Through your BSC experiments you have demonstrated that there is something missing between sims and real situations.
Sims are accurate enough but they are only as good as the data you give them. It is quite a step to take full polar plots, calculate power responses and decide on a listening axis. You are already reaching the limits of a single axis sim.
For a quicker and less intensive journey, use a common sense approach to building your speaker, placing it, treating your room and finding a good listening axis... then get yourself an EQ. Your ears will get you close if you are persistent and have the ability.
Sims are accurate enough but they are only as good as the data you give them. It is quite a step to take full polar plots, calculate power responses and decide on a listening axis. You are already reaching the limits of a single axis sim.
For a quicker and less intensive journey, use a common sense approach to building your speaker, placing it, treating your room and finding a good listening axis... then get yourself an EQ. Your ears will get you close if you are persistent and have the ability.
I'm now using a 3rd order crossover on the tweeter (electrical) and 2nd order on the woofer and two notch filters (one to remove a peak at 4k and the other to to get the baffle step right). The harshness has gone and the music sounds better than ever
Schematic please, or it's not happening!
Vifa M21WG-09-08 8" and Monacor DT-300 tweeter with waveguide, IIRC.
An externally hosted image should be here but it was not working when we last tested it.
Can't be a million miles away from George Krilov's Optima Tower design, can it?
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Schematic please, or it's not happening!
What, and have you ridicule all my hard work
- I'll upload the Schematic when I get a chance.Oh, I forgot to say, i'm using the standard tweeter now because I couldn't get the modified one to work.
What, and have you ridicule all my hard work
TeeHee. System7 starts warming up his choicest phrases...
"That's the STOOPIDEST crossover I've ever seen...."
"This makes DUMB look positively INTELLIGENT...."
No, seriously, I only do that to designs that people see some merit in, when there is none. It doesn't make me popular, but then neither does correcting people's grammar.
You have had a struggle with this, and I'm on your side. That AR SXO design was pretty hopeless, but you weren't to know. I can see a case for the 4-5kHz bass notch. I'm interested.
Oh dear. I think I'm gonna upset someone. I did run that past Visaton Boxsim, and frankly it didn't want to play nicely. Whatever were you thinking of? You can't abandon all known principles of crossover design and then fix it with a few random notches and resistors.
Much better to start with something that makes sense. Try this as a start. I can't say exactly how the red elements in the tweeter crossover will work and adding a 20uF to make it third order might be better since you have stripped out the ferrofluid.
But it is at least CONVENTIONAL and ECONOMICAL in design.
FWIW, I enclose the SEAS CA18RLY response and a Troels design to compare with your Vifa driver and Monacor tweeter. Not really too different, are they?
Uploaded with ImageShack.us
Hope it helps.
Much better to start with something that makes sense. Try this as a start. I can't say exactly how the red elements in the tweeter crossover will work and adding a 20uF to make it third order might be better since you have stripped out the ferrofluid.
An externally hosted image should be here but it was not working when we last tested it.
But it is at least CONVENTIONAL and ECONOMICAL in design.
FWIW, I enclose the SEAS CA18RLY response and a Troels design to compare with your Vifa driver and Monacor tweeter. Not really too different, are they?
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Uploaded with ImageShack.us
Hope it helps.
Attachments
I've tried 4.5R but the frequency response looks like post #72.
Even if I could get the response and phase right with your crossover, without the notch on the woofer vocals sound too powerful, not harsh, just very mid forward. It takes about 3db off (could be more) between 500 - 1000Hz, and without the notch at 4k some vocals sound a bit bright.
Even if I could get the response and phase right with your crossover, without the notch on the woofer vocals sound too powerful, not harsh, just very mid forward. It takes about 3db off (could be more) between 500 - 1000Hz, and without the notch at 4k some vocals sound a bit bright.
I think you need some inspiration here to make a silk purse out of a sow's ear. This woofer is really a horror with its puny magnet and soft surround...
The underdamped tweeter is causing that resonance at 4kHz and the subsequent 7 kHz dip. I did much better on phase with a regular SC10N tweeter.
For all that, the model that works best with a high Qts woofer in a box that is effectively too small is to use LESS bafflestep and a lower order filter. Troels' CA18RLY design was a good start. I ended up with something quite well-behaved and tweeter phase was much better. The higher crossover is just something you have to live with. These drivers are very difficult and I would have given up on them long ago.
Again, the red components are select-on-test. I modelled it as a freestander, away from the wall. What else can you do?
The underdamped tweeter is causing that resonance at 4kHz and the subsequent 7 kHz dip. I did much better on phase with a regular SC10N tweeter.
For all that, the model that works best with a high Qts woofer in a box that is effectively too small is to use LESS bafflestep and a lower order filter. Troels' CA18RLY design was a good start. I ended up with something quite well-behaved and tweeter phase was much better. The higher crossover is just something you have to live with. These drivers are very difficult and I would have given up on them long ago.
Again, the red components are select-on-test. I modelled it as a freestander, away from the wall. What else can you do?
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