Class D amps

Discussion in 'Car Audio, Electronics & Security' started by Shields, Feb 19, 2015.

  1. Shields

    Shields Veteran Member

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    How hot do class D amps really run? I've got a clarion amp and an ultimate t-2 monoblock an was wondering what space they would need for sufficient cooling. Both amps will be running about half their max wattage, they'll see a total of about 700 watts combined. Love to know everyone's take on a class D amplifier
     
  2. 75Camaro4x4

    75Camaro4x4 Veteran Member Lifetime Gold Member

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    I have 2 Class D amps (One is NVX the other a Hifonics) and they both get warm, but I've never felt either get super hot.

    The NVX I have tucked under a seat (Still plenty of airflow due to how small NVX's amps are) , and the Hifonics is mounted in trunk.

    The heat would depend on your ohm load, and clipping doesn't help. The user manuals normally state the max temperature for the amp.

    And as far as Class D amps, I've had no problems with them. They are what I use the most lol.
     
  3. Shields

    Shields Veteran Member

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    Awesome! Thank you
     
  4. 75Camaro4x4

    75Camaro4x4 Veteran Member Lifetime Gold Member

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    Also, you said each amp will be running half of their max wattage... are you familiar with the terms RMS and what the gain knob does? If not, I would highly recommend looking into that. I can post links if needed.
     
  5. Shields

    Shields Veteran Member

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    We'll my clarion xr2420 is rated at 240 watts rms, 440 watts peak, and my kenwoods will pull 130 watts from it, my ultimate t2-5001 is rated at 600 watts rms, 1000 watts peak and my subs pull 300 watts rms each so it should match pretty well. Can you tell me what I should know about gain?
     
  6. camarolife78

    camarolife78 Veteran Member

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    Gain is the "power" knob that turns up to volume so to speak, to the speakers. I used to install all kinds of car audio for many years, and what we did in the install bay was turn the radio to the volume number we wanted to where it was up almost max and then adjust the amp gain and other settings. We would almost max out the speakers but would keep it adjusted so that the sound was clean without distortion. Doing it this way we typically saw long life out of the stereo unless the customer chose to change our settings.

    As far as your amp space is concerned, we installed them in many places, under seats, between the box and seatback, and they typically needed minimal space to stay cool. I think it was due to the internal heat sinks built into the design. So unless you were thinking about putting them in a closed box or upside down, I think just about anywhere will work.
     
  7. 79ZED

    79ZED Veteran Member

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    We'll my clarion xr2420 is rated at 240 watts rms, 440 watts peak, and my kenwoods will pull 130 watts from it, my ultimate t2-5001 is rated at 600 watts rms, 1000 watts peak and my subs pull 300 watts rms each so it should match pretty well. Can you tell me what I should know about gain?

    The speakers don't pull anything, the speaker rating is the maximum power they can handle. Most of the time, the manufacturers are very vague on what they can handle...peak, continuous power , and at what frequency... and for how long, all vary from one company or another.

    Class D ampifiers are very efficient, roughly 90% of the power consumed will go to the load, depending on frequency. Class A/B, on the other hand, generally reach a maximum of about 75% at full power output, but can be far lower, especially around 1/3 rated power.
     
  8. Bikefixr

    Bikefixr Veteran Member Lifetime Gold Member

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    Your Kenwood speakers will draw about 7-10 watts each at normal listening levels. "Loud" volume might require 25 watts. Painful volume will draw 30-40 watts. The reason the amps are capable of higher outputs is for momentary high-bass notes that might require 60-80 watts...for a half second. Every time you double your volume, it requires about 4 times the power. But, the way the ear/brain responds isn't linear. At a certain point, volume almost ceases to increase as your auditory nerves become maxed out. Ever been to an indoor concert where the 'music' becomes unintelligible? That's because it's so loud that it has become noise..not music.

    Some of the best sounding systems I have installed ran off of a high-end (ADS) 25w x 4 amp with a 200 watt 2ch amp for the 2 subs. That's all you need. It's the common misunderstanding that speakers 'put-out' wattage that leads the manufacturers to place meaningless specs. They feed the ignorance.
     
  9. 75Camaro4x4

    75Camaro4x4 Veteran Member Lifetime Gold Member

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    Your headunit puts out a signal to the amp. The gain, matches the amp to the signal. Too much gain, and your amp will send out a clipped signal to yuor speakers. Not enough gain, and you are losing pontential power.

    In your case, you will probably hear distortion from overpowering before you run into clipping.
     

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