leon garrity wrote on Sun, 09 January 2011 10:46 |
all i know is this im having to nearly get my FP3400 to nearly clip to get the SM60f loud around 110 db but if i run say a 800 watt amp on it its very quiet even at full on power????
If i run the SM60 on a tiny 60 watt amp in my home cinema its stupid how loud it goes.....if i put the SM60F on my Lab amp its getting over 20 x the power at full on power....
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The SM60 is about 96 dB one watt one meter so peak output should be 106 dB at10 watts, 116 dB with 100, and 126 dB at 1000 watts.
In your home cinima situattion, the room is probably small enough that there is not much level change anywhere in the room when measured with a dB meter, and with a pair, each driven with 60 watts, 110 should not be a problem.
In a larger room, or outside, level sound drops 6 dB per doubling of distance. Your meter also may not catch the peaks, it could read another 6 dB lower than the theoretical output of 120 dB at 2 meters, 114 dB at 4 meters, 108 dB at 8 meters.
“110 dB” should be tops at 8 meters (26 feet), especially if read on the dBA scale.
If you are burning drivers, you are using too much long term power, which means you must turn it down or get more speakers.
Four eight inch and a pair of 5” mid/1" high can only get so loud before they vaporize.
Sub alignment, as Ivan says, depends on the crossover frequency and other variables.
You want the phase of the subs to align to the phase of the low mids. If you look at your speaker's phase charts, you will see that varies with frequency.
Rather than going over sub alignment in detail, I’d suggest doing a search, the subject has been covered in the Lounge many times.