cab with it will 'suck the life' right out of it if >3/8" thick IMO assuming today's offerings are close in its specs to what I've used.
As always though, YMMV.
GM
dmason said:
Greets!
'Rebond' and 'high grade' carpet padding are mutually exclusive by design, though ~10 years ago I in-home tested a sample of a rebond product that was marketed as a high grade carpet underlayment so I can't call him a liar, but it in no way came close to matching my decades old 5/8" jute in subjective 'feet' performance. That said, the ultra cheap rebond is used extensively in 'el cheapo' consumer speakers to damp the effects of cheap/shoddy materials and/or construction, or at least was back when I was still paying attention to discarded speaker cabs, so for sure it can work well in a 'shotgun' sort of way.
Regardless, thanks for the insight!
GM
McFaBs said:
Something you might try, that should be available, is sill foam seal. This is used between the top of house foundations and the bottom of the wall to seal against air infiltration. This should have a LONG life span, should you decide to just leave the speaker as-is
.Tom.
Hi!
GM : As usual very exhaustive answers! And luckily, reading between the lines, BIBs doesn't need such damping..... So, another thing rubbed out from the shopping list!
Last but not least THANKS TO EVERYBODY! I really like this forum, I've learned soooooo many things, and for a novice like I am, it's really comforting.
Just sorry If I can't fully contribute in sharing infos; maybe in the future...
Ciao.Fab.
P.s.:
Loninappleton : good hint, and cheap too.
Renfrow : I've glanced that link and sound interesting. Tomorrow I will ask to a friend of mine who's a house builder.
GM : As usual very exhaustive answers! And luckily, reading between the lines, BIBs doesn't need such damping..... So, another thing rubbed out from the shopping list!
Last but not least THANKS TO EVERYBODY! I really like this forum, I've learned soooooo many things, and for a novice like I am, it's really comforting.
Just sorry If I can't fully contribute in sharing infos; maybe in the future...
Ciao.Fab.
P.s.:
Loninappleton : good hint, and cheap too.
Renfrow : I've glanced that link and sound interesting. Tomorrow I will ask to a friend of mine who's a house builder.
Greets!
IIRC my cork usage was limited to a decorative form of controlling room and baffle reflections, but it doesn't seem to be space efficient enough for speaker internals. IOW, acoustic fiberglass, felt, foams reduce net Vb much less for the same amount of attenuation, but if you want something relatively rigid, acoustic tile (aka Celotex) like BB uses is a better choice IMO.
GM
IIRC my cork usage was limited to a decorative form of controlling room and baffle reflections, but it doesn't seem to be space efficient enough for speaker internals. IOW, acoustic fiberglass, felt, foams reduce net Vb much less for the same amount of attenuation, but if you want something relatively rigid, acoustic tile (aka Celotex) like BB uses is a better choice IMO.
GM
Scottmoose said:
Dave as in Dave Dormer.... my only role was to help convince Dave that an FE108eS was not a bad move. Scott & Jeff are responsible for his choice of BIB.
His Black BIBs with his newly aquired Decware Taboo was a really synergistic match. They really rocked. They lack the finese and the ultimate extension (even thou they sim to 40 Hz) of the little horn but are still very listenable and did i say that they really rock ...
dave
Attachments
Curses. I forgot to actually attach that picture didn't I? ;-) Sorry about that!
Glad they rock out -something these boxes are rather good at for FR units. Regarding the limited extension, I don't know the exact dimensions that were used (I've PMed Dave about them, and for the measurements), but for what it's worth, going by the info Dave has posted on the FR forum, my suspicion is that the driver position too far along the line is lowering LF output by reducing gain, and that some of the terminus output is being shorted by the floor-venting. Back cutting it at an angle a la TC's could probably help out there.
