I need some suggestions on replacement amp placement and possible heat issues.
Starting at the beginning, I got a couple BP-8020st speakers for a great price because the subs weren’t working—power LED was coming on, but no sound. I figured something I should be able to fix by replacing a part or two in each. After trying, I hit more walls and had no success. I decided to just replace the amp altogether. The woofers are 60 ohms so I knew I’d need a powerful enough amp and I planned on figuring out how to use the factory preamp. I got a couple “1000 watt” amps to use and went to wire them up to realize these preamps are connected to the amps with a PWM signal, where the amp board decoded the signal then amplified. Using the schematic, I figured out where the last place a useable audio signal was Pin 7 on U1, for anyone else looking to do a similar mod). I finally got everything connected and tested and works well, sounds great. However, when buying these amps I had not thought about how to mount them. I did see that a fan should be used with these amps (they have a 23c plug on each board) but wanted to check how hot they got before worrying about that. After testing the amps, the amp side of the board hit temps around 150°F sitting on the table.
Here’s where I need help! Im still not sure how I’m going to mount these inside the cabinets. Im sure I can get creative and figure something out, but the heat is my real hesitation. Will the heat be too much in the speaker cabinet? It’s ported at the base, and with the heat rising, my concern is will it get too hot?? If so, how should I connect a fan to have sufficient air flow without affecting the sound?
Starting at the beginning, I got a couple BP-8020st speakers for a great price because the subs weren’t working—power LED was coming on, but no sound. I figured something I should be able to fix by replacing a part or two in each. After trying, I hit more walls and had no success. I decided to just replace the amp altogether. The woofers are 60 ohms so I knew I’d need a powerful enough amp and I planned on figuring out how to use the factory preamp. I got a couple “1000 watt” amps to use and went to wire them up to realize these preamps are connected to the amps with a PWM signal, where the amp board decoded the signal then amplified. Using the schematic, I figured out where the last place a useable audio signal was Pin 7 on U1, for anyone else looking to do a similar mod). I finally got everything connected and tested and works well, sounds great. However, when buying these amps I had not thought about how to mount them. I did see that a fan should be used with these amps (they have a 23c plug on each board) but wanted to check how hot they got before worrying about that. After testing the amps, the amp side of the board hit temps around 150°F sitting on the table.
Here’s where I need help! Im still not sure how I’m going to mount these inside the cabinets. Im sure I can get creative and figure something out, but the heat is my real hesitation. Will the heat be too much in the speaker cabinet? It’s ported at the base, and with the heat rising, my concern is will it get too hot?? If so, how should I connect a fan to have sufficient air flow without affecting the sound?
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This is great. I'd like to do this as well. I am thinking you should keep these amps externally. Get some sort of box for them. And put RCA jacks or some sort of connector on the back. This will keep the amps cool and away from the severe vibration from the subs. What did you end up doing?
I actually kept trying to fix the original amps. I ended up basically making one irreparable (for my skillset, anyway) and in the process learned where I messed up. My initial thought of replacing the caps was the correct path but I put the two radial electrolytic caps on the amp board in with reversed polarity. Once figuring this out I corrected on the second of the pair, tried it out, and worked again! I found another amp board online for a reasonable price and used it to replace the fried amp. All is working well now—not sure what I’ll end up using the “1000 watt” amps for now.
Did you upgrade the caps in any way? Or would they be the original spec... Also, how did you handle all the glue? Thanks..