MOX in parallell with a 1 mH inductor for the B200

ChuckT · « **Reply #40 on:** 23 Sep 2006, 05:45 am »

Hi all,

Thought I'll join in as I got the b200 not too long and almost immediately feel a need (and did) to use a BSC (or L-R) circuit to tame the raising responds.

I feel using a bsc gives a much more balanced sound, so even one uses a sub, it is still "needed", as the responds starts raising at 200hz to 7khz with over 10dB increase! My casual measurement actually gives a larger increase. However, in actual listening it doesn't sound as bright as the measurements, which is strange. Maybe it is the excellent quality of the midrange and details that will let a listener to forgive the top end.

In addition, I would agree with mcgsxr that b200 in OB requires a compatiable amp to get that bass. As mine b200 doesn't seem to work with a low power T-amp. One tends to get this feeling when mine tiny Fostex FE103 produce better bass then the b200.
My baffles is 14.5"x35" with 7" wings and driver is 19" off the floor.

Also, for a clearer picture of a bsc (or L-R) circuit, try out the excellent spreadsheet by Jeff Bagby.
http://www.pvconsultants.com/audio/targetgen/pcdc.htm
Also, a zobel is necessary with the bsc, otherwise, the bsc wouldn't not work as intended due to impendance raise.

fu_man · « **Reply #41 on:** 23 Sep 2006, 06:02 am »

okay I'm way out of my depth on this one... I should have stopped at the title but so far I've got some brilliant music flowing so far from just following along..... a quick visit down to the local electronics store and I now have a handful of things with wires sticking out

Anyone care to help out with a photo showing how i stick these bits together and how i might attach to the +++line? ... just got to go borrow one of those hot metal things...

fu_man · « **Reply #42 on:** 24 Sep 2006, 02:30 pm »

oh, oops... i didn't mean to kill this thread

well... never mind with the pic. after what can only be described as a very ugly soldering job I now have an inductor and resistor hanging off the back of my B200 driver.

The balance of channels seems somehow affected, something not quite right. Mind you i had to change the positioning and wing settings of the baffles to make the changes, maybe i didn't set them back right - I try again after more sleep.

Otherwise for now, yeah it seems a bit smoother.. but with with the Sig 30 always changing (getter better) it's hard to tell. The set up i have used doesn't allow me to quickly change back - I'll have another hack next week and see if i can fix this so i can do quick comparisons.

However the most interesting thing that seems to have happened: Bass from sub (REL Storm) had 'separated' from the baffles (less integrated sounding) Turning down the crossover and gain fixes this. Previously the gain was maxed out on the REL and I still couldn't get 'too much', which was so different to what i was used in my previous system that at first i thought the sub wasn't working in it's new position with the Sig 30. (Thanks for the technical advice Vinnie, "...have you turned up the gain"!)
Now I have much more headroom.

BTW The bass from the sub, when not overdone, totally fulls out the whole sound in a way which is much more satisfying to me.

jkelly · « **Reply #43 on:** 24 Sep 2006, 05:32 pm »

I don't have a junk drawer so... does anyone have part numbers
to purchase the "1mH inductor in parallel with an 8-ohm resistor" circuit components
that work well with the B200?

thanks,

Jeff

Danny Richie · « **Reply #44 on:** 24 Sep 2006, 05:44 pm »

Hey Jeff,

I stock all of those parts. I can even through in the small cap value that you'll need to pick the rolled off highs back up. You can order on line or just call me and tell me to send you what you need and a wiring diagram...

jkelly · « **Reply #45 on:** 24 Sep 2006, 05:56 pm »

Thanks Danny - order going in.

Jeff

Wind Chaser · « **Reply #46 on:** 24 Sep 2006, 06:05 pm »

I don't imagine most of us have measured the actual response of what they are getting from their implementation in their room. I'm not technically equipped as such and so I depend on my ears, which is fine because at the end of the day that's the final test. About 4 months ago Don Nodiak posted the results of what he achieved in his room without BSC, EQ etc. With only one B200 per baffle and nothing else he recorded a very flat response of +/- 2.5db between 250Hz and 8K.

