So here's an update: I've been offered SCW 300 at the same price per pair as SBacoustic Bianco 15op350. Looking at the specs, SBa has significantly higher Xmax and Qts. Which one to go for? SCW300 was already recommended to me as a better match (previous post), for the reason I don't yet understand.
Goal is 40-45Hz. To go on two woofers per speaker with one amp or one woofer, that would be separately amplified to a higher gain and hence get much more power?
Thanks!
Goal is 40-45Hz. To go on two woofers per speaker with one amp or one woofer, that would be separately amplified to a higher gain and hence get much more power?
Thanks!
Hi Stefan,
For OB applications, you can´t simply judge a woofer by the given numbers. I use AJHorn simulations for OB bass predictions and found those simulations quite accurate at a number of occasions, matching reality quite closely.
I suggested the double SWR300 mainly for style, would be a perfect optical match with the SFR145... no, that´s not the whole story. The SWR300 is indeed not optimized for OB and will run out of Xmax sooner than others. It won´t go as deep as other drivers, too. So you´ll sacrifice a few dBs of headroom and a few Hz of deep bass. For what? For a potentially very accurate and precise upper bass/lower midrange presentation, and for a potentially good acoustic integration with the 145, assuming that voicecoil former and cone materials of both drivers will be a good match with each other. Istvan may be able to tell you more on this point...
The assumption is that both drivers will have a similar "tone" due to that.
The double SWR300 will have a slightly higher efficiency as the other solutions, and will roll off south of 50 Hz without room gain with a passive filter, a little bit more early with dsp (of course you can EQ that with a dsp, but it will quicly be overdone with a low Xmax driver...). Baffle size is an important factor here.
It will be an experiment. Please don´t do it if you feel you don´t want to take this risk, buy something proven (like this: Lautsprecher Shop | PowerDuo_HH | Lautsprecher Selbstbau or many other kits).
Active dsp crossovers and passive crossovers are different approaches. Both require quite some efforts and investment if you don´t want to compromise overall quality. A measurement system is a must if you want to do it by yourself, and software like Xsim helps a lot for passive XOs.
Sorry, I can´t tell you anything about angled drivers NOT at ear height, as I never built such devices. For a good 3-D presentation, I aim at:
- FR at ear height. Can be angled by a few degrees, the final FR should take the angle into account.
- FR baffle as small as possible.
- Back of the FR as open as possible.
- Avoid diffraction.
- XO phase tracking.
- High quality XO parts.
This is of course my personal opinion.
All the best
Mattes
For OB applications, you can´t simply judge a woofer by the given numbers. I use AJHorn simulations for OB bass predictions and found those simulations quite accurate at a number of occasions, matching reality quite closely.
I suggested the double SWR300 mainly for style, would be a perfect optical match with the SFR145... no, that´s not the whole story. The SWR300 is indeed not optimized for OB and will run out of Xmax sooner than others. It won´t go as deep as other drivers, too. So you´ll sacrifice a few dBs of headroom and a few Hz of deep bass. For what? For a potentially very accurate and precise upper bass/lower midrange presentation, and for a potentially good acoustic integration with the 145, assuming that voicecoil former and cone materials of both drivers will be a good match with each other. Istvan may be able to tell you more on this point...
The assumption is that both drivers will have a similar "tone" due to that.
The double SWR300 will have a slightly higher efficiency as the other solutions, and will roll off south of 50 Hz without room gain with a passive filter, a little bit more early with dsp (of course you can EQ that with a dsp, but it will quicly be overdone with a low Xmax driver...). Baffle size is an important factor here.
It will be an experiment. Please don´t do it if you feel you don´t want to take this risk, buy something proven (like this: Lautsprecher Shop | PowerDuo_HH | Lautsprecher Selbstbau or many other kits).
Active dsp crossovers and passive crossovers are different approaches. Both require quite some efforts and investment if you don´t want to compromise overall quality. A measurement system is a must if you want to do it by yourself, and software like Xsim helps a lot for passive XOs.
Sorry, I can´t tell you anything about angled drivers NOT at ear height, as I never built such devices. For a good 3-D presentation, I aim at:
- FR at ear height. Can be angled by a few degrees, the final FR should take the angle into account.
- FR baffle as small as possible.
- Back of the FR as open as possible.
- Avoid diffraction.
- XO phase tracking.
- High quality XO parts.
This is of course my personal opinion.
All the best
Mattes
Hi Mates, I listened to your advice.
I ordered one pair of FR (sfr145) and one pair of SCW300. Istvan said he could modify scw300 to a sensitivity of 98 db. I'll take that lower midrange performance and similar tune compromise. Might be a better idea to invest into a separate active subwoofer, instead of buying another set of drivers and/or another amplifier, active crossovers...
I ordered the alnico magnet versions of both drivers to cope with higher volumes, at least I was told it could help. Full range driver's coil is kapton and lower woofer's is aluminum, other materials should be the same.
