Some suppliers are unwilling to send stuff to SA, unless it's by courier. That's the reality that we live in here. I find it amusing when someone in a first world country (e.g. USA) complain about shipping, whether it's cost or the time it takes. They have no idea what's it like for us. Only the die-hards here get anything done when stuff from abroad is needed.
Thanks X, will try that. It's all very new to me, being my first DIY hi-fi project: B1, ACA's and speakers. But I'm already smiling from ear to ear. The sound from those K's is amazing! And I still haven't done the ACA's yet...
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Hi Skylar,
I am sure your dual 3FE25-16’s in a Karlsonator must be something to hear. Having 97dB/W sensitivity in a full range is not something most people ever get to hear apart from a Lowther or high end Feastrex etc. And to have it with some decent bass and soundstage of a fairly compact K transmission line is quite something else. So glad you are enjoying them.
X
I am sure your dual 3FE25-16’s in a Karlsonator must be something to hear. Having 97dB/W sensitivity in a full range is not something most people ever get to hear apart from a Lowther or high end Feastrex etc. And to have it with some decent bass and soundstage of a fairly compact K transmission line is quite something else. So glad you are enjoying them.
X
Today I wound a 0.9mH inductor and connected a 5 Ohm resistor in parallel (2x 10 Ohms paralled). This circuit was connected in series on the + line of one Karlsonator speaker to my TDA7297 amp and it damaged the channel on the amp instantly.
Now the channel just hums. Any idea why? I've read that these chip amps are delicate, but this is ridiculous.
Now the channel just hums. Any idea why? I've read that these chip amps are delicate, but this is ridiculous.
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The BSC shouldn’t hurt your amp. I use a similar one on my TDA7297 and it’s fine. I think the TDA7297 is even protected against short circuits. So an inductor and a resistor in parallel should present a softer load than a plain piece of wire.
Maybe you just have an amp that went bad. Do you have another amp to try? There’s nothing inherently dangerous about that circuit to an amp, unless it caused an oscillation. Try adding a 10ohm in series with whole thing to absorb any potential oscillation the next time you try it as a safety precaution. Then remove the 10ohm series.
Maybe you just have an amp that went bad. Do you have another amp to try? There’s nothing inherently dangerous about that circuit to an amp, unless it caused an oscillation. Try adding a 10ohm in series with whole thing to absorb any potential oscillation the next time you try it as a safety precaution. Then remove the 10ohm series.
I'm happy to say that there is nothing wrong with the TDA amp. An interconnect was unplugged and I didn't notice it in the limited time I had last night. Sorry for the scare. 
The baffle step also works very well. Too well for my liking, actually. The sound from the Karlsonator is quite a bit darker. It also lost a lot of sensitivity. Will the 0.9mH inductor be ok if I play around with the resistor? If I settle on say, 1.8Ohm, should I use a different inductance or can I keep it?
Christo
PS Image below of 0.9mH inductor wound on a bobbin normally used for PTFE plumbing tape.
The baffle step also works very well. Too well for my liking, actually. The sound from the Karlsonator is quite a bit darker. It also lost a lot of sensitivity. Will the 0.9mH inductor be ok if I play around with the resistor? If I settle on say, 1.8Ohm, should I use a different inductance or can I keep it?
Christo
PS Image below of 0.9mH inductor wound on a bobbin normally used for PTFE plumbing tape.
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Hi Skylar,
Good news then. The inductor value sets the baffle step frequency which, at 0.9mH is just about right for an circa 1kHz shelf frequency. The resistor value affects how much attenuation of the high frequency shelf above 1kHz (a fairly flat cut). Try lower values of R and this can be really fine tuned by adding bigger resistors in parallel to effect fractional ohm changes if you don’t have the perfect 1.4ohm resistor for example.
Good luck!
Btw, you can bring the highs back up by paralleling a film cap with the inductor - about 1uF or 2.2uF should brighten things up above 8k and leave the mids alone. Also, adjust to taste.
