Want to know spec on replacement fuses for the Crest LQ 15 speaker

Just pull the installed fuse out and look at the voltage printed on the side of it if that information isn't already printed by the fuse holder. Should be 110-120 volt. Just make sure it's not a slo-blo or some other type

An amp with 700 watts power per channel at 4 ohms as recommended in the spec sheet, depending on the crest factor or your program material you may want to go with the continious power rating of the speaker.

It may NOT have a fuse. If too much power was sent or an amplifier drove DC to the speaker, the voice coil may have fried. The specs do NOT brag aboput protection, so it is likely either the speaker is blown or the internal wiring is broken. Open the unit and use an ophmmeter to tesst the speakers.

First of all the 70 volt line is used when we are dragging long lengths of speaker wires. hence to counter the drop we use a high voltage line brring it further down without any remarkable drop and use a step down matching transformer to power the speaker according to the impedance of the speaker to the secondary of the transformer. Connect the 70 volt to the 70 volt output in the amplifier. Now connect the other end of the wires tto the primary of the 70 volt transformer. Use the secondary output to connect to the speaker using the tap most suitable..2, 4,6,8 ohms . Check the phasing when you connect or reverse if the bass quality is less.
Hope this helps. Good day

disconnect you load (speakers) power amp up. If this fault persists there might be a problemm with the amp

Test the regulator chips FIRST before ANY replacement. These chips are very reliable and the problem is LIKELY elsewhere.

The 7815 and 7915 ar 15 volt three terminal regulators in TO220 style packages. Three leads. The 7815 is plus 15 and the 7915 is minus 15.

CAREFUL as the input and ground pins are in different order between the two.

FIND the specs and picture with Googling the numbers.

These chips will be soldered in AND MAY be screwed or clamped to a heatsink OR just standing up from the board.

Protect is a mode that it goes into that prevents future damage, i would recommend replacing the fuses.

disconnect all speakers and test if the problem corrected you will have a problem in your speakers(either wire or speaker itself)-try to connect the speakers one by one until you find the bad one and change it--if all above does not work send your amp to service center near you

if you are bridged in parallel instead of in series the amp wont support the load so it turns the power protect on till the amp cant handle nomore then the amp will go if you have two subs bridged run them left speaker possative to to the amp possative for bridged mode then laft speaker negative to the right speaker possative then right speaker negative to your amp negative for bridged mode if you have them left and right speaker possative to amp possative and left and right speaker neggative to your negative to your amp thats parallel the ampwont support the 2 ohm load

These fuses are most likely 3 Amp fuses. Please note that if the replacements blow as well, that there is a problem within the amp section that will require repair.

Dan