Hi Nelson!
Nice to hear that B5 is being released. But, you know us, and nothing is as exciting as do-it-yourself 😀
I've been playing with these for a while, and figured out the most part (you know I use OB and need B5-like circuit). What is still a bit mystical is the way equalization is done. On some conceptual schematic I saw that the equalization for hi-pass is done with a sort of line-level notch filter.
I am curious to know if you are using real inductors there, or a gyrator (j-fet one, of course)?
Regards,
Vix
Nice to hear that B5 is being released. But, you know us, and nothing is as exciting as do-it-yourself 😀
I've been playing with these for a while, and figured out the most part (you know I use OB and need B5-like circuit). What is still a bit mystical is the way equalization is done. On some conceptual schematic I saw that the equalization for hi-pass is done with a sort of line-level notch filter.
I am curious to know if you are using real inductors there, or a gyrator (j-fet one, of course)?
Regards,
Vix
Thank you Ra7,
I was analyzing various active crossovers and noticed that Mr. Linkwitz uses baffle step compensation and a notch for mid-hi section of his open baffle speakers. However, he uses an opamp-based gyrator to simulate an inductor. Not surprising that Nelson uses real inductors!😎
Vix
p.s. Pics are nice, but I prefer the naked ones! 😀
I was analyzing various active crossovers and noticed that Mr. Linkwitz uses baffle step compensation and a notch for mid-hi section of his open baffle speakers. However, he uses an opamp-based gyrator to simulate an inductor. Not surprising that Nelson uses real inductors!😎
Vix
p.s. Pics are nice, but I prefer the naked ones! 😀
Hey Vix, did you see this:
http://www.diyaudio.com/forums/multi-way/176117-rubber-sheets.html
No nakedity but, first I thought the title might have a discussion involving latex or something??? 😀
I just want to throw my 2 cents in about active crossovers in general.
There aren't too many out there for hi-end, non-studio/live situations.
The ones that are available are pricey. E.g., Bryson and Pass Labs.
I believe these 2 simple XOs will be very popular. They do fill a need. How it was over looked for so long by manufactures is beyond me. I hope FW sells thousands!
That's all I'm going to say about that subject.
Vince
There aren't too many out there for hi-end, non-studio/live situations.
The ones that are available are pricey. E.g., Bryson and Pass Labs.
I believe these 2 simple XOs will be very popular. They do fill a need. How it was over looked for so long by manufactures is beyond me. I hope FW sells thousands!
That's all I'm going to say about that subject.
Vince
B5
Nelson sent out a preliminary version of the B5 a while back. This version, which ra7 has, is a bit different than the final version. A peak on the inside will not tell you much about the final version.
There is no notch filter or step filter in the release version. The original version had the crossover frequency limited to 150 hz, the new release extends this to 300 hz, which works really well with some of the smaller baffles and smaller drivers.
I have taken a number of orders for these already. They will probably be quite popular.
Nelson sent out a preliminary version of the B5 a while back. This version, which ra7 has, is a bit different than the final version. A peak on the inside will not tell you much about the final version.
There is no notch filter or step filter in the release version. The original version had the crossover frequency limited to 150 hz, the new release extends this to 300 hz, which works really well with some of the smaller baffles and smaller drivers.
I have taken a number of orders for these already. They will probably be quite popular.
Agree with Jon here. Although, on the FW website, it says there are two versions, B4
and B5, one which is solely geared towards OBs with full rangers and the other is a more
flexible crossover.
Either way, it is sure to be a hit.
Oh and the innards are a work of art. The craftsmanship is of the highest standard.
and B5, one which is solely geared towards OBs with full rangers and the other is a more
flexible crossover.
Either way, it is sure to be a hit.
Oh and the innards are a work of art. The craftsmanship is of the highest standard.
Jon,
Just to clarify, is the high CO point at 200Hz, like it says on your Web site, or 300Hz, as you state here?
Thanks
Just to clarify, is the high CO point at 200Hz, like it says on your Web site, or 300Hz, as you state here?
Thanks
The B5 has bass boost for open baffles, 1st and 2nd order crossovers up to 300 hz.
The B4 has no bass boost, but 1st, 2nd, 3rd, and 4th order crossovers up to 12kHz. More details will be on my web site tomorrow if you are interested in either. B4 will begin shipments sometime in December.
Gotta believe Nelson knows what he designed. The 200 Hz notation on my site is from an earlier design, and should be ignored. Again, I will update that shortly.
