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Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=116129
Printed Date: April 29, 2024 at 3:45 AM


Topic: amp

Posted By: 93_civic
Subject: amp
Date Posted: September 06, 2009 at 5:11 AM

whats the diffrence between a Class A/B Operation amp, and a Class D Operation amp?

also, if the amp says 1 ohm stable, does that mean i will get the best performance out of my sub if i run it on 1 ohm?

thanks in advance! :D




Replies:

Posted By: yimke
Date Posted: September 06, 2009 at 9:28 AM
Class A/B is a hybrid between A and B. I would recommend these for running 4 channels. The efficiency on these are around 60-70% depending on the design. Class A amplifiers are on 100% of the time and are known for their great "no distortion" characteristics. Class B on the other hand are switched on/off so they are on only 50% of the time. They suffer mass "crossover distortion" so I would NEVER use this for pushing speakers, only subs. But luckily today most of the amps out there are the hybrid between the two and much better design/efficiency.

Class D amplifiers are typically called switching amplifiers. The signal or Sine wave is broken down into individual segments switching on/off. And the actually output it slightly after the input sine wave. This usually causes distortion at the higher frequencies, so a LP filter is recommended on them and these are meant for subs. The greatest benefit of this is efficiency though. Class D amps are around 90% or above efficiency now.

Just because an amp says it is 1 ohm stable doesn't mean that you absolutely have to run it at 1 ohm. The downside to running it this low of impedance is the amp runs HOT. This can lead to less efficiency and possible overheating damage to the circuits of the amp. If you ran it at 2 ohms on the same amp theoretically you would only lose 3db. Most people cant notice the difference, and your amp will be happier in the long run.




Posted By: DYohn
Date Posted: September 06, 2009 at 9:29 AM
Amplifier class describes how it is designed electronically.  A/B is generally the best sounding and D is the highest efficiency.  1-ohm stable means the amplifier will handle any speaker load down to 1-ohm.  Amplifiers tend to sound best and function the best with higher loads.

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Posted By: DYohn
Date Posted: September 06, 2009 at 9:33 AM

yimke] wrote:

lass A/B is a hybrid between A and B. I would recommend these for running 4 channels. The efficiency on these are around 60-70% depending on the design. Class A amplifiers are on 100% of the time and are known for their great "no distortion" characteristics. Class B on the other hand are switched on/off so they are on only 50% of the time. They suffer mass "crossover distortion" so I would NEVER use this for pushing speakers, only subs. But luckily today most of the amps out there are the hybrid between the two and much better design/efficiency.

Class D amplifiers are typically called switching amplifiers. The signal or Sine wave is broken down into individual segments switching on/off. And the actually output it slightly after the input sine wave. This usually causes distortion at the higher frequencies, so a LP filter is recommended on them and these are meant for subs. The greatest benefit of this is efficiency though. Class D amps are around 90% or above efficiency now.

Just because an amp says it is 1 ohm stable doesn't mean that you absolutely have to run it at 1 ohm. The downside to running it this low of impedance is the amp runs HOT. This can lead to less efficiency and possible overheating damage to the circuits of the amp. If you ran it at 2 ohms on the same amp theoretically you would only lose 3db. Most people cant notice the difference, and your amp will be happier in the long run.

1) There are no "Class B" amplifiers available today.

2) the high-pass filter in a Class D amplifier is to remove the noise from the switching frequency of the output device and is generally not in the audible band.  There are plenty of great sounding full-range class D amplifiers: they are NOT just "meant for subs."



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Posted By: 93_civic
Date Posted: September 06, 2009 at 5:33 PM

ok thanks for the help guys!

im planning on running a 600 watt RMS Performance Technique 12" DVC Sub at 2ohms,

can anyone tell me if this amp would sound good with it?

    • Amplifier Class : Class A/B
    • Number of Channels : 1-Channel
    • Maximum Power : 1100 Watts
    • RMS Power Output @ 4 Ohms : 250 Watts x 1-Channel
    • MAX Power Output @ 2 Ohms : 1100 Watts x 1-Channel
    • Bridged Power : N/A
    • THD : 0.01%
    • Signal-to-Noise Ratio (dB) : 103dB
    • Frequency Response (Hz) : 9Hz~50kHz
    • Built-in Crossover : Yes
    • High-Pass Crossover Frequency : Fixed, 200Hz
    • Low-Pass Crossover Frequency : 35Hz~160Hz
    • Bass Boost : 0dB~+18dB
    • Bass Remote : Yes
    • Fan Cooled : N/A
    • Fuse Rating : 25A x 1

-Thanks again for all your help!!!  posted_image





Posted By: i am an idiot
Date Posted: September 06, 2009 at 5:56 PM

Can't tell you how it is going to sound, but if you look closely at the power ratings, notice that they give you the RMS into 4 ohms and they give you max into 2 ohms.
So as long as you know you are going to be sending no more than 500 watts to your speaker, and that is enough power for you, then so be it.





Posted By: DYohn
Date Posted: September 06, 2009 at 6:49 PM
93_civic wrote:

Fuse Rating : 25A x 1


25A @ 14.4 volts, with 65% Class A/B efficiency means this amp will produce approximately 234 watts.  Must be a marginal brand to publish the bogus specs you list.



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Posted By: 93_civic
Date Posted: September 06, 2009 at 11:05 PM

my bad! hey DYohn, can u tell me what approximate wattage this amp will get?

thanks again!

Model: MA Audio HK-601

Hard Kore Series 1200 Watt 1 Channel High Performance Mono Block Car Amplifier

1200 Watts Rated Output Power

1 x 600W RMS @ 2 Ohm Mono

1 x 500W RMS @ 4 Ohm Mono

Fully Unregulated MOSFET Power Supply

2 Ohm Stable @ Mono

Temperature, Voltage, and Output Level LCD Display

Thermal, Short, and Overload Protection Circuitry

Power/Protection LED Indicators

Stainless Steel Finish Heat Sink

Double Sided Black Epoxy PCB Board

Quiet Internal Fan Cooling System

Gold Plated RCA Jacks

Gold Plated Block Terminals

Low Level RCA Inputs

Specifications:

Variable Subsonic Filter: 20Hz-50Hz

Variable Bass Boost: 0-18dB

Adjustable Input Sensitivity

Frequency Response: 20Hz-20 kHz

THD: <0.05% @ 4 Ohm

THD: <0.1% @ 2 Ohm

Channel Separation: 60dB

S/N Ratio: >90dB

Dimensions (L x W x H) 11.81" x 12.4" x 2.7"

(3) 30A Fuses






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