I will try to come up with some different baffle design, I will eventually post it here.
Thank you for your help, it means a lot for a start.
Sincerely,
Stefan
I ordered one pair of FR (sfr145) and one pair of SCW300. Istvan said he could modify scw300 to a sensitivity of 98 db. I'll take that lower midrange performance and similar tune compromise. Might be a better idea to invest into a separate active subwoofer, instead of buying another set of drivers and/or another amplifier, active crossovers...
I ordered the alnico magnet versions of both drivers to cope with higher volumes, at least I was told it could help. Full range driver's coil is kapton and lower woofer's is aluminum, other materials should be the same.
I will try to come up with some different baffle design, I will eventually post it here.
Thank you for your help, it means a lot for a start.
Sincerely,
Stefan
Hi Stefan,
I´m afraid that a single SWR300 will run out of gas very soon... your original intend was to use 2 12"?
A single SWR300 will be very low in efficiency in an OB - around 84dB/2,8V/1m depending on baffle size.
Please forget about the 98dB... even if that value may be correct for upper middle/lower treble frequencies, it´s absolutely useless. Your 145 will be in duty long before that value is reached.
Bass area will not be on that level without using gigantic horns - mechanical resonators.
With an OB, the approach is to have the least mechanical amplification which is possible, in order to have a precise presentation. The main price to pay is efficiency, which goes down 6dB/oct towards lower frequencies, again depending on baffle size. The typical response of a driver with a relatively light cone and a relatively strong motor (hoping that Istvan´s TSP are correct) tends to rise with higher frequencies as well, so a lot has to be corrected to regain a balance.
These corrections will lower your final overall efficiency a lot. If you´re happy with an unbalanced speaker, you´ll get efficiency back.
Therefore I would suggest to use 2 12" for the bass... by the way, what amps are you using?
Of course, design decisions will also depend on how loud you like to hear - for me, 2 12" per channel is a minimum for the recreation of small jazz trios in a 26m² room...
Looking forward to see your results! Good luck and all the best!
Mattes
I´m afraid that a single SWR300 will run out of gas very soon... your original intend was to use 2 12"?
A single SWR300 will be very low in efficiency in an OB - around 84dB/2,8V/1m depending on baffle size.
Please forget about the 98dB... even if that value may be correct for upper middle/lower treble frequencies, it´s absolutely useless. Your 145 will be in duty long before that value is reached.
Bass area will not be on that level without using gigantic horns - mechanical resonators.
With an OB, the approach is to have the least mechanical amplification which is possible, in order to have a precise presentation. The main price to pay is efficiency, which goes down 6dB/oct towards lower frequencies, again depending on baffle size. The typical response of a driver with a relatively light cone and a relatively strong motor (hoping that Istvan´s TSP are correct) tends to rise with higher frequencies as well, so a lot has to be corrected to regain a balance.
These corrections will lower your final overall efficiency a lot. If you´re happy with an unbalanced speaker, you´ll get efficiency back.
Therefore I would suggest to use 2 12" for the bass... by the way, what amps are you using?
Of course, design decisions will also depend on how loud you like to hear - for me, 2 12" per channel is a minimum for the recreation of small jazz trios in a 26m² room...
Looking forward to see your results! Good luck and all the best!
Mattes
Curious, I used basta for open baffle simulation and got decent results - 65 Hz of bass extension (flat on axis) and something between 55-60 on -3 dB. Are those numbers real? Using one pair of SCW300 with stock specs (95db). I'm not sure how will he raise the efficiency, maybe he will just use a bigger magnet.
I'm using Naim power amp Nap100 (50w per channel) with Naim DAC V1. Recently I put a tube preamp in-between.
I don't intend to throw parties, but occasionally I know to turn it up a bit. Not too much. Room will be eventually bigger - 30-35 m2.
I'm using Naim power amp Nap100 (50w per channel) with Naim DAC V1. Recently I put a tube preamp in-between.
I don't intend to throw parties, but occasionally I know to turn it up a bit. Not too much. Room will be eventually bigger - 30-35 m2.
These SB 's are special made to use only in an OB . And perfectly useable above 150Hz with a max of 400Hz .
Ideal is 250Hz .
This is turning into a very expensive endeavour. I left the room gain checked, as per MJK instructions. Without it, I'm kinda limited to 70 Hz (using basta). And that's -3 dB. Not great, not terrible.
Is it possible to connect two scw300 (8 ohms each) and a full range (8ohms) to the same amp channel?
Nice looking project meanman!
Is it possible to connect two scw300 (8 ohms each) and a full range (8ohms) to the same amp channel?
Nice looking project meanman!
Hi Stefan,
The SB drivers are of course cheaper and even more "powerful" than the SWR 300, as already stated. Quantity vs. quality, maybe. Depending on SWR300 quality...
