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zeron

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Everything posted by zeron

  1. I have a Klipsch SW12 which has 6 db boost at 30 Hz. Many have criticized it for being boomy. I'm thinking of buying a new sub and R-112SW is one of candidates. I mainly listen to music, so I want to buy a subwoofer that doesn't add boost at its low frequency region.
  2. A possibility: https://www.parts-express.com/yung-sd200-6-200w-class-d-subwoofer-plate-amplifier-module-with-6-db-at-35-hz--301-506 Power rating will be likely to be about 100W into 8 ohm, similar to the amp from SW10 you had been using. What you want to make sure is that the replacement amp will fit into your current cabinet. Dimensions: 8" W x 7" H x 2-1/4" D; Cutout dimensions: 7-1/4" W x 6-1/4" H. SW12 has +6db boost at 30 Hz. I don't know if SW8 or SW10 has +6db boost around 30 Hz. IF you had wished you had tighter base, you may want to select an amp without boost. There are many plate amps at parts express: https://www.parts-express.com/search.aspx?N=4294967118&No=16&Nrpp=16&Nrs=collection()%2Frecord[endeca%3Amatches(.%2C"P_PortalID"%2C"1")+and+endeca%3Amatches(.%2C"P_Searchable"%2C"1")]&Ntt=plate*+amplifier*&PortalID=1 Try "plate amplifier" to do search. This may be good, too: https://www.parts-express.com/dayton-audio-sa100-100w-subwoofer-plate-amplifier--300-802 100W into 8 ohm. But probably no boost. However, you may have to rotate it 90 degrees to fit into the cabinet, and then the fins on the heatsink may not radiate heat as well as it can in its normal orientation. I haven't tried any of these plate amps. I'm just suggesting possibilities.
  3. I'm considering to buy a new active sub. I'm interested in knowing how much life span I can expect from today's decent active subs because most of today's subs are powered by D-class amps and I've read that due to their design, they are not expected to last as much as A/B amps. (Is this true?) If today's active subs are expected to last only a few years (2+ years), I don't think I want to invest too much in one.
  4. 45 Hz. pure sine wave 40 Hz. pure sine wave 35 Hz. pure sine wave 30 Hz. pure sine wave (All of these are one tone lasting 30 seconds or more, no wobbling or sweeping.) I have an old Klipsche SW12. It produces slightly fluttering sounds when it plays pure sine waves at or below 42 HZ. I wonder if this is due to the inherent limitation of the SW12 or mine is not functioning 100% perfectly. I created a test CD by burning sample sine waves I obtained online. I checked for the files integrity by looking at the wave form in Audacity. Here us a picture of the 30 Hz. pure sine wave my subwoofer seems to have difficulty reproducing without fluttering:
  5. I found this picture at another site. May give you a hint as to where one end of the green wire goes: https://images.crutchfieldonline.com/ImageHandler/trim/620/378/products/2017/37/958/g958MAC7200-F.jpg I'll definitely take care of the loose end of the green wire. If you want to repair the amp, the following will be a great help: https://www.audiolabga.com/pdf/SW12-15 I.pdf As to getting parts, I use AliExpress. If you're not in a hurry, their prices are uneatable. If you want parts fast, you could try the following: https://www.newark.com/ https://www.mouser.com/
  6. Update: The seller of the driver just responded to my question what would be the easiest way to connect the old speaker wires. His answer: "You should be able to slide those connectors right onto the subwoofer binding post." I ordered one. I'll see if he is right. Thank you all for your suggestions. Good to know I have a few options.
  7. Thank you for this link, jason str. I think I can make short (~2") patch cables by crimping/soldering these connectors on one side and leaving the other side bare.
  8. The wires coming out of my old amp have these spade type connectors that attach to the original woofer I have. The connectors on the original woofer look like the connectors in the woofer below: If I could, I want to retain the original connectivity between the old amp and the original woofer because I may eventually decide to keep using the original woofer.
  9. I'm thinking of connecting a subwoofer driver like this and the endings of two speaker wires like the following: Note: The driver's manufacturer says the unit has "Large binding posts for heavy gauge wire." Are there adapters/plugs with or without speaker wires that can go between these two types of connectors?
  10. You're very welcome. While there seem to be very knowledgeable people at the two sites I suggested, they have rather strict rules for types of posts acceptable there. You might want to re-iterate what you want (like the type of equipment or circuit) at the end of your post as a question or a set of questions as clearly and directly as possible. Good luck.
  11. Update: It appears that I'll have to change R87, R88, R89, and R90 to 7W 750 ohm or 5W with resistance higher than 750 ohm. The service manual's part list specifies that they be 5W 1.5K ohm while the schematic indicates 5W 750 ohm. The originals are all 5W 750 ohm, and apparently they've been getting very hot, maybe too hot to be stable and functioning properly.
