No, this measurements is made with a 6,5" driver (Seas CB17 something) and there is no compensation made at all so this is not a finished loudspeaker just a random driver that happends to be monted in one of my test boxes.
The reason for measurement was to show that above 500Hz the frequency scale with -6dB when doubling the distance and below 500Hz down to approx. 100 Hz sound pressure reduces more than -6dB when it starts to spread in full space volume instead of half space volume above 500 Hz.
The curves in the last picture are scaled +6, +12, +18 and +24 dB to make comparision possible for what happends during transition region where the driver goes from half space to full space distribution.
Thank you, this explains why.
Now that I know that the SPH-250KE will no longer be in production I was thinking of opting for the HiVi D10.8.
What you think about: HiVi D10.8 vs SPH-250KE ?
Now that I know that the SPH-250KE will no longer be in production I was thinking of opting for the HiVi D10.8.
What you think about: HiVi D10.8 vs SPH-250KE ?
You could still buy the woofers now, toutlehautparleur.com has 4 of them in stock:
https://en.toutlehautparleur.com/speaker-monacor-sph-250ke-8-ohm-10-16-inch.html
But I also think that while it's a great driver, you will probably find lots of more modern spec drivers in that price range, e.g. sb acoustics, faitalpro, sica, dayton, ...
The only "disadvantage" is that most modern drivers have a much lower VAS, usually leading to smaller enclosures.
To be honest I don't want pucharse a woofer if is out of production. If tomorrow will If it breaks it might be complicated to replace it.
However just checked HiVi D10.8 is not the right choice becouse it is not raccomanded cut over 200/250Hz.
One possible solution could be Scan Speak 26W/8534G00 that seem not too different from SPH-250KE and the cost is the some.
Hope can be fine as alternative of SPH-250KE.
However just checked HiVi D10.8 is not the right choice becouse it is not raccomanded cut over 200/250Hz.
One possible solution could be Scan Speak 26W/8534G00 that seem not too different from SPH-250KE and the cost is the some.
Hope can be fine as alternative of SPH-250KE.
@marcop999
When you designed your current speaker with Monacor SPH250 KE, did you had both bass and treble at the same amplitude level?
Out of what you have learned about baffle step compensation, will you have bass driver level 3-4 dB higher than midrange to start with?
I need to know that to be able to make a suggestion of bass driver.
Yes ScanSpeak 26W/8534G00 is fairly equal to Monacor SPH250 KE but give 1 dB higher bass level compared to SPH250 KE.
If you want to go flat out brutal Scan Speak Revelator 32W/8878T01 gives very similar response to your SPH250 KE but in 56 liter cabinet.
It's a bigger driver, but suspension is stiffer which will give a cleaner, more dynamic driver with less distortion.
Have not checked the price but I assume it is quite high.
Here is something to think about regarding 26W/8534G00.
http://www.troelsgravesen.dk/DISC-4.htm
The bass module with 10" and 8" bass drivers might be a good foundation to start with, and then make your own top speaker with TeXtreme 5" mid and Bliesma tweeter. Here you have a good solution for bass and lower mid with crossover.
When you designed your current speaker with Monacor SPH250 KE, did you had both bass and treble at the same amplitude level?
Out of what you have learned about baffle step compensation, will you have bass driver level 3-4 dB higher than midrange to start with?
I need to know that to be able to make a suggestion of bass driver.
Yes ScanSpeak 26W/8534G00 is fairly equal to Monacor SPH250 KE but give 1 dB higher bass level compared to SPH250 KE.
If you want to go flat out brutal Scan Speak Revelator 32W/8878T01 gives very similar response to your SPH250 KE but in 56 liter cabinet.
It's a bigger driver, but suspension is stiffer which will give a cleaner, more dynamic driver with less distortion.
Have not checked the price but I assume it is quite high.
Here is something to think about regarding 26W/8534G00.
http://www.troelsgravesen.dk/DISC-4.htm
The bass module with 10" and 8" bass drivers might be a good foundation to start with, and then make your own top speaker with TeXtreme 5" mid and Bliesma tweeter. Here you have a good solution for bass and lower mid with crossover.
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In my actual loudspeaker the level of bass at 60/80 Hz is higher then the level of tweeter.
The 32W/8878T01 is too expensive.
I have already checked the kit: ScanSpeak Discovery-4
http://www.troelsgravesen.dk/DISC-4.htm
while in the actual project I have used the inductor: Mundorf air coil L140, 3.0 mH/0,55 Ohm
that have 0.55 ohm DC resistance, in the new project I will use jantzen c coil toroidal (like Troels) so I expect to get DC resistance not more of 0.1-0.2 Ohm.