Good news then. The inductor value sets the baffle step frequency which, at 0.9mH is just about right for an circa 1kHz shelf frequency. The resistor value affects how much attenuation of the high frequency shelf above 1kHz (a fairly flat cut). Try lower values of R and this can be really fine tuned by adding bigger resistors in parallel to effect fractional ohm changes if you don’t have the perfect 1.4ohm resistor for example.
Good luck!
Btw, you can bring the highs back up by paralleling a film cap with the inductor - about 1uF or 2.2uF should brighten things up above 8k and leave the mids alone. Also, adjust to taste.
Thanks X, that is good information. I've been wondering about all that.
I'm down to 3.3Ohm and it sounds better, but still too dark. Will try combinations of resistors. It's easy enough to do. But I wonder if one can use a pot to determine the ideal R.
So, if the inductor value is ok, what happened to the sensitivity? I have to turn that channel quite a bit higher now.
I'm down to 3.3Ohm and it sounds better, but still too dark. Will try combinations of resistors. It's easy enough to do. But I wonder if one can use a pot to determine the ideal R.
So, if the inductor value is ok, what happened to the sensitivity? I have to turn that channel quite a bit higher now.
What is the DC resistance (DCR) of your choke? If more than 0.5ohm it will cause some reduction overall. But BSC is in general, a sensitivity killer (mids and highs get a cut in order to be balanced with the bass, which can be up to -6dB weaker.) The Karlaonator is in general very efficient at producing bass. Sounds like you may only need about 1.5ohms of BSC.
I normally don’t use any baffle step on a Karlsonator so probably very minor values needed.
I normally don’t use any baffle step on a Karlsonator so probably very minor values needed.
DC resistance of the inductor is 1.36Ohm and I've settled for a 1 Ohm resistor. It's really sounds a lot better than without the BSC. No more sensitive ears even at high volume. I still need to make a BSC for the other channel, but I'm confident that I'll be very happy. And the sensitivity is better with the lower value resistor. It's not a bad trade-off for the sound quality I can now enjoy.
I suspect that I only needed the BSC because I'm using dual 3FE25-16's. I've heard the sound of Single TC9FD 0.4X K's and it didn't have the same problem.
PS I've just realized that it's possible to wind 0.9mH chokes with lower resistance by using thicker wire. Hmm, that may be the way to get back some sensitivity!
I suspect that I only needed the BSC because I'm using dual 3FE25-16's. I've heard the sound of Single TC9FD 0.4X K's and it didn't have the same problem.
PS I've just realized that it's possible to wind 0.9mH chokes with lower resistance by using thicker wire. Hmm, that may be the way to get back some sensitivity!
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Yes, and it is ok to wind thick 18 ga wire on a ferrite core or toroid. Will only take about 15 turns probably around a 1in dia toroidal choke. The ferrite will substantially reduce the length of wire. Actually, if using ferrite, your wire length is reduced so DCR may go down quite a bit. You must have an LCR meter? You don't have to worry about saturation distortion too much as the currents are relatively low and it's all AC.
One other trick to try is to make the speaker a 1.5 way by making the driver on top mostly low passed below 1kHz. You can do this with a 2nd order passive XO on the top driver to pass stuff below 1khz. But what you did with BSC seems to be working.
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Ah, more great suggestions - thanks X. I have some ferrite rods, but will see if I can get such big torroids.
Will run a few calcs on inductor programs and see what's possible. I don't have an LCR meter or even an oscilloscope. I'm bargaining on the programs being accurate enough. I am however, able to measure resistance very accurately with the Kelvin 4-wire method.
I have lots of 17 gauge wire due to my other hobby overlapping with this new one.
Will run a few calcs on inductor programs and see what's possible. I don't have an LCR meter or even an oscilloscope. I'm bargaining on the programs being accurate enough. I am however, able to measure resistance very accurately with the Kelvin 4-wire method.
I have lots of 17 gauge wire due to my other hobby overlapping with this new one.
Ferrite rods work well too. I actually use these in my small full range speakers. Truth be told, you don’t need expensive air cores for a low power BSC.
