Hi
I've done some more experimentation today with active crossovers...
The result: I feel exhausted,and disappointed.
Ok, there are some observations:
1. I've been trying low pass crossover, 1st order,(active), and, no matter which frequency I chose (from 50-200 Hz), it doesn't sound good. (I also high-passed Visaton from 50-350 Hz).
Tried many combinations. None of them sounded good. Visaton sounds nice and clean, but then Eminence kicks in and muddies the high bass and even midrange.
Second option,listenable, but still not good is:
Visaton high-passed at around 80 Hz.
Eminence low passed via 2nd order active crossover, also at around 80 Hz. Then, I inserted a 3.3 mH choke (because that's what I had at hand) between a bass amp (now I am using NAD 3020) and the Eminence. (reversed polarity of the bass amp).
Still, the most enjoyable sound comes from Visaton alone, midrange is great, but I miss the raw quantity of bass. Eminence tries to provide that, but inserts too much BS...
Vix
Now I just need a
I've done some more experimentation today with active crossovers...
The result: I feel exhausted,and disappointed.
Ok, there are some observations:
1. I've been trying low pass crossover, 1st order,(active), and, no matter which frequency I chose (from 50-200 Hz), it doesn't sound good. (I also high-passed Visaton from 50-350 Hz).
Tried many combinations. None of them sounded good. Visaton sounds nice and clean, but then Eminence kicks in and muddies the high bass and even midrange.
Second option,listenable, but still not good is:
Visaton high-passed at around 80 Hz.
Eminence low passed via 2nd order active crossover, also at around 80 Hz. Then, I inserted a 3.3 mH choke (because that's what I had at hand) between a bass amp (now I am using NAD 3020) and the Eminence. (reversed polarity of the bass amp).
Still, the most enjoyable sound comes from Visaton alone, midrange is great, but I miss the raw quantity of bass. Eminence tries to provide that, but inserts too much BS...
Vix
Now I just need a
Hi Choky,
I didn't look at the cone...it was muddy to my ears. I also tried to turn off the Pass amp (for the Visatons), and play with the bass crossover until I get a nice, clean bass from the Eminence.
There was too much midrange coming out of Eminence. Even at 60 hz first order low pass it sounded flabby . Up the frequency and it was just worse, sounding more honky. (as if it was mounted on a big plastic can). It just didn't have the quality of bass that I heard from Visatons alone.
I didn't try the pass amp for both drivers, as I don't have the big inductors to try the passive approach. (3.3 mH is too small I guess)
It seems that my best bet is to borrow a high power SS amp and see if it will "cure" the Eminence...
Thanks,
Vix
I didn't look at the cone...it was muddy to my ears. I also tried to turn off the Pass amp (for the Visatons), and play with the bass crossover until I get a nice, clean bass from the Eminence.
There was too much midrange coming out of Eminence. Even at 60 hz first order low pass it sounded flabby . Up the frequency and it was just worse, sounding more honky. (as if it was mounted on a big plastic can). It just didn't have the quality of bass that I heard from Visatons alone.
I didn't try the pass amp for both drivers, as I don't have the big inductors to try the passive approach. (3.3 mH is too small I guess)
It seems that my best bet is to borrow a high power SS amp and see if it will "cure" the Eminence...
Thanks,
Vix
If I look at the data sheets for these two drivers.
Visaton B200 is 96 dB/W/m
Eminence Beta 15A is 96 dB/W/m with an fs = 36 Hz and Qts = 0.59
So the Eminence bass response is already rolling off starting at several hundred Hz due to the low Qts. Add to that the OB roll off and the combined effective efficiency of the Beta 15A for bass is really low compared to the B200. Then add the crossover and I bet you are only getting 80 dB/W/m best case out of the Beta 15A at 40 Hz. You will need huge amounts of boost to put enough power into the Eminence to bring it up the the 96 dB of the B200. This means a lot of power into the voice coil and large deflections. In my opinion this combination of drivers is dead right out of the gate, definitely not an optimum driver combination.
If you want to use the B200 crossed over to separate bass driver(s), you will probably need a starting bass efficiency approaching 105 dB/W/m before adding the impact of the baffle and the crossover.
