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highvoltamps

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Posts posted by highvoltamps

  2. Amp Rack

    in Radio/Electronics/Security

    Posted · Edited by highvoltamps (see edit history)

    Well I am torn down and ready to install am amp rack. What do I do with the cab vents??

     

     

    You can make little ducts and ducted to the sides or reuse the stock rubber duct and reverse it if your not worried about presentation . That's what I have to do with my setup. Going to dynamat and ensolite the inside of aluminum ducts to reduce outside noise.

     

     

    Just analzed my vents with the trims and going to duct to the sides and down, the depth staying tight to the trim pieces. Going to be competing and the little things count. Plus I love doing this shit. Check out the progress http://s1142.photobucket.com/albums/n616/highvoltamps/

  8. Wildlife Pics - 2011

    in Video & Photography

    Posted

    Here are the king kong sunflowers I did last year. I used advanced nutrients and super thrive with a daily watering. They were bad ass but a lot of work, especially battling the squirals and birds. If I do they again they will be spaced out more in the back yard and build a netted greenhouse when they start budding. Ended up with about 8 good heads that I dried, soaked and roasted. All the little heads I dried over the winter and when those damn squirrals came back out, I had some target practice. Got pretty good with the blow dart gun.:yellow_loser:

     

    post-3906-088942000 1308221046_thumb.jpgpost-3906-005097900 1308221058_thumb.jpgpost-3906-019012800 1308221070_thumb.jpgpost-3906-073133500 1308221081_thumb.jpgpost-3906-038324200 1308221093_thumb.jpg

  15. Rear Brake Squeal With Hawk Lts Pads

    in Suspension & Brakes

    Posted

    Yes, sand them lightly with 80 grit sandpaper and repeat the bedding process with the freshly cut rotors.....

     

     

    Thanks good buddy. Since you know your brakes, I got one more for you. The shop that did my brakes used an air gun to tighten the caliper bolts and now the the one side both spin when tightened. I have to put channels around the pin and tighten the bolts. Is this bad pins or the caliper?

  17. Custom Systems

    in Radio/Electronics/Security

    Posted · Edited by highvoltamps (see edit history)

    That makes sense. I knew a fuse took double it's load before it trips, but i didn't know about the 'crest factor'. I usually do fuse my system a little on the small size, and they never blow.

     

    Not all fuses are like that, the slow blow would be that particular fuse. There are also current limiting, time delay and fast acting type fuses. I spoke with Stinger and the use slow blow on the anl type fuses.

  18. Rear Brake Squeal With Hawk Lts Pads

    in Suspension & Brakes

    Posted

    I think you arleady figured out your answer, as you stated, you should have cut the rotors before installing the new pads. New pads + old scored/warped/worn rotor surface = noise, glazing, improper pad bedding, and premature pad wear......

     

     

    Yeah but do you think they can already be messed up after 3 weeks of use with the old pads. I took a sanding block with 120 grit and took of the old transfer film and they looked near new again.

  19. Rear Brake Squeal With Hawk Lts Pads

    in Suspension & Brakes

    Posted

    Oh no, the rear brake squeal is back but not as bad. I noticed the wear is mainly on the middle of the rotor with some scoring marks but still smooth. Think the squealing is brake dust from an uneven surface on the rotor. Should have waited to put the new pads on with the new rotors. I think I need the rotors resufaced from the old pads not wearing flat or I need new calipers or new brake pads. Just don't understand why the front has the same setup and has not made any noise and the rotor wear is even from top to bottom.

  20. Custom Systems

    in Radio/Electronics/Security

    Posted · Edited by highvoltamps (see edit history)

    Hope so. Off the alarms, I came across this from the IASCA rule book. Thought you might like. Going to fuse my alternator at 250 amps after reading this.

     

    A fuse is required to carry its rated load continuously, 135% of rated load for 1 hour,

    and double its rated load for 30 seconds. So, if a 500 amp fuse is used and the

    cable shorts to ground, it must generate 1,000 amps of current through the short to

    blow the fuse quickly, which isn't likely. Using too large a fuse is potentially very

    dangerous!

     

     

    THE CREST FACTOR

    Now that we know the basics of a fuse, how does it apply to use with audio

    equipment? To understand how it applies, we need to know about the Crest Factor.

    The Crest factor is simply the ratio of the peak signal level to the average signal

    level. An un-clipped sine wave has a crest factor of 3 dB (i.e. the peak level is double

    the power of the average level). Pink noise has a crest factor of 6 dB (the peak level

    is 4 times the power of the average level). For every 3 dB increase in the crest

    factor, the power level is divided by 2.

    A crest factor of 10 dB means the peak power is 10 times the average power. 20 dB

    yields a peak power of 100 times the average. And a 30 dB crest factor yields a

    peak power 1,000 times the average!

    Most music has a crest factor between 10 and 20 dB. Some of the newer popular

    recordings unfortunately have very low crest factors, often less than 10 dB. Music

    with a very low crest factor is not dynamic, has little impact, and typically sounds

    loud all the time.

    Music that is very well recorded will have crest factors above 15 dB, and sometimes

    well into the 20+ dB range. (The James Newton Howard and Friends recording from

    Sheffield Labs has a 30 dB crest factor).

    Now, amplifiers are rated at an RMS power output, which is simply the average

    output when reproducing an un-distorted sine wave. Since a sine wave has a crest

    factor of 3 dB, a 1,000 watt RMS rated amplifier will reproduce 2,000 watt peaks

    cleanly.