Sure, and we want to find out how he did it! 😎🙂
That's why I was wondering how he executed baffle-step compensation. On other schematics, the simplest form involves a capacitor in series with the (variable) resistor to ground, after the hi-pass filter block. Some others (Linkwitz) include an opamp-based gyrator to emulate an inductor. It seems that Nelson uses real inductors.
Thanks
Vix
The more I read about Linkwitz crossover, I try to figure out similarities and differences between it and B5. Both have low-hi crossovers and baffle equalization. Linkwitz uses opamps, Nelson uses J-fets. However,Linkwitz also uses a couple of notch filters and I am not sure how they are handled in B5...
I understand that both the B4 and B5 will be pretty versatile, but I´m have a hard time figuring out which will be the right one for my use. I am leaning towards B5, but I have a few questions I hope someone would be so kind to help me with.
Firstly, I´m not going for OB (for now, anyhow), mostly because of limited space. I cannot place the speakers much more than 50-100cm from back and side walls. I do however want to experiment with OB later, so would it be wize to go with the B5 now anyway?
I´m going to use a Seas Exotic F8 (but also test other fullrange speakers), and till I find a woofer I want to settle with, I´ll be using it from top to bottom. Is it possible for me to use the crossover to only compensate for baffle step, thus only use the ´high output´ with the lowest crossover frequency (how low will it go)? This would give me a great flexibility while testing, and at the same time be able to fast and easy convert to a working setup when a woofer is absent.
As I´m going for a fullrange pluss a woofer, I feel the B5 will be appropriate for my use, but advices are highly appreciated.
Thank you for your time.
Firstly, I´m not going for OB (for now, anyhow), mostly because of limited space. I cannot place the speakers much more than 50-100cm from back and side walls. I do however want to experiment with OB later, so would it be wize to go with the B5 now anyway?
I´m going to use a Seas Exotic F8 (but also test other fullrange speakers), and till I find a woofer I want to settle with, I´ll be using it from top to bottom. Is it possible for me to use the crossover to only compensate for baffle step, thus only use the ´high output´ with the lowest crossover frequency (how low will it go)? This would give me a great flexibility while testing, and at the same time be able to fast and easy convert to a working setup when a woofer is absent.
As I´m going for a fullrange pluss a woofer, I feel the B5 will be appropriate for my use, but advices are highly appreciated.
Thank you for your time.
Linkwitz Riley
Vix:
You are confusing a particular implementation of a crossover with the crossover slope. Linkwitz-Riley is a specific type of crossover slope, like a Butterworth slope, that is independent of exactly how it is implemented. See here: Linkwitz-Riley Crossovers: A Primer
Nelson implements this slope with discrete components, Linkwitz implements it with op-amps. But it is the slope that we are discussing here, not the implementation. If you want Linkwitz Riley slopes, you have to order a B4 with that slope. You can get Butterworth slopes in either the B4 or the B5.
Vix:
You are confusing a particular implementation of a crossover with the crossover slope. Linkwitz-Riley is a specific type of crossover slope, like a Butterworth slope, that is independent of exactly how it is implemented. See here: Linkwitz-Riley Crossovers: A Primer
Nelson implements this slope with discrete components, Linkwitz implements it with op-amps. But it is the slope that we are discussing here, not the implementation. If you want Linkwitz Riley slopes, you have to order a B4 with that slope. You can get Butterworth slopes in either the B4 or the B5.
B4 vs B5
The B4 has much greater flexibility in terms of slopes, 1st, 2nd, 3rd or 4th order. It also has a greater range of crossover frequencies, up to 12,600 Hz.
The B5 has the ability to have bass boost, as well as a high pass filter for the bass to avoid excessive excursion at lower frequencies. It is limited to 1st or 2nd order slopes, and will not crossover higher than 300 hz.
If you are using a pure open baffle, without a subwoofer, the bass boost of the B5 will be very helpful, along with the extra high pass filter for the bass.
Otherwise, chose the B4.
There is a bit more on my site which you may find helpful.
The B4 has much greater flexibility in terms of slopes, 1st, 2nd, 3rd or 4th order. It also has a greater range of crossover frequencies, up to 12,600 Hz.
The B5 has the ability to have bass boost, as well as a high pass filter for the bass to avoid excessive excursion at lower frequencies. It is limited to 1st or 2nd order slopes, and will not crossover higher than 300 hz.