  12. " What I am about to describe may sound a little crazy or abstract, but I am in need of help, as I was told technicians and engineers post in these forums. Please bare with me." You might want to ask your questions at the following sites: http://sound.stackexchange.com/ http://electronics.stackexchange.com/
  13. The manual for my SW-12 says the same thing. I had been using a 3 to 2 prong adapter for my SW-12 until recently myself. It helps to eliminate or reduce severe hums but apparently takes away protection against some electrical surges and shorts. (I wonder if the adapter had something to do with the noises I started hearing from my SW-12. I noticed them for the first time on a stormy day.)
  14. Didn't you write that you had tried two other subs at the same location and had no noise problems?
  15. No, I wouldn't think the whole amplifier is dying. Klipsch engineers must have designed and implemented a section in the amplifier of SW-10 to counter RF interference, like they did for my SW-12. So, this section of the circuit in your SW-10 may have weakened and/or have been weakening, and replacing resistors and/or capacitors in this section will be restoring the original condition of the section as intended by its designers. Have you tried connecting only one cable to L or R of LINE Input connectors? I'm looking at the schematic of SW-12 and I see only 6 resistors and 3 capacitors in this section that deals with RF interference. If I were you, I'd check these.
  16. "I'm just wondering if the old girl is starting to die." Probably not. Most likely, a small part of her is weakening. Should be curable. http://electronics.stackexchange.com/questions/71727/why-is-my-audio-amp-picking-up-am-and-fm-radio-stations Try connecting only one RCA cable to only one of LINE IN Left or LINE IN Right (not both at the same time or through a Y-adaper) to see if you hear less radio signal on one. If that's the case, all you need to do could be as simple as replacing one resistor. near the input connector on the other side. If there's no difference, you may have to change at least one capacitor, too. Will involve labor, but required parts should cost only a few bucks.
  17. I replaced the old R88 with a new one. I put the R90 back in its original spot. The amplifier works now, but one noise came back. It's the crackling kind. The static-like noise seems to have disappeared. Basically, I spent about a week restoring the amplifier to its previous (bad) state. I didn't destroy it with my bad soldering job, though. ============================================== Update (4:12 p.m. Pacific Time): I listened to music for about 90 minuets with my subwoofer ON. I heard no noise. I left the cover off, so, I haven't proven I fixed the amplifier. The noise I heard earlier may have been due to the fact one resister is not soldered to a PCB yet.
  18. I think my re-soldering job was bad. I found one solder-joint was over two conductive tracks of one PCB in the amplifier causing, a short. This explains why one resistor (R88) read got so hot it came loose when the amplifier was on. After turning off the amplifier I took the readings of all 12 ceramic resistors. R88 and R90 read funny. R88 read 423 ohm and R90 0 ohm while they were still on the PCB. Yes, it seems cooling down restored R88's resistance to some degree Off the PCB, R88 and R90 read 428 and 756 ohm, respectively. They are both supposed to read 750 ohm +/- 5%, so R88 must be definitely replaced, but R90 being 0 ohm (in circuit) and resistance between two plates where the two leads of R90 were attached to being 0 after R90 was removed worried me for two days because it could mean that a transistor/transistors connected to it electronically may have been shorted. However, after testing all 12 transistors in the POWER AMP section of the amplifier, I concluded that NONE of them was shorted. I found the cause for the strange reading on R90 last night by tracing relevant conductive tracks of the PCB. The two conductive tracks it was attached to was shorted by one solder joint I touched up before the noises changed. I fixed this problem already. (By the way, both R88 and R90 are bulged and cracked on one side. So, I'm going to replace R90 as well.) The replacement resistors should arrive by this Friday (2/3/17), so hopefully, I can test the subwoofer this weekend. I have a rather strong feeling that I had fixed the problem causing the original noises before I introduced this new problem. I think it was bad connection between R131's three leads and the PCB's conductive tracks, which I had corrected already.
  19. A breakthrough! The amplifier went completely dead while I was testing it. The resistor that was getting really hot (750 ohm 5W ceramic type; R88 or R90 on the schematic) used to measure about 750 ohms. It seems completely open now. Obviously, I'll have to replace this open resistor. The question is whether the new replacement resistor will burn itself up, too?
  20. I had a little progress yesterday evening. The noises definitely changed. I could say the two kinds of noises I had been having, static kind and crackling kind, disappeared completely, but a more regular kind of noise started coming on, still only after the amplifier is warming up. This noise is like that of water dripping from a faucet with drops about 5~8 seconds apart. What I did yesterday evening was re-soldering all solder joints on the circuit boards that didn't look quite robust (not plump, wet-looking, etc.). One notable group of solder joints that I touched up was directly beneath a variable resistor (R131 in the CURRENT SENSE section). During the test I performed last night, I noticed that 6 of 12 ceramic resistors in the POWER AMP section getting extremely hot. One of them was loose during the test. During the test, I thought I didn't solder its leads to the circuit board well, but when I turned off the amplifier, it became solidly anchored to the circuit board within 10 seconds or so. It was just getting hot enough to melt solder. I also re-soldered ends of about 10 wires running between the circuit boards. Any idea what could be causing this new kind of noise?
