I was reading around the forums and came across a design with 2 beyma 15p80nd's and the TPL150.
Using a passive crossover this would be a nice speaker to have I think.
I like the idea of simple 2 speakers connected to an amplifier and be done with it.
No extra crossovers/DSP/ etc.....
I have used the 15p80 before and they really give a big punch,have very strong motors and sound clean.
2 of them in a BR box of 250l tuned to 35Hz will give a -6db shelving response.
Cross over of around 150-200Hz and a passive shelving filter will make it flat.
Ok you will lose 6 db efficiency but -3db will then be 33Hz.
They are verry efficient 101db so using 2 of them will get you around 104db and then losing 6db it will still do 98db so not a big deal...
Actually the FE version is a little better then the ND for the lowend.
so two of those will do -3db/33hz with an effciency around 98 db
Now the TPL150 (or the new version TPL200) is a very nice driver and I have heard them in a line array (PA) and also in a small PA speaker.
I wouldn't cross them lower as 1600Hz. It is possible but the sound quality suffers. (depends also on how loud you want it....)
The 15p80 will go high but using two of those I wouldn't go higher then 200Hz otherwise Combing could be a problem.
So a good mid driver to go in between would be nice.
I was thinking for an 8inch driver and use it between 150-200 and 3000Hz (or as high as possible)
This way all the basic musical information comes from 1 speaker driver.
Most speaker I like use this approach. Crossing as high as possible outside the ciritical hearing range.
So i was searching for a nice midrange and come across this 8m400 from 18sound.
Looks nice. I think it could be used from around 200Hz. it starts beaming from 3kHz and the 4kHz they state in the datasheet is really the maximum I would take it. https://en.toutlehautparleur.com/media/catalog/product/datasheet/eighteen_sound/8M400-8.pdf
Then altough the tpl150 is a really nice driver it is expensive also...
So when looking around i found these fountek drivers.
Fountek NeoPro5i
Not to bad and they go almost flat past 40kHz, they are high sensitivity and can handle 60w/120wpeak
Oh and they are cheaper then the tpl150
TPL150 is only measured to 20Khz and they state 23kHz range.
So this fountek ribbon looks nice to me.
I will have to pad down both the mid and the ribbon by a few db but that's ok.
So to summarize.
2*15inch beyma 15p80fe crossover around 200Hz
1*8inch 18sound 8m400 (8pe21 from b&c is also an option) crossover around 200Hz and 3-4Khz
1*fountek NeoPro5i ribbon crossover around 3-4kHz
A few simulations in Winisd:
2*beyma 15p80fe in 250L tuned to 35Hz
Response
Group delay
lo pass Butterworth 2nd order 150Hz and small filter @ 120Hz
Then a few simulations of the 8m400 in a closed box of 5L (don't want to make this to small as it will have a boxy sound then.
and then the filtered response
filtered with butterworth 2nd order at 200Hz Hi-pass and 3000Hz Lo-pass
And putting the 2 simulations together:
8m400 has been padded down 3db.
altough the crossover frequency's are not exactly the same I think they would have a nice acoustically crossover of around 250Hz but When I would build this I would first try things out with a DSP and when that measures ok I would start designing the passive crossover.
Then there is also the group delay.
They almost overlap around the crossover frequency. Also keep in mind that the acoustical centre of the mid (blue line) is a little bit more forward then the 15 inch low woofers. So even if the mid has a little bit more group delay I think it wouldn't matter that much. The group delay also changes in the same way so I believe they would combine nicely.
Then the fountek driver wouldn't have problems crossing over at 3kHz and has more then enough sensitivity.
In reality the sensitivity of the speaker would be around 98db/2.83v/1M
For a front loaded speaker that is really not bad and this is without room gain etc....
it will go from 33Hz (-3db, many brands specify -10db, -10db is around 26Hz ....) to 40kHz
It's just an idea again.... (I have lots of ideas popping into my head)
Just have to make room and convince the WAF......
Using a passive crossover this would be a nice speaker to have I think.
I like the idea of simple 2 speakers connected to an amplifier and be done with it.
No extra crossovers/DSP/ etc.....
I have used the 15p80 before and they really give a big punch,have very strong motors and sound clean.
2 of them in a BR box of 250l tuned to 35Hz will give a -6db shelving response.
Cross over of around 150-200Hz and a passive shelving filter will make it flat.
Ok you will lose 6 db efficiency but -3db will then be 33Hz.
They are verry efficient 101db so using 2 of them will get you around 104db and then losing 6db it will still do 98db so not a big deal...
Actually the FE version is a little better then the ND for the lowend.
so two of those will do -3db/33hz with an effciency around 98 db
Now the TPL150 (or the new version TPL200) is a very nice driver and I have heard them in a line array (PA) and also in a small PA speaker.
I wouldn't cross them lower as 1600Hz. It is possible but the sound quality suffers. (depends also on how loud you want it....)
The 15p80 will go high but using two of those I wouldn't go higher then 200Hz otherwise Combing could be a problem.
So a good mid driver to go in between would be nice.
I was thinking for an 8inch driver and use it between 150-200 and 3000Hz (or as high as possible)
This way all the basic musical information comes from 1 speaker driver.
Most speaker I like use this approach. Crossing as high as possible outside the ciritical hearing range.
So i was searching for a nice midrange and come across this 8m400 from 18sound.
Looks nice. I think it could be used from around 200Hz. it starts beaming from 3kHz and the 4kHz they state in the datasheet is really the maximum I would take it. https://en.toutlehautparleur.com/media/catalog/product/datasheet/eighteen_sound/8M400-8.pdf
Then altough the tpl150 is a really nice driver it is expensive also...
So when looking around i found these fountek drivers.
