Hello everyone,
I wanted to build a 3 way speaker. For the lows i wanted to have a sealed enclosure. Its quite hard to find drivers for that but i fond a really nice one.
https://voltloudspeakers.co.uk/loudspeakers/sb220-1-8/
Heres the thing: I want it to crossover between 600-800 with my bliesma M74S.
BUT: They call the SB220.1 "optimised for bass performance in sub-woofer applications" or "Sub Bass Driver".
Is this just marketing? Or will this driver be as good in the low mids as others? Is there something I dont see? For the Frequency range they even say 25-1000hz.
Their actual mid bass driver BM228.8 (https://voltloudspeakers.co.uk/wp-content/uploads/2017/11/BM228.8_v1.1.pdf) doesn't even look that good in the response curve vs "the sub".
Thanks everyone,
Johannes
I wanted to build a 3 way speaker. For the lows i wanted to have a sealed enclosure. Its quite hard to find drivers for that but i fond a really nice one.
https://voltloudspeakers.co.uk/loudspeakers/sb220-1-8/
Heres the thing: I want it to crossover between 600-800 with my bliesma M74S.
BUT: They call the SB220.1 "optimised for bass performance in sub-woofer applications" or "Sub Bass Driver".
Is this just marketing? Or will this driver be as good in the low mids as others? Is there something I dont see? For the Frequency range they even say 25-1000hz.
Their actual mid bass driver BM228.8 (https://voltloudspeakers.co.uk/wp-content/uploads/2017/11/BM228.8_v1.1.pdf) doesn't even look that good in the response curve vs "the sub".
Thanks everyone,
Johannes
According to manufacturer a sealed box of 20 liters volume will give you an f3 of 53Hz. Cone breakup peaks at about 1.3kHz so crossing it at about 600Hz should be no problem with 2nd order crossover maybe even 1st order and a notch filter to dampen the breakup region.
Take T/S parameters and simulate it
Take T/S parameters and simulate it
Thanks @Toaster79 thats exactly what I did. And the simulation looked good to me. I'll use a Hypex dsp module and maybe a 4th oder (just because ATC does it ... idk, I'll play around with it).
It just worried me because they specifically call it a sub and nothing else. Maybe theres something I just dont know about speaker selection.
@JMFahey ok but whats the problem then with using this "sub" in the speaker until ˜600/800 hz? Is there a parameter where I could see if it fits?
It just worried me because they specifically call it a sub and nothing else. Maybe theres something I just dont know about speaker selection.
@JMFahey ok but whats the problem then with using this "sub" in the speaker until ˜600/800 hz? Is there a parameter where I could see if it fits?
One difference between the two is the sensitivity. The SB220.1 sub is 86 dB and the BM228.8 mid-bass is 89 dB. Not a huge difference but the mid-bass is closer to the 97 dB of the M74S which may make the crossover easier.
What is sub?
What is mid driver?
There are many charts, but this one was already posted many times.
Sub bass is 18Hz to 50Hz.
Mid driver is 220Hz to 1.8kHz.
No one can mistake these for each other. Your thread title sucks.
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So can I conclude from this that no one can see a good reason (except spl) why this woofer cant be used up into the low mids?
There are a few other compromises apparent from looking at the specs. The SB220.1 has:
- Higher inductance, which means the frequency response rolls off earlier.
- Much higher Xmax. This might come at a cost in linearity, but it would require measurements to be sure.
- A bit of a peak in the frequency response just above 1kHz.
- Slightly larger Sd. This might make it start beaming slightly earlier.
On paper, and if you are happy for a driver to cope with high Xmax for reproducing the bass whilst simultaneously reproducing the important midrange, yes, sort of, but you are missing the huge trick of taking the high excursion load off the lower midrange reproducing driver.
But to address your question, the reason why sb220.1 is woofer or subwoofer, because it can not be used high enough into midrange. Just like you posted on the graph for JMFahey, it has terrible breakup peak past 1kHz.
So crossing it 600-800 Hz makes sense.
You do not want this one for 2way.
The second one you posted, is clearly midbass, and can be used all the way to 3kHz. Its not too flat for my taste, but it would be ok for 2way bookshelf. Its rolling of much sooner in low frequencies, ~150Hz and its response is going sharply down.
Since you are building 3way, and i assume you will select ~4" midrange, and cross is like 300 - 3000Hz, it does not matter if you choose first or second one. I would go for first, since it has lot more response below 100Hz. But 8" is small for me...i use four 15". But its up to you. Still thread title sucks.
So crossing it 600-800 Hz makes sense.
You do not want this one for 2way.
The second one you posted, is clearly midbass, and can be used all the way to 3kHz. Its not too flat for my taste, but it would be ok for 2way bookshelf. Its rolling of much sooner in low frequencies, ~150Hz and its response is going sharply down.
Since you are building 3way, and i assume you will select ~4" midrange, and cross is like 300 - 3000Hz, it does not matter if you choose first or second one. I would go for first, since it has lot more response below 100Hz. But 8" is small for me...i use four 15". But its up to you. Still thread title sucks.
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@MrKlinky @Mr Evil I just want to make sure I get this right: thats the doppler effekt problem right?
But thats not a problem for just this specific driver, its just that it would play something like -3 on 50hz and 500 at the same time right?
What would be the solution? Get a driver with a higher fs?
But thats not a problem for just this specific driver, its just that it would play something like -3 on 50hz and 500 at the same time right?
What would be the solution? Get a driver with a higher fs?
@adason yea idk how low i can crossover. Thats the mid: https://doc.soundimports.nl/pdf/brands/Bliesma/Bleisma_M74S6_midrange.pdf
I guess i could do a 4th order on 500hz?
I guess i could do a 4th order on 500hz?
Please post response for both drivers in the same post. That will answer your question.
I like dome mids, used them many times, but not the one you selected. I usually select 900Hz, as domes do not like it lower, unless its atc.