Foam Core Board Speaker Enclosures?

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Squeak,
I had to pull the drivers from the Cornu's to put in the FIB's so I have not been able to do a true A/B comparo. But, my impression is that the BIB's have lower bass extension than the 20 in Cornu's, however they do not sound as "expansive" as the Cornu's. I think for certain music where a harder driving bass sound is needed, the FIB's are better, but for most music, the Cornu's sound better, especially jazz or anything with horns or woodwinds. I may pull the drivers from my cardboard MLTL's and put them in the Cornu's so that I can do a true A/B test and update this response. One thing that I have found with the FIB is that it is very sensitive to stuffing, I had to play with it quite a bit to get the sound I wanted. Maybe I just got lucky with how I did the stuffing on the Cornu's because it was good the first time.

UPDATE: I put another set of drivers in the Cornu's and did an A/B test with the FIB's. My impression from above is still correct. The lower bass on the FIB's is a definite advantage on songs that have deep kick drums or bass guitar that goes below 100 Hz. The sound stage of the Cornu's is still really special - it feels like you are listening to larger speakers in a larger room. Amazing what the spiral enclosure can do. The imaging and musicality of vocals between the two are about even. Although on many songs, the speakers are very close and with my eyes closed, it is hard to tell the difference other than a warmer coloration to FIB sound. I think this may be the characteristic 'BIB' signature sounds and really depends on how much damping and stuffing you apply - YMVV.
 
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Foam on the white channel, the black one have a layer of paper laminate on it.

Ravener,
It may be the type of glue you are using which has a higher melt temperature. It might be special industrial strength hot melt glue. The stuff I use is the budget all-purpose craft store stuff. You must be getting close! Looking forward to seeing the finished product, your listening impressions, and if you are able to do it - a mp3 sound clip :)
 
Finally, here's a photo of my 20" Vifa TC9FD masonite/foam hybrid with banana leaf paper.[/ATTACH]
Those look great.
Using a 40W glue gun<snip>melting the foam.
Happ ens to me too. Just lay the bead and be patient enough for it to cool before moving the foam into place. Also, maybe do a spot weld and caulk method.
Ravener,
It may be the type of glue you are using which has a higher melt temperature.
My thoughts also but remember he does have a 40 gun. I know the idea is to get the glue hot faster but it may be hotter overall too.
 
Ravener,
It may be the type of glue you are using which has a higher melt temperature. It might be special industrial strength hot melt glue. The stuff I use is the budget all-purpose craft store stuff.

Happ ens to me too. Just lay the bead and be patient enough for it to cool before moving the foam into place. Also, maybe do a spot weld and caulk method.

My thoughts also but remember he does have a 40 gun. I know the idea is to get the glue hot faster but it may be hotter overall too.

I got my glue gun and glue sticks from a local arts and crafts store.

Probably due to the heat of the gun, don't think there is a cutoff switch for when the gun gets too hot.

If i use it after leaving it for idle for more than 5min, the glue will come out with lots of tiny bubbles in them, and the glue stays fluid for about 3min even after i turn the switch off.

Anyway, will try to work on it in the evening after I get home from work, with Chinese New Year approaching at the weekends, I still have to clean my room. So much to do, so little time.
 
A little update:

Have yet to seal up the enclosure yet, trying to figure out the mounting for the drivers as I do not have any spare screws lying around, therefore using back the original screws, which have about 1cm of threadless area for the original baffle.

probably gonna glue the screws tight (not going to keep the first prototype, planning to scrap it once I've figured out how to properly do everything and make a new pair).

Testing it out laid on a flat table, with the original beside, I can hear an obvious difference; the spiral enclosure has definitely a bigger soundstage(sounds like I'm in a concert hall). Source is my Galaxy S2 (FLAC) with a Fiio E11 headphone amp.

