Inductor.
I'm sorry, I do have the zma files. Manuf's data in black, red = the MCA in 1.5litre closed above, or P25 in 40 litre vented below. It looks like the MCA resonance has moved up to about 160Hz? I'm wondering if changing the MCA box to 4.3litre vented would bring its resonance back down, and if so, by how much , I wonder? thanks, grant
I'm sorry, I do have the zma files. Manuf's data in black, red = the MCA in 1.5litre closed above, or P25 in 40 litre vented below. It looks like the MCA resonance has moved up to about 160Hz? I'm wondering if changing the MCA box to 4.3litre vented would bring its resonance back down, and if so, by how much , I wonder? thanks, grant
Attachments
Inductor,
I think our posts 'crossed', sorry. A vented mid-box is unnecessary and a 1.5litre closed will be ok - thanks! I haven't bought any crossover parts as yet. My last xo was just an idea that needs refinement. I could be wrong of course, but I thought a larger mid box would take the MCA lower and enhance the P25's bass a bit?
This is why I noted Troels G's PMS 4.3 litre vented mid-box. Many thanks, grant
I think our posts 'crossed', sorry. A vented mid-box is unnecessary and a 1.5litre closed will be ok - thanks! I haven't bought any crossover parts as yet. My last xo was just an idea that needs refinement. I could be wrong of course, but I thought a larger mid box would take the MCA lower and enhance the P25's bass a bit?
This is why I noted Troels G's PMS 4.3 litre vented mid-box. Many thanks, grant
If you want to go with a 4,3L box for the mid your speaker size will be bigger. I joined here a graph from WinISD with a closed box of 4,3L and a resonant frequency of 105Hz. Again with a vented box a have a feel that is going in the wrong path, because output under 100 Hz that's what the woofer is for and you don't get any improvement, your filter is much over that. Anyway the vented box have a double impedance for the box/driver and for the vent, and that one goes up always in frequency (impedance and phase interference in the mid linear output), that's what you don't want because it will be in your way and in the job of designing the xover (more complex and unnecessary). In this region you want an active xover because components are so big and heavy that you don't have space and money to accommodate. At these low frequencies (100s or lower) your xover (x2 speakers) get's more expensive than your drivers.
Attachments
Inductor,
Thanks...I understand! As long as the 160Hz MCA resonance for the mid box is ok, I'll stay with the 1.5 litre closed mid-box. Much appreciated, grant
Thanks...I understand! As long as the 160Hz MCA resonance for the mid box is ok, I'll stay with the 1.5 litre closed mid-box. Much appreciated, grant
Yes, thanks me...
I understand you. I know what you want. If it's about to copy a speaker (just that) go on and do that. But you know, I know, is not that what you are doing, is more than that, and you want all the good ideas that everybody can bring to the project. So... your project is unique, and it will be the best for that speaker size and price (drivers, wood, xover, etc). Is always good to have an open mind and collect all the benefits from that.
I understand you. I know what you want. If it's about to copy a speaker (just that) go on and do that. But you know, I know, is not that what you are doing, is more than that, and you want all the good ideas that everybody can bring to the project. So... your project is unique, and it will be the best for that speaker size and price (drivers, wood, xover, etc). Is always good to have an open mind and collect all the benefits from that.
Inductor,
My sentiment exactly! For me as well, its all about learning and eventually tweaking to get the best sound for me. Thanks for your helpful advice, grant
My sentiment exactly! For me as well, its all about learning and eventually tweaking to get the best sound for me. Thanks for your helpful advice, grant
Grant, I would not advise you to copy all too much from Troels "PMS"
PMS has a slanted and wide curved baffle
These things are built into the crossover
So yours have to be compensated differently
Mid box volume - you obviously dont need the lowend from the mid, BUT the different rolloff should be compensated fore in xo
Be aware that impedanse ressonanse peak with a higher frequency will interfere with xo behaviour
Some few designers insist to have a LCR "notch" on this ressonanse peak - I have tried it too, but didnt like it, so I dont do that, but you will have to play with xo to get a smooth rolloff
But I still have LCR on woofer and tweeter ressonanse - but my next speaker wont need that
PMS has a slanted and wide curved baffle
These things are built into the crossover
So yours have to be compensated differently
Mid box volume - you obviously dont need the lowend from the mid, BUT the different rolloff should be compensated fore in xo
Be aware that impedanse ressonanse peak with a higher frequency will interfere with xo behaviour
Some few designers insist to have a LCR "notch" on this ressonanse peak - I have tried it too, but didnt like it, so I dont do that, but you will have to play with xo to get a smooth rolloff
But I still have LCR on woofer and tweeter ressonanse - but my next speaker wont need that
Ahhh, Troels really have a "classical 3way" - I thought you were referring to "classical way of building a 3way"
Yep, it looks pretty straight forward with xo points around 500hz and 4000hz
Should be easy to tilt box too
Yep, it looks pretty straight forward with xo points around 500hz and 4000hz
Should be easy to tilt box too
Hi,
grant, are you going to simulate (or did you already in WinISD or other software) the box for the woofer with 40L vented (?). You don't count the speakers volume and vent volume. Everything you add to the 40L air volume you have to make it bigger like insulaton on the interior of the cabinet, speakers volume (3) and port (also xover when it's inside). You can always change your internal volume until the last day when you cut your panels. After that, only (if) making a new speaker box. Measure twice, cut once.🙄
grant, are you going to simulate (or did you already in WinISD or other software) the box for the woofer with 40L vented (?). You don't count the speakers volume and vent volume. Everything you add to the 40L air volume you have to make it bigger like insulaton on the interior of the cabinet, speakers volume (3) and port (also xover when it's inside). You can always change your internal volume until the last day when you cut your panels. After that, only (if) making a new speaker box. Measure twice, cut once.🙄
Hi guys! (Wow, thanks for helping me...I should explain some things!)
