I managed to load up the frequency and also the traced ZMA's into PCD.
Interesting the original txt impedance curves loaded straight into PCD once I had changed the extension from txt to ZMA.
Just a thought that occurred to me, the files I posted are for the measurement without the protection capacitors in place (12uF on tweeter and 39uF on Mid) and so if you are modelling an active crossover then these will need to be added on the passive side of PCD as I will always use these for an active crossover.
Interesting the original txt impedance curves loaded straight into PCD once I had changed the extension from txt to ZMA.
Just a thought that occurred to me, the files I posted are for the measurement without the protection capacitors in place (12uF on tweeter and 39uF on Mid) and so if you are modelling an active crossover then these will need to be added on the passive side of PCD as I will always use these for an active crossover.
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Nothing is ever as easy as thought at first! Thanks for persevering.
The mid and tweeter are not the easiest to work with but I have found with the active crossovers once you get it right they just sound great, very natural, enough detail and a decently large soundstage.
Would you care to share the crossover details so I can see how they look in Vituixcad.
The mid and tweeter are not the easiest to work with but I have found with the active crossovers once you get it right they just sound great, very natural, enough detail and a decently large soundstage.
Would you care to share the crossover details so I can see how they look in Vituixcad.
Sure, but before I do, how important is an impedance dip in the lower treble?
What Z offsets? At a glance, I would think the mid and tweeter are the same.
Is there something diffraction related causing the tweeter to have a rising response? Is it possible that some damage has occurred? Factory forgot ferrofluid possibly? Overheating vaporized it? I have 40 year old Morels tweeters in use today. I've wondered about the fluid in mine, but top end is not elevated.
I have an idea.. Can you post the on axis REW measurement of the speaker response that you like with the active filters. I want to gate it, and compare with my sim results.
What Z offsets? At a glance, I would think the mid and tweeter are the same.
Is there something diffraction related causing the tweeter to have a rising response? Is it possible that some damage has occurred? Factory forgot ferrofluid possibly? Overheating vaporized it? I have 40 year old Morels tweeters in use today. I've wondered about the fluid in mine, but top end is not elevated.
I have an idea.. Can you post the on axis REW measurement of the speaker response that you like with the active filters. I want to gate it, and compare with my sim results.
The REW measurements should have the offsets baked in as the measurements were taken with a feedback reference but they are approx 5mm for the mid to tweeter, mid behind the tweeter, and 75mm for the woofer to tweeter. This tallies quite well with the physical geometry and a bit of Pythagoras.
Got a few jobs to do this afternoon but will post the on axis later.
Not sure about the tweeters, they were brand new and both measure the same.
Here is a pic of the speaker for reference, front baffle is 560mm x 360mm. So as you said there may be some diffraction issues. I did model the baffle and driver placements using published data in VituixCad to try and reduce these effects but it may not have worked.
I may send an email to Morel to see what they say. I also found a pdf on the Facebook Loudspeakerprojectpad that Jeff Bagby wrote on both the EM1308 and ET448, his measurements are pretty flat with a 2-3dB bump at 11khz only. Also the published FS is 750hz, Jeff Bagby measured 880hz and I am getting more lie 1khz which may point to an issue.
Many thanks for the pointers, will follow them up.
Got a few jobs to do this afternoon but will post the on axis later.
Not sure about the tweeters, they were brand new and both measure the same.
Here is a pic of the speaker for reference, front baffle is 560mm x 360mm. So as you said there may be some diffraction issues. I did model the baffle and driver placements using published data in VituixCad to try and reduce these effects but it may not have worked.
I may send an email to Morel to see what they say. I also found a pdf on the Facebook Loudspeakerprojectpad that Jeff Bagby wrote on both the EM1308 and ET448, his measurements are pretty flat with a 2-3dB bump at 11khz only. Also the published FS is 750hz, Jeff Bagby measured 880hz and I am getting more lie 1khz which may point to an issue.
Many thanks for the pointers, will follow them up.
I had offset issues. Mid, and tweeter Y were switched. That is likely why it was difficult. I just found that, and revised everything. I think this x-over is closer to correct. I also need to get some yard work done. Will post something later.
Having mentioned Tweeter issues with either bad manufacture or no ferro fluid I thought I'd compare to data sheets and do a bit of digging -
So Impedance curves are quite offset -
Frequency plots are actually not a million miles away, maybe the modelling scales make you look in a bit too deep, but still different and it is the same on both drivers I have (dodgy batch).
Then looked at distortion plot and there is a bump in 2nd order at 1700hz, an issue ?
Will contact morel to see if they have anything to say.
Note these are 3 years old so well run in and have been played quite a bit with a protection cap and active crossover and never played more than around 80dB (I don't listen very loud).
If I get the chance I may have time to measure the tweeter with a larger baffle to see if there is a difference.
So Impedance curves are quite offset -
Frequency plots are actually not a million miles away, maybe the modelling scales make you look in a bit too deep, but still different and it is the same on both drivers I have (dodgy batch).
Then looked at distortion plot and there is a bump in 2nd order at 1700hz, an issue ?
Will contact morel to see if they have anything to say.
Note these are 3 years old so well run in and have been played quite a bit with a protection cap and active crossover and never played more than around 80dB (I don't listen very loud).
If I get the chance I may have time to measure the tweeter with a larger baffle to see if there is a difference.
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I see you did this already in post #16. You like this tonal balance? I thought you mentioned somewhere about tilting the top end down, so I did in my sim. Would you prefer a more level response?
@temp25 many thanks, I will have a look in more detail later.
@shadowplay62 many thanks also, will study in more detail later as well.
Thanks both for you input it is much appreciated.
@shadowplay62 many thanks also, will study in more detail later as well.
Thanks both for you input it is much appreciated.
@temp25 and @shadowplay62
Aaarrrrggghh. Don’t you hate to when work gets in the way of playtime! Probably not going to get time to look at this until next week, apologies for the radio silence in advance.
Aaarrrrggghh. Don’t you hate to when work gets in the way of playtime! Probably not going to get time to look at this until next week, apologies for the radio silence in advance.
Ah, ah. No worry. Life is good anyway, and you will appreciate your hobby much more after a long wait.