    Now, let's take this 1,000 watt amplifier being driven to its maximum un-distorted

    output level of 2,000 watts with a music track having a crest factor of 20 dB. 2,000

    watts divided by 100 = 20 watts average power output. If the crest factor is dropped

    to 10 dB, then the average power output will be 200 watts. And if really poorly

    recorded music is used with a crest factor of only 6 dB, the average power output

     

     

    would be 500 watts. So as you can see, the actual power output of an amplifier

    reproducing music is nowhere near the theoretical maximum output. It may be as

    high as 1/2 the rated output with really poor recordings, but will likely be much less

    than this.

    NOTE: This does not apply to SPL competition, where amplifiers are typically driven

    to their maximum output with sine waves, and are often driven into substantial

    clipping as well.

    With the crest factor considerations in mind, I would suggest the following:

    First, a maximum allowable fuse value can be calculated based simply on adding up

    the recommended fuse values for all the amplifiers, any larger than this would be

    grounds for points deductions or disqualification. And quite honestly, this would be

    severe overkill on the main system fuse anyway.

    A more precise fuse rating can be calculated using the following method:

    Determine the maximum peak power output of each amplifier by multiplying the

    rated RMS power by a factor of two.

    Allow for the efficiency of each amplifier. For class-A/B amplifiers, assume

    60% efficient, and for switching or class-D amplifiers, assume 80%.

    Assume supply voltage is 12 volts (This can be argued to be higher or lower,

    depending on the system, but 12 volts is a good average)

    Assume a worst case music crest factor of 6 dB, which means the average

    output power is 1/4 of the peak output.

    (continued next page)

    Calculation Example:

    A system has (3) 1,000 watt Class-D amps, (2) 500 watt class-A/B amps, and (2)

    150 watt class-A/B amps.

    The recommended fuse values for the amplifiers are as follows:

    1,000 watt amplifiers - 100 amps each

    500 watt amplifiers - 70 amps each

    150 watt amplifiers - 25 amps each

    The maximum allowable main system fuse size would be:

    (100 amp X 3) + (75 amp X 2) + (25 amp X 2) = 500 amp

    Now calculate the fuse value with peak outputs utilizing Crest factors:

    The maximum peak outputs will be the RMS outputs multiplied by 2 to get the peak

    output for each amplifier:

    1,000 watts X 2 = 2,000 watts

    500 watts X 2 = 1,000 watts

    150 watts X 2 = 300 watts

    Taking efficiency into account:

    2,000 / 0.8 = 2,500 watts

    1,000 / 0.6 = 1,667 watts

    300 / 0.6 = 500 watts

     

     

    So the total power draw for the amplifiers would be:

    2,500 X 3 amplifiers = 7,500 watts

    1,667 X 2 amplifiers = 3,334 watts

    500 X 2 amplifiers = 1,000 watts

    The total power required for all the amplifiers to be driven to maximum peak output

    simultaneously would be 11,834 watts.

    Now, take the 6 dB crest factor into account by simply dividing the above peak

    output by 4:

    11,834 / 4 = 2959 watts

    Now divide this by 12 volts: 2959 / 12 = 247 amps

    A 250 amp fuse would be a much more realistic value than the 500 amp fuse that

    would be required by adding the recommended fuse values for all the amplifiers.

    Notice that for a crest factor of 6 dB, the fuse value would be approximately 1/2 that

    of the fuse calculated by adding the recommended fuses together. If the crest factor

    is 9 dB, the fuse value would be 1/4, and for a crest factor of 15 dB, the fuse value

    would be 1/16th.

    I have tested this technique, and have never had a problem burning a main fuse

    calculated simply by adding the ratings of all the amplifiers and dividing by two. This

    is the same as going through the entire calculation for a crest factor of 6 dB.

    I know going through the entire calculation is somewhat confusing, and may be

    difficult to fully explain in the rule book, but this is how it works. And, using a fuse as

    large as that calculated by simply adding up the recommended fuses values for each

    amplifier will be overkill, and could even be dangerous.

     

     

     

  23. Custom Systems

    in Radio/Electronics/Security

    Posted · Edited by highvoltamps (see edit history)

    Because the motor wires rest at ground, i don't think you can just pulse the wire with current. You could hook up some relays to break the motor wires when the module is triggered, that way your windows would still work like factory and still have the windows roll down.

     

    Nice, I was thinking the same with adding the relays. Thanks for the explanation. Some of the alarm wiring can be very tricky. Got to draw it out on paper before I attempt anything. What do you think about the VG800? Pretty self explanitory with a lot of options. Should be easy since I have an aftermarket already installed. Looking to run multi conductor cable to all of the locations to tap and terminated in the center concole under the bucket. Going to remove the factory amp for mounting the alarm equipment. In the center console storage will be the keyed valet switch. My daughter and I finished the polished aluminum center console control panel and head unit/EQ face over the weekend. I came out to a mirror finish like the amp rack, getting excited. All I got left is dynamat/ensolite, running the wires, mounting equipment, termination and a RTA tune.

  25. Custom Systems

    in Radio/Electronics/Security

    Posted · Edited by highvoltamps (see edit history)

    I ended up buying the XK01, not to worried about the heated seats but definitely want the window rollup to work. I have the Scytek WR-16 smart window control module that can do 2 windows roll-up and down. On the schematic its wired to the door switches, but when the key is not in the ignition or not auto started this will not work. Should I just use the XK01 for the windows but can I roll down thw windows with this module?

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