So this this should compensate partially the 1 dB difference (90 dB for Monacor, 89 dB for Scan Speak)
About the baffle step compensation I will do different meausure to find the right compromse.
What could happen practically if I lower the level of the woofer crossover inductor too much is that I might hear less mid-bass frequencies and consequently more high frequencies.
So based on the experiments I'm going to do I might have to modulate something else besides the value of the woofer inductor as well.
The 32W/8878T01 is too expensive.
I have already checked the kit: ScanSpeak Discovery-4
http://www.troelsgravesen.dk/DISC-4.htm
while in the actual project I have used the inductor: Mundorf air coil L140, 3.0 mH/0,55 Ohm
that have 0.55 ohm DC resistance, in the new project I will use jantzen c coil toroidal (like Troels) so I expect to get DC resistance not more of 0.1-0.2 Ohm.
So this this should compensate partially the 1 dB difference (90 dB for Monacor, 89 dB for Scan Speak)
About the baffle step compensation I will do different meausure to find the right compromse.
What could happen practically if I lower the level of the woofer crossover inductor too much is that I might hear less mid-bass frequencies and consequently more high frequencies.
So based on the experiments I'm going to do I might have to modulate something else besides the value of the woofer inductor as well.
I have find this llink:
that explain with pratical example how compensate.
what do you think ?
Baffle step calculator – with circuit examples
https://audiojudgement.com/baffle-step-calculator/that explain with pratical example how compensate.
what do you think ?
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Yes, they talk about diffraction and baffle step compensation, but try to treat them as separate issues.
Theoretically the baffle step are -6dB for lower frequencies, but in reality more lie -4dB because of room reflections and reverb.
The article they refer to describe it even better.
Read that too...
https://audiojudgement.com/speaker-baffle-design-and-diffraction/
Theoretically the baffle step are -6dB for lower frequencies, but in reality more lie -4dB because of room reflections and reverb.
The article they refer to describe it even better.
Read that too...
https://audiojudgement.com/speaker-baffle-design-and-diffraction/
Thank you @flex2 this explan better the concept.
Unfortunately in a speaker generally speaking with we can have a spherical surface. So certainly the problem will be there.
From a design point of view apart from rounding the edges the ways to go do not solve the problem but can only reduce it slightly.
I find the idea of adding an additional inductor to the woofer and a resistor in series with the inductor as described here:
https://audiojudgement.com/baffle-step-calculator/
is a great way to compensate for the baffle step.
This at negligible cost and with the possibility to act precisely (just do some tests by changing the value of the resistor once identified the right value of the inductor to be added for compensation).
To tell the truth I do not believe too much in absolute numbers 4 dB ,6 dB etc.. because when we measure too many factors come into play that we cannot calculate with a mathematical formula (not least the distance of the speaker from the wall also matters).
I think it will be a long job and certainly won't work on the first try but we are all used to that ....
Unfortunately in a speaker generally speaking with we can have a spherical surface. So certainly the problem will be there.
From a design point of view apart from rounding the edges the ways to go do not solve the problem but can only reduce it slightly.
I find the idea of adding an additional inductor to the woofer and a resistor in series with the inductor as described here:
https://audiojudgement.com/baffle-step-calculator/
is a great way to compensate for the baffle step.
This at negligible cost and with the possibility to act precisely (just do some tests by changing the value of the resistor once identified the right value of the inductor to be added for compensation).
To tell the truth I do not believe too much in absolute numbers 4 dB ,6 dB etc.. because when we measure too many factors come into play that we cannot calculate with a mathematical formula (not least the distance of the speaker from the wall also matters).
I think it will be a long job and certainly won't work on the first try but we are all used to that ....
Great.
Now you have full understanding about the concept of baffle step and if you select a midrange of the same sensitivity as the woofer you always can attenuate for what ever leveling you want to have and put a baffle step compensation on the woofer.
I think you will end with a baffle step compensation of 3-4 dB, but that is for you to find out during the design and evaluation process.
Good luck...
Now you have full understanding about the concept of baffle step and if you select a midrange of the same sensitivity as the woofer you always can attenuate for what ever leveling you want to have and put a baffle step compensation on the woofer.
I think you will end with a baffle step compensation of 3-4 dB, but that is for you to find out during the design and evaluation process.
Good luck...
thank you @flex2 I will try do my best.
Only for my curiosity:
My actual midrange Visator DSM0FFL is rated 120 Watt (nominal power) while the Satori MW13TX-8 with its huge magnet only 40 watts.
