I don't think so 
Probably a bigger Ikea bowl...a steel one like someone used as a subwoofer enclosure ?!
Think of the infinite baffle principle - for regulating with the different alignement type - a pneumatic suspension that holds a little "load"->mechanical ( Cms-Vas-Xmax) and acoustical ( benefit of a tapering shape of the front baffle-> general coverage of the cone of emission ) would be a start , though car speakers are designed to work with big losses ( mounting inside the vehicle is tricky )
Probably a bigger Ikea bowl...a steel one like someone used as a subwoofer enclosure ?!
Think of the infinite baffle principle - for regulating with the different alignement type - a pneumatic suspension that holds a little "load"->mechanical ( Cms-Vas-Xmax) and acoustical ( benefit of a tapering shape of the front baffle-> general coverage of the cone of emission
) would be a start , though car speakers are designed to work with big losses ( mounting inside the vehicle is tricky )Doh, I finally ran into a thread about auto speakers and figured out they will sound rubbish in such an enclosure.
Now the question is: Alpair 7 or Alpair 10 ? 10 seems to need 9.13 lts enclosure size, so it sounds about right?
Now the question is: Alpair 7 or Alpair 10 ? 10 seems to need 9.13 lts enclosure size, so it sounds about right?
Well, back to page 1 and with OP, I see that he used a mid-woofer and a tweeter, plus I see a big sub on the floor.
ATM, I'm listening to a 5" plus 8 " passive radiator+ 1 1/2 "cone tweeter.
So it depends on your preference- Too much bass is obnoxius, too little or no ( deep ) bass might be forgivable - but it goes together with acoustic power and how loud you want ( to feel it, the bass !! )
Same could be said about the treble
This is ( supposely ) a good speaker :
Audison Prima - APX 6.5
And...maybe a sphere is not very good for internal reflections, because it's full reflective with the focus on the center; angles might be good...
ATM, I'm listening to a 5" plus 8 " passive radiator+ 1 1/2 "cone tweeter.
So it depends on your preference- Too much bass is obnoxius, too little or no ( deep ) bass might be forgivable - but it goes together with acoustic power and how loud you want ( to feel it, the bass !! )
Same could be said about the treble
This is ( supposely ) a good speaker :
Audison Prima - APX 6.5
And...maybe a sphere is not very good for internal reflections, because it's full reflective with the focus on the center; angles might be good...
Thanks for suggesting that speaker. I tried using the enclosure calculator for it and it looks like it wants an infinite baffle, so probably not a good option for a small enclosure like this.
Looks like the size of this enclosure is either 9.2 or 11.5 liters, depending on whether the 28cm is the internal or external diameter. Going to go buy tomorrow 4 pieces and measure them.
Looks like the size of this enclosure is either 9.2 or 11.5 liters, depending on whether the 28cm is the internal or external diameter. Going to go buy tomorrow 4 pieces and measure them.
With Fostex FE166 En
Hello!
Just to share my experience about Blanda Matt.
My project is a 2-way (before going 3), with a SBAcoustics SB34 woofer in a curved 136L box (not build yet). The Ikea bowls are used with a Fostex 166En.
For now, I wonder how to improve the bowl damping because my measurements are not sooo good.
I have put some bitume inside & sonofil in different quantities; not changing a lot of things to measurements though.
I want to stay with a closed box as much as possible, bass is not a goal here, but this may be where the problem lies. Opening with a tube might reduce inside reflexions ?
First graph is from a 5cm measure. This is where i am today. No windowing, no smoothing.
Second one is an older measure comparing between empty bowl (in purple), and stuffing with sonofil (blue).
Thanks for your ideas !
Hello!
Just to share my experience about Blanda Matt.
My project is a 2-way (before going 3), with a SBAcoustics SB34 woofer in a curved 136L box (not build yet). The Ikea bowls are used with a Fostex 166En.
For now, I wonder how to improve the bowl damping because my measurements are not sooo good.
I have put some bitume inside & sonofil in different quantities; not changing a lot of things to measurements though.
I want to stay with a closed box as much as possible, bass is not a goal here, but this may be where the problem lies. Opening with a tube might reduce inside reflexions ?
First graph is from a 5cm measure. This is where i am today. No windowing, no smoothing.
Second one is an older measure comparing between empty bowl (in purple), and stuffing with sonofil (blue).
Thanks for your ideas !
Attachments
Actually, that's not a bad measurement.
a) Any driver with a whizzer will measure something like that. They are not 'ideal' pistons.
b) A 'flat' speaker will show many ~5dB anomalies as you move the mic around a typical room.