For the record, here is his post...

http://www.audiocircle.com/index.php?topic=19253.msg249958#msg249958

I think this is worth looking at again just to prove if nothing at all, that we shouldn't get too hung up on Visaton's FR graph. As with any speaker the end result will depend on many factors. The B200 is an amazing driver and I have yet to hear ANYTHING at ANY PRICE that sounds even half as good as the B200 in OB. Best of all it is a true point source that doesn't depend on multiple drivers, crossovers and all the other compromises that are so prevalent in modern speaker design.

John

opnly bafld · « **Reply #47 on:** 24 Sep 2006, 07:07 pm »

Quote from: Wind Chaser on 24 Sep 2006, 06:05 pm

I don't imagine most of us have measured the actual response of what they are getting from their implementation in their room. I'm not technically equipped as such and so I depend on my ears, which is fine because at the end of the day that's the final test. About 4 months ago Don Nodiak posted the results of what he achieved in his room without BSC, EQ etc. With only one B200 per baffle and nothing else he recorded a very flat response of +/- 2.5db between 250Hz and 8K. For the record, here is his post...

http://www.audiocircle.com/index.php?topic=19253.msg249958#msg249958

I think this is worth looking at again just to prove if nothing at all, that we shouldn't get too hung up on Visaton's FR graph. As with any speaker the end result will depend on many factors. The B200 is an amazing driver and I have yet to hear ANYTHING at ANY PRICE that sounds even half as good as the B200 in OB. Best of all it is a true point source that doesn't depend on multiple drivers, crossovers and all the other compromises that are so prevalent in modern speaker design.

John

I agree and I know of some others that probably would also.

Lin

markC · « **Reply #48 on:** 25 Sep 2006, 02:04 am »

I also agree and would like to add that I think that they are very much room dependant.

I have to agree with Danny, there is a bit of a hole between about 300 & 800hz but it's not as irritating as a box speak with similar problems.

ChuckT · « **Reply #49 on:** 25 Sep 2006, 11:09 am »

Quote from: Wind Chaser on 24 Sep 2006, 06:05 pm

I don't imagine most of us have measured the actual response of what they are getting from their implementation in their room. I'm not technically equipped as such and so I depend on my ears, which is fine because at the end of the day that's the final test. About 4 months ago Don Nodiak posted the results of what he achieved in his room without BSC, EQ etc. With only one B200 per baffle and nothing else he recorded a very flat response of +/- 2.5db between 250Hz and 8K. For the record, here is his post...

http://www.audiocircle.com/index.php?topic=19253.msg249958#msg249958

I think this is worth looking at again just to prove if nothing at all, that we shouldn't get too hung up on Visaton's FR graph. As with any speaker the end result will depend on many factors. The B200 is an amazing driver and I have yet to hear ANYTHING at ANY PRICE that sounds even half as good as the B200 in OB. Best of all it is a true point source that doesn't depend on multiple drivers, crossovers and all the other compromises that are so prevalent in modern speaker design.

John

I hate to say it, but is there something wrong with the measurement? Assuming the guy is not using digital EQ, there is no way the responds drops starting from 1K and -5dB at 8k. My measurement is exactly the opposite, is the guy measure 30 degree off-axis? Also, even with -5dB roll-off at 125hz, this looks like a dream compare to what I have for my B200. I am not sure we are even talking about the same driver.

But I would concur that the B200 is an excellent driver, and very easy to get great sound. But so far, I don't think it can replace my 2-way scanspeak just yet.

Vinnie R. · « **Reply #50 on:** 25 Sep 2006, 12:54 pm »

Quote from: Danny on 20 Sep 2006, 12:02 am

Hey Vinnie,

Are you bringing any of this stuff to the RMAF next month?

