Wharfdale W60 and W60Ds

[yoho]

Do think there it’s any problem using Wharfdale W60 tweeters in W60D speakers? I realize the difference in speakers but the tweeters should be similar, at least they’re both purple? Any thoughts? Thank you.

 

[klipschorn]

I'm assuming the main difference between the two tweeters is the size of the purple diaphragms, one being a 1 inch dome and the other being about 3" with a larger donut surround which is part of the inner dome and also purple and transparent. I have both types here but unfortunately, the pair with the larger diaphragm have open voice coils and also a larger face plate. the others have a smaller face plate.

Now, to answer your question, if the impedance of the two types are the same or even close, there should be no problem, electrically. Mounting them may require slight modification. T the magnet assemblies on the four I have are the same so any mod required would most likely occur if going from the smaller face plate to the larger if the tweeters are very close to an adjacent speaker.

My smaller face plate units measure 4.8 ohms DC resistance and 5.8 ohms DC resistance which makes them close to 8 ohms impedance. The larger face plate units are unmeasurable due to the open coils.

A difference of one ohm in speaker impedance will have a negligible effect unless one has very keen ears. Consider the following scenarios.

Capacitors used in commercially manufactured systems have a tolerance of +/-10%. Assume the crossover point is 3000hz and the tweeter impedance is 8 ohms. That would set the required capacitor at 6.6uF, assuming a first order filter. With a 10% tolerance, that capacitor can be anywhere between 7.6uF and 5.9uF which can place the actual crossover point anywhere between 2740hz to 3371hz, with no physical harm to the tweeter and most likely unnoticeable to the listener.

Let's suppose the capacitors in each system are equal and are 6.6uF but the replacement tweeters are 7 ohms. A 7 ohms tweeter placed in place of an 8 ohms tweeter with shift the crossover point to 3445hz.

Measure the DC resistance of the tweeters. If they are within one ohm, don't be concerned. Heck, unless you playing these things at rock concert levels, even a few ohms difference will not harm the tweeter although there may be an audible difference, however slight.

Robert

 

[yoho]

I'm assuming the main difference between the two tweeters is the size of the purple diaphragms, one being a 1 inch dome and the other being about 3" with a larger donut surround which is part of the inner dome and also purple and transparent. I have both types here but unfortunately, the pair with the larger diaphragm have open voice coils and also a larger face plate. the others have a smaller face plate.

Now, to answer your question, if the impedance of the two types are the same or even close, there should be no problem, electrically. Mounting them may require slight modification. T the magnet assemblies on the four I have are the same so any mod required would most likely occur if going from the smaller face plate to the larger if the tweeters are very close to an adjacent speaker.

My smaller face plate units measure 4.8 ohms DC resistance and 5.8 ohms DC resistance which makes them close to 8 ohms impedance. The larger face plate units are unmeasurable due to the open coils.

A difference of one ohm in speaker impedance will have a negligible effect unless one has very keen ears. Consider the following scenarios.

Capacitors used in commercially manufactured systems have a tolerance of +/-10%. Assume the crossover point is 3000hz and the tweeter impedance is 8 ohms. That would set the required capacitor at 6.6uF, assuming a first order filter. With a 10% tolerance, that capacitor can be anywhere between 7.6uF and 5.9uF which can place the actual crossover point anywhere between 2740hz to 3371hz, with no physical harm to the tweeter and most likely unnoticeable to the listener.

Let's suppose the capacitors in each system are equal and are 6.6uF but the replacement tweeters are 7 ohms. A 7 ohms tweeter placed in place of an 8 ohms tweeter with shift the crossover point to 3445hz.

Measure the DC resistance of the tweeters. If they are within one ohm, don't be concerned. Heck, unless you playing these things at rock concert levels, even a few ohms difference will not harm the tweeter although there may be an audible difference, however slight.

Robert

Thank you, I’m going to give it try.

 

[klipschorn]

Let me know how it worked out.

 

[RTally]

I'm assuming the main difference between the two tweeters is the size of the purple diaphragms, one being a 1 inch dome and the other being about 3" with a larger donut surround which is part of the inner dome and also purple and transparent. I have both types here but unfortunately, the pair with the larger diaphragm have open voice coils and also a larger face plate. the others have a smaller face plate.

Now, to answer your question, if the impedance of the two types are the same or even close, there should be no problem, electrically. Mounting them may require slight modification. T the magnet assemblies on the four I have are the same so any mod required would most likely occur if going from the smaller face plate to the larger if the tweeters are very close to an adjacent speaker.

My smaller face plate units measure 4.8 ohms DC resistance and 5.8 ohms DC resistance which makes them close to 8 ohms impedance. The larger face plate units are unmeasurable due to the open coils.

A difference of one ohm in speaker impedance will have a negligible effect unless one has very keen ears. Consider the following scenarios.

Capacitors used in commercially manufactured systems have a tolerance of +/-10%. Assume the crossover point is 3000hz and the tweeter impedance is 8 ohms. That would set the required capacitor at 6.6uF, assuming a first order filter. With a 10% tolerance, that capacitor can be anywhere between 7.6uF and 5.9uF which can place the actual crossover point anywhere between 2740hz to 3371hz, with no physical harm to the tweeter and most likely unnoticeable to the listener.

Let's suppose the capacitors in each system are equal and are 6.6uF but the replacement tweeters are 7 ohms. A 7 ohms tweeter placed in place of an 8 ohms tweeter with shift the crossover point to 3445hz.

Measure the DC resistance of the tweeters. If they are within one ohm, don't be concerned. Heck, unless you playing these things at rock concert levels, even a few ohms difference will not harm the tweeter although there may be an audible difference, however slight.

Robert

Your description of crossover frequencies relative to dc resistance of the driver is not entirely correct. What matters is the impedance of the driver at the crossover frequency, not the dc resistance of the driver. Differences in dc resistance do not matter other than to help identify the nominal impedance of the driver. Generally, the impedance of a driver will vary over its frequency range and the actual impedance at the crossover frequency is what is important. Some manufacturers publish impedance vs. frequency graphs. Absent that, the impedance graph for a driver can be easily measured with very little equipment.

Ideally, the TS parameters of the drivers should be compared to determine if a replacement is suitable. Most important are going to be frequency range, sensitivity, and impedance. If the frequency response is suitable, the crossover can be tweaked to accommodate sensitivity and impedance differences.

 

[klipschorn]

I'm quite aware of all that you say. My reference to using the dcr was for the OP to compare the replacements with the originals to make a somewhat close determination as to whether both pairs are 8 ohms or 16 ohms.