Of course you may connect 2 SWR300 in parallel and will end up with 4Ohms nominal and a decent bass reach/maximum level. It´s no problem to combine those 2 with the SFR145 with one amp.
Regarding bass reach, what is your baffle size?
All the best
Mattes
Without EQ? That´s quite something!
I had a 15" ~0.7 Qts woofer in a h-frame that fell off pretty quickly below 60Hz.
I´d guess you have a higher Qts-woofer and/or bigger woofer?
I like the design of the ML´s.
As an U-frame the resonance would be quite low in frequency though.
Realistically it must be shorter to support higher crossover frequencies.
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Hi,
A H-frame with the SWR300? I wouldn´t do that... wrong driver and concept.
For a H-frame you´ll need a big driver with large Xlin. Then a powerful amp (efficiency will be even lower than OB, due to air load). Then an active/dsp XO, to deal with the geometrical resonance. You´ll need a steep filter at 150Hz or 200Hz max, depending on size, and you´ll be in trouble meeting the SFR145.
All the best
Mattes
A H-frame with the SWR300? I wouldn´t do that... wrong driver and concept.
For a H-frame you´ll need a big driver with large Xlin. Then a powerful amp (efficiency will be even lower than OB, due to air load). Then an active/dsp XO, to deal with the geometrical resonance. You´ll need a steep filter at 150Hz or 200Hz max, depending on size, and you´ll be in trouble meeting the SFR145.
All the best
Mattes
Hi Mattes,
You are really giving me a hard time
I will stick with the open baffle then. As for the baffle width, it would be around 45-50 cm. I wouldn't go wider out of aesthetic reasons.
By the way, how much power is needed for 90-91ish dB speakers? Has anyone tried to run a full range driver with an 3-4w valve amp?
Thanks everyone for posting,
Stefan
You are really giving me a hard time
I will stick with the open baffle then. As for the baffle width, it would be around 45-50 cm. I wouldn't go wider out of aesthetic reasons.By the way, how much power is needed for 90-91ish dB speakers? Has anyone tried to run a full range driver with an 3-4w valve amp?
Thanks everyone for posting,
Stefan
Hi Stefan,
Please don´t get me wrong.. I´m just offering suggestions, you´re free to build whatever comes into your mind...
50 cm is fine if you add some amount of wings for the bass. Again, I would suggest something trapezoidal and slanted, small for the 145, larger for the double 300, wings in the bass area. It´s a compromise between an acoustically "good" OB and a built that with some efforts should be doable. Maybe not that easy, but you´re spending a lot of cash for the drivers and you will spend a lot more for XO parts later, so I think some baffle efforts are in line with your project.
The Naim is fine for a 90dB speaker. Many here have much more experience with valve amps than me... but in general, it will depend on your listening levels. 3 watts of tube power are fine for moderate levels. Before you try this: most tube amps have a highish output impedance and will thus interact with the speaker impedance. This needs to be understood in general before thinking of tube/speaker pairings.
All the best
Mattes
Please don´t get me wrong.. I´m just offering suggestions, you´re free to build whatever comes into your mind...
50 cm is fine if you add some amount of wings for the bass. Again, I would suggest something trapezoidal and slanted, small for the 145, larger for the double 300, wings in the bass area. It´s a compromise between an acoustically "good" OB and a built that with some efforts should be doable. Maybe not that easy, but you´re spending a lot of cash for the drivers and you will spend a lot more for XO parts later, so I think some baffle efforts are in line with your project.
The Naim is fine for a 90dB speaker. Many here have much more experience with valve amps than me... but in general, it will depend on your listening levels. 3 watts of tube power are fine for moderate levels. Before you try this: most tube amps have a highish output impedance and will thus interact with the speaker impedance. This needs to be understood in general before thinking of tube/speaker pairings.
All the best
Mattes
I know, it was a joke. As I have said, any advice is very welcome, and a moneysaver in some way.
This was an original design, simple baffle with no wings. Simulation is made using Basta with two SCW300 drivers and one full range SFR145. Crossovers in this example are at 120 Hz and 400 Hz, both second order. A very mild room gain is applied.
According to the sim, bass extension is around 40 Hz (-3dB) with a slight room gain and 40 Hz (-5 dB) with no room gain. What do you think about this results?
I am going to go with a simple baffle first and see the results. At least until I come up with something for trapezoidal/slanted shaped baffle.
Thanks for posting! This project is starting to take shape
This was an original design, simple baffle with no wings. Simulation is made using Basta with two SCW300 drivers and one full range SFR145. Crossovers in this example are at 120 Hz and 400 Hz, both second order. A very mild room gain is applied.
According to the sim, bass extension is around 40 Hz (-3dB) with a slight room gain and 40 Hz (-5 dB) with no room gain. What do you think about this results?
I am going to go with a simple baffle first and see the results. At least until I come up with something for trapezoidal/slanted shaped baffle.
Thanks for posting! This project is starting to take shape
