Hello,
ial
I am modifying my Spatial Audio M3 Turbo S speakers and would like a little crossover help. I used to modify and build speakers many years ago before software and DSP was even a thought. I added a horn and a SB Audience 65CDNT and and designing a new crossover for it to integrate this new driver and horn. I have the woofer figured out and am trying to integrate the tweeter. I currently have a contour circuit on the tweeter with a 2.2 uf cap and 10 ohm resister to bring down the horn rise to flatten the response. The compression driver in the horn starts rolling of at around 550 to 600 Hz which is good but a little to low to properly integrate with the woofers. When I try to install a cap on the tweeter before the contour circuit the added capacitor does not crossover the tweeter it just changes the contour circuit! How do I keep my contour circuit and add an additional crossover to the tweeter without either one being effected and letting me cross the tweeter over higher? I put a hand drawn diagram in this post to show what I mean.
ial
I am modifying my Spatial Audio M3 Turbo S speakers and would like a little crossover help. I used to modify and build speakers many years ago before software and DSP was even a thought. I added a horn and a SB Audience 65CDNT and and designing a new crossover for it to integrate this new driver and horn. I have the woofer figured out and am trying to integrate the tweeter. I currently have a contour circuit on the tweeter with a 2.2 uf cap and 10 ohm resister to bring down the horn rise to flatten the response. The compression driver in the horn starts rolling of at around 550 to 600 Hz which is good but a little to low to properly integrate with the woofers. When I try to install a cap on the tweeter before the contour circuit the added capacitor does not crossover the tweeter it just changes the contour circuit! How do I keep my contour circuit and add an additional crossover to the tweeter without either one being effected and letting me cross the tweeter over higher? I put a hand drawn diagram in this post to show what I mean.
In front of the contour network should be a high pass filter consisting of a series capacitor and a parallel inductor.
There will be interaction. Are you simulating? That would let you try more things in less time.
Using a second order filter would reduce the interaction, perhaps making your task a little easier.. and since you probably want more than first order, although that's up to you.
This is a comparison of with and without the high pass filter, and the point was that I didn't have to change the contour network to do it but if I had I wouldn't have been surprised. (Values are only to make the point, not for actual use.)
Using a second order filter would reduce the interaction, perhaps making your task a little easier.. and since you probably want more than first order, although that's up to you.
This is a comparison of with and without the high pass filter, and the point was that I didn't have to change the contour network to do it but if I had I wouldn't have been surprised. (Values are only to make the point, not for actual use.)
So what's you're saying basically is a first order capacitor will not work because it will interfere with the contour circuit. Where with a second order filter the inductor will shunt off and not interfere with the contour circuit?
Well what do you say! You were right. I had to move to a 2nd order filter to keep the cap from messing with the contour filter. Man I love it when people come together to figure stuff out. rock on thank you honestly I was thinking about using a second order filter anyway just to have a little bit better integration so this kind of push me that direction
Well thanks for The information. I was on the fence whether to go second order or not anyway so I just went ahead and went second order filter and it fixed the problem because of the coil. I've got a few other parts on order when they come in I should be in business. Going second order woofers and tweeters!
It also reduces the problem of sharp impedance variations with compression drivers. Not that you can’t deal with that in any number of ways. This reduces unwanted response variations that can be difficult to filter.
I was simulating at first getting used to the programs and such after being away from the building and modifying hobby for a while. But soon found out that simulating is great to start the process to base your crossover design around but it doesn't sometimes show you interactions between components like I learned with this one.
Yes, I agree. A simulator is just a tool. In fact like any tool, if you come to it from a background of experience it will make life easier, however if you begin with it you could quickly pick up bad habits as easily as good ones.
Yeah I always use proper testing/measuring and listening in final design work. I really only use the simulation to help flatter driver responses and to see crossover point reactions. But I understand it's limitations as well. It's great to get started but designing and ordering parts just off of simulations is a recipe for a lot of wasted money
So what is it that is the actual problem? You'll always have to equalise the overall result (after you cross) to give a natural tone. That's not easy to guess and it's easier to do by ear.
On the other hand, using single measurement per driver does not help show the character of the speaker and tell you where to cross and why. Even still, it's better used than not..
On the other hand, using single measurement per driver does not help show the character of the speaker and tell you where to cross and why. Even still, it's better used than not..
I used a combination of single driver measurements to see what the drivers themselves are doing. Then I do what I need to do circuit wise to flatten and correct responses. I should have mentioned before I even do that I study East driver to make sure that they will work well together before even starting. Then I work on combining the drivers into a crossover that will be a seamless as possible. Some of this can be done and simulation software while other parts of it just simply cannot. Then like the stage I'm at now I work through any issues between contour circuits, notch filters etc and the crossover components I plan to be installing. Just like now I'm having to move to a second order crossover because the first order crossover just took away from the overall capacitance of the contour circuit. And at this stage is when I am installing components and then doing listening and measuring to see the overall tonality and to make any corrections. That's the stage I'm at now or I've installed the components for my design and I'm spending a few days listening to the combo to make sure that I'm satisfied both measurement and listening
Just to let you know there's a way forward, better choices on using each of them can be had by looking at their polars. Better crossing can be done by using polars in the cross.
I have had good luck using polars in the past with good drivers with good flat responses but in this case with open baffle I used a different crossover for the woofers since they are in open baffle to bring down the dipole rise so I did not go polar. I have used polars in stand mount speakers with really well matched drivers and it worked great