Sorry 650 Hz. Since the time of my post I have realized that this is not an issue and one should not replace the electrolytics at all (or only replace them with similar bipolar electrolytics). They have a frequency variation (both for the ESR and capacitance that B & W appears to have included in their original design. See:
Non-Polar Electrolytic vs. Polypropylene Film Capacitors
After much on line searching I have come to the conclusion that most of the bipolar electrolytics have similar frequency characteristics. This characteristic needs to be included in any design if they are used. This is not a simple ESR as it increases at low frequencies along with variation in capacitance. This greatly affects the performance. In order to do much better one must measure the response and input impedance of the drivers as well as the caps. I have since pulled the film caps from the bass and midrange and put in some electrolytics obtained from Meniscus audio. The sound is much better and probably similar to what they were when new.
I have now completed my project and am very happy. In general just replacing components with something that is "better" is not the correct solution. B & W has spent many man hours designing this network and probably tied much measured data to its optimization.
Non-Polar Electrolytic vs. Polypropylene Film Capacitors
After much on line searching I have come to the conclusion that most of the bipolar electrolytics have similar frequency characteristics. This characteristic needs to be included in any design if they are used. This is not a simple ESR as it increases at low frequencies along with variation in capacitance. This greatly affects the performance. In order to do much better one must measure the response and input impedance of the drivers as well as the caps. I have since pulled the film caps from the bass and midrange and put in some electrolytics obtained from Meniscus audio. The sound is much better and probably similar to what they were when new.
I have now completed my project and am very happy. In general just replacing components with something that is "better" is not the correct solution. B & W has spent many man hours designing this network and probably tied much measured data to its optimization.
B&W 803 S3 FRD and ZMA files
Any body can point me to place I can get FRD and ZMA files for B&W 803 S3 please. Trying to simulate (XSim ) crossover for B&W 803 S3 but without FRD and ZMA files makes little sense.
Trying to redesign XO for B&W Matrix 802 S3 changing to 2d order to 3rd order Butterworth.
Any body can point me to place I can get FRD and ZMA files for B&W 803 S3 please. Trying to simulate (XSim ) crossover for B&W 803 S3 but without FRD and ZMA files makes little sense.
Trying to redesign XO for B&W Matrix 802 S3 changing to 2d order to 3rd order Butterworth.
Last edited by a moderator:
I merged some of your posts which were asking for the same thing.
🙂 It might be tough to find what you're looking for.
There are some graphs which you can manually trace for the midrange, I doubt you will find anything for the tweeter.
You might be better served by looking for a cheap measurement microphone and taking some measurements by yourself.
VituixCAD has a handy trace tool where you can trace FRD and ZMA files. It's pretty simple to use.
Thank you Sangram, that is what I suspected. B&W refused to share this information citing proprietarity.
Pida, Regarding B&W-802-Upgrade post. This is an attempt to replace B&W stock components with better grade components (L's and C's) keeping the same 2nd order Butterworth configuration. I would like to upgrade to 3rd order Butterworth design and need FRD and ZMA files for simulation.
Pida's link (which I had zero clue about) has the frequency response of all three drivers so that's a start.All should be traceable for FRDs.
ZMA files will be tougher. I don't think Troels would have them still around, but you might want to email him and check.
ZMA files will be tougher. I don't think Troels would have them still around, but you might want to email him and check.
I contacted Troels, he has all FRD and ZMA files, but he said that these files are his IP and he is not willing to share them.
5 year old post? ,the first question of altering the woffer circuit is fine..you say to clean up sound, B&w is CLEAN sound../ With that crossover circuit The woffers already make no midrange , yes you can change that , but not to get"cleaner".HERES THE WAY ID DO THIS , add a 3ohm 20 or 25watt (the factory 7watt is just unbelievable) resistor before the 150uf woffer cap (sandcast is fine) to ground , now replace the midrange resistor with 3ohm 20watt (sandcast is fine) NOW the tweeter ,change the first tweeter cap to 3.3uf AND add a 3ohm 10watt resistor(sandcast is fine) after the tweeter coil to ground./you can use expensive capacitors if cost is no object. other wise all propylene Caps are fine dont spend big money on the 3.3 and follow it with the stock 10 you will have wasted money./electrolytic caps can be replaced if your in there anyways .almost any 150uf will be fine.