I got mine from the Visaton site. What are you thinking/saying you can't do with it exactly? Don't get me wrong, I use lots of software and I'm not trying to get everyone using Boxsim, but it does do quite a lot of things.
ok modeled the visaton ws200 and the phenolic as best I could. Im concerned because I don't have an impedance graph for the tweeter but here are my results. a 30 ohm resistor across the tweeter pulls the right side of the graph down just a little bit if that is preferred.
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I think you've got the hang of it very quickly! That's heading towards an 18dB/octave BW3 response, with the flattish power dispersion at crossover. Phase is quite fiddly with BW3, the theory tells you to get a 90 degree difference around crossover on either tweeter polarity. I look upon BW3 as being LR4 with more overlap between the drivers.
The phenolic ring tweeter is a bit flatter on frequency response than the TW70 in my estimation, but electrically it must be very similar. Probably around 6 ohms DC and 0.15mH.
Although they are different looking and sounding animals, because they have similar electrical and frequency response characteristics, these two tweeters are interchangeable without mod to the crossover.
TW 70 - 8 Ohm
DT 94 - 8 Ohm
Similarly, I wouldn't bat an eyelid in interchanging either of these:
W 200 S - 8 Ohm
H1471-08 CA22RNY
Because the SEAS is slightly smaller voicecoil inductance, the bass shunt resistor could however be a bit smaller.
If you take the crossover lower than 3kHz, you will run into phase problems. The negative polarity solution will then need a recessed bass, which might not be practical here. It's all about the half wavelength.
FWIW, a rising slope on the bass sounds bass light. Flat or a slight downward slope gives a more balanced presentation. A slight rise at the top end on the tweeter is no bad thing with cone tweeters, because their dispersion and power response is worsening.
The phenolic ring tweeter is a bit flatter on frequency response than the TW70 in my estimation, but electrically it must be very similar. Probably around 6 ohms DC and 0.15mH.
Although they are different looking and sounding animals, because they have similar electrical and frequency response characteristics, these two tweeters are interchangeable without mod to the crossover.
TW 70 - 8 Ohm
DT 94 - 8 Ohm
Similarly, I wouldn't bat an eyelid in interchanging either of these:
W 200 S - 8 Ohm
H1471-08 CA22RNY
Because the SEAS is slightly smaller voicecoil inductance, the bass shunt resistor could however be a bit smaller.
If you take the crossover lower than 3kHz, you will run into phase problems. The negative polarity solution will then need a recessed bass, which might not be practical here. It's all about the half wavelength.
FWIW, a rising slope on the bass sounds bass light. Flat or a slight downward slope gives a more balanced presentation. A slight rise at the top end on the tweeter is no bad thing with cone tweeters, because their dispersion and power response is worsening.
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Hi,
I looked at it a while ago, and couldn't see how you
you could simply add extra driver data to it. I might
have missed something though, it was a while back.
rgds, sreten.
It's not super simple because it doesn't really let you do halfway simulations. You have to start a new project (so you get empty driver data), and then you go to each driver through the menu, enter all the parameters, import the data, tell it some things about the data and what type of measurement made it, enter the bass enclosure data (if you're going to simulate response below 2*fc), and generally you'd want to select "common outer housing" under the baffle position tab, and then choose that from the menu to put in all your dimensions and driver locations. Oh yeah, and the acoustic delay offset relative to the baffle is set on the driver screens as well.
When you load Visaton drivers from the database, it also uses information about the diaphragm to simulate off-axis HF rolloff. If there is a way to do that for driver data you import yourself, I haven't found where it is, so obviously without that you have to imagine the real off-axis magnitudes when looking at polar data / power response / etc.
When you load Visaton drivers from the database, it also uses information about the diaphragm to simulate off-axis HF rolloff. If there is a way to do that for driver data you import yourself, I haven't found where it is, so obviously without that you have to imagine the real off-axis magnitudes when looking at polar data / power response / etc.
Ok looking for you final stamp of approval to go ahead and purchase the visaton driver and the phenolic tweeter and that you approve of the values for the crossover. One thing I'm not clear on is the necessary wattage rating I need for the resistors. is 20w for the woofer and 10w for the tweeter sufficient? amp is rated 100w.
I threw the dt 94 in to see how it changed my model. the dt94 would actually be a better fit to my box as the phenolic is slightly to large and ill need to shave the hole larger. The only thing about the dt 94 or the tw 70 is the dip in response at the 3khz xo point from the woofer.
I threw the dt 94 in to see how it changed my model. the dt94 would actually be a better fit to my box as the phenolic is slightly to large and ill need to shave the hole larger. The only thing about the dt 94 or the tw 70 is the dip in response at the 3khz xo point from the woofer.
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You can get away with LR2 and BW3 with well behaved drivers, and in threeways where you are not taking a driver out of its comfort zone. 8" bass plus 1" tweeter is hard, because the time alignment is poor and the bass is close to its cone breakup region at 3kHz.
IMO, the steep 24dB/octave slopes of LR4 works best with this combination overall. It has a very clean sound.
You must just put up with the dip in power response at crossover. It is hardly noticeable and is just what LR4 does. Tweeters that get my approval are cone and ring-radiator (XT25) types, which both have an unfatiguing and detailed sound.
