SB Acoustics SB20FRPC30-8 (8" Fullrange Cheap Monster II)

you mean something like this?
View attachment 1110005
Yes, but I think I will have a one part baffle, will see.

Out of interest, how do you plan to wire/crossover the Biancos with the FR drivers?
Very simple (for the start) with an inductor (low pass) for the woofer and a capacitor (high pass) plus attenuation for the FR.
I will keep you informed... but today I'll have a surgery, so first things first :Popworm:
 
I am thinking about building a pair in wide & shallow boxes similar to Heco Direkt Einklang. 45 liters volume and about 400mm vide by 800 mm high and 200 mm deep. Anyone tried this? Bass reflex this time no convoluted transmission line or Voigt pipe.

Anyone that tried passive filters to correct frequency response?
 
Another update - I tilted the speakers back slightly using a thick book under the front of each speaker - this helped a bit with depth and perceived bass response.

I then decided to ‘treat’ the front wall by placing a 3 inch thick seat cushion (from our garden furniture that I built last year) on the front wall behind the speakers. The has made a very big difference:
1) What I perceive as a ‘cupiness’ has disappeared completely.
2) The sound stage moved backwards but also gained height.
3) bass response is considerably more full, almost to the point where I wonder if a larger supporting woofer is actually needed (bear in mind the room is small and my amp has tone controls!).
4) The sound is considerably more relaxed, intelligible and realistic and I can listen more comfortably at higher volumes.

I am guessing but I assume that the ‘room treatment’ is attenuating and diffusing the back wave which cleans the sound up in the mid and high ranges but also helps reduce back wave cancellation in the bass? Whatever is happening the sound is more to my liking than it was before.
 
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Another update - I tilted the speakers back slightly using a thick book under the front of each speaker - this helped a bit with depth and perceived bass response.

I then decided to ‘treat’ the front wall by placing a 3 inch thick seat cushion (from our garden furniture that I built last year) on the front wall behind the speakers. The has made a very big difference:
1) What I perceive as a ‘cupiness’ has disappeared completely.
2) The sound stage moved backwards but also gained height.
3) bass response is considerably more full, almost to the point where I wonder if a larger supporting woofer is actually needed (bear in mind the room is small and my amp has tone controls!).
4) The sound is considerably more relaxed, intelligible and realistic and I can listen more comfortably at higher volumes.

I am guessing but I assume that the ‘room treatment’ is attenuating and diffusing the back wave which cleans the sound up in the mid and high ranges but also helps reduce back wave cancellation in the bass? Whatever is happening the sound is more to my liking than it was before.
nice you can put a resistor in series or use a single ended amp , the tube ones can rise the qts 30% by Qes...
At what high use ? my 8" with 0.7 Qts is at 65cm to floor, a bit low but helps on bass
 
Last edited:
Another update - I tilted the speakers back slightly using a thick book under the front of each speaker - this helped a bit with depth and perceived bass response.

I then decided to ‘treat’ the front wall by placing a 3 inch thick seat cushion (from our garden furniture that I built last year) on the front wall behind the speakers. The has made a very big difference:
1) What I perceive as a ‘cupiness’ has disappeared completely.
2) The sound stage moved backwards but also gained height.
3) bass response is considerably more full, almost to the point where I wonder if a larger supporting woofer is actually needed (bear in mind the room is small and my amp has tone controls!).
4) The sound is considerably more relaxed, intelligible and realistic and I can listen more comfortably at higher volumes.

I am guessing but I assume that the ‘room treatment’ is attenuating and diffusing the back wave which cleans the sound up in the mid and high ranges but also helps reduce back wave cancellation in the bass? Whatever is happening the sound is more to my liking than it was before.
I can suggest to buld a Nelson F3/2 current source amp for fullrange
https://www.firstwatt.com/pdf/art_cs_amps.pdf
 
Well, well, well...
I think, this speaker, in combination with the 12" Bianco, has huge potencial in an OB system.
After three foam baffle trials including the tweaking the xo and searching for the right position/distance of the driver I ended up to use an "old" baffle with a new cutout for the FR.
Tweaking/tuning only via my ears, later I of course will make the measurements too.
Oh, yes, I almost forgot it, I like VERY much what I hear, altough there is some more work to be done. And of course a new baffle will follow too. Until then I let the drivers burn in and enjoy the music. I'll keep you informed🙂

PSX_20221118_204506.jpg


PSX_20221118_204559.jpg
 
Well, well, well...
I think, this speaker, in combination with the 12" Bianco, has huge potencial in an OB system.
After three foam baffle trials including the tweaking the xo and searching for the right position/distance of the driver I ended up to use an "old" baffle with a new cutout for the FR.
Tweaking/tuning only via my ears, later I of course will make the measurements too.
Oh, yes, I almost forgot it, I like VERY much what I hear, altough there is some more work to be done. And of course a new baffle will follow too. Until then I let the drivers burn in and enjoy the music. I'll keep you informed🙂

View attachment 1110950

View attachment 1110951
Looks great. Do you mind me asking what the specs are for your crossover please?

I see you use IKEA chopping boards too! I bought a job lot earlier this year - well worth the money!
 
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nice you can put a resistor in series or use a single ended amp , the tube ones can rise the qts 30% by Qes...
At what high use ? my 8" with 0.7 Qts is at 65cm to floor, a bit low but helps on bass
Thanks for the info - very interesting. I have just finished ‘bracing’ the baffles with a frame and oiled the wood so will assemble everything, take pictures and listen tomorrow to what difference (if any) a more rigid baffle structure makes.