Question about Mirage BPS-400 amplifier.

[Pandaman617]

So a month ago I picked up a Mirage BPS-400 for $80. I initially thought it was in great shape until I finally got around to connecting it and found the amp was dead. So I replaced it with a new old stock amp I found online luckily. The amp definitely works as the power light comes on and I know I wired both 12” drivers correctly but regardless of the input I use I get zero sound output. I’m stumped. Is it possible the board that has the RCA inputs on it is shorted out? What I don’t understand is that upon connecting a signal the amplifier successfully activates the auto on feature. Anyway, any ideas would be greatly appreciated!

 

[lovinthehd]

Just because a light comes on doesn't mean the amp works. Sounds like another dead amp, what is it particularly?

 

[Pandaman617]

Basically I’ve tried every connection option possible from using a single input, to a Y adapter, to trying the LFX input (apparently it was for the external Mirage LFX crossover) and I get zero sound. I’ve found a few options for replacement amps in terms of external ones and going that route isn’t something I’m opposed to. My audio knowledge is still pretty amateurish compared to some of the guys on here but it’s certainly reached the point where connecting a subwoofer to my AVR isn’t something I need to make a forum post about. My father is an electrical engineer and I know he has a multi-meter and has helped me in the past with small fixes but I honestly don’t know where to start.

 

[lovinthehd]

Sorry, I intended to ask, have you inspected/tested the driver?

 

[Pandaman617]

I have. They both read what they should and there’s no visible damage and they both move relatively freely if I lightly apply pressure to them

 

[lovinthehd]

You could maybe still try another known working amp connection just in case, even if just one from your receiver? (just last ditch thing I could think of)

 

[Pandaman617]

I’m borrowing a Snell subwoofer amplifier at one point tomorrow to see and hear what the results are. Inside the cabinet everything is compartmentalized and sealed in its respective area so the positive, negative and ground wires for both drivers run through these tiny holes into the area where the amp is and where the drivers are. Initially I wanted to see if the wires were disconnected or damaged somewhere but it’s more or less impossible without damaging the cab. So I figure I’ll run the Snell tomorrow and if it works fine just wire the two 12’s to whatever external amp I end up with. I paid $200 for this “new old stock” amp but luckily I was able to get refunded today as the guy stated it worked and so far the lie detector has determined that was a lie . Thanks for your input man!

 

[Pandaman617]

So it turns out my novice level electronic skills have resulted in a major “DUH” moment. I wasn’t measuring the drivers for this sub the right way. After my electrical engineer dad showed me this morning the proper way I discovered both 12” drivers are blown. I plugged a 4ohm driver from a Mirage PS-12-180 into one of the outputs and it worked fine. So I now know my amp is good. I just ordered a pair of 12” 4ohm Dayton Audio reference drivers to replace the blown ones so all together I’m into it for $280. I actually paid more for the two drivers than the cabinet and replacement amp that I was refunded for. All in all I’m pretty happy to actually figure out what the issue was, I know the BPS isn’t that much better than the pair of OM-200’s I’m running now but the 110lb monster just looks cool.

 

[Pandaman617]

 

[Pandaman617]

Got the BPS-400 up and running. REW measured 84dB at 18HZ in my room. I’m using two of the Dayton Audio Reference 12” drivers that have a little over half of the rated RMS/peak power of the original BPS drivers but so far with the gain at 2-3 it shakes my entire house with no sloppiness. Eventually I’d like to find some better drivers that can handle the full 400 watt RMS/1400 watt peak power output but for the time being and a total investment of exactly $202 I’m pretty happy.

 

[lovinthehd]

Got the BPS-400 up and running. REW measured 84dB at 18HZ in my room. I’m using two of the Dayton Audio Reference 12” drivers that have a little over half of the rated RMS/peak power of the original BPS drivers but so far with the gain at 2-3 it shakes my entire house with no sloppiness. Eventually I’d like to find some better drivers that can handle the full 400 watt RMS/1400 watt peak power output but for the time being and a total investment of exactly $202 I’m pretty happy.

Why would power handling spec particularly change things, though? Could be something as simple as your newer drivers are more sensitive....and the gain setting is only relevant to the input level really.

 

[Pandaman617]

Why would power handling spec particularly change things, though? Could be something as simple as your newer drivers are more sensitive....and the gain setting is only relevant to the input level really.

I honestly wasn’t sure if it would or not. But that’s a very good point. I’m still very much a novice in my understanding of a lot of speaker related info and what not.

 

[lovinthehd]

I honestly wasn’t sure if it would or not. But that’s a very good point. I’m still very much a novice in my understanding of a lot of speaker related info and what not.

Think about the gain control....it's merely there to match the capacity of the amp to the input level.....a higher gain setting simply reflects a lower input signal level.

Power handling could be based on some actual increase in capacity. Hard to know from that spec alone, tho. Your replacement drivers could well be of higher quality than the originals, too.

 

[Kingnoob]

Never had a duel driver sub , I nearly got a mtx once but it was all internal so if anything blew they were junk. Still wish ida bought them ..
Discontinued like forever ago

How loud is it ? Sucks you had to spent so much to repair
I’m using 15” in bedroom but I rarely use that system... no sub downstairs


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