kegman Posted March 12, 2005 Share Posted March 12, 2005 I've got my rc7's apart right now and I'm going to do some tweeking on the horn part of the xover and was wondering if one should leave or replace the mica caps with poly's. (2 rc7's as mains) What I'm planning on doing is Bypassing whatever caps I use with pio's that I have and up the 2 ohm resistor in line with the horn to a four. The speakers are a little to bright for me and I figured the pio's may give me a little more juice per say and the extra padding on the horn to tame the brightness a little! Any thoughts? Sound about right? I've got mills & dale wirewound resistors to replace the originals with. And I have plenty of quality poly caps in various sizes. The pio caps I have range in brand but mostly around .10uf in size. Quote Link to comment Share on other sites More sharing options...
leok Posted March 12, 2005 Share Posted March 12, 2005 I have been very happy with the more natural sound from my RF-7s after installing Jensen PIOs in the series cap locations. Hovland Musicaps may be OK also, but I am very pleased with the Jensens. I strongly recommend you voltage condition any cap, before installing it, by applying a substantial voltage (under the cap's rating) for a few seconds in both polarities. I use about 70V through a 5KOhm resistor. The resistor is there just in case I happen to be unfortunate enough to get a completely faulty cap that shorts. The purpose of the Voltage conditioning is to "clear" any minor defects in the dielectric layer. Some people consider this practice unnecessary, but cap defects do exist and they can sound pretty bad. You may wish to try the caps before you change the resistor. The caps may be all you need. The change in my RF-7s was substantial. Leo Quote Link to comment Share on other sites More sharing options...
kegman Posted March 12, 2005 Author Share Posted March 12, 2005 Thanks for the reply! So you just use 2 caps, the series ones on the horn section of say 12uf and 3.75uf "that's what the rc7's use anyways" ? Not bypassing any other caps just two large pio caps? Just wondering as it would seem most people use a smaller pio cap to bypass the larger with as the larger value pio's are very expensive! Not critcizing at all just making sure that is what your doing. Any thoughts as to bypassing with pio's? Quote Link to comment Share on other sites More sharing options...
Dflip Posted March 12, 2005 Share Posted March 12, 2005 Having had the originals, inexpensive polys, Hovlands and Jensens in my Cornwalls, I will venture an opinion. If you are looking to have a less bright sound, then the Jensens will do the trick. The Hovlands are very accurate, but they are brighter. I have found I needed to add another 1/2 - 3/4" of rope caulk to my Cornwalls after adding the Peach which has Hovlands in it. The Peach has great detail, but it was brighter, so a slight tweak was necessary. The Jensens are good with "brighter" speakers, but I would not try them with a pair of a more lush sounding speakers. The Jensens provide the same level of detail, but are "easier on the ears". The only problem, it is not a cheap tweak, but if you don't like it, I'm sure Dean would take the Jensen's off your hands to use in one of his networks, so it would not be too expensive of a risk, other than shipping and a usage cost. Good luck. edit: Just took a look at the prices for Jensens, 4.0 uF $31.95 and the 12 uF $83.85 each. http://www.partsconnexion.com/catalog/CapacitorsFilm.html They 4.0's are okay price wise, but the 12's are a very big expense. Maybe Dean could offer up his best suggestion? Quote Link to comment Share on other sites More sharing options...
kegman Posted March 12, 2005 Author Share Posted March 12, 2005 Dflip: Thanks for the info but I'm not sure what this means! "I have found I needed to add another 1/2 - 3/4" of rope caulk to my Cornwalls" Could you please explain a little? Much appreciated! Quote Link to comment Share on other sites More sharing options...
Dflip Posted March 12, 2005 Share Posted March 12, 2005 I have rope caulked the squawker horn from the magnet towards the mouth of the horn. Some go all the way and even put two layers of rope caulk on the horn. I only go a certain distance, I think it was about 4 inches and found I needed to add a bit more. I was trying to "tame the squawker" a bit and make the horn easier to listen to at volume. By adding a bit more rope caulk, I get a deader sound (too much and it sounds too dull to me and too little is too bright). I find it a lot like Goldilocks trying to find the porridge that is just right. Rope caulk is availabe from Home Depot or Lowes and is about $2.49 for a two foot strip that has eight thin pieces joined together. At least that is the price in Canada. It comes off easily if you don't like the result and therefore is an attractive option. Dynamat and similar products are more expensive, and more difficult to remove if you don't like the result. Don Quote Link to comment Share on other sites More sharing options...
kegman Posted March 12, 2005 Author Share Posted March 12, 2005 Thanks don! I may try that. Quote Link to comment Share on other sites More sharing options...
leok Posted March 12, 2005 Share Posted March 12, 2005 I have had some mixed results with "bypassing." I know the PIOs are expensive, but for me, worth the cost (one can understand that Klipsch has to hold the line on expense of crossover components). The two caps you mention are equivalent to what I changed in the RF-7s, although of different value. I would have upgraded others, and probably eventually will, but have delayed because of cost and time. I suspect the nonseries caps will prove important also. Leo Quote Link to comment Share on other sites More sharing options...
kegman Posted March 12, 2005 Author Share Posted March 12, 2005 Leo, Agree with your whole post and I'll look into the correct size pio's when I get a few extra bucks. For right now since it's easy and I have the parts I'm bypassing the series caps with new .22uF @ 400V Mil Spec german PIO Caps and replaced the series resistor with a mills 3.5ohm verse the original 2ohm. We'll let that fly for awhile and see what happens, I'll probably replace the caps with the larger jensen pio's in the future when I get some. But let's see what this sounds like for now! Thanks and anymore suggestions from you or anyone else is welcome and wanted. Se yu! Quote Link to comment Share on other sites More sharing options...
kegman Posted March 12, 2005 Author Share Posted March 12, 2005 First impressions seem pretty good, I believe the horns not to be harsh now and have tamed down some without being anywhere near dull! More listening and maybe even some parts breakin will tell! Quote Link to comment Share on other sites More sharing options...
kegman Posted March 14, 2005 Author Share Posted March 14, 2005 Well still a little bright even after the work! But better! So it's time to do some cap replacement. Ordered some kimber caps, we'll try those. If that doesn't get me where I want I'll try some jenson pios, first just the 3.75uf in the last chain of the series caps then from there if needed. Quote Link to comment Share on other sites More sharing options...
Deang Posted March 14, 2005 Share Posted March 14, 2005 Did you parallel a 10 ohm resistor with the 2 ohm value next to the 18uF? If not, shame on you. Quote Link to comment Share on other sites More sharing options...
kegman Posted March 14, 2005 Author Share Posted March 14, 2005 Unfortunitaly dean I had allready done the mods I praposed before I got your info. (live and learn) Now when the other parts come in I will do as you say. Didn't feal it necasary to rip it apart again just to do the resistors until I get the other parts. Just have to wait for my parts order then we'll go at it again! Thanks! Any thoughts on internal box treatments? Stuffing and such? Quote Link to comment Share on other sites More sharing options...
Deang Posted March 14, 2005 Share Posted March 14, 2005 A good brace or two would be good, but adding material to the inside is a no-no. Adding material to a speaker designed without it is a good way to ruin the bass response. Quote Link to comment Share on other sites More sharing options...
m00n Posted March 14, 2005 Share Posted March 14, 2005 Don't get me wrong, I wanted to understand all that was being said, but... Sadly this is all I heard... Quote Link to comment Share on other sites More sharing options...
Deang Posted March 15, 2005 Share Posted March 15, 2005 You heard right Rick, it even sounds that way to us. The RC-7's are already braced -- I would leave them alone. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.