stepher

Old thread, but thought I'd chime in in 2020.... Am original owner of a pair of KG2.5s that I use as my front mains coupled with some Bose 401 for side/rears and a Klipsch KSW-150. Recently updated the crossovers and installed a set of Crites Titanium tweeters (my process is documented here: Updating the X-Overs and Tweeters It was like getting new speakers. Great sound and very full and rich with the KSW-150. I'm in a townhome so this setup is more than enough to fill the space. I'm using an Onkyo TX-NR626 and am very pleased. Cheers....

I have been using an Aoyue 937+ digital controlled for over 5 yrs. (Came with an xtra heating element that I have yet had to use). Used it for redoing my Klipsch x-overs recently as well as small IC design/prototyping and receiver/subwoofer repairs. Compatible with Hakko 936 (937?) tips. Paid $50 new. This particular version may no longer be available (company may have gone more upscale/commercial) and/or may have been replaced by this one https://www.amazon.com/Aoyue-9378-Programmable-Digital-Soldering/dp/B00BSW69LI You may be able to find some used on ebay or AliExpress (if you don't mind waiting for delivery https://www.aliexpress.com/w/wholesale-aoyue-937.html I originally bought mine at SRA Soldering Products. Here's their current list of Aoyue products: https://sra-solder.com/soldering-equipment/soldering-stations Depending on your present and future soldering needs, finding a relatively inexpensive 60W soldering iron (as opposed to station) might serve your needs just fine. The brands others have mentioned (Weller and Hakko..not familiar with Pace) are also good suggestions. Cheers....

It could be old caps as @ngen33r stated. If the system has auto-turn on (using audio from the amp, which many subs have), if the audio detect circuit has gone haywire (bad caps, transistor issues, etc.), it may behave "squirrelly". Also take a close look at the solder connections at, and around, the connector. It may be that when the connector is plugged in, a good solder joint becomes really cold. I had this happen on my KSW-150 (and a Sony 5.1 receiver). Over time, heat can bring out the worst in a perfectly good solder joint. On the Sony it was the output transistors and must have been due to heat. On the sub, first it was a "scritching" noise which turned out to be in the low-level amp section (thought the spkr itself had blown a voice coil And then it was a hum which was a cold solder joint on the linear p/s filter caps. Often the shortest distance between 2 points is not a straight line. Cheers....

I typically have set the receiver LFE x-over @ 70-80Hz making the woofers a bit more midrange. I did the comparison of new vs old when I started the tweeter upgrade. I could tell there was a nice difference tho it wasn't striking. However, once I got both installed and set the system back up into "normal" mode the differences were definitely noticeable, and in a good way. So, yes, I am very much enjoying the upgrade! Funny thing is that with the tinnitus I've developed in my old age (from Stones, Jethro Tull, Fleetwood Mac, etc. concerts in my younger days), I figured the subdued high end was, literally, in my head. So, being able to hear any kind of difference is greatly appreciated (and, kind of a surprise I am now listening to a lot of my music again and certainly noticing nuances I have not heard in a long while. Overall, I am pleased and gratified that I went for the upgrade.... Cheers....

I'm actually not too worried abt "burn in" time...except as it pertains to my ears (I kinda use "burn in" as a euphemism for my ears becoming adjusted to the sound). Maybe there is...maybe there isn't. I'll just keep listening and when I feel things are settled in (meaning ME) I will listen more closely to see what differences I notice. More interesting to me is the fact that the 20+ yr. old "woofers" now reach 10 Hz lower in their response and why that might be.

This is a curious question for those who may be more knowledgeable about this than I...... I bought my receiver (Onkyo TX-NR626) about 5 yrs. ago. When I did an eq testing on it (Audyssey MultiEQ in the receiver) then, it showed the -3db low end of the KG2.5s @ 50Hz. Made sense since that was where the spkrs. were spec'd. Fast forward to a couple of weeks ago when I replaced the x-over caps and did a re-eq. Again, KG2.5s were shown to have a -3db point @ 50Hz (didn't really expect any changes). So, a few days ago I replaced the tweeters and yesterday did another re-eq. Interestingly, this time it showed the low end -3db @ 40Hz for the KG2.5s. Other than the x-over upgrades 3 weeks ago and tweeter upgrade (diaphragms only), nothing has changed. The sprks were repositioned to within 1/4" of where they were (relative to the wall behind them) before any upgrades. And, while things may have changed (but not much) in the living room between the time of when I bought the receiver and re-eq'd after the x-over upgrade, nothing has changed (except maybe the weather?) between the x-over mods and the tweeter upgrades. Only thing that might be of significance....When I did the x-overs, I noticed 1 of the 8 screws that mounted the front panel to the cabinet had stripped its threads (actually, the 1"x1" wood furring strip had developed a crack across the screw hole thus making it really easy to remove the screw). At that time, I reglued and clamped the piece back in place. Then, when I did the tweeters recently I drilled a new screw hole (actually kind of redrilled the screw hole in a slight different angle away from the crack) which tightened down the screw. Any insight on this? Could it be the new electrolytic NPOs have "settled in" (doubt the mylars I replaced would have anything to do with the low end since they're in the tweeter circuit)? Thx. Quick update on perception of the new tweeters...I have found the spkrs a bit "brighter" so I turned down the treble 2 db (only allows 2 db increments/decrements Will continue to listen and observe a while longer....