Visaton B200 is 96 dB/W/m
Eminence Beta 15A is 96 dB/W/m with an fs = 36 Hz and Qts = 0.59
So the Eminence bass response is already rolling off starting at several hundred Hz due to the low Qts. Add to that the OB roll off and the combined effective efficiency of the Beta 15A for bass is really low compared to the B200. Then add the crossover and I bet you are only getting 80 dB/W/m best case out of the Beta 15A at 40 Hz. You will need huge amounts of boost to put enough power into the Eminence to bring it up the the 96 dB of the B200. This means a lot of power into the voice coil and large deflections. In my opinion this combination of drivers is dead right out of the gate, definitely not an optimum driver combination.
If you want to use the B200 crossed over to separate bass driver(s), you will probably need a starting bass efficiency approaching 105 dB/W/m before adding the impact of the baffle and the crossover.
Thanks Martin!
I may play with these a bit more (try a high power amp to push the Eminence), but, as things are looking now, this may be the end of my OB adventure.I will probably dismantle the whole d*** thing. While Eminence might get sold, Visatons will stay cause' I like their sonics. As far as I could see, a BIB for Visatons may be too big. Dave (planet 10) seems to have a promising box for the Visatons- "Loreena 1v1"...(still big but acceptable)
Thank you very much for the support,
Vix
I may play with these a bit more (try a high power amp to push the Eminence), but, as things are looking now, this may be the end of my OB adventure.I will probably dismantle the whole d*** thing. While Eminence might get sold, Visatons will stay cause' I like their sonics. As far as I could see, a BIB for Visatons may be too big. Dave (planet 10) seems to have a promising box for the Visatons- "Loreena 1v1"...(still big but acceptable)
Thank you very much for the support,
Vix
Vix,
I could not get good bass response from a woof driver with Qts about 0.55 on an open baffle, I then convert it to U-frame, the bass now starts to rolling off starting 50 hertz.
this arrangement introduces resonances at higher frequencies(145hz, 175Hz etc measured), luckily I have equipment that can measure this. I use 4th order LR low pass filter to reduce the resonance(it can be removed by using notch filter) to a mininum(still there), x-over frequency at 100-110hz(i use active x-over filter).
I use 2 woofers in parallel, with total efficiency about 92-93db which matches my mid range driver fostex FE167 with efficiency of about 94db.
this arrangement is not final I need to remove resonance freqency(the dominant one) all together. So far the sound is quite good, even though the freq. integration is not perfect.
once I finish my designing and making speakers I will publish here.
cheers.
I could not get good bass response from a woof driver with Qts about 0.55 on an open baffle, I then convert it to U-frame, the bass now starts to rolling off starting 50 hertz.
this arrangement introduces resonances at higher frequencies(145hz, 175Hz etc measured), luckily I have equipment that can measure this. I use 4th order LR low pass filter to reduce the resonance(it can be removed by using notch filter) to a mininum(still there), x-over frequency at 100-110hz(i use active x-over filter).
I use 2 woofers in parallel, with total efficiency about 92-93db which matches my mid range driver fostex FE167 with efficiency of about 94db.
this arrangement is not final I need to remove resonance freqency(the dominant one) all together. So far the sound is quite good, even though the freq. integration is not perfect.
once I finish my designing and making speakers I will publish here.
cheers.
Hi Vix!
I've heard the original Nobox in Hamburg. They sounded excellent with an extension to approximately 40Hz. But be aware of the efficience is only 90db of these. Nobox has a pretty hefty filter and a 6-7db choke on B200.
I have some sim's on Alpha and Beta on a flat panel, I will see if I can find them. Othervise you have MJK's sim on his home page.
If you're going to run them active you must have a quite power ful bass amp to make up for the more efficient B200.
Peter
I've heard the original Nobox in Hamburg. They sounded excellent with an extension to approximately 40Hz. But be aware of the efficience is only 90db of these. Nobox has a pretty hefty filter and a 6-7db choke on B200.
I have some sim's on Alpha and Beta on a flat panel, I will see if I can find them. Othervise you have MJK's sim on his home page.
If you're going to run them active you must have a quite power ful bass amp to make up for the more efficient B200.