Hi Danny,

I just was re-reading through this thread and I missed your question...sorry about that.

I'm actually not attending RMAF this year. Maybe I'll be back next year...

Best regards,

Vinnie

Danny Richie · « **Reply #51 on:** 25 Sep 2006, 01:12 pm »

Bummer,

I was hoping to hear one of those B200's and those battery powered digital amps.

JohninCR · « **Reply #52 on:** 25 Sep 2006, 05:56 pm »

Quote from: ChuckT on 25 Sep 2006, 11:09 am

I hate to say it, but is there something wrong with the measurement? Assuming the guy is not using digital EQ, there is no way the responds drops starting from 1K and -5dB at 8k. My measurement is exactly the opposite, is the guy measure 30 degree off-axis? Also, even with -5dB roll-off at 125hz, this looks like a dream compare to what I have for my B200. I am not sure we are even talking about the same driver.

But I would concur that the B200 is an excellent driver, and very easy to get great sound. But so far, I don't think it can replace my 2-way scanspeak just yet.

ChuckT,
I think it's that some of us are far more sensitive than others to what goes on in the critical range, because it is almost like we're talking about 2 different drivers. While preferences in music may have something to do with the perception, I don't think the B200 lovers are deaf. I just think we hear differently. I used the FE206E in OB for almost a year, which is flatter from 200hz up than the B200. The uptilted sound was still noticeable to me, but I never could get past or cure the peak around 3khz which was like fingernails on a chalkboard to my ears.

The thing you need to replace your scanspeak 2-way is to free it from the box and make it a 3-way OB with added bass fill.

ChuckT · « **Reply #53 on:** 26 Sep 2006, 05:05 pm »

Let me say again the B200 is an excellent driver, it produce the best midrange details of the speakers I had. But for my taste, both ends of the responds needs a little work, so maybe in the end a 3-way is needed, or maybe put the b200 in an aperiodic box

.

I don't think my 2-way can be unseated, it gives a different sound compare to an OB. The imaging is more sharp and believe it or not, better soundstage than b200. The OB b200 has a more wider soundstage but the instruments/voices are more diffuse.
I don't think the b200 can produce better violins than the scanspeak without using a tweeter.

Anyway, I want to see how far I can get with just a filter tweak.
I'll probably need to built another baffle to see if I can squeeze a bit more bass.

JohninCR · « **Reply #54 on:** 26 Sep 2006, 06:22 pm »

Quote from: ChuckT on 26 Sep 2006, 05:05 pm

I don't think my 2-way can be unseated, it gives a different sound compare to an OB. The imaging is more sharp and believe it or not, better soundstage than b200.

I've yet to meet a driver that didn't sound better freed from its box as long as you handle the bass.
Great imaging is also possible with OB. OB's get knocked for imaging, because almost no attention
is paid to the shape of the baffle edge, and I believe it is doubly important than for boxes.

BTW, Omega sells a B200 aperiodic box speaker.

scorpion · « **Reply #55 on:** 26 Sep 2006, 08:32 pm »

Hi all,

I would like to respond to all who have mailed/messaged to me. I will try to put a long story short.
First about the LR-circuit, 1 mH + 8 ohms. If you don't use equalization this is quite essential.
It will shape response in a way that no other thing will do. It will be for the better, believe me. If you don't believe stay in the Dark.

I have been asked questions about how I deduced this. The answer is quite easy. I used a wellknown simulating
software (see DarkStar thread) and this came up with an answer which I believed in. Why do I believed ? Because I could see the resulting
simulations performance. And compare to other sources.

It is not more complicated than this. So in some way the circuit is a result of careful considerations. Be that the way it is, it is no accident !

Now, as I have admitted to use Zobel filter and other values inductors, what to believe ?

These have been used for testing purposes. In the end changes from the ground setting formula 1 mH + 8 ohms are only of not easily estimated value.
How can I say this. Well, in fact I can not, but changes away from this firm ground produce just infinitesmal changes to me. The point is when you have got this speakers balance right, it will produce its full capacity for you.