25pcs 1mH 0.5A Power Inductor 9x12mm Inductor choke Radial Lead | eBay
Maybe 10 turns around these will be several mH. You need an LCR meter though. I use my DATS speaker impedance and TS meter to measure LCR.
10pcs Green Iron 25mm Outside Diameter Power Ferrite Toroid Core #F0058 CY | eBay
25pcs 1mH 0.5A Power Inductor 9x12mm Inductor choke Radial Lead | eBay
Maybe 10 turns around these will be several mH. You need an LCR meter though. I use my DATS speaker impedance and TS meter to measure LCR.
10pcs Green Iron 25mm Outside Diameter Power Ferrite Toroid Core #F0058 CY | eBay
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While ferrite toroids were available, it proved impractical to purchase from our local Radio Shack due to the items costing a lot less than shipping would have been. Therefore I opted to make air core chokes with 1.15mm (17 gauge) wire I already had. I used 1 Ohm resistors to complete the baffle steps.
The addition of BSC's completely transformed the dual 3FE25-16Ohm 0.53X Karlsonators. The sound is now much more 'mature' and extra bass appeared out of nowhere. I'm so chuffed with them now, I can't stop listening, and without any sign of ear fatigue. The painful ear syndrome is gone and I'm enjoying room filling sweet sound with plenty bass. Before I added the BSC's, a sub woofer was used to augment bass, but it now stays switched off.
Pictured below is the final version of the 0.9mH choke that I made on a 50mm former. I used this Air Core Inductor Calculator to design it: https://m0ukd.com/calculators/air-cored-inductor-calculator
The addition of BSC's completely transformed the dual 3FE25-16Ohm 0.53X Karlsonators. The sound is now much more 'mature' and extra bass appeared out of nowhere. I'm so chuffed with them now, I can't stop listening, and without any sign of ear fatigue. The painful ear syndrome is gone and I'm enjoying room filling sweet sound with plenty bass. Before I added the BSC's, a sub woofer was used to augment bass, but it now stays switched off.
Pictured below is the final version of the 0.9mH choke that I made on a 50mm former. I used this Air Core Inductor Calculator to design it: https://m0ukd.com/calculators/air-cored-inductor-calculator
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That’s a very pro-looking air core. Jantzen couldn’t make a better one and it probably saved you a bundle.
I just saved a bundle by pulling a 67mH 1.9DCR choke from a dead microwave oven to use in a SE Class A MoFo amp. Those things are heavy!
http://www.diyaudio.com/forums/pass-labs/313649-build-mofo-32.html#post5263537
The choke is reactive so allows an output voltage swing greater than the Vcc. Kind of cool, extra power for free.
You may recognize a Juma Easy Peasy cap multiplier on the left there.
I’m driving an XKi with W5-2143 (with BSC) and it sounds very good.
Here is FFT for 2.83vrms into 8ohms.
I just saved a bundle by pulling a 67mH 1.9DCR choke from a dead microwave oven to use in a SE Class A MoFo amp. Those things are heavy!
http://www.diyaudio.com/forums/pass-labs/313649-build-mofo-32.html#post5263537
The choke is reactive so allows an output voltage swing greater than the Vcc. Kind of cool, extra power for free.
You may recognize a Juma Easy Peasy cap multiplier on the left there.
I’m driving an XKi with W5-2143 (with BSC) and it sounds very good.
Here is FFT for 2.83vrms into 8ohms.
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Hey X,
Just to let you know i got around to building the 0.4x Karlsons this weekend and am currently breaking them in. I used the Faital 3FE25s since they would be running off a DIY F6 and i was looking to try something with higher efficiency than my current Dynaudio Excite X16s.
My impressions so far:
Midrange and treble sounds fantastic, vocals especially are crisp and beautifully rendered. Much more clarity in the midrange in general than the Dyns (though they have a certain sweetness to vocals that i am a big fan of). They present a nice and sharp soundstage also. I have no idea how this will change with breakin but time will tell.
