Hi guys, I'm building an audio note an-e/ snell type clone (using cheaper drivers) and I can see that from the pictures on the internet, the low pass filter for the bass driver is composed of a 1.7mH inductor and a 14uF capacitor. Now I know that the crossover frequency is around 3000Hz, but from some online crossover calculator the resulting values for 3000Hz and 8ohm woofer are 8.4mH and 3.3uF, very different from the values in the an-e type speakers.. Could you explain the difference please??? Thanks!!
Online crossover calculator are useless. They work on the assumption on a constant load and a flat FR, but no driver works that way. The crossover must be tailored to the specific drivers used. If the clone you are building is with different drivers than the original speaker, you may have to adapt the crossover, and also to change crossover point.
Have a read here (post #20 describes the methodology I use): http://www.diyaudio.com/forums/multi-way/189847-introduction-designing-crossovers-without-measurement.html
Ralf
Have a read here (post #20 describes the methodology I use): http://www.diyaudio.com/forums/multi-way/189847-introduction-designing-crossovers-without-measurement.html
Ralf
Much of the difference is likely to be because the response of the driver isn't constant, it rolls off on its own at the top end and since this acts like the low pass filter, adding another low pass filter means yours needs to split the difference.
As mentioned it also is probably not workng into exactly 8 ohms, and what it is working into differs with frequency so it needs to chase this.
As mentioned it also is probably not workng into exactly 8 ohms, and what it is working into differs with frequency so it needs to chase this.
Hi guys, thanks for your quick responses!! some datas for the woofer:
this is the link for the frequency response:
http://www.jaycar.com.au/medias/CW2...A2ZDllMTc3MmVmOGNlZjA3NDBmZmIzYjEyZWRlOGQzNTM
some specifications:Nominal impedance: 8 ohms
• Power nominal: 90WRMS
• Frequency response: 38Hz - 4.5kHz
• Sensitivity:89dB (1W@1m)
• Qms: 1.458
• Qes:0.426
• Qts: 0.33
• Fs: 28.14Hz
I was thinking of crossing it around 3kHZ with a vifa d19td-05-08
would you be able to give me a hand with the crossover please?
Thank you!!!!
this is the link for the frequency response:
http://www.jaycar.com.au/medias/CW2...A2ZDllMTc3MmVmOGNlZjA3NDBmZmIzYjEyZWRlOGQzNTM
some specifications:Nominal impedance: 8 ohms
• Power nominal: 90WRMS
• Frequency response: 38Hz - 4.5kHz
• Sensitivity:89dB (1W@1m)
• Qms: 1.458
• Qes:0.426
• Qts: 0.33
• Fs: 28.14Hz
I was thinking of crossing it around 3kHZ with a vifa d19td-05-08
would you be able to give me a hand with the crossover please?
Thank you!!!!
you should aim to cross lower, and using 3/4" dome tweeter is not wise.
look for bigger dome tweeter, such as SB29 or Dayton D28 so you can cross lower.
the 8" seemed got a pretty good response though, but after baffle step, you probably going to lose at least 10dB by looking at the response at 100hz, if you want reasonable bass out of it.
look for bigger dome tweeter, such as SB29 or Dayton D28 so you can cross lower.
the 8" seemed got a pretty good response though, but after baffle step, you probably going to lose at least 10dB by looking at the response at 100hz, if you want reasonable bass out of it.
Hi Allenb.. I'm not using the same drivers.. just some cheap drivers I had, I posted some data for the woofer above, it's a jaycar response 8" with treated paper cone and rubber surrounds. I was thinking of using the same crossover design as the audio note/snell speakers with first order with notch filter on the tweeter, and second order on the woofer, though I was not sure what values inductor/capacitor to use for the woofer, thanks!!!
tortello77, I suspect a Snell Clone is not the right thing to do here. Your drivers are not similar enough. The Snell style used a 4 ohm woofer and a lowish crossover. Fs notch filtering on a tweeter is not the easiest thing to do either.
The D19TD 3/4 inch polydome tweeter is good for about 3kHz crossover. It's quite bright at the top, as are most plastic tweeters. Your woofer looks quite well-behaved, though Le inductance is not specified.
The D19TD was used in the Monitor Audio R352 and smaller R252 with that simple 4 element filter. I prefer a higher order filter these days. But both suggestions use a 1.5mH bass coil.
