RusselC: There are good reasons that people are not just trying this despite the small parts count. It's a technical change that does increase the cost of the crossover. Many of us would undertake that only with a sound scientific basis behind the idea. I understand from reading the white paper on the K2.S5500 what they SAY it does but they don't cite any evidence that the capacitor bias produces measurable effects that have audible consequences. This is the hallmark of sound technology: measurable results that can be repeated by anyone. I'm not saying it's snake oil, just that they should at least send a sample to the lab and show us that the composition lacks all reptile ingredients.
Lots of us have been down this road before with unsupported audiophile tweaks. I've spent fortunes on power cords, speaker cables, interconnects, green paint for CDs, contact treatments, record weights, tube dampers, special plugs, footers, shelves, tuning cones and myriad audiophile folderol. Those products ranged from moderately useful to outright lies. The best and most reliable tweaks are those that have some science behind them.
When I built my EWave crossovers I spent an extra hour sorting resistors and capacitors to match them up within a couple of percent between channels. I know the differences between the drivers and other variables in the system swamp the small variations in the crossovers, but component values are one thing that I can control so I make sure my parts are in tight tolerance.
I'm not saying I won't try the biased crossover for my next pair of ewaves but I probably won't devote much cost or time to the experiment unless some hard evidence comes up.
The seriesed capacitors issue brings up another possibility for testing for the audibility of the bias effect. Since they're seriesed, polarized caps could be used in this circuit. All of the crossovers we've been building have used film caps so far because the values are small. In place of the .47 film cap, a pair of 1uf 25V electrolytics could be used. The positive terminals would be placed together and that would be the +9vdc bias point. 1uf 25VDC electrolytics are WAY smaller than film caps. They should have advantages in terms of inductance. Also, the dielectric should have a much less linear characteristic around zero than a film cap. This means that if there is any audible effect from biasing it should be very clearly heard using back to back electrolytics. If the sound of back to back electrolytics did not improve with biasing then I would seriously doubt that biasing film caps could have an audible effect in that application.
You could even raise the stakes: in place of a .47uf film cap use a .5uf film cap in series with a 100uf 25V polar electrolytic. If there's a benefit to polarizing a dielectric, you'd definitely hear it there.
I really dont mean to belabor the argument/discussion, but just a min....you state that this mod is a "technical change" and "increases cost" so you need a "good scientific basis" in order to go forward, yet you go to the trouble to match resistors and caps within a couple of percent between channel. I suppose the upshot is that you see that as an improvement in performance
over the standard 5 percent or so. Where's the proven scientific basis for that change that also increases cost? I think once you try it you will find a greater improvement with CC than matching that last couple of percent.
As to the decreased inductance, my thought is that is a red herring, the amount is trivial when compared to that naturally existing in the set up, i.e., the voice coil, and the coils themselves. While it may have some measurable effect, I've never seen it make an audible one, (and Ive used some big film caps,) other than improved sound over non P. electros. If that were of signifigance, why dont we all use tiny electros instead of films? The reason I dont is they dont sound good, and no scientific basis is needed for that., whether they have less inductance or not.
I dont mean to be argumentative, but several here continue to dismiss the idea without trying it. Fairly non objective viewpoint. I mean really, this came from those who have forgotten more than most of us here will ever know, its installed in speakers costing as much as a really nice luxury cars, some of which have frequency extention to 30khz. Plus, I have tried it and would be the first to admit I didnt detect an improvement, but the simple fact is I did, and I feel it is signifigant enough to encourage its use. for all you I need proof types, build it. If you have time and parts to match resistors and caps so close, this should be a walk in the park. I just used the regular Daytons as they came from PE. The regular ones, not the 1 % ones.
I like things to be verified to, especially when I'm being doubted, so rather than speculate why it wont work, why not try it, then if you are right you can give your validated opinion, rather than unsubstantiated criticism. It is begining to seem you only need validaton for what you are not in agreement with here. I do not mind being critiqued on this, I am inviting it. Otherwise, I would have kept it to myself, after all.
I have nothing to prove, the circuit represents an improvement, whether anyone else tries it or not. If you have strong feelings against it, dont try it. But its not fair to validate your own points and criticize mine, based on no more than some observations that you havent taken time to make. I do not want this to sink to an argument, thats not my purpose. Then all learning stops.
For the curious, build the circuit carefully, make sure all is right and try it.
perhaps if a handful of us bought the parts, had someone who makes pretty crossovers build it, we could send it around to each other to try? I'll be glad to contribute, as I honestly feel this cross over represents a definate improvement in the Ewave.
If anyone has questions, feel free to ask, and I encourage all of you to try this circuit and see if you agree. I feel fairly strongly it will be perceived as an improvement, Honest, I dont have investments in PE or Dayton! I present this information in the spirit of econowave, as an honest improvement. Those not interested, OK... I mean really, the basic crossover is great.
Nothing wrong with it. At all.
Russellc
]