If you are using a pure open baffle, without a subwoofer, the bass boost of the B5 will be very helpful, along with the extra high pass filter for the bass.
Otherwise, chose the B4.
There is a bit more on my site which you may find helpful.
its great to see finally b5 and b4 is available
jon, what exactly do u mean by "pure open baffle, without subwoofer"? means separate active subwoofer?
ur setup in RMAF is with BASS DRIVER / SUBWOOFER...
cheers
henry
jon, what exactly do u mean by "pure open baffle, without subwoofer"? means separate active subwoofer?
ur setup in RMAF is with BASS DRIVER / SUBWOOFER...
cheers
henry
Jon,
Thank you very much for the responses. I am sorry if I was not clear about what I wanted to find out. In the end, the schematic is copyrighted and I fully understand if Nelson, or you can not disclose fine details of the circuit.
So, at first I wanted to know what was the order of the crossover and Q, in the particular case of Open baffles with the Lowther fullrange on top. You answered that; 80 Hz low pass, 150 Hi-pass, 2-nd order with the Q of 0.707 (butterworth alignment). That is clear. It is also known that the Sallen-Key topology was used and J-fet buffers are used.
Later however, I was trying to figure out how the equalization (both hi-pass and low pass) on B5 was done. I turned out to Linkwitz web site and read his articles about open baffles and active crossovers. I noticed that he was using "shelving low pass" together with certain notches to equalize response on the open baffle. Then I realized that B5 must be using similar principles (the difference being that Nelson uses J-fets while Siegfried uses opamps). However, it was bugging me to find out how exactly did Nelson apply these EQ circuits in B5. It was clear that there are J-fets, but other details are less known. For example, Siegfried uses notch filters that employ opamp based inductors (emulated inductors-gyrators), and I was curious to find out if Nelson did something along these lines (with the J-fets of course) or he opted to use real inductors, or yet some other, less known solution.
Nevertheless, it is most important that Open baffle lovers know that B5 will make their life easier, and once you get it (B5), active solutions are not hard to implement at all.
Thank you very much for your time and patience
Regards
Vix
Thank you very much for the responses. I am sorry if I was not clear about what I wanted to find out. In the end, the schematic is copyrighted and I fully understand if Nelson, or you can not disclose fine details of the circuit.
So, at first I wanted to know what was the order of the crossover and Q, in the particular case of Open baffles with the Lowther fullrange on top. You answered that; 80 Hz low pass, 150 Hi-pass, 2-nd order with the Q of 0.707 (butterworth alignment). That is clear. It is also known that the Sallen-Key topology was used and J-fet buffers are used.
Later however, I was trying to figure out how the equalization (both hi-pass and low pass) on B5 was done. I turned out to Linkwitz web site and read his articles about open baffles and active crossovers. I noticed that he was using "shelving low pass" together with certain notches to equalize response on the open baffle. Then I realized that B5 must be using similar principles (the difference being that Nelson uses J-fets while Siegfried uses opamps). However, it was bugging me to find out how exactly did Nelson apply these EQ circuits in B5. It was clear that there are J-fets, but other details are less known. For example, Siegfried uses notch filters that employ opamp based inductors (emulated inductors-gyrators), and I was curious to find out if Nelson did something along these lines (with the J-fets of course) or he opted to use real inductors, or yet some other, less known solution.
Nevertheless, it is most important that Open baffle lovers know that B5 will make their life easier, and once you get it (B5), active solutions are not hard to implement at all.
Thank you very much for your time and patience
Regards
Vix
Just found one piece of the puzzle:
http://www.diyaudio.com/forums/full-range/138863-l-cao-ob-w-eminence-woofer-3.html#post1751840
http://www.diyaudio.com/forums/full-range/138863-l-cao-ob-w-eminence-woofer-3.html#post1751840
Last year ('09) I used an Altec 416B in an open baffle without a subwoofer. Without the bass boost of the B5, it would have sounded very thin. This is a pure open baffle, and where you really want the B5 instead of the B4.
This year an integrated, closed box subwoofer at RMAF. It would have worked with either the B4 or the B5. This is an impure open baffle, with the bass provided by a sealed box.
You could have an Altec 416 B providing mid-bass support using an open baffle, and a subwoofer to provide true bass support. Depending on the crossover frequencies, (i.e. subwoofer crossing over at 80 hz or so) you could probably get by with the B4.
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