Hi there
Here's my new creation: the (fostex) fe87e Superbowls.
The wooden bowls are from IKEA (link to danish IKEA-bowls here:
http://www.ikea.com/dk/da/catalog/products/60057258
It's simply a 9 liter closed box with no parallel sides. The bowls are Ø 28 cm (about 11 inches).
I made holes for the fe87e and the speaker wires, attached the wires and screwed the fe87e's into one of the bowls, then glued two bowls together with superglue/istant glue (with a 5 minute long, light pressure).
No stuffing at all (tried half and quarter-full - none at all was absolutely best (the other solutions more or less dull and undynamic).
One hour later I used transparent silicone for airtightening.
A total of two hours work at all.
The fe87e is modified with a thin layer of Dammar (Dammar is a sort of painters' varnish), which made a night-and-day difference in sound reproduction: It's going deeper and is clear in sound, but absolutely non-fatiguing.
The Dammar had to dry out for 3-4 days in a warm environment.
I chose the fe87e ahead of the fe83e, because it has a falling frequency response (which I prefer). Fe83e is rular-flat according to fostex.
Now, another detail:
The speakerwires are just pressed towards the drivers wires: in that way, the signal isn't lead into the "big, bulky speakerterminals of unknown quality", but lead wire-to-wire. I feel this gives a little more presence than traditional "speakerwires-into-bulky-terminals-solution").
The speakers are placed on two heavy bags, which I bougt in a diving shop. The purpose is eliminating resonances - and it seems to work.
This little speaker has a fs of 140 hz before dammar-treatment, so a bass-solution could be fine.
But I'm perfectly happy - uses foobar with a 4th order Chebychev rolloff at 180 Hz to avoid too big xmax. I can hear the bass-notes (but not feel the physical presence) - and the bass is fast and enjoyable (so is the speaker overall).
Final note
Tried building the same Chebychev-filter - and it rolled off as expected, but also took some of the dynamics - and subjectively 25% of the sound level (I guess it's about 3-4 db sensitivity I lost).
Conclusion: Steep x-overs at low frequencies eats sensitivity and dynamics. Cannot be recommended.
Here's my new creation: the (fostex) fe87e Superbowls.
An externally hosted image should be here but it was not working when we last tested it.
The wooden bowls are from IKEA (link to danish IKEA-bowls here:
http://www.ikea.com/dk/da/catalog/products/60057258
It's simply a 9 liter closed box with no parallel sides. The bowls are Ø 28 cm (about 11 inches).
I made holes for the fe87e and the speaker wires, attached the wires and screwed the fe87e's into one of the bowls, then glued two bowls together with superglue/istant glue (with a 5 minute long, light pressure).
No stuffing at all (tried half and quarter-full - none at all was absolutely best (the other solutions more or less dull and undynamic).
One hour later I used transparent silicone for airtightening.
A total of two hours work at all.
The fe87e is modified with a thin layer of Dammar (Dammar is a sort of painters' varnish), which made a night-and-day difference in sound reproduction: It's going deeper and is clear in sound, but absolutely non-fatiguing.
The Dammar had to dry out for 3-4 days in a warm environment.
I chose the fe87e ahead of the fe83e, because it has a falling frequency response (which I prefer). Fe83e is rular-flat according to fostex.
Now, another detail:
An externally hosted image should be here but it was not working when we last tested it.
The speakerwires are just pressed towards the drivers wires: in that way, the signal isn't lead into the "big, bulky speakerterminals of unknown quality", but lead wire-to-wire. I feel this gives a little more presence than traditional "speakerwires-into-bulky-terminals-solution").
The speakers are placed on two heavy bags, which I bougt in a diving shop. The purpose is eliminating resonances - and it seems to work.
This little speaker has a fs of 140 hz before dammar-treatment, so a bass-solution could be fine.
But I'm perfectly happy - uses foobar with a 4th order Chebychev rolloff at 180 Hz to avoid too big xmax. I can hear the bass-notes (but not feel the physical presence) - and the bass is fast and enjoyable (so is the speaker overall).
Final note
Tried building the same Chebychev-filter - and it rolled off as expected, but also took some of the dynamics - and subjectively 25% of the sound level (I guess it's about 3-4 db sensitivity I lost).
Conclusion: Steep x-overs at low frequencies eats sensitivity and dynamics. Cannot be recommended.
Hi Lejaybo
Well, I tried with a AudioPro Ace Bass 2, which is considered a very fast and good sounding sub (new price around 1000 us $ in EU, 500 us$ used in EU) - but it wasn't fast enough in the lower notes.
Be aware that you have to get some kind of filter on the Superbowls - or they'll blow out on the lower notes.
Most subs only have a 6 db/octave roll-off for the satellite speakers - and that's not enough in this case.