Sreten,
I'm SO sorry - I must be blind!!! ..Use the 3WAYC ..*.MID.*..driver!.. The MCA12! Aarrgh! I must have mixed up your
recommendation for the MCA15! Problem: its too small for the existing hole I think. You must be pulling your hair out in frustration with me! I would have seen it if you had said MCA12, I just didn't twig to 'mid'.....oops. I did post the attached graph before though, and politely, I still can't see any MCA12 advantage except for better 60degree off-axis at 3kHz. Otherwise, to me still, the MCA15 response looks much better - the SPL is higher. Can you please help me as to why the MCA12 is preferable over the MCA15? I've been searching your previous posts....Anyway, what follows is for what I have done for the MCA15:
Yes I did indeed try Troels 3WayClassic xo for my boxes with Curts files, but the 'starting point' graphs looked unacceptable, so I didn't bother posting it (but I can if you want). The mid had some nasty peaks. Not knowing the best way to proceed from there, I just tried trial and error experimentation. My goal was to lower the xo-points,
smooth the response and increase Z while keeping phase +-40. One of the things I tried was your suggested LCR filter on the mid - slight improvement, but by this stage the parts count was already high and the Z very low. Then I tried the PMS vs 5 xo which was also unsatisfactory. So I thought maybe a hybrid of the two would work? My latest posted version deleted the LCR trap on the mid and the contour network on the tweeter, but its now 3rd order
(2nd might do here). I also went for 2nd order on the woofer with a Zobel. All variants used the same input files and driver Z-offsets. So I did try to initially follow your recommendations. I'm using files that have been very kindly provided to me but I can't say for sure, exactly how they were derived as I received no 'intermediate-step' baffle effect info. However, as I previously posted them, they do look feasible for my box(es)/baffle, I think.
Also re WinISD and the mid-box. I recently input the T/S parameters correctly (I hope!), ie Le in particular. So I was eager to try it out 'properly' and see for myself the differences. I was just curious about the PMS mid-box, thats all. Anyway, doing that would rob me of another already precious (lol) 2 litres or so of P25 volume! And yes, I still agree that 1.5 litres closed as you suggested eons ago - is fine! Its great that I can use some of these programs and see it for myself.
Just in case this scenario of the drivers in my existing boxes doesn't actually sound good, I was thinking of a 'fallback' plan. A safety net , if you will. Hence my recent post in the 'PMS' thread. Its great to see that you're still here and as always, thanks! I have yet to sim your suggested mixed series/parallel xo - but I will!
Tinitus,
Many thanks indeed! I understand and very much appreciate your comments. The 3WayClassic xo-points at 500 and 3800(?) would probably work in my case, but I was hoping for (unrealistically?) something more like 280-360 and 2800. If the MCA's resonance at 160 in the 1.5litre box is not too close to 280+ that is! Unfortunately, I can't use the BDS program anymore which
simulates baffle tilt among many other things. cheers!
Inductor,
Hi!. My boxes are already built. They are approximately 40 litres internal volume after, the xo, mid-box etc have been subtracted.
