I'm planning on building a 2 way with a vifa25-35-06 aluminum tweeter and vifa M21WG-19 8". The driver is a little big, but I got em cheap so that's what I'm going to work with. My question is about importance of components in a 2nd order crossover. Is the inductor more important in the driver section than the tweeter? Same with the cap on the tweeter crossover.
I'm looking at copper foil's on PE, and was wondering if it would be a waste of time to buy foils for the tweeter side. Theta caps are out of the question at this point, but if anyone has some suggestions for caps which would be better then the Dayton or Solens that PE carries, I'd love to hear them.
I'm looking at copper foil's on PE, and was wondering if it would be a waste of time to buy foils for the tweeter side. Theta caps are out of the question at this point, but if anyone has some suggestions for caps which would be better then the Dayton or Solens that PE carries, I'd love to hear them.
My Story
In 2nd order crossover, the inductor is more important in the woofer, then mid, then tweeter. Not only because high current low frequency bass is more critical to be properly reproduced (in the mid it is related to image), but because the inductor is in series with the real sound generator (we pass the signal to speaker, not to ground).
Many says that DIY is the right way to get a quality system with limited budget. The fact is many DIYers build many systems with lots of money (it is just not spent at the same time, but what's the difference?) and end up with a poor system (relative to the money spent). The only acceptable excuse for that is that DIY is a hobby.
An important yet difficult lesson to learn in this hobby is to understand that a sound system comprises of components working together to generate sound. One component offers strengths that the other components in the audio chain cannot, and it's weakness is compensated by other components. It is also important to recognize a weak link in the audio chain. For example, will an upgrade on a single resistor will be better than an upgrade on the whole speaker? Will a resistor more expensive than a speaker?. For example, AC cord may be a weak link in a high class system so that an upgrade on the cable will improve the system but may be not so so if the sound system is of a lower class. But then if the price of a "good" cable is not expensive, upgrade is no sins.
As with the copper foil for the tweeter, what improvement do you expect? It is surely not the weak link because the driver themselves are cheap. And of course you're not building the speaker to match your Krell CDP and amplifier. And what can be offered by a "perfect" inductor? Non-oxidized, best insulatoion material between cables/foils, compact winding, low resistance/impedance, low loss, low Q, they are not critical for system of Vifa class, and IMO a waste of time in the tweeter side, especially if it is thought to be a magical upgrade from the cheapest inductor already on hand.
As with the caps, many think that it is about preference (well, not to me, especially if the price is different). I never used Jensen in series with the tweeter but many said they have a drawback (drawback means preference). I'm a fan of oilcap and paper capacitors. This type of capacitor have special strength that cannot be offered by other easy tweaks. If they offer a certain drawback, then put them on parallel with other capacitor type! I have used Siemens oilcap and Rifa paper capacitors in the tweeter line and I have never been dissapointed. Stocking expensive oil is fine with me because I can always reuse them (low voltage ones are cheap and rare). The value is not a problem because I can parallel them with MKP and achieve even better result.
In 2nd order crossover, the inductor is more important in the woofer, then mid, then tweeter. Not only because high current low frequency bass is more critical to be properly reproduced (in the mid it is related to image), but because the inductor is in series with the real sound generator (we pass the signal to speaker, not to ground).
Many says that DIY is the right way to get a quality system with limited budget. The fact is many DIYers build many systems with lots of money (it is just not spent at the same time, but what's the difference?) and end up with a poor system (relative to the money spent). The only acceptable excuse for that is that DIY is a hobby.
An important yet difficult lesson to learn in this hobby is to understand that a sound system comprises of components working together to generate sound. One component offers strengths that the other components in the audio chain cannot, and it's weakness is compensated by other components. It is also important to recognize a weak link in the audio chain. For example, will an upgrade on a single resistor will be better than an upgrade on the whole speaker? Will a resistor more expensive than a speaker?. For example, AC cord may be a weak link in a high class system so that an upgrade on the cable will improve the system but may be not so so if the sound system is of a lower class. But then if the price of a "good" cable is not expensive, upgrade is no sins.
As with the copper foil for the tweeter, what improvement do you expect? It is surely not the weak link because the driver themselves are cheap. And of course you're not building the speaker to match your Krell CDP and amplifier. And what can be offered by a "perfect" inductor? Non-oxidized, best insulatoion material between cables/foils, compact winding, low resistance/impedance, low loss, low Q, they are not critical for system of Vifa class, and IMO a waste of time in the tweeter side, especially if it is thought to be a magical upgrade from the cheapest inductor already on hand.
As with the caps, many think that it is about preference (well, not to me, especially if the price is different). I never used Jensen in series with the tweeter but many said they have a drawback (drawback means preference). I'm a fan of oilcap and paper capacitors. This type of capacitor have special strength that cannot be offered by other easy tweaks. If they offer a certain drawback, then put them on parallel with other capacitor type! I have used Siemens oilcap and Rifa paper capacitors in the tweeter line and I have never been dissapointed. Stocking expensive oil is fine with me because I can always reuse them (low voltage ones are cheap and rare). The value is not a problem because I can parallel them with MKP and achieve even better result.
thanks. last night I decided not to mess with copper foil. When I was looking at them, I was asking myself "Whats another $5?" Since this is my first real speaker build (except for 2 tempests), I'm just going to try to keep it simple, and not go all out with crossover parts since, like you said, my drivers aren't going to come alive with better parts.