OK. Had a chance to complete my tweeter upgrades yesterday. Obviously, they'll need more time to burn/settle in, but here are my initial reactions (more later after I've gotten used to the new parts). My music sources included older analog material, as well as, digitally mastered recordings, all from disk. Music style was both rock and roll and smooth jazz/new age (don't have any classical in my collection). A couple of folks here used the term "sparkle" to describe how the new tweeters would sound. Not sure exactly what that means, but I did find my high end/mids more "filled in" than with the poly tweeters. I guess it gave it more "breadth" of sound in that range. More specifically, some of the good (if there is such a thing) harmonics helped to better define things like cymbals, snares, bongo-like instruments and even the sound of air blowing across the flute. I also heard more guitar fingering in some of the songs. Triangle and chimes were a bit more pronounced. If that's what people mean by "sparkle", then yes, I got that Overall, the improvement was not very pronounced, but enuf in areas that I noticed. Highs were, indeed, sweet and smooth. Like I said, tho, more time is needed so the tweeters can burn in and I can become more accustomed to the new sound. Then I'll report back with an updated experience.

UPDATE (4/3/20): Actually, I'm going to search for some PC S/W and see if I can use the setup mic that came with the receiver to develop some EQ curves. Will take a bit of time, but who doesn't have time these days ---------------------------------------------------------------- Sorry. Don't have that kind of equipment to do that sort of thing. I just use the mic and eq s/w provided by the receiver and do finer adjustments by ear. As for the sub cross, I have set the LFE in the rcvr at 80Hz to make the 6" drivers in the 2.5s a bit more midrange. Kind of like the sound.

Appreciate the feedback from your experience. Did both x-overs at the same time (becuz I figured after 20 yrs. it was prob'ly due anyways) and was pleased with the results (I'm running an Onkyo TX-NR626 and did a re-multieq followed by a manual adjustment after the new caps were installed). I'm hoping to get to the tweeters sometime this week or next and am looking forward to listening to the speakers with the Tis (will do a re-multieq then, as well). As mentioned in my previous post, will come back here and provide my feedback. BTW - Both KG2.5s are my main speakers (don't have a big enuf room to do justice to Heresys) without a center channel. Using Bose 401s as rear/sides and a Klipsch KSW-150 (10", 150W) sub to fill in the low end. Be smart. Be safe. Stay healthy.....cheers...

Just a quick update..... Bought the Ti tweeters. Figured can't go wrong either way. Have not yet installed them (who knew I would have to schedule specific time for this with the way things are right now I''ll post back once they're installed and I've had a chance to burn them in and listen to them. Be smart. Stay safe. Keep healthy.....cheers....

Not to change the focus of this thread but rather to bring a more philosophical perspective.... "A man with no watches never knows the time. A man with 2 watches is never sure". (unsure of original source)....and related is Occam's Razor which, at it's most basic, "keep it simple". In essence, there appears to be a number of variables going on here, many of which interact and/or impact the others. I commend you on your effort to improve the sound of your system with the new additions, but I don't envy the effort (and frustrations) in getting it right, again. BTW - Always wanted bigger Klipsch (would have settled for Heresys). Alas, never lived in a place to do them justice (had to settle for going over to a freind's house who did buy them after my recommendation). Wish I had technical insight to help you out. I'm an engineer but not my area of expertise. Best of luck in sorting it out. I am envious of your audio environment....cheers....