Ideally the P25 should be in a 70 litre vented box. My P25 data files are for 40 litres vented. Thanks for your help and best regards to
all, grant
Sreten,
I'm SO sorry - I must be blind!!! ..Use the 3WAYC ..*.MID.*..driver!.. The MCA12! Aarrgh! I must have mixed up your
recommendation for the MCA15! Problem: its too small for the existing hole I think. You must be pulling your hair out in frustration with me! I would have seen it if you had said MCA12, I just didn't twig to 'mid'.....oops. I did post the attached graph before though, and politely, I still can't see any MCA12 advantage except for better 60degree off-axis at 3kHz. Otherwise, to me still, the MCA15 response looks much better - the SPL is higher. Can you please help me as to why the MCA12 is preferable over the MCA15? I've been searching your previous posts....Anyway, what follows is for what I have done for the MCA15:
Yes I did indeed try Troels 3WayClassic xo for my boxes with Curts files, but the 'starting point' graphs looked unacceptable, so I didn't bother posting it (but I can if you want). The mid had some nasty peaks. Not knowing the best way to proceed from there, I just tried trial and error experimentation. My goal was to lower the xo-points,
smooth the response and increase Z while keeping phase +-40. One of the things I tried was your suggested LCR filter on the mid - slight improvement, but by this stage the parts count was already high and the Z very low. Then I tried the PMS vs 5 xo which was also unsatisfactory. So I thought maybe a hybrid of the two would work? My latest posted version deleted the LCR trap on the mid and the contour network on the tweeter, but its now 3rd order
(2nd might do here). I also went for 2nd order on the woofer with a Zobel. All variants used the same input files and driver Z-offsets. So I did try to initially follow your recommendations. I'm using files that have been very kindly provided to me but I can't say for sure, exactly how they were derived as I received no 'intermediate-step' baffle effect info. However, as I previously posted them, they do look feasible for my box(es)/baffle, I think.
Also re WinISD and the mid-box. I recently input the T/S parameters correctly (I hope!), ie Le in particular. So I was eager to try it out 'properly' and see for myself the differences. I was just curious about the PMS mid-box, thats all. Anyway, doing that would rob me of another already precious (lol) 2 litres or so of P25 volume! And yes, I still agree that 1.5 litres closed as you suggested eons ago - is fine! Its great that I can use some of these programs and see it for myself.
Just in case this scenario of the drivers in my existing boxes doesn't actually sound good, I was thinking of a 'fallback' plan. A safety net , if you will. Hence my recent post in the 'PMS' thread. Its great to see that you're still here and as always, thanks! I have yet to sim your suggested mixed series/parallel xo - but I will!
Tinitus,
Many thanks indeed! I understand and very much appreciate your comments. The 3WayClassic xo-points at 500 and 3800(?) would probably work in my case, but I was hoping for (unrealistically?) something more like 280-360 and 2800. If the MCA's resonance at 160 in the 1.5litre box is not too close to 280+ that is! Unfortunately, I can't use the BDS program anymore which
simulates baffle tilt among many other things. cheers!
Inductor,
Hi!. My boxes are already built. They are approximately 40 litres internal volume after, the xo, mid-box etc have been subtracted.
Ideally the P25 should be in a 70 litre vented box. My P25 data files are for 40 litres vented. Thanks for your help and best regards to
all, grant
Attachments
Hi,
the difference, grant, is that with a 12 Mid you go up in the xover, the speaker is smaller in size and the frequency goes up. With the bigger 15 Mid like you have the resonance frequency (Fs=51Hz in Free Air) is lower and you come down in the xover frequency.
1,5L -> 160Hz
4,3L -> 105Hz
Free Air -> 51Hz
Now you can play with the xover frequency 200/300Hz if you get the Fsc of the pair (Mid speaker/enclosure box) out of the way. But as you go down, the sound improves and the price of components, volume of the Mid enclosure and size of components and speakers goes up.
the difference, grant, is that with a 12 Mid you go up in the xover, the speaker is smaller in size and the frequency goes up. With the bigger 15 Mid like you have the resonance frequency (Fs=51Hz in Free Air) is lower and you come down in the xover frequency.
1,5L -> 160Hz
4,3L -> 105Hz
Free Air -> 51Hz
Now you can play with the xover frequency 200/300Hz if you get the Fsc of the pair (Mid speaker/enclosure box) out of the way. But as you go down, the sound improves and the price of components, volume of the Mid enclosure and size of components and speakers goes up.
Hi,
the problem with the MCA15 is it is too sensitive for the bass to
be used without building some baffle step compensation into its
higher midrange level response.
You can do this if you use a lower crossover frequency but
you cannot use Troels crossover as the starting point.
🙂/sreten.
the problem with the MCA15 is it is too sensitive for the bass to
be used without building some baffle step compensation into its
higher midrange level response.
You can do this if you use a lower crossover frequency but
you cannot use Troels crossover as the starting point.
🙂/sreten.
TangBand W3-872SC is said to be quite fantastic as a wideranged mid - and I believe it, because I know the person who says so is not easily satisfied 😉
Hi,
Grant, I checked your xover and I have difficulty finding a place for a 6.5 mH inductor in your woofer filter.
I designed a new xover for you. But before I would like to know how do you feel about that. I would like you to give a try, what do you think? The tweeter filter is a 2.order and has a small value Lpad. The Mid filter design is a bit different and also a 2.order, the mid is connected in inverted polarity (180º phase). The woofer is a more difficult outcome but I would try a second order filter with a 3.9mH instead.
