RTIA7 Crossover Mod. To bypass or not to bypass? That is the question.
Porcupinepuffer
Posts: 1
I have an older set of used RTIA7's. I noticed in the Marantz room setup for dolby atmos that the mid/tweeters on these speakers appear weaker than my RTIA3, CSIA6, RTIA9, and Polk ceiling speakers. Upon closer inspection, I have founder capacitor C1 and C5 bulged on both speakers. More bulged is C1... Big shocker, the only ones I ever bought used from a guy who blasted them with an emotiva amp. Long story short, I am going to rebuild the crossovers. Ran a lot through the mod threads and I'm still on the fence about what to do about the bypass capacitors. I spent quite a bit of time flipping the crossovers back and forth before finally having what seems to be a correct schematic on how these are put together. My questions relate to the bypass caps and their values and whether they could be ignored. Most of my research on bypass caps throws me down a road of caps with lower tolerances. Such as .01uf to .05uf, and with those low numbers, they don't appear to alter much by simply ignoring them with higher quality caps.
However, these bypass caps have a higher value and make it questionable whether I can just ignore them and stick with the existing values given, or if I have to take into account adding that value to sourcing a replacement capacitor of higher value... Now if I try and simply source a capacitor with a slightly higher value, it becomes difficult to find ONE capacitor that meets that criteria without drastically overshooting. With how it stands, the 8.2uf and 10uf are quite common capacitors among many manufacturers. So it seems I can either stick with those numbers and either leave out or install bypass caps of .47uF? I just wouldn't want to leave them out completely and realize I may leave myself missing better sound if someone can say this will not work properly without them.
What would some of you experts do? I see vr3 keeps them within a certain quality of clarity caps.
However, these bypass caps have a higher value and make it questionable whether I can just ignore them and stick with the existing values given, or if I have to take into account adding that value to sourcing a replacement capacitor of higher value... Now if I try and simply source a capacitor with a slightly higher value, it becomes difficult to find ONE capacitor that meets that criteria without drastically overshooting. With how it stands, the 8.2uf and 10uf are quite common capacitors among many manufacturers. So it seems I can either stick with those numbers and either leave out or install bypass caps of .47uF? I just wouldn't want to leave them out completely and realize I may leave myself missing better sound if someone can say this will not work properly without them.
What would some of you experts do? I see vr3 keeps them within a certain quality of clarity caps.
According the Polks "not a robot" security feature for joining the site, a residential mailbox is a form of a parking meter! ...I've seen nobody dumping money in my mailbox to park!
Comments
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Drop the bypass caps, you don't need them when using film caps. Keep the 8.2 and 10uF values.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
thanks for the nice schematics! how did your mod go - how much difference did it make in sound quality and which brand caps did you end up using?
does this mid circuit look a bit weird or is if just me?
