Originally Posted by
DaveW
Hi folks,
I am a long-time proud owner (40 years now) of a nice pair of early C36's with the 030 system, who just now discovered your wonderful site.
Anyway, I'd like to upgrade them, not because they don't sound good, but just because I am a tinkerer at heart, and I like to try to improve everything I get my hands on. I'd like to get your comments on these ideas.
First of all, I am considering putting an LE175DLH between the D130 and the 075. I plan to feed it from the HF of the N2400, and then tie the 075 to it with a capacitor to achieve a simple first-order high-pass filter with a cf of approx 9000hz. I'll just let the LE175 roll off on its own above that. My specific question is, will the highs be sufficiently improved by essentially adding the 075 on top of the 175? My research tells me that the 175 is significantly better than the 075 between 2400 and 9000, so that seems like a no brainer to use it for that. But does the 175 really need the help of the 075 above 9000? I think so. Your thoughts?
The second thing I would do would be to replace the N2400 with a home-made modern version. I'd keep the same first-order topology, just replace the components with modern polypropylene caps and large wire, air-core inductors. I will keep the original crossovers, since I want to ensure that the speakers can be returned to original without any blemishes.
Finally, in order to improve the lows, I am thinking about having the surrounds redone on the D130's with a more flexible material (which I believe is a popular mod). Again, I don't want to swap out the D130's, just improve them if possible. Also, the ports on my C36's do not have any tunnels at all. The factory spec calls for 5" tunnels. I am guessing that my boxes were very early models (the grills sure look that way), so the port tunnel may have been a later improvement. What exactly would that change? I'm guessing, lower the response.
I'm sure that by now some of you thinking "what a wacko"! Believe me, I'm not. I dearly love these speakers, I'd just like to make them the best they can be, without doing anything that can't be undone without a trace.
BTW, all this is being inspired by "finally" finishing my home-brew amp, similar (but I think much better than) the ST-70.
Dave in San Jose