3-Way Xover points at 350Hz and 1900Hz.
Grant, I checked your xover and I have difficulty finding a place for a 6.5 mH inductor in your woofer filter.
I designed a new xover for you. But before I would like to know how do you feel about that. I would like you to give a try, what do you think? The tweeter filter is a 2.order and has a small value Lpad. The Mid filter design is a bit different and also a 2.order, the mid is connected in inverted polarity (180º phase). The woofer is a more difficult outcome but I would try a second order filter with a 3.9mH instead.
3-Way Xover points at 350Hz and 1900Hz.
Attachments
"Stradivari" tinitus,
(OK, I cheated - 😀 - I looked at your profile to find out what you do during payed time). Friends of mine (one of them a violin buider too) say that TB is one of the few "quality for little money" drivers available nowadays.
Greetings
Pit
(OK, I cheated - 😀 - I looked at your profile to find out what you do during payed time). Friends of mine (one of them a violin buider too) say that TB is one of the few "quality for little money" drivers available nowadays.
Greetings
Pit
Hi, Yes, violin builders do have good ears, and to be trusted - nice to hear you have a friend with this "hobby", and I am NOT a genuine violin builder, only a happy amateur of which there are maybe a couple of hundred in my country
BTW,...Stradivarius must have had fantastic ears, to be able to build those instuments
BTW,...Stradivarius must have had fantastic ears, to be able to build those instuments
Hi Inductor, Thanks! re your MCA12/15 comments.
I've been 'playing in' WinISD with these drivers in closed boxes of 1.5 and 3 litres. Please see the attached. I hope I have input the parameters correctly? The results seem weird to me! The MCA12
'blue graph' in 3 litres has the best bass extension of the lot! I can't understand why the MCA15 is 'higher' based upon what you kindly advised? Did I make a mistake somewhere? Thanks, much
appreciated, grant
I've been 'playing in' WinISD with these drivers in closed boxes of 1.5 and 3 litres. Please see the attached. I hope I have input the parameters correctly? The results seem weird to me! The MCA12
'blue graph' in 3 litres has the best bass extension of the lot! I can't understand why the MCA15 is 'higher' based upon what you kindly advised? Did I make a mistake somewhere? Thanks, much
appreciated, grant
Attachments
Hi Tinitus and Pit!
I did search in Au before, but unfortunately I don't think TangBand are available here in Oz, but thanks!
Hi Sreten,
I'm still ...thinking... lol. I'll reply asap, also thanks!
Inductor, Hi ..Wow thats great thanks! The mid 'topology' looks a little different. Vance Dickason says that the '3 permutations' of 2nd-order mid HP/LP will all have different responses? Interesting nevertheless, but 1900Hz could be too low, with respect to driver conflict?
Omni!! G'day. Any luck with your crossover? I miss you in here! cheers to all, grant
I did search in Au before, but unfortunately I don't think TangBand are available here in Oz, but thanks!
Hi Sreten,
I'm still ...thinking... lol. I'll reply asap, also thanks!
Inductor, Hi ..Wow thats great thanks! The mid 'topology' looks a little different. Vance Dickason says that the '3 permutations' of 2nd-order mid HP/LP will all have different responses? Interesting nevertheless, but 1900Hz could be too low, with respect to driver conflict?
Omni!! G'day. Any luck with your crossover? I miss you in here! cheers to all, grant
Grant,
*Pit takes Grant's bottle away from him, looks at him in a menacing way* Have you ever looked at a globe, matey? You live closer to any Asian factory than most of yrs.truly! Asking them about a pair sent XF (XF means ex factory - you pay all the p&p and costs, but you cut out all the importers, wholeselalesellers etc)
The price you normally pay means you are entitled to all the knowledge Dave and the likes can offer - but as long as there is no official seller in Aussieland (business idea?) giving you help instead of having the drivers shipped once around the globe means Dave and suchlike are better at being friends than they are at selling.
Oh wow - Germans do tend to long sentences, don't we?
Get yourself a new beer or come visit,
Pit
*Pit takes Grant's bottle away from him, looks at him in a menacing way* Have you ever looked at a globe, matey? You live closer to any Asian factory than most of yrs.truly! Asking them about a pair sent XF (XF means ex factory - you pay all the p&p and costs, but you cut out all the importers, wholeselalesellers etc)
The price you normally pay means you are entitled to all the knowledge Dave and the likes can offer - but as long as there is no official seller in Aussieland (business idea?) giving you help instead of having the drivers shipped once around the globe means Dave and suchlike are better at being friends than they are at selling.
Oh wow - Germans do tend to long sentences, don't we?
Get yourself a new beer or come visit,
Pit
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