I think I haven't seen a design using those drivers on the net. If you will design your own speaker and for the first time, I must say you are "brave" 😉
Foil inductors are very precision. In designing a speaker/crossover you are very likely to have to unwind inductors. Even if you use a software, you may want to tune it in by listening (if you can trust your ears). Once you get a correct crossover, changing inductors to a better ones may means changes to it's other properties (DCR etc). But make sure you don't underestimate the inductor for the woofer by using a ferrite (even worse a steel) core. The effect of this on the bass quality is the easiest to recognize.
Foil inductors are very precision. In designing a speaker/crossover you are very likely to have to unwind inductors. Even if you use a software, you may want to tune it in by listening (if you can trust your ears). Once you get a correct crossover, changing inductors to a better ones may means changes to it's other properties (DCR etc). But make sure you don't underestimate the inductor for the woofer by using a ferrite (even worse a steel) core. The effect of this on the bass quality is the easiest to recognize.
My experience
I also recently finished my own design with Scanspeak D2905/9300-00 and 21W8552.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=18401
1St I used very cheap NP electrolytic caps and ferite inductors. For tweeter i use 2nd order and for woofer I use 1st order with zobel. For a 1st design it sounds surprisingly well. I just dis not like the high frequencies. Very metal sounding and too sharp. I then found some (also cheap) polypropolene caps - used in flueorescent lights - and that already made quite a differance. Highs still litlle too "loud" but I am going to try a 1ohm in serie to soften it abit. I also found some empty fishingline reels to wind my own coils on. The reels dimensions are just right for a nice air core. I am sure this will be better then the ferrite core ones.
I also recently finished my own design with Scanspeak D2905/9300-00 and 21W8552.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=18401
1St I used very cheap NP electrolytic caps and ferite inductors. For tweeter i use 2nd order and for woofer I use 1st order with zobel. For a 1st design it sounds surprisingly well. I just dis not like the high frequencies. Very metal sounding and too sharp. I then found some (also cheap) polypropolene caps - used in flueorescent lights - and that already made quite a differance. Highs still litlle too "loud" but I am going to try a 1ohm in serie to soften it abit. I also found some empty fishingline reels to wind my own coils on. The reels dimensions are just right for a nice air core. I am sure this will be better then the ferrite core ones.
Hi Baz, I love the links you provide on that thread. I also like the sound of that Monitor Audio, so if the Scan-Speak is better, it must be better, isn't it? 😀
Quite surprising that for such a good tweeter you got a terrible highs. Even with cheaper tweeters, I have always used better capacitor in series. Many said that cheaper tweeter plus good oil or paper cap is better than expensive tweeter plus bad capacitor. I have always assummed that the capacitor price is an integral part of the tweeter price. Cheap tweeters are indeed harsh and fatiguing, but with oil/paper the highs become smoother and airy.
I don't know if you already have experience with the fishing line. IMO you will get into trouble with doing that (well, that's mine). Even with special winding tool (manual), the winding is too loose and dificult to form into a neat lamination. Look, even now Jeff can see another fellow underestimate the crossover components of his good drivers 😀 (But I believe you will upgrade the components once you get the crossover circuit correct, won't you Baz?)
When trying to get the crossover correct usually I don't pay attention to the quality of highs lows etc. Rather, I pay more attention to the sonic and details of instrument around the crossover frequency, the soundstage, and the phase matching (?) between tweeter and woofer. Once I got those correct and the sound is not okay (harsh etc), I think that's the price I have to pay for a cheap driver 😀
Quite surprising that for such a good tweeter you got a terrible highs. Even with cheaper tweeters, I have always used better capacitor in series. Many said that cheaper tweeter plus good oil or paper cap is better than expensive tweeter plus bad capacitor. I have always assummed that the capacitor price is an integral part of the tweeter price. Cheap tweeters are indeed harsh and fatiguing, but with oil/paper the highs become smoother and airy.
I don't know if you already have experience with the fishing line. IMO you will get into trouble with doing that (well, that's mine). Even with special winding tool (manual), the winding is too loose and dificult to form into a neat lamination. Look, even now Jeff can see another fellow underestimate the crossover components of his good drivers 😀 (But I believe you will upgrade the components once you get the crossover circuit correct, won't you Baz?)
When trying to get the crossover correct usually I don't pay attention to the quality of highs lows etc. Rather, I pay more attention to the sonic and details of instrument around the crossover frequency, the soundstage, and the phase matching (?) between tweeter and woofer. Once I got those correct and the sound is not okay (harsh etc), I think that's the price I have to pay for a cheap driver 😀
I think that is not your name 
Sorry then. My fingers and mouth are always faster than my head - Status
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