I didn't have any bigger caps, have to buy some - so no whizzer cutting🙂
I simulated it with 22 uF.
Yes, I don't use wings on the FR, only for the woofer. "Claustrophobic"... yes, it applies.
Two 55 litres sealed boxes for 4 pieces of SB20FRPC in progress....I will try them without any filtering first, with near wall or corner placement these should do real 98 dBWm...I want to hear what can they do in corner and close to the floor. If I will not like sound completely, plan is 2.5 way with some large tweet in waveguide, probably monacor DT300...
I will do and post measurements, also make record of sound with pro music microphone...
I will do and post measurements, also make record of sound with pro music microphone...
Thanks for sharimg your experiences.
Starting with Ikea:
yes - it's a nice board; but my CD on first floor sounds better on a 10mm plywood
But i like this peace of bamboo also as a front für diy-speakers ( router and saw gives it the right angles )
This is a 35liter BR-box - the SB-8" just installed (the one in my avatar). Although empowering the motorsystem by adding an magnet - it's to small !! ( it was that, what i had ready to play ). A better volume with magnet would be 45-50liters.
I'm really impressed on this driver - playing without any correction. Had the Seas F22RCZ before for a longer tim - i like this one better. more controlled bass ( the Seas was driven in this enclosure to ), excellent mids and very fine highs.
Question to everyone, who drives this speaker: how long does ist take for burn in ? After a few day, it isn't ready, I think....
What is planned ? a MLTL very close to one mentioned above ( about 650cm² and 0,9m long, 3"-tube)- thanks für sharing - seems to me to be an the right way ....
Starting with Ikea:
yes - it's a nice board; but my CD on first floor sounds better on a 10mm plywood
But i like this peace of bamboo also as a front für diy-speakers ( router and saw gives it the right angles )
This is a 35liter BR-box - the SB-8" just installed (the one in my avatar). Although empowering the motorsystem by adding an magnet - it's to small !! ( it was that, what i had ready to play ). A better volume with magnet would be 45-50liters.
I'm really impressed on this driver - playing without any correction. Had the Seas F22RCZ before for a longer tim - i like this one better. more controlled bass ( the Seas was driven in this enclosure to ), excellent mids and very fine highs.
Question to everyone, who drives this speaker: how long does ist take for burn in ? After a few day, it isn't ready, I think....
What is planned ? a MLTL very close to one mentioned above ( about 650cm² and 0,9m long, 3"-tube)- thanks für sharing - seems to me to be an the right way ....
Some people have mentioned that putting a resistor in series with a driver will raise the Qts.
I see here that a 2 ohm resistor raises the Qts to 0.59 for this SB-8 driver and 3 ohm raises it to about 0.65
Is that a bad idea to do it? ie, Lost efficiency (and maybe some "magic"?) in exchange for what?
@Plott maybe it's another thing you can try - it's a cheap and reversible experiment. 😉
Intuition tells me this is a bad idea for the FR driver but maybe could be helpful on a helper/bass driver.
I see here that a 2 ohm resistor raises the Qts to 0.59 for this SB-8 driver and 3 ohm raises it to about 0.65
Is that a bad idea to do it? ie, Lost efficiency (and maybe some "magic"?) in exchange for what?
@Plott maybe it's another thing you can try - it's a cheap and reversible experiment. 😉
Intuition tells me this is a bad idea for the FR driver but maybe could be helpful on a helper/bass driver.
Love the look of that. The warm color and visually interesting and functional beveled edge.
Doing this on a woofer decreases the SPL and my goal was to make a high sensitivity thingie 🙂 But I´m offen to this and I´m still learning, so I´ll try it, just for fun.
Asolutely right, now I tried 4.7 uF and it's better so. 3.3 is next.
does the resistor trick improve the performance of a driver in an OB in some way?
This is 4.7= 8500 hz crossover vs your previous 4000 so it makes sense this would sound better as it's acting more as a super-tweeter leaving more of the FR driver response untouched. 3.3 would be 12000 hz. Sorry, you prob already know this ;-)
Now I have to find the tonal balance, so I will go back to 5.1 ohms attenuation for the FR instead of 3.5, and will check if an attenuation is required for the tweeter.
I have a pair of SB20 PFCR30-8.....the paper woofer. Confusingly close 'name' to the FR unit talked about here. I assume this is the same driver but without the whizzer. I am thinking of a dust cap ectomy and add a coaxial tweeter...?!
No it's not the same without whizzer, it's a completely different driver design. eg., even without the whizzer it has a heavier cone moving mass.
Lot of other driver specs are different, eg. lower Fs. This is a bass/midbass driver. I might make for a decent addition to the FR-8 in this thread to improve/augment the bass response, though one could argue a larger driver would prob work better for that.
Sure, you could mate it with a tweeter like this for a simple 2-way in a small BR cabinet.
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Sure. Floor/room interaction is more with OBs but dunno how predictable it is. I never did detailed study or measurement of this. Why?Is it possible that tilting of an OB speaker creates more and more clear bass?
Just because I tilted my speakers now and noticed the above effect. I don't know if it's just me or fact.
What I tilted mine back (about 10 - 15 degrees from vertical) the effect was enhanced bass presence and a seemingly smoother midrange from the LP. Whether it is the woofer coupling with the floor or a phase/alignment thing I don’t know but it worked.