Fountek NeoPro5i
Not to bad and they go almost flat past 40kHz, they are high sensitivity and can handle 60w/120wpeak
Oh and they are cheaper then the tpl150
TPL150 is only measured to 20Khz and they state 23kHz range.
So this fountek ribbon looks nice to me.
I will have to pad down both the mid and the ribbon by a few db but that's ok.
So to summarize.
2*15inch beyma 15p80fe crossover around 200Hz
1*8inch 18sound 8m400 (8pe21 from b&c is also an option) crossover around 200Hz and 3-4Khz
1*fountek NeoPro5i ribbon crossover around 3-4kHz
A few simulations in Winisd:
2*beyma 15p80fe in 250L tuned to 35Hz
Response
Group delay
lo pass Butterworth 2nd order 150Hz and small filter @ 120Hz
Then a few simulations of the 8m400 in a closed box of 5L (don't want to make this to small as it will have a boxy sound then.
and then the filtered response
filtered with butterworth 2nd order at 200Hz Hi-pass and 3000Hz Lo-pass
And putting the 2 simulations together:
8m400 has been padded down 3db.
altough the crossover frequency's are not exactly the same I think they would have a nice acoustically crossover of around 250Hz but When I would build this I would first try things out with a DSP and when that measures ok I would start designing the passive crossover.
Then there is also the group delay.
They almost overlap around the crossover frequency. Also keep in mind that the acoustical centre of the mid (blue line) is a little bit more forward then the 15 inch low woofers. So even if the mid has a little bit more group delay I think it wouldn't matter that much. The group delay also changes in the same way so I believe they would combine nicely.
Then the fountek driver wouldn't have problems crossing over at 3kHz and has more then enough sensitivity.
In reality the sensitivity of the speaker would be around 98db/2.83v/1M
For a front loaded speaker that is really not bad and this is without room gain etc....
it will go from 33Hz (-3db, many brands specify -10db, -10db is around 26Hz ....) to 40kHz
It's just an idea again.... (I have lots of ideas popping into my head)
Just have to make room and convince the WAF......
Last edited:
I have a measurement Mic.
Another Idea was to use the 6nd410 from 18sound 6ND410
A 6" driver would be possible to crossover higher indeed.
I'd have to agree that I like 8inch most of the time over a 6inch.
Can go lower and therefore I think it sounds more natural.
Personally in general I like tweeters to be crossed as high as possible. Otherwise it starts to sound harsh and constraint. (compression drivers have more problems with this then AMT or ribbons)
In PA applications many speakers are crossed very low sounding harsh.
Going from 15" to tweeters without a mid is asking for trouble. The mid suffers.
In PA this happens a lot and it becomes difficult to hear the voice.
Offcourse this is not for PA but for home HIFI still I like the basic music info coming from 1 speaker (the mid) and the rest is assisting the mid speaker.
the 15" drivers can go low and really have the ability to pound.
The AMT or ribbon will add the soft top end.
I think there are 2 ways of approuching this problem.
Or you add the mid between the tweeter and the woofer to fill in the gap.
Or you start from the mid and add a tweeter and the woofers.
I most of the time like the last approuch as it sounds more natural.
In PA it get's difficult because powerwise everything should be balanced and choosing crossover freuency's becomes important to keep your drivers alive.
For HIFI It's easier because there will be more headroom.
So I'm still looking around for the best mid driver
Now another part for discussion. The BR ports? How big is enough?
I would say the bigger the better less port noise.
I was thinking for an area at least the same as the woofers SD.
Problem will be that the BR port needs to be bent as it will get to long and I don't have experience how it will affect Tuning.
I was thinking something in the style of the onken enclosures with big ports that are braced.
Wood will probably be 21mm birch ply.
Then another question. the 2 Woofers. Each their own box or use a combined box?
If I would use each there own box then if needed I could put an extra lo pass on the lower woofer using a coil and avoid combing.
I know it has been done to avoid combing.
I think if they used the same box they will interfere to much.
Just some toughts thinking out loud
Can go lower and therefore I think it sounds more natural.
Personally in general I like tweeters to be crossed as high as possible. Otherwise it starts to sound harsh and constraint. (compression drivers have more problems with this then AMT or ribbons)
In PA applications many speakers are crossed very low sounding harsh.
Going from 15" to tweeters without a mid is asking for trouble. The mid suffers.
In PA this happens a lot and it becomes difficult to hear the voice.
Offcourse this is not for PA but for home HIFI still I like the basic music info coming from 1 speaker (the mid) and the rest is assisting the mid speaker.
the 15" drivers can go low and really have the ability to pound.
The AMT or ribbon will add the soft top end.
I think there are 2 ways of approuching this problem.
Or you add the mid between the tweeter and the woofer to fill in the gap.
Or you start from the mid and add a tweeter and the woofers.
I most of the time like the last approuch as it sounds more natural.
In PA it get's difficult because powerwise everything should be balanced and choosing crossover freuency's becomes important to keep your drivers alive.
For HIFI It's easier because there will be more headroom.
So I'm still looking around for the best mid driver
Now another part for discussion. The BR ports? How big is enough?
I would say the bigger the better
less port noise.I was thinking for an area at least the same as the woofers SD.
Problem will be that the BR port needs to be bent as it will get to long and I don't have experience how it will affect Tuning.
I was thinking something in the style of the onken enclosures with big ports that are braced.
Wood will probably be 21mm birch ply.
Then another question. the 2 Woofers. Each their own box or use a combined box?
If I would use each there own box then if needed I could put an extra lo pass on the lower woofer using a coil and avoid combing.
I know it has been done to avoid combing.
I think if they used the same box they will interfere to much.
Just some toughts thinking out loud
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