Inevitably you have to adjust tweeter level to personal taste. I like them quite bright personally. The below circuit is my current thinking. The second tweeter coil is optional, but does something IMO. I have the modelling and FRD and ZMA files for an XT25 somewhere, but that is not my current interest. As it is, the similar phenolic ring tweeter should behave well enough here. This is a very good sounding speaker.
IMO, the steep 24dB/octave slopes of LR4 works best with this combination overall. It has a very clean sound.
An externally hosted image should be here but it was not working when we last tested it.
You must just put up with the dip in power response at crossover. It is hardly noticeable and is just what LR4 does. Tweeters that get my approval are cone and ring-radiator (XT25) types, which both have an unfatiguing and detailed sound.
Inevitably you have to adjust tweeter level to personal taste. I like them quite bright personally. The below circuit is my current thinking. The second tweeter coil is optional, but does something IMO. I have the modelling and FRD and ZMA files for an XT25 somewhere, but that is not my current interest. As it is, the similar phenolic ring tweeter should behave well enough here. This is a very good sounding speaker.
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Reference the mylar Visaton DT94, it's a very good tweeter. It's not quite as good as the old balanced drive mylar cone tweeters though. It does have noticeably better dispersion, and sounds brighter, than a cone tweeter. But to my ears loses the magic.
Not bad though.
An externally hosted image should be here but it was not working when we last tested it.
Not bad though.
OK so I've opted for the Dt94 as it fits my box without modification. I'd love to do the LR4, but I'm already over my budget so I'm gonna make do with the bw3. I've attached images for what I hope you think is an okay setup.
I don't know what to look for in the phase graphs at all so let me know if anything is out of wack.
Finally I'm still unclear on the necessary wattage rating for my resistors. is 20w woofer and 10w tweeter sufficient?
Thanks for bearing with me! I've had to pound a bunch of information in my head over the last week.
-Mike
I don't know what to look for in the phase graphs at all so let me know if anything is out of wack.
Finally I'm still unclear on the necessary wattage rating for my resistors. is 20w woofer and 10w tweeter sufficient?
Thanks for bearing with me! I've had to pound a bunch of information in my head over the last week.
-Mike
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Dunno What? the preceding postings were about.
Can't be arsed to read it all though
IMO JBL ..IF.. of pre Harmon International.. mfg ? The intrinsic 'goodness' Value/Worth is in the Drivers..NOT the goofy wooden box that houses them.
IMO Sweating over what to fill the Empty coffins with is erm Silly.
However.. Were you in the possession of the Genuine JBL drivers? then the wooden box would be a secondary/tertiary concern.
Can't be arsed to read it all though
IMO JBL ..IF.. of pre Harmon International.. mfg ? The intrinsic 'goodness' Value/Worth is in the Drivers..NOT the goofy wooden box that houses them.
IMO Sweating over what to fill the Empty coffins with is erm Silly.
However.. Were you in the possession of the Genuine JBL drivers? then the wooden box would be a secondary/tertiary concern.
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cant be arsed to read? than your commenting without any kind of basis at all. Who reads a thread title and jumps to the end of a 3 page thread? Busted drivers are worthless regardless of brand. Also the drivers that came in this cabinet seem to be considered among the worst ones released by jbl in that era(reference series). Did I mention these drivers are busted?
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I still like the near LR4 circuit here, with or without the second tweeter coil: http://www.diyaudio.com/forums/multi-way/262335-reviving-vintage-jbl-cabinets-3.html#post4072225
But it is all trial and error IMO, and I've never built something that didn't evolve a bit with time. For some reason your modelling is coming out very slightly different to mine. I never use more than 10W wirewounds. But I do have a feel for how much power is going through most components. Most of the power is at the low frequencies, and once you get into the midrange and treble, power dissipation is minimal.
I've accumulated a lot of components and swap things around a lot. Is that because I don't know what I'm doing as sreten unhelpfully says, or perhaps that it's all quite a subtle business and you always want to try things?
For sure, the crossover makes or breaks a design. Aligning phase and dispersion around the crossover point makes for good driver integration. You should be unaware that there are two drivers behind the grille when you get it right. Getting the bass balance right is important too. Little peaks in SPL at certain frequencies are quite annoying, since certain notes then jump out at you.
I could go on, but won't. Welcome to our hobby, which by definition is "An interesting waste of time". Here's a few pictures from system7 labs. Onwards and upwards!
But it is all trial and error IMO, and I've never built something that didn't evolve a bit with time. For some reason your modelling is coming out very slightly different to mine. I never use more than 10W wirewounds. But I do have a feel for how much power is going through most components. Most of the power is at the low frequencies, and once you get into the midrange and treble, power dissipation is minimal.
I've accumulated a lot of components and swap things around a lot. Is that because I don't know what I'm doing as sreten unhelpfully says, or perhaps that it's all quite a subtle business and you always want to try things?
For sure, the crossover makes or breaks a design. Aligning phase and dispersion around the crossover point makes for good driver integration. You should be unaware that there are two drivers behind the grille when you get it right. Getting the bass balance right is important too. Little peaks in SPL at certain frequencies are quite annoying, since certain notes then jump out at you.
I could go on, but won't. Welcome to our hobby, which by definition is "An interesting waste of time". Here's a few pictures from system7 labs. Onwards and upwards!
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