The D19TD 3/4 inch polydome tweeter is good for about 3kHz crossover. It's quite bright at the top, as are most plastic tweeters. Your woofer looks quite well-behaved, though Le inductance is not specified.
The D19TD was used in the Monitor Audio R352 and smaller R252 with that simple 4 element filter. I prefer a higher order filter these days. But both suggestions use a 1.5mH bass coil.
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Is that the one with the inverted dust cap (ie you could eat cornflakes out of the cone)?
I bought a pair of those a few years back. After listening to them I only used them as subs for a short while. I don't know how well they'd go if crossed well but I wasn't inclined to spend the time on them.
They have a reasonably sized magnet but it's hard to see where the specs go, they probably get absorbed into ease of manufacture. I was going to use them in a tapped horn once but ended up dismantling them one day when I woke up and thought I'd build a field coil driver. But back to reality
Hi Allen, it is indeed.. I've never seen such a design, but I have to say, to my ears it doesn't sound too bad, especially for $40... so far I tried 3 crossovers:
-second order on the vifa (0.72mH;2.7uF) and first order on woofer (0.45mH)
- first order tweeter with notch filter and 6uF, sec order woofer (0.82mH;3.3uF)
-same as above for tweeter, and second order woofer (1.64mH; 15uF)
I found that with the first crossover there is a quite a bit of bass but midrange a bit muddy
with the second things clear up in the midrange with a small loss of bass, the third one reduces the midrange considerably and pushes the bass...
I think I like the first order tweeter with notch filter and l-pad(forgot to mentioned it), but it's the low pass filter that I'm still working on.. what do you think? thanks!!
-second order on the vifa (0.72mH;2.7uF) and first order on woofer (0.45mH)
- first order tweeter with notch filter and 6uF, sec order woofer (0.82mH;3.3uF)
-same as above for tweeter, and second order woofer (1.64mH; 15uF)
I found that with the first crossover there is a quite a bit of bass but midrange a bit muddy
with the second things clear up in the midrange with a small loss of bass, the third one reduces the midrange considerably and pushes the bass...
I think I like the first order tweeter with notch filter and l-pad(forgot to mentioned it), but it's the low pass filter that I'm still working on.. what do you think? thanks!!
I did try simming the Snell single cap and Fs notch style, 1700Hz here, and TBH it works in much the same way as a second order tweeter. But needs a biggish capacitor in the tweeter filter, and also a shallow slope on the woofer which might let through a lot of cone breakup.
Cone breakup between 3 and 7kHz is the big problem with 8" paper woofers. Sounds harsh to the ear. Best to get it down.
Here's your driver frequency responses. And the simple bass coil/2nd order filter and the second/third order one. You might want to put 15R across the tweeter to tame the rising top end a bit.
Cone breakup between 3 and 7kHz is the big problem with 8" paper woofers. Sounds harsh to the ear. Best to get it down.
Here's your driver frequency responses. And the simple bass coil/2nd order filter and the second/third order one. You might want to put 15R across the tweeter to tame the rising top end a bit.
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Steve - out of curiosity, what was the woofer in your example in post #9 above?
Agreed that a poor man's "Snell / AN-E clone" might not be as easy/affordable as one would hope - and don't forget that the version by AN had some "interesting" ideas regarding enclosure construction - in terms of material ("baltic" birch plywood only) and minimal bracing and stuffing.
Agreed that a poor man's "Snell / AN-E clone" might not be as easy/affordable as one would hope - and don't forget that the version by AN had some "interesting" ideas regarding enclosure construction - in terms of material ("baltic" birch plywood only) and minimal bracing and stuffing.
It's an ELAC 8" paper bass with a rubber dustcap and surround, and small diameter voicecoil. Qts must be about 0.4 since it works closed box or reflex.
Very nice simple unit with a lightweight cone, but really they don't make 'em like that any more. Robin Marshall designed the R252 and R352.
Robin Marshall: A Modicum of Genius | Stereophile.com
Good read, that.
Very nice simple unit with a lightweight cone, but really they don't make 'em like that any more. Robin Marshall designed the R252 and R352.
Robin Marshall: A Modicum of Genius | Stereophile.com
Good read, that.
Ps, sorry Steve, I don't understand.. are both graphs simulating the response of my drivers with a first order (coil) on the woofer and second order on the tweeter? sorry again, it just gets complicated for me..
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