  21. My old Klipsch subwoofer SW-12 started making noises. I may be able to get it work without overheating (by applying a dirty fix), but probably I won't be able to fix the overheating problem itself. One option I've started considering is replacing its amplifier with a compatible plate amplifier. The following is the specification for my SW-12 from its service manual: Input Sensitivity for max Rated Output: Line input 60mVrms @ 30Hz. Speaker input 700mVrms @ 30Hz. Maximum Rated Output: 150 Watts into 8 ohms. Max. Hum: 3.5mV @ 60Hz. Max. Distortion: 4% At Full Rated Output. Freq Response: 27 to 120Hz +0/-3dB w/12dB per Octave Rolloff. Bass Boost: +6dB Boost @ 30Hz. Low Pass Crossover: Variable from 40 - 120 Hz. 24dB/Octave slope above 120 Hz. High Pass Crossover: Line outputs fixed at 80 Hz, 6dB/Octave slope. Speaker outputs fixed at 120 Hz, 6dB/Octave slope. The following is the specification for Yung SD300-6 300W Class D Subwoofer Plate Amplifier Module with 6 dB at 30 Hz: • Measured power output: 300 watts RMS into 4 ohms @ < 1.0% THD • Signal to noise ratio (at rated power): >90 dB • Input sensitivity (@ low level): 210 mV/50 Hz • Bass boost: 6 dB @ 30 Hz • Low pass adjustment: 40 Hz to 200 Hz • Phase adjustment: Continuously variable from 0º (normal) to 180º (reverse) • Power requirements: Switchable, 115/230 VAC, 50/60 Hz • Dimensions: 10" W x 7-3/8" H x 2-1/2" D; Cutout dimensions: 9-1/4" W x 6-5/8" H. From: http://www.parts-express.com/yung-sd300-6-300w-class-d-subwoofer-plate-amplifier-module-with-6-db-at-30-hz--301-510 Do you think this model by Yung is a good match for my SW-12?
  22. "I'll test with source signal next to see if the noises come back in this setup." I turned on the amplifier in this setup at 4:57 a.m. I left it on until 8:16 a.m. I had heard no unusual noise during this period, which was well over 3 hours. I turned off the amplifier to connect the control pots and LED to the amplifier and turned the amplifier on immediately and started playing music through my LaseDisc player and AVR for about 25 minutes. I heard no unusual noise either. I turned off the amplifier. This test result suggests that I could try one of the following: 1. Drill more holes on the plastic cover. 2. Install the amplifier on the subwoofer enclosure without the plastic cover.
  23. Thank you for your suggestions, Srinath. 1. I see no apparent burnt parts or bad solder joints on the top circuit board. I can't check well how the second circuit board and components on/below it are, but as far as I can see, they look all right. 2, The four things on the front panel [The LED and the three pots for LEVEL, PHASE, and LOW PASS] are connected to the amplifier through two connectors. I've tested the amplifier with the driver attached but without connecting any of the above to the amplifier. I have confirmed that the noises come on this way.. 3. I have not been able to pinpoint which component or components get hot to cause the noises with the cold air method so far. 4. Thinking that lowering the inside temperature of the amplifier covered with the black plastic cover without any vent holes might keep everything in the amplifier cool enough to operate without making any abnormal noises, I made some holes on the plastic case. I put everything back together except two foam sheets (to help air movements inside the subwoofer enclosure easier) to test with music. In about 20 minutes the noises came back. It seemed the holes on the plastic case didn't change anything. 5. I disassembled the subwoofer again to check/test further. 6. I turned on the amplifier (without any source signal) with the plastic cover completely off more than two and a half hours ago. I have not detected any noise (except very faint hum that is expected) so far. Attached pictures: SW12_012: The amplifier with the cover off. The amplifier is resting on its heatsink. The gold dots on the plastic cover are makings for drilling. SW12_013: The darkened area under the cluster of transistors I mentioned in the opening post. SW12_015: The amplifier resting on the top of the subwoofer enclosure with its plastic cover completely off. SW12_016: Closeup of the amplifier and its cover. You can see on the top panel of the cover, the softened (deformed) area due to heat that I mentioned in the opening post. ---------------------------------------------------- I'll test with source signal next to see if the noises come back in this setup. Any comments, questions, and suggestions are appreciated.
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