UPDATE (3/19/20) Wanted to add a link I just found on Quora (how timely It's goes to a paper from Dartmouth that discusses using uninsulated stranded wire to create Litz wire. This could be cheaper and much easier than braiding together separate single-strand wires to do this. There's more than a bit of math in the paper that might not be of much interest to you, but some of the narrative may offer you some really good insight if you are a "roll-your-own" kind-of technician. To quote the 1st paragraph of the conclusion: "Stranded wire can be a useful low-cost alternative to high-cost litz wire. Both the cost of insulating individual strands, and the cost of terminating the litz wire can be avoided or decreased." ...and here's the link: https://engineering.dartmouth.edu/inductor/papers/stranded.pdf I don't have a schematic and am not familiar with this particular product (I own a KSW-150 which has a linear p/s...much easier to work on There are various forms of SMPS, one which you mention: PWM. There are other methods, as well. In fact, PWM can look like a variable frequency implementation. Current IC technology easily allows SMPS to hit well beyond 1 MHz (some go to 6MHz and beyond). The best suggestion is to use a frequency counter. Use care when setting it up both for voltage (which could blow out the front end of the counter) and trigger levels (since PWM signals can sometimes appear a bit strange). Also, if you want to "roll your own", there are websites and YouTube vids that can show you how to take insulated single strand copper wire and braid it so it will work as Litz wire. Here's a few to get you started....Cheers.... https://en.wikipedia.org/wiki/Litz_wire

Maybe. Maybe not. I read that you went with OEM specs, and that was the right thing to do. I wanted to make sure others don't get the idea that substituting without fully understanding how something is used in a circuit design can lead to serious problems. SMPSs (Switch Mode Power Supplies) typically output DC for the amp, and that may sound straightforward. Getting to that point is not. An SMPS is a complex design. It takes AC (110 or 220) from the wall, converts it to high voltage DC, turns it back to AC (really more oscillating DC/digital), reduces it, rectifies and then filters before it goes to the load (the amp, in this case). Oh, and don't forget the regulation part, which is a feedback circuit to the input to maintain output voltage(s) with both line and load changes, and more. If one is not well versed in the design or, a least, the circuit operation of an SMPS, messing around with anything in the circuits can cause catastrophic problems. As @efzauner stated abt measuring inductance, that is only part of the equation. The wire resistance (due to skin effect) also plays an important role and failure to consider that can have a serious impact on circuit performance. You mentioned harmonic distortion or extra ripple. True, except that the ripple can be enuf to impact sound quality and/or tear the circuit apart. And distortion can come in the form of clipping due to the power supply not being fully functional. You're right. It may not matter under certain circumstances. At low volumes...hopefully not. However, because of the typical power of a subwoofer amp (50W and up) and the frequency range in which the subwoofer operates, it may matter a lot. Having said all that, it's possible that the Litz wire was a cost consideration. If a number of other coils/inductors/transformers in the p/s design used Litz wire, then using it in the coil referenced here may have been only an incremental cost, as opposed to having to order a small quantity of solid copper wire at a higher price, and using copper wire may not make a noticeable difference. On the other hand, would you want to have to face a customer who returned a unit you repaired that worked for only a short time and then went ballistic again. There goes whatever profit you might have made the first time (I used to repair TVs, stereos, etal when I was in high school and college). Whatever choice is made, be ready to deal with possible consequences. Cheers....

wrt to rewinding a coil..... FYI, I am not a design engineer, but do have an engineering degree with a concentration in computer architecture. First off, there is an important reason for using Litz wire in the windings of inductors used at high (i.e. radio) frequencies which would include switching power supplies. It has to do with what's called "skin effect" and "proximity losses" (Litz Wire Info (on Wiki)). It means that the effective resistance of the wire is increased (which can reduce the "q factor") which can cause all sorts of other problems, the least of which is reduced efficiency of the circuit it's in. Not using Litz wire where it was used in an original design is setting things up for imminent (and possibly, catastrophic) failure again soon. Having said that, while Litz wire can be expensive depending on the guage used, there are articles and websites that discuss creating your own Litz wire out of fairly normal enameled copper wire. Invest some time and save a few bucks...and do it right Good luck and cheers......

Appreciate the feedback. I have been very tempted to make the upgrade. I've heard mostly good stuff from other folks with whom I've spoken, but I've also read on other forums that some folks thought upgrade was barely noticeable and not really worth it. BTW - my polys are in perfect condition. @wuzzzer What was it specifically you liked abt the mod? @geoff. "...grabs you by the boo-boo!..." wtf Good suggestion (not abt the "boo-boo" I can also sell the polys as a replacement for someone who needs them, or sell the tis if I decide I'm not impressed. Sounds like a win-win. I'll give a bit more thought and see if anyone has any input. Thx....