As for the bass, there is markedly less than the Dyns (but they are a 6.5" woofer in a 25-30L box, and are helped alot by being relatively close to a wall), so for certain types of music i still prefer the Dyns for the fullness they deliver. I wonder if the bass level changes with breakin also?
That said, for 12-ish euros for the driver + cheapo foam core i am amazed what they deliver! For the building experience alone i will recommend this to anyone curious about trying a DIY speaker (this is my first), and am definitely interested in trying more of this kind. I dont have access to woodworking facilities so all building happens at the kitchen table (we live in a small flat), so being able to do something like this in a weekend is fantastic...
In the art supplies store i noticed they had 1cm thick foam core also. I wonder, has anyone tried this? It would likely be more rigid, which i guess would be an advantage?
Another question, i am intrigued by the Onken designs of Planet-10, and i was wondering if anyone has tried something like a foam core Onken? Is there are good high efficiency fullranger Onken design anywhere? I am happy to pay for planet-10 designs but am a bit confused as to which drivers are supported...
Added a picture from last night, sorry about the crappy image quality, but at least it doesnt show off the dodgy hot glue work so much
Best,
Silas
Just to let you know i got around to building the 0.4x Karlsons this weekend and am currently breaking them in. I used the Faital 3FE25s since they would be running off a DIY F6 and i was looking to try something with higher efficiency than my current Dynaudio Excite X16s.
My impressions so far:
Midrange and treble sounds fantastic, vocals especially are crisp and beautifully rendered. Much more clarity in the midrange in general than the Dyns (though they have a certain sweetness to vocals that i am a big fan of). They present a nice and sharp soundstage also. I have no idea how this will change with breakin but time will tell.
As for the bass, there is markedly less than the Dyns (but they are a 6.5" woofer in a 25-30L box, and are helped alot by being relatively close to a wall), so for certain types of music i still prefer the Dyns for the fullness they deliver. I wonder if the bass level changes with breakin also?
That said, for 12-ish euros for the driver + cheapo foam core i am amazed what they deliver! For the building experience alone i will recommend this to anyone curious about trying a DIY speaker (this is my first), and am definitely interested in trying more of this kind. I dont have access to woodworking facilities so all building happens at the kitchen table (we live in a small flat), so being able to do something like this in a weekend is fantastic...
In the art supplies store i noticed they had 1cm thick foam core also. I wonder, has anyone tried this? It would likely be more rigid, which i guess would be an advantage?
Another question, i am intrigued by the Onken designs of Planet-10, and i was wondering if anyone has tried something like a foam core Onken? Is there are good high efficiency fullranger Onken design anywhere? I am happy to pay for planet-10 designs but am a bit confused as to which drivers are supported...
Added a picture from last night, sorry about the crappy image quality, but at least it doesnt show off the dodgy hot glue work so much
An externally hosted image should be here but it was not working when we last tested it.
Best,
Silas
Hi Silas
Your findings about fantastic midrange and treble, but with a lack of good bass sounds a lot like what I experienced with my Dual 3FE25 in 0.53 Karlsonator build. Btw, the bass level didn't change with break-in.
I'm pretty sure X is going to suggest a baffle step, but I'm going to beat him to it.
If you look a few posts back in this thread, you'll see the inductors I made for my speakers with FaitalPro drivers, and you'll also read how it changed the characteristics completely. These boxes ooze bass now. I used 1 Ohm resistors with my home made 0.9mH inductors, but want to give 1.8 Ohm resistors a try soon.
Christo
Your findings about fantastic midrange and treble, but with a lack of good bass sounds a lot like what I experienced with my Dual 3FE25 in 0.53 Karlsonator build. Btw, the bass level didn't change with break-in.
I'm pretty sure X is going to suggest a baffle step, but I'm going to beat him to it.
If you look a few posts back in this thread, you'll see the inductors I made for my speakers with FaitalPro drivers, and you'll also read how it changed the characteristics completely. These boxes ooze bass now. I used 1 Ohm resistors with my home made 0.9mH inductors, but want to give 1.8 Ohm resistors a try soon.
Christo