Peter
Read post no3 in this thread. Excellent explanation of your problem,me thinks.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=110583
Good luck
http://www.diyaudio.com/forums/showthread.php?s=&threadid=110583
Good luck
According o the datasheet the Eminence is peaking towards its upper end. Together with your early rolloff in the bass this may lead to your problems.
Have the woofer perform flat first (by the use of EQing) and THEN try to design a crossover for your woofer.
I could imagine that a lag filter or even a first order lowpass might do the trick to get this woofer's response flat.
Regards
Charles
Have the woofer perform flat first (by the use of EQing) and THEN try to design a crossover for your woofer.
I could imagine that a lag filter or even a first order lowpass might do the trick to get this woofer's response flat.
Regards
Charles
I cant imagine any PA driver that will sound good with only 6db filter
It appears to me that you are NOT being very patient ... it took me several years to learn how to make an xo work ... I believe the drivers are ok, and shoud be able to work properly, with the right care
12db passive on woofer ... big inductor and small C and then a notch is probably needed too ... maybe a bit exstra weight on woofer cone
And as mentioned ... you might need to pad down midrange
Invert polarity on midrange
Your chipamp may not be strong enough fore such a woofer ... or too small power supply
It appears to me that you are NOT being very patient ... it took me several years to learn how to make an xo work ... I believe the drivers are ok, and shoud be able to work properly, with the right care
12db passive on woofer ... big inductor and small C and then a notch is probably needed too ... maybe a bit exstra weight on woofer cone
And as mentioned ... you might need to pad down midrange
Invert polarity on midrange
Your chipamp may not be strong enough fore such a woofer ... or too small power supply
peterbrorsson said:
well ......... my friend Igor made Aion proto ........ ugly rectangular tall box , which plays niiiiiiiiiiiice ! with dreky DIY A1 power amp , or with half mini Aleph or .......
I just have no time for them
, even if MDF is cut and just lay in my garage ; that will be Mau 12 for my Oly (pcb guru ) ;I think that I'll prepare second set of MDF for Mau 12 and make two pairs at once ........ in next few weeks , or in 3 months ; depends of few plain everyday life things.......
anyway - what's count is that I heard them naked and on quickie OB
you know - my problem is that I have too much good sounding spks
Zen Mod said:
well ......... my friend Igor made Aion proto ........ ugly rectangular tall box , which plays niiiiiiiiiiiice ! with dreky DIY A1 power amp , or with half mini Aleph or .......
I just have no time for them
I think that I'll prepare second set of MDF for Mau 12 and make two pairs at once ........ in next few weeks , or in 3 months ; depends of few plain everyday life things.......
anyway - what's count is that I heard them naked and on quickie OB
you know - my problem is that I have too much good sounding spks
Hmm, have same problems(except too many good spkrs)and had Sonido's on a piece of mdf also. YUMM!
And vix, pardon for OT
Peter
I know this is a fullrange forum, but B200 still being a FR ... I wonder if anyone has tried a 1.5way OB with 3 drivers like the B200 ... 2 playing bass/mid and 1 playing fullrange ... cleaner design, less hazzle
Another crazy idea ... bottom bass drivers with 12db filter and the other with 6db ... they still share the same inductor
Another crazy idea ... bottom bass drivers with 12db filter and the other with 6db ... they still share the same inductor
Nope, they cannot share the same inductor ... a paralel C on one driver will cut both drivers as they are in paralel ... ehhh, let see ...
Maybe 6db with 2 inductors in series ... 1 driver connected at the "middle point", and the other through both inductors ... THEN the bottom driver could still be 12db, as they are seperated by the coils ... fellows, just ignore this
Maybe 6db with 2 inductors in series ... 1 driver connected at the "middle point", and the other through both inductors ... THEN the bottom driver could still be 12db, as they are seperated by the coils ... fellows, just ignore this
tinitus said:I know this is a fullrange forum, but B200 still being a FR ... I wonder if anyone has tried a 1.5way OB with 3 drivers like the B200 ... 2 playing bass/mid and 1 playing fullrange ... cleaner design, less hazzle
Another crazy idea ... bottom bass drivers with 12db filter and the other with 6db ... they still share the same inductor
"Praise the Lord and send me your money" and I will try it
Peter
on the other hand, if it really does work it may be heaven, and well worth the effort- Status
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