So you either have to make a steep crossover at a low frequency, or a not-so-steep crossover at higher frequencies - and the last solution demands a bass-system with output longer up (and not an ordinary sub, which usually crosses over at maximum 100-120 Hz).
regards,
jesper
Well, I tried with a AudioPro Ace Bass 2, which is considered a very fast and good sounding sub (new price around 1000 us $ in EU, 500 us$ used in EU) - but it wasn't fast enough in the lower notes.
Be aware that you have to get some kind of filter on the Superbowls - or they'll blow out on the lower notes.
Most subs only have a 6 db/octave roll-off for the satellite speakers - and that's not enough in this case.
So you either have to make a steep crossover at a low frequency, or a not-so-steep crossover at higher frequencies - and the last solution demands a bass-system with output longer up (and not an ordinary sub, which usually crosses over at maximum 100-120 Hz).
regards,
jesper
Looks good.
My dad has one of those woodturning machines (old 1, hoping it still works) and was planning to make some small spherical fullrange satelites in the future, but this is a much less hassle then creating the sphere yourself.... wish i thought of using Ikea or any other bowls
Very Nice.
My dad has one of those woodturning machines (old 1, hoping it still works) and was planning to make some small spherical fullrange satelites in the future, but this is a much less hassle then creating the sphere yourself.... wish i thought of using Ikea or any other bowls
Very Nice.
Hi Everybody
Kazoo-John's bowls can be seen at :
http://www.diyaudio.com/forums/showthread.php?s=&threadid=113172&perpage=25&pagenumber=1
They are absolutely stunning.
I guess there are several advantages, using fullrange speakers in round, closed enclosures:
1) No standing waves, since no parallel sides
2) No need for baffle step compensation, since ALL sound can travel behind the speaker
3) Closed enclosure gives best impulse treatment
4) No xover = no degradation
... If it also could play sub-20 Hz-notes, then
Kazoo-John's bowls can be seen at :
http://www.diyaudio.com/forums/showthread.php?s=&threadid=113172&perpage=25&pagenumber=1
They are absolutely stunning.
I guess there are several advantages, using fullrange speakers in round, closed enclosures:
1) No standing waves, since no parallel sides
2) No need for baffle step compensation, since ALL sound can travel behind the speaker
3) Closed enclosure gives best impulse treatment
4) No xover = no degradation
... If it also could play sub-20 Hz-notes, then
I actually considered this build too but time makes fools of us all. Very nice work I must say.
The subs I originally planned for was/is to made of a cardboard tube with the outer diameter as the balls, ie 28 cm, and then strengthen it with several layers of carbonfiber cloths around the outside. And in the bottom placing 2 10" drivers in coupled cavity configuration in a closed box, ie the tube.
Using the right drivers, I was thinking Peerless XXXLS's it could go all the way to sub-20 Hz.
Putting the ball on top of that would make the speaker appear from all sides like a lower case "i". I even have come up with a cool name for it, The i-ball.
The subs I originally planned for was/is to made of a cardboard tube with the outer diameter as the balls, ie 28 cm, and then strengthen it with several layers of carbonfiber cloths around the outside. And in the bottom placing 2 10" drivers in coupled cavity configuration in a closed box, ie the tube.
Using the right drivers, I was thinking Peerless XXXLS's it could go all the way to sub-20 Hz.
Putting the ball on top of that would make the speaker appear from all sides like a lower case "i". I even have come up with a cool name for it, The i-ball.
Hi, Saturnus
I go t an Idea - A 10" driver in each end of a long tube. One firing down, the other firing up.
You can buy tubes at:
http://www.joma-pack.dk/
or
http://www.greif.dk/g_deko_design.asp
I go t an Idea - A 10" driver in each end of a long tube. One firing down, the other firing up.
You can buy tubes at:
http://www.joma-pack.dk/
or
http://www.greif.dk/g_deko_design.asp
Juspur,
I have a question/suggestion. I like the idea of the wire being crimped from the speaker to the wire from the amp. I did notice the holes the wires passed through look open. Did you seal them? If not I would, using something like a 100% silicon or glue. Just a suggestion so they don't produce unwanted sound.
John
I have a question/suggestion. I like the idea of the wire being crimped from the speaker to the wire from the amp. I did notice the holes the wires passed through look open. Did you seal them? If not I would, using something like a 100% silicon or glue. Just a suggestion so they don't produce unwanted sound.
John
B&W has a round subwoofer enclosure.
An externally hosted image should be here but it was not working when we last tested it.
Well, it depends on the order of the sub-crossover:
If it's a 12 db/octave, I would suggest it to begin rolloff around 120 Hz,
If it's a 24 db/octave, I would suggest it to rolloff from 150 Hz.
Please remember to make a crossover that also protects the superbowls - otherwise they'll be damaged at moderate to high volume, due too large movements.
If it's a 12 db/octave, I would suggest it to begin rolloff around 120 Hz,
If it's a 24 db/octave, I would suggest it to rolloff from 150 Hz.
Please remember to make a crossover that also protects the superbowls - otherwise they'll be damaged at moderate to high volume, due too large movements.
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