Glad they rock out -something these boxes are rather good at for FR units. Regarding the limited extension, I don't know the exact dimensions that were used (I've PMed Dave about them, and for the measurements), but for what it's worth, going by the info Dave has posted on the FR forum, my suspicion is that the driver position too far along the line is lowering LF output by reducing gain, and that some of the terminus output is being shorted by the floor-venting. Back cutting it at an angle a la TC's could probably help out there.
hey scott,
while you're on the topic... i have been listening to my upward firing fe108ez bibs for a few months now and while i definitely like them, there is something missing. i have never heard other full rangers so do not really know what to expect. it could be that the ceilings are too high, the room too small and i only have access to one corner but there must be a way to work with the setup i have.
i built with the dims given a while back and things improved with some stuffing in the top corner and along the bottom but is there anything i can do to further improve them? any ideas on how to alter them to downward firing or do i just add some legs? as i recall gm gave some advice on proper coupling distance but i don't think i had any idea how to figure it out.
thanks for any suggestions!
larry
while you're on the topic...
i have been listening to my upward firing fe108ez bibs for a few months now and while i definitely like them, there is something missing. i have never heard other full rangers so do not really know what to expect. it could be that the ceilings are too high, the room too small and i only have access to one corner but there must be a way to work with the setup i have.i built with the dims given a while back and things improved with some stuffing in the top corner and along the bottom but is there anything i can do to further improve them? any ideas on how to alter them to downward firing or do i just add some legs? as i recall gm gave some advice on proper coupling distance but i don't think i had any idea how to figure it out.
thanks for any suggestions!
larry
Only problem with flipping them over is that the driver will be a bit low. Check that, very low, so simply inverting them probably isn't going to work too well -you'd have to build a new box for them. Not what you want to hear I know -sorry! Is the second box hard against a wall at least? Closer the better for LF extension, which I assume is what's lacking?
OTOH, Dave's BIBs have given me a bit of a prod and I'm working on a longer BIB for the 108 and 126E at the moment (FrugelBIB anyone?). You're never going to get massive bass out of a 4in driver, but this should squeeze a little more out of them. You just need to be careful not to breech the 0.707 Fs limit Greg warned me about before -a lesson I've taken to heart, if you don't want the mid-bass to vanish on you.
What amps and wire are you running? Try shifting to a pair of 24AWG twisted conductors extracted from a run of Cat5 if your existing cable is thicker than that. 30AWG magnet wire is probably a little extreme for the 108, which has a good mid Q, and will probably need morew current than the 30AWG could provide.
OTOH, Dave's BIBs have given me a bit of a prod and I'm working on a longer BIB for the 108 and 126E at the moment (FrugelBIB anyone?). You're never going to get massive bass out of a 4in driver, but this should squeeze a little more out of them. You just need to be careful not to breech the 0.707 Fs limit Greg warned me about before -a lesson I've taken to heart, if you don't want the mid-bass to vanish on you.
What amps and wire are you running? Try shifting to a pair of 24AWG twisted conductors extracted from a run of Cat5 if your existing cable is thicker than that. 30AWG magnet wire is probably a little extreme for the 108, which has a good mid Q, and will probably need morew current than the 30AWG could provide.
thanks scott!
i'm currently using single strands of cat5 soldered directly to the drivers, run by a charlize amp with smps from nuuk. apple lossless into airport express with a kookaburra or millett hybrid for a pre. i'm sure the dac in the airport express could use upgrading but i'm still trying to get my monica 2 dac to work with an optical input.
the main problem for me is when i turn up the volume i find the speakers very fatiguing. i had vandy 2ces a few years back and listened at much higher levels. part of the problem was remedied with stuffing but i'm not sure how much has to do with the room setup. i get much more bass when i'm near the back wall but i don't prefer the sound. actually there is a big glass door that opens to the terrace on the back wall and this may be contributing to the problem. before i write off the speakers i should probably work on treating the room a bit. guess i better head back to the search button!
just got an email from dave explaining that the dimensions he used for the inverted bib are basically the same except the front and sides are extended about 14(?) inches and attached to a base. would it be preferable to scallop the sides a la terry cain or just attach some legs leaving the bottom open? when flipped over the driver is less than 18" from the floor so they would have at least 12" long and strong enough to hold the substancial weight of the bib. i can only imagine the mdf monsters some are building.
i'm currently using single strands of cat5 soldered directly to the drivers, run by a charlize amp with smps from nuuk. apple lossless into airport express with a kookaburra or millett hybrid for a pre. i'm sure the dac in the airport express could use upgrading but i'm still trying to get my monica 2 dac to work with an optical input.