Now to seal up the thing and enjoy it monologue-ly, for the time being :D
 

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Exactly, no harm done because it is fast and cheap to try out wacky crazy stuff with foam core. I think foam core has been really good for trying out things, but at the same time I am finding that it ends up sounding really good most of the time - generally true if design is good. What I have been able to do is to do a study of the effect of different alignments and cabinets while keeping the driver fixed. I have tested about 7 different ones now in the course of 3 months. How many builds do you think I would have done if they were in wood? Anyhow, it's been a blast. I am settling to see which I want to pursue in wood now.
 
Have sealed up the enclosure, does make a difference in the sound signature as compared to the original satellite; it definitely sounded more open and spacious.

But, as the driver is only 2"(actually, i measured 1.9"), it can't move enough air to make the bass pronounced. I can clearly hear the presence of a deep bass if i were to put my ears at the horn mouth, and bass can still be heard about 20cm away, any further than that, there's no bass.

Wonder how it would be if i just remove the 2" driver, and chuck in a 3 incher in its place...

edit: I probably need to scale it down further, I have a hunch that the enclosure just have too much air for the driver to move about, therefore weakening it's bass response...
 
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........it is hard to tell the difference other than a warmer coloration to FIB sound. I think this may be the characteristic 'BIB' signature sounds and really depends on how much damping and stuffing you apply

FWIW, i.e. not much since it's an apples n' oranges comparison, using snip-its of Jeff Beck's 'Emotion & Commotion' CD through a cheap computer sound card/Windoze Media player feeding an ancient Creative 2.1 system, your clip comes off as very 'colored', to the point that it drove the system to unacceptable distortion in comparison.

All things considered though, The [mid] bass line was a bit of an eye opener.

Anyway, nice to see folks finally experimenting with these types of 'miniatures'; early on I learned quite a bit about TL/horn design, especially back loaded, along with room interaction and how different materials affected its sonic 'signature' from comparing ~scale models of proven designs with many variations.

GM
 
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Ravener,
You might want to give the Cornu a try if you want to do a 4 in driver. It is a proven design with lots of people liking the sound and the bass comes out on 4 sides vs just one with the Fibonacci. You should try the Fibonacci in foam in the 4 in first before cutting wood though. A 3 in stuffed in your current one should work better - get a bigger amp! At least 3 to 8 watts.
 
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FWIW, i.e. not much since it's an apples n' oranges comparison, using snip-its of Jeff Beck's 'Emotion & Commotion' CD through a cheap computer sound card/Windoze Media player feeding an ancient Creative 2.1 system, your clip comes off as very 'colored', to the point that it drove the system to unacceptable distortion in comparison.

All things considered though, The [mid] bass line was a bit of an eye opener.

Anyway, nice to see folks finally experimenting with these types of 'miniatures'; early on I learned quite a bit about TL/horn design, especially back loaded, along with room interaction and how different materials affected its sonic 'signature' from comparing ~scale models of proven designs with many variations.

GM

GM,
I don't understand how Jeff Beck has anything to do with my FIB soundclip? I checked the sound levels in the mp3 during recording and in the mp3, they should be well below distortion or clipping levels and sound ok on my computer's sound card. Room acoustics have a lot to do with how it sounds probably. Anyone else hearing bad distortion on the mp3 clip? I can make a better one if that is the case. If you want to compare my clip with what it may sound like if you had CD, try this link www.youtube.com/watch?v=-Oga5lYb9EA
 
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X,

All in due time, all in due time, now i gotta review this build and see in what way can i make it more perfect.

edit: IMO, i think the most important aspect is to make sure the curves are as smooth as you can get them to be.

Not trying to rush you, just saying that if you are going to try a larger project without a model or design, you might be better off trying something tested first. I think the smoothness of the curve is not that important if you are concerned about this acting as a back loaded horn to enhance bass. In fact smooth will allow higher frequencies to come through and this may mess your imaging with main driver output.

I actually purposely put sharp corners inside the spirals at beginning to low pass output.
 
I actually purposely put sharp corners inside the spirals at beginning to low pass output.

Ah I see, will try to work that into my design.

Anyway, I tried to record while playing Espana, there are quite a bit of distortion when the drums and the cymbals come on together, not sure if there isn't enough 'buffer' power from the amp, or I'm actually overloading the driver (probably the latter).