As the title states my upgrade and mod to the SDA2Bs has been an odyssey and continues to be. It all started when my Yamaha R9 give up the ghost and I went hunting for more gear. I have loved audio since a kid but strayed from the fold years ago because I simply did not have a place to sit and enjoy my music. Well that changed, I bought some used power gear, and went to town on everything with new caps, etc....
I went with the 2BTL mod for the 2Bs but took a different approach. The House and Senate still sees fit not to straighten out the economy so I had to rein in a few cost items. In other words I did what they should be doing. Below is what they look like at this time (please don't bust my chops about the Erse metallized polypropylene film cap ok):
I purchased some metallized polypropylene film capacitors for the tweeter section and replaced the mid-section with the same electrolytics that were there, my budget cut. Took the bypass cap out and replaced the polyswitch. Listened for awhile and things sounded real good. Here is where my learning began. The change in sound was nice but the more I listened the less I liked what I was hearing. The highs were scratchy. So I removed the polyswitch and run the jumper between the leads. Fired it up. Not bad again but the more I listened the more I disliked things. Talked with F1nut about it and he suggested that I install a .5 ohm Mills capacitor there. which would smooth the highs out and replace the resistance the polyswitch put into the circuit. Did that and things got better and I liked that for a day or two. Let me say that the addition of the .5 ohm Mills really changed things. I believe I am able to hear the SDA affect much more now that the tweet is not drowning out some things. I am also able to hear more detail in the music. Still not happy though. I still have this scratchy sound at times in the speakers. Not often but with certain tones it shows up. And some of the music at higher levels meshes together rather than the instruments staying separate. I am sure it is there all the time but just more noticeable at a little higher level.
So now I am to the point of replacing the electrolytics in the mids with the metallized polypropylene film also. EVERYONE said I should have done this from the start but I wanted to see if it was nirvana on their part with these audio capacitors. It was not nirvana I can assure you. I learned a lot doing it my way but I would suggest you listen to them if you do not like to pull your speakers down to solder components on a bizzillion times.
I am now sitting here waiting on the new caps to show up. Just ordered them last night so I will not be able to hear them until next week probably. One other change that I might make after replacing the mid caps is in the .5 Mills resistor. I will wait until I get the new electrolytics out before I do though. My tweet is just a little to low now maybe. I am hoping that the metallized polypropylene film caps in the mid will take care of that as I believe I may get a little more high out of them when those go in. And more detail which may help my that small but annoying problem. If not I may go in and replace that .5 Mills with a little smaller Mills resistor. Again the .5 Mills really changed things and I was surprised to see that it made that much difference in the highs.
That is where I stand at this point. If you are new and doing an upgrade to your speakers you can listen to the folks here who make suggestions to you and save a lot of time. Or you may wade in and do it your way to only find that you will probably be doing that anyways! I have had good help here and I really appreciate those who have helped me with this, my 1st mod and upgrade.