the main problem for me is when i turn up the volume i find the speakers very fatiguing. i had vandy 2ces a few years back and listened at much higher levels. part of the problem was remedied with stuffing but i'm not sure how much has to do with the room setup. i get much more bass when i'm near the back wall but i don't prefer the sound. actually there is a big glass door that opens to the terrace on the back wall and this may be contributing to the problem. before i write off the speakers i should probably work on treating the room a bit. guess i better head back to the search button!
just got an email from dave explaining that the dimensions he used for the inverted bib are basically the same except the front and sides are extended about 14(?) inches and attached to a base. would it be preferable to scallop the sides a la terry cain or just attach some legs leaving the bottom open? when flipped over the driver is less than 18" from the floor so they would have at least 12" long and strong enough to hold the substancial weight of the bib. i can only imagine the mdf monsters some are building.
Yeah, got one from Dave just now. It's a good idea to get the driver nearer to ear-height. The only possible issue I can forsee with doing that is that you move the terminus away from the floor, and it might loose out on some of the room's loading. So do the upward-firing versions though.
Fatiguing? I'm begining to see the light, especially when you mention the glass doors to the rear. Sounds to me as if you're getting a bit too much midrange out through the terminus, so before experimenting with adding a stand to allow it to be flipped, try increasing the density of the stuffing on the base, which should help somewhat, and then possibly add some thick grill material over the terminus -Greg suggested this a while back. Not only will it keep the dust out, it should help attenuate the highs coming out of the horn without damaging the LF. If this doesn't help, the stand and flipping it inverted will be probably help out.
Best
Scott
Fatiguing? I'm begining to see the light, especially when you mention the glass doors to the rear. Sounds to me as if you're getting a bit too much midrange out through the terminus, so before experimenting with adding a stand to allow it to be flipped, try increasing the density of the stuffing on the base, which should help somewhat, and then possibly add some thick grill material over the terminus -Greg suggested this a while back. Not only will it keep the dust out, it should help attenuate the highs coming out of the horn without damaging the LF. If this doesn't help, the stand and flipping it inverted will be probably help out.
Best
Scott
Hello all,
Thanks for the interest in my BIB. When I first got the dims to build a BIB for the 108, I knew I wanted to change it up a little bit and have it firing downward and I wanted to have the driver higher up from the floor. Then I saw a pic of the TC design for the 108 and I thought hey I'll style them after that. I used all 1/2''baltic birch ply and it only comes in 5'x5' sheets here.
My Bib is exactly the dims that were given to m except I made the front piece 60'' and the sides 60'' and attached a 3/4'' fir base to support the cab. The round baffels are two pieces of 1/2'' baltic birch glued together and the circle diameter is 9.25''. The one thing I forgot to allow for was to increase the depth to allow for the internal divider, so whatever depth you were given for a 108 bib build just keep it the same if your using 1/2'' material and you'll be exactly how I did mine. I wired with cat5 which is just so stupid good for the price, I think I paid under $3.00 to have speaker wire for both speakers.
In my room they sound really nice, great detail and good bass, the 108 driver amazes me all the time that such a small driver can do so much, I love it.... Dave.......
Thanks for the interest in my BIB. When I first got the dims to build a BIB for the 108, I knew I wanted to change it up a little bit and have it firing downward and I wanted to have the driver higher up from the floor. Then I saw a pic of the TC design for the 108 and I thought hey I'll style them after that. I used all 1/2''baltic birch ply and it only comes in 5'x5' sheets here.
My Bib is exactly the dims that were given to m except I made the front piece 60'' and the sides 60'' and attached a 3/4'' fir base to support the cab. The round baffels are two pieces of 1/2'' baltic birch glued together and the circle diameter is 9.25''. The one thing I forgot to allow for was to increase the depth to allow for the internal divider, so whatever depth you were given for a 108 bib build just keep it the same if your using 1/2'' material and you'll be exactly how I did mine. I wired with cat5 which is just so stupid good for the price, I think I paid under $3.00 to have speaker wire for both speakers.
In my room they sound really nice, great detail and good bass, the 108 driver amazes me all the time that such a small driver can do so much, I love it.... Dave.......