In fact I think that my simulatition lead directly to a right value. Whats the difference by using other values ? It is just a personal preference situation if you prefer a Zobel or not or if you prefer a bypass capacitoror or if you prefer higher resisistor values. . It has not, as the initial LR-filter, to do with fundamentals of the speaker behaviour. It is just scracthing the surface.

The Zobel I have been using is 5.6 ohms + 8 microfarads. This should egualize impedance all the way. What happens when I use my LR-filter with the Zobel ?
The great thing that is happening is that the LR-filter grabs a litte deeper in the 1k to 8 k's response. How do I like that ? Well, that is up to you. There is no objective answer to this question. You have to listen and decide for yourself.

And so is the suggestion about the bypass condensator 1 to 1.5 microFarads and to use higher resistor values. You have to decide yourself.

Because the differences are not that great. Once you have decided that the B200's response partnerad with 1 mH inductor + 8 - 10 ohms resistors is your way to go, you certainly is way behind mere superstition.

I have used high quality compoments for my circuits. Air wound or foil-type inductors and Metal Oxide Resistors, you owe this to the speaker.

As my research is fully independent, I would say that my results are valuable for Baffle-widths 30 cms or greater. Wings are included in baffle-width and height should be at least be 2 meters or 1 meter less.

Have fun,

/Erling

Vinnie R. · « **Reply #56 on:** 26 Sep 2006, 11:26 pm »

Hi Erling,

Thank you for sharing your findings.

I am currently using a BSC consisting of a 1mH inductor and 10-ohm resistor and am extremely impressed with the results

I really liked my B200 OBs before (and have posted about them in the past), but with this BSC in place, there is so much improvement that it is hard to believe considering how inexpensive it is to do this.

I knew that I liked this BSC from the moment I put it in place. Everything has fallen into place and has become very realistic and extremely engaging. I've been doing some late night listening and going through many CDs (all different types of music) and I LOVE what I am hearing. The sound is much more fleshed out and tonally balanced than ever before. I now also enjoy the sound at louder levels than I would play before. I recently tried going back to running w/o the BSC circuit and it didn't take long before I had to put it back in. This should be been done a lot sooner!

After listening for over a week with the BSC, I cannot live without it. It does the trick like you wouldn't believe. My love for the B200s has grown stronger than ever!

I'll probably experiment some more with a few other resistor values, but so far I like the 1mH and 10-ohm combo with my OBs. I'll probably try the Zobel at some point as well. The Sig 30 sounds amazing driving them with the BSC in place. aa
It pushes them with exceptional speed, clarity, warmth, dimensionality, and control.

Thanks again, Scorpion!

Vinnie

konut · « **Reply #57 on:** 27 Sep 2006, 12:37 am »

ChuckT-
I own a pair of Omega Aperiodic 8s. I was hoping the inductor and resistor network would work equally as well for these speakers as it does for OBs. But Vinnie posted previously that this was suitable for OBs only.

Vinnie
Is that strictly the case, or would different inductor and resistor values be needed? Or am I to understand that this particular alignment just isn't suitable with this kind of adjustment?

I just visited the Omega site and the Aperiodic 8s are no longer in the product list.

Vinnie R. · « **Reply #58 on:** 27 Sep 2006, 01:01 am »

Hi Konut,

I'm sorry if I gave the impression that the BSC only applies to OBs.... it does NOT. I meant to say that the values of 1mH and 8-ohm that Scorpion recommended were used by him for his OB. You might need to tweak the values for the Omega Aperiodic 8s. Maybe I'm wrong here and you can start with 1mH and 8-ohm

Best regards,

Vinnie

EProvenzano · « **Reply #59 on:** 27 Sep 2006, 01:27 am »

Newbie questions:

What awg is appropriate for the inductor?
What wattage is appropriate for the resistor?

Thank you.

EP