This one at is balanced overall over the important bits (output 200-6,000Hz is roughly level).
Out of curiosity, did you / could you measure specs for the SB34 woofers? Are they new? I have some where the Qts measures a bit higher than advertised.
Hello,
Thanks for your feedback hollowboy.
I did not measure off axis yet because I'm still investigating in damping materials. Anyway, a tweeter will be added to this system (soft dome or radiator). I think about Scan-Speak Illuminator D3004/602010 for the size. Maybe R3004 but again, this will be for future.
My SB34 are brand new and I tried to measure them last week. I did my measurements with the added mass method in Limp. I give you my results and it should be taken with a grain of salt because the differences made me call into question my setup.
EDIT : attached are graphs of Fostex FE166En (5cm & 50cm away) and a PDF, my pair of SB Acoustics SB34NRX75-6.
Those SB34 speakers were reported to be watt-eaters by some french diyers. Needs a big amp to give them life, moreover if the enclosure is small & closed (< 100L).
Regards from France...
Thanks for your feedback hollowboy.
I did not measure off axis yet because I'm still investigating in damping materials. Anyway, a tweeter will be added to this system (soft dome or radiator). I think about Scan-Speak Illuminator D3004/602010 for the size. Maybe R3004 but again, this will be for future.
My SB34 are brand new and I tried to measure them last week. I did my measurements with the added mass method in Limp. I give you my results and it should be taken with a grain of salt because the differences made me call into question my setup.
EDIT : attached are graphs of Fostex FE166En (5cm & 50cm away) and a PDF, my pair of SB Acoustics SB34NRX75-6.
Those SB34 speakers were reported to be watt-eaters by some french diyers. Needs a big amp to give them life, moreover if the enclosure is small & closed (< 100L).
Regards from France...
Attachments
Last edited:
Here is an interesting and old version of the Ikea speaker.
http://www.diyaudio.com/forums/multi-way/289204-shperical-omni-directional-vintage-speakers.html
http://www.diyaudio.com/forums/multi-way/289204-shperical-omni-directional-vintage-speakers.html
The external measurment is 28 cm, internal is 26. The bottom is a little bit flat so count on 9 liters minus all other internal stuff (speaker, filters, etc.).
For the mid sized IKEA bowl, the measurments are 20/18 cm and the smallest has the measurment 12/10 cm. I have use them all.
Well, the sensitivity is 88 dB but the parameters are good for that speaker. This could end up being a great sub! Please keep the project posted (I'm interested in that speaker
).Some more pictures for the gallery (
I suppose you planning to flush mount the speaker into the bowl to get rid of the sharp edges. That will give you much better measurment (and sound) and that is the idea with a spheric external. I could measure (and hear) the difference on my bowls and it is worth the job.
My 20 cm IKEA speaker sketch
The vented speaker doesn't leave much volume left (1,8 liters out of totally 3) but with the Seas speaker it works well but the speaker is also made for a small vented enclosure. The 28 cm bowl is not enough for the the Scan-Speak 8545 I used. The nice thing why I did it anyway is o try the sperical shape and I really enjoy how much better it sounds when the edge reflexes are decreased.
The Tang Band might work well in a vented version, might be worth a try?
The vented speaker doesn't leave much volume left (1,8 liters out of totally 3) but with the Seas speaker it works well but the speaker is also made for a small vented enclosure. The 28 cm bowl is not enough for the the Scan-Speak 8545 I used. The nice thing why I did it anyway is o try the sperical shape and I really enjoy how much better it sounds when the edge reflexes are decreased.
The Tang Band might work well in a vented version, might be worth a try?
Attachments
Hello,
I don't plan to flush mount the fostex. It's face is a square shape and would ask for skills i don't have. A speaker with a round shape looks way better than the fostex in a bowl. A fact already reported.
For my project, 28cm bowls are used in closed setup.
I played with another speaker this week. That one is a 6.5" Davis paper bass/medium driver. My t/s measurements are ok for 8L, with linkwitz transform. This experiment gave me far better results, and makes me reconsider the use of a fullrange in this kind of box. With the Davis, cut-off starts at 100hz instead of 220hz with the fostex. Imho, 100-200 range is better suited to a 6.5" than a 12" driver like the sb34.
I can't use those Davis for this project.
So my question : what kind of driver could i use in 8l closed sphere, round face, to play 120-3kHz range with a budget < 200$ per speaker ?
Regards
Hmm that's 4" fullrange. I need a 6.5" driver (or something fitting a 145mm hole).
I found the Seas CA18RLY/RNX in a 2way study (Troels G). Will try to find something about this driver in a 3way system.
Thanks for your comments (i will run active crossover).