stepher

Came across this thread while looking for something else.....down the rabbit hole once more I have a KSW-150 Sub. Am original owner and have had it for decades(?). A few years back my system developed first a hum and then a buzz problem (solved the hum before the buzz showed up). I did a ground loop check (didn't expect that to be the issue becuz I had changed nothing in the system for over a year before the hum showed up). Since the sub was decades old, I considered it might be the filter caps. However, before buying and replacing the caps (may do that sometime soon anyways, just becuz) my go-to process for this kind of symptom is to first check solder joints. So I pulled out my trusty temp-controlled soldering iron and redid the filter cap connections in my best engineering fashion. Problem solved A few years later the buzz showed up. It seemed to be related to higher levels of low freq (LF). I localized the problem to the sub (again using a scope and signal gen. I first checked the sub speaker itself for physical issues. Nope. Cone movement was free and quiet (the buzz had a kind of "scritching" sound that reminded me of a voice coil going bad). Then I remembered the filter cap issue. Out comes my trusty soldering iron to redo any solder joints in the amp section that even hinted at issues (and many that didn't). Fired up the system and problem was gone (and has been for nearly 5 years.😣 Moral of the story....don't assume a familiar sound indicates a familiar problem. The shortest distance between two points is almost always never a straight line In closing, for any who may need it, I have pdf copies of both the KSW-100/150/200 and SW12/15 subwoofer service manuals with schematics. Let me know and I'm happy to email. Cheers....

@Alexander I have yet to do that. However, the individual on audiokarma.org forum said he'd done that and a couple of the capacitors (iirc, the LP electrolytics) were unmarked (except for "Klipsch" stamped on them). I suppose I'll have to open one up and see if mine are different. Is @BEC on this forum very often? Thx and cheers...... Also, for those who might be interested, I have pdf copies of the KSW-100/150/200 and SW12/15 subwoofer service manuals if anyone needs any of them. I got them directly from Klipsch. Cheers.....

Hi All, UPDATE: Brain must not yet be engaged Forgot to attach a schematic I found (iirc on audiokarma.org). I added the notes on the lower left from someone's comments...thus not sure what's valid. ----------------------------------------------------------------------------------------------------------------------------------------------------------- I'm looking to "refresh" the x-over caps in my KG 2.2s (I'm original owner). I was wondering if there was a "real" schematic out there for these spkrs (might also be for KG2.5s since they are somewhat similar...or maybe not). I've come across a couple of schematics but some cap and res values are different (old saying: "A man with no watch never knows the time. A man with 2 is never sure."...I'm a man with 2 Thanks in advance...cheers.... KG2.2 Crossover Schematic (maybe).pdf

Thanks for the help. I did some prelimiinary checking and the replacement speaker looks to be about $140 or so. So, your point's well-taken about not fixing/replacing the speaker. I'll troubleshoot the sub amp and if that doesn't solve it, I'll figure where to go from there. Just out of curiosity....is this kind of "old age" something that is somewhat common to subs or speakers in general? I expect that subs might be susceptible because of the focus on lower frequencies. Thanks again and cheers....Steph

Appreciate the input. After I saw your posting, I went and did another pressing on the cone and pushed it beyond the 1/4", close to a half inch, and no sound at all, not even any sense of bottoming out. Feels fairly firm, too. I know the sound you mention. I've heard it in other speakers I've blown...cheap ones, fortunately I also took a closer look at the rolled rubber edging and it shows no signs of tears or any wear and appears to be solidly attached both to the paper cone and the frame. In fact, other than a bit of dust, it looks almost as new as the day I bought it. I hadn't thought about it being just an age-related issue, but what you say makes sense. I've had it over 10 years, prob'ly closer to 13. I think the speaker is of the K1049 series. I still plan to look at the sub amp audio circuitry with a scope and check the power supply under load, just to be sure. If one of the filter caps dried up or a diode got leaky, or a bypass cap went bad, it could still be an electronic issue (certainly easier to fix than the speaker). So, assuming it is an age thing, any suggestions other than replace or rebuild (or keep the volume lower) to fix it. Thanks and cheers....Steph

Hi all, Happy holidays to everyone!!! I have a KSW-150 10" @ 150W (supporting a set of KG 2.5s). I'm original owner. I've had some minor problems along the way (hum because of a cold solder joint on one of the filter caps, for example), but the sub has performed flawlessly, otherwise (there's a reason I won't settle for less than Klipsch Within the last 6 months I've notice what sounds like "clipping" at higher volumes (I expect it could also sound like voice coil problems for the sub speaker, but it doesn't sound quite that "scritchy", if you know what I mean). When I first noticed this, it seemed to be related to HD/surround sound (it was very obvious during some intensive room-filling, low-end material on the movie Oceans...environmental flick, not the George Clooney ones since I never noticed it when playing 2-channel programs (CD, etc.). My initial thought was it might be something in the receiver decode circuitry causing the problem. However, the other day out of curiosity I cranked up the sub during 2-channel play and discovered the "clipping" noise was there, just at much higher volume levels than during surround sound material (why I never noticed it). I've done minimal testing on the sub speaker itself. Since it's a down-firing unit, I did flip over the box and carefully pressed the speaker in ~1/4" and heard no rubbing or "scritching" noises (associated with a loose voice coil). I plan to test the coil with a DMM, tho I'm expecting that may not be much of an indicator except for a catastrophic failure (which doesn't seem to be the case, yet). I read somewhere about performing a "battery" test by momentarily connecting a 1.5V battery across the speaker pins and listening for some sort of "wooomfp" (sans "scritching" and "clipping" sounds). Any input on the wisdom of doing this. I'm hoping it may still be a clipping issue, but related to the amp/power supply. Only problem is I'm not sure what normal is supposed to be (i.e. supply voltages both with and without loading, etc.). Schematics don't seem to be available (readily or otherwise) so I have no roadmap. I have looked at the LFE signal (from the receiver) using a scope during both single LF tone and the Oceans video and saw nothiong obvious (makes me want to eliminate the receiver as a culprit). I suppose I could get ambitious and look at the output of the sub amp to see if the clipping is occuring there. I'd be grateful to anyone with knowledge or experience with these kinds of subs for any suggestions in this area. Cheers....Steph