So, we have C2 = 6.8 uF; L2 = 0.42 mH; L1 = 2.85 mH
Putting those values into a simple Butterworth crossover simulator gives a crossover frequency of 2,750 Hz, so the measured inductor values would appear to be reasonable.
P.S. Standard wire wound resistors have inductance, but at audio frequencies its effect is so vanishingly small as not to require accounting for. However you can obtain resistors with non-inductive characteristics if you so desire.
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@Galu, yes, pretty good!
I was simming this in a rough sort of way:
I still like the idea of a shunt LCR or even just shunt 7.5R and 4.7uF as impedance correction. I tried the Tannoy circuit (dotted) and the one with some extra.
Shunts on the bass surprise by lifting the midrange.
Useful bits at Wilmslow Audio:
https://wilmslowaudio.co.uk/crossovers/crossover-pcb
I have used these PC boards and they make things easy.
Coils:
https://wilmslowaudio.co.uk/inductors
You can unwind them to lower values. Inductance is the square of the number of turns.
Harbeth use ferrites exclusively, and they aren't shabby!
Capacitors:
https://wilmslowaudio.co.uk/monacor-mkp-polypropylene-capacitors
Why pay more?
Resistors? I usually use 10W wirewound aka ceramic. Wire is wire IMO.
Best, Steve.
I was simming this in a rough sort of way:
I still like the idea of a shunt LCR or even just shunt 7.5R and 4.7uF as impedance correction. I tried the Tannoy circuit (dotted) and the one with some extra.
Shunts on the bass surprise by lifting the midrange.
Useful bits at Wilmslow Audio:
https://wilmslowaudio.co.uk/crossovers/crossover-pcb
I have used these PC boards and they make things easy.
Coils:
https://wilmslowaudio.co.uk/inductors
You can unwind them to lower values. Inductance is the square of the number of turns.
Harbeth use ferrites exclusively, and they aren't shabby!
Capacitors:
https://wilmslowaudio.co.uk/monacor-mkp-polypropylene-capacitors
Why pay more?
Resistors? I usually use 10W wirewound aka ceramic. Wire is wire IMO.
Best, Steve.
Bringing all the inductor specs together for ease of reference:
Air core: 0.42 mH; 1.4 ohm; 0.3 mm wire
Iron core: 2.85 mH; 0.7 ohm; 0.7 mm wire.
Am I correct in assuming that the person you tasked with measuring the inductance also measured the DC resistance?
Air core: 0.42 mH; 1.4 ohm; 0.3 mm wire
Iron core: 2.85 mH; 0.7 ohm; 0.7 mm wire.
Am I correct in assuming that the person you tasked with measuring the inductance also measured the DC resistance?
I have already done it in the previous post. The dotted lines!
You can do it for yourself too:
https://www.diyaudio.com/community/...-from-visaton-free.267787/page-2#post-7126272
Air core: 0.42 mH; 1.4 ohm; 0.3 mm wire
Iron core: 2.85 mH; 0.7 ohm; 0.7 mm wire.
That air core is abysmal, but you probably won't hear it. My Wilmslow Audio ones never go above 0.4R for aircore or ferrites. Ferrite multiplies inductance by about X4 for a given coil.
This 0.5mH measures 0.49mH and 0.3R. Probably 0.7mm. Always good to calibrate with a known reference first.
Interestingly it works quite well for speaker drivers too.
I measured an Elac 6" midbass at 5.5R and 0.418mH which makes it lowish inductance. A Visaton W200S came out at about 6R and 1.5mH, which agrees with it being a high-inductance woofer.
You tend to treat woofers differently depending on inductance. Think of inductance as bafflestep and rolloff naturally built in.
A Morel CAT278 1" tweeter came out at 5.2R and 0.174mH, and you can hear the 1kHz test tone when you do this.
Best, Steve.
You can do it for yourself too:
https://www.diyaudio.com/community/...-from-visaton-free.267787/page-2#post-7126272
Air core: 0.42 mH; 1.4 ohm; 0.3 mm wire
Iron core: 2.85 mH; 0.7 ohm; 0.7 mm wire.
That air core is abysmal, but you probably won't hear it. My Wilmslow Audio ones never go above 0.4R for aircore or ferrites. Ferrite multiplies inductance by about X4 for a given coil.
This 0.5mH measures 0.49mH and 0.3R. Probably 0.7mm. Always good to calibrate with a known reference first.
Interestingly it works quite well for speaker drivers too.
I measured an Elac 6" midbass at 5.5R and 0.418mH which makes it lowish inductance. A Visaton W200S came out at about 6R and 1.5mH, which agrees with it being a high-inductance woofer.
You tend to treat woofers differently depending on inductance. Think of inductance as bafflestep and rolloff naturally built in.
A Morel CAT278 1" tweeter came out at 5.2R and 0.174mH, and you can hear the 1kHz test tone when you do this.
Best, Steve.
I know I'm going dotty, but I find it difficult to separate the signal from the noise!
P.S. The reason I asked is because in your sim you used made up values for the DCRs, not the measured ones we now have - does that make a difference?
@Galu. Just to indulge you I reran the sim. The coil resistances made very little difference. The tweeter coil at 1.4R let a tiny bit more low frequency in, but hardly worth losing sleep over.
It is my opinion that what makes a good speaker is good or controlled dispersion, good impedance to help it work well with an amplifier, and freedom from cone breakup and tweeter distortion from aggravating the Fs resonance.
Your ears, which are a very fine measuring system in themselves, really don't notice a couple of dBs here and there or a few degrees of phase. I think most people make it more difficult than it is.
It is my opinion that what makes a good speaker is good or controlled dispersion, good impedance to help it work well with an amplifier, and freedom from cone breakup and tweeter distortion from aggravating the Fs resonance.
Your ears, which are a very fine measuring system in themselves, really don't notice a couple of dBs here and there or a few degrees of phase. I think most people make it more difficult than it is.