So one of my trusty adcom 555's finally died after a hard life running bridged into a 4 ohm load. I picked up a crown xli 2500 to replace it at least until repairs. The very first song I played with the crown, Christine and the queens "tilted", I noticed that the bass was not nearly as tight and then a synth bass tone gave a horrendous crackle from both of my woofers. Every time thst nite played, the noise was back.
Dayton 12" hf sub drivers running up to 600hz. In reviews of the driver people mentioned "oil can" noises which I've never heard, but I don't know if this could be it. I switched back to a single adcom unbridged and the sound was as good as ever, back to normal. I'm scratching my head. Output level was moderate, and no clip light came on needless to say. I was at maybe 50 watts on a 750w amp. Any ideas? I'm so doubtful that an amp could be that different. Yet it seems to be functioning normally. Other songs sounded fine except bass not as tight.
Dayton 12" hf sub drivers running up to 600hz. In reviews of the driver people mentioned "oil can" noises which I've never heard, but I don't know if this could be it. I switched back to a single adcom unbridged and the sound was as good as ever, back to normal. I'm scratching my head. Output level was moderate, and no clip light came on needless to say. I was at maybe 50 watts on a 750w amp. Any ideas? I'm so doubtful that an amp could be that different. Yet it seems to be functioning normally. Other songs sounded fine except bass not as tight.
It could be that the input of the amplifier is being overdriven. Is it possible to turn something down, upstream of the amplifier?
That makes a lot of sense. Source was a minidsp hd. Seems unlikely it would over drive a pa amp input, but its the best explanation i can think of. I'll give it a try and report back. Come to think of it, I had some hum when i plugged it in so I did turn up the minidsp and turn down the volumes on the crown. Thanks!
The miniDSP HD got an output voltage of 2 Vrms. The Crown XLi 2500 got an input sensitivity of 0.775V or 1.4V (depending on the mode) for full power. So yes, it's absolutely possible it's overdriven.
That was it. Dang, it seems obvious now. I should have thought a bit on it before bothering you guys. What happened to 6v being the standard for pa line levels? I must have imagined that? Thanks guys.
If you have the gains at half on the Crown, it would likely be okay. Remember the higher the gain, the lower the voltage input to the amp has to be to achieve full power.
Later,
Wolf
Later,
Wolf
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