I suppose as is often said the manufacturers declare powers with rather arbitrary values, it seems very strange to me that my small midrange is able to sustain 3 times more power than the Satori MW13TX-8 at the same frequency range for more time.
What do yoy think ?
Only for my curiosity:
My actual midrange Visator DSM0FFL is rated 120 Watt (nominal power) while the Satori MW13TX-8 with its huge magnet only 40 watts.
I suppose as is often said the manufacturers declare powers with rather arbitrary values, it seems very strange to me that my small midrange is able to sustain 3 times more power than the Satori MW13TX-8 at the same frequency range for more time.
What do yoy think ?
visaton is a 50 mm dome with 50 mm voice coil
satori has a 30 mm voice coil.
also, the rated power is probably calculated using pink noise spectrum and "useful" crossover frequencies. these are probably higher for the visaton dome.
generally for home use the power rating is quite insignificant, unless you abuse the drivers for loud parties or you chose unsuitable crossover frequencies and slopes.
I took a look at its big brother Satori MW16TX-8, which practically costs the some.
What you think if I choose the MW16TX-8 instead of MW13TX-8 ?
What you think if I choose the MW16TX-8 instead of MW13TX-8 ?
I think you will probably have your reasons to do so! 😊
A bigger mid has more displacement, so can be crossed to the woofer lower and/or has more spl headroom.
breakup resonances will be lower, so Xover to the tweeter usually also needs to be lower.
Bigger diaphragm also starts beaming sooner, which may be desirable or not, depending on your target for directivity.
others may know more about these drivers!
If you want to go for a bigger driver like https://sbacoustics.com/product/6-5-satori-mw16tx-8-textreme/ for midrange.
Then I would suggest that you look at the dedicated midrange version https://sbacoustics.com/product/6½-satori-mr16tx-8-textreme/
If you look at spread at 3kHz then the midrange version have 3db down for 60° while the midbass version have 6dB down for 60° at 3 kHz.
Midrange version have higher sensitivity and have 20% stiffer suspension, so the midrange version probably have lower distortion and have better performance at LP filter. Breakup are also higher in frequency.
For MW I would suggest crossover at max 2 kHz and for MR max 2,5 kHz.
I think the MR have the potential to be able to give you a little bit better performance with the Bliesma tweeter you selected.
Then I would suggest that you look at the dedicated midrange version https://sbacoustics.com/product/6½-satori-mr16tx-8-textreme/
If you look at spread at 3kHz then the midrange version have 3db down for 60° while the midbass version have 6dB down for 60° at 3 kHz.
Midrange version have higher sensitivity and have 20% stiffer suspension, so the midrange version probably have lower distortion and have better performance at LP filter. Breakup are also higher in frequency.
For MW I would suggest crossover at max 2 kHz and for MR max 2,5 kHz.
I think the MR have the potential to be able to give you a little bit better performance with the Bliesma tweeter you selected.
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Thank you @flex2
To be honest there are other reasons that made me evaluate it MW16TX-8 instead of MW13TX-8:
1) More power. While normally I don't listen at high volume, I don't exclude the possibility that maybe someday I might. I wouldn't want to run the risk of getting close to the power limit of the midrange since it's only 40Watt. The MR16TX-8 is only 30 Watt, My amplifier is 100 Watt RMS 8 ohm.
2) The MR16TX-8 need volume of 15 liters, that is better for me, becouse make it easy to design the loudspeaker.
3) With MR16TX-8 In theory I can cut to 300 Hz instead 400Hz and this can have its positive sides.
4) The cost MW16TX-8 is the some of MW13TX-8, while MR16TX-8 cost a little more, but have less power.
Cut at 2 kHz or 2,5 kHz, don't change too much, because in both case I need to put the RLC circuit on tweeter.
To be honest there are other reasons that made me evaluate it MW16TX-8 instead of MW13TX-8:
1) More power. While normally I don't listen at high volume, I don't exclude the possibility that maybe someday I might. I wouldn't want to run the risk of getting close to the power limit of the midrange since it's only 40Watt. The MR16TX-8 is only 30 Watt, My amplifier is 100 Watt RMS 8 ohm.
2) The MR16TX-8 need volume of 15 liters, that is better for me, becouse make it easy to design the loudspeaker.
3) With MR16TX-8 In theory I can cut to 300 Hz instead 400Hz and this can have its positive sides.
4) The cost MW16TX-8 is the some of MW13TX-8, while MR16TX-8 cost a little more, but have less power.
Cut at 2 kHz or 2,5 kHz, don't change too much, because in both case I need to put the RLC circuit on tweeter.