The Quantum Audio QA4000D replaces the older QCA4000D.  The inside of the amp is almost the same, with some minor upgrades to make the amp even better!  The new look of the amplifier is much nicer, and it will match the style of any install.

The upgrades done to this amp are all just improvements.  The older model was already the best value on the market for a high powered mono amp, so Quantum did not want to make too many changes to it.  This new model now has a stronger heat management system that keeps the amp cool even when running it at a 1 ohm load.  Quantum also added some extra MOSFETS into the power supply to give the amp more strength.  Other than these 2 very minor upgrades the inside of this amp is virtually the same as the older QCA4000D.

The QA4000D is a 4,000 watt mono-block car amplifier.  This is a class A/B amp with a very efficient power supply.  This amp is way more powerful than the cheaper brands who rate there amps at 5,000 watts or 10,000 watts (or whatever number they are up to by now).  These amps are rated and tested during production.  Quantum is known to make great sounding amps.  We guarantee you will not be let down by the performance of this amp.  This amp will make your subs sound extremely loud!  In terms of sound quality, this amp is top of the line!  This amp has a built in low pass crossover network so you can fine-tune and adjust the bass frequencies.  It has a built in sub-sonic filter, which works very accurately!  This amp is equipped with (2) 60A fuses.  The fuse rating is one of the best ways to see how powerful an amp is.  120A of fuse power means this amp will be crazy powerful!!

We have tested these Quantum amps against some of the headliners in the industry such as Sony, Kenwood and Pioneer and these amps time over time outperform the competition.  If you are looking for top of the line quality without overpaying this is definitely the amp for you.  We guarantee you will be impressed with the performance. (We were blown away with how good these were when we tested them at the CES show in Las Vegas).

Other name brands spend a ton of money marketing there products, so you are not really getting what you are paying for. With Quantum you get way more than what you would pay for an amp at a similar price, labeled under a different brand name.

Features:

• 1 x 4000 watts @ 1 ohm at 14.4 Volts
• 1 x 2000 watts @ 2 ohms at 14.4 Volts
• 2,000 watts RMS output!
• Top of the line Components
• QSINK heat management system
• Continuously Variable 12dB Low Pass X-over
• Continuously Variable 12dB Bass boost @ 45Hz
• Continuously Variable Subsonic Filter (15-55Hz)
• DC-DC PWM Mosfet power supply
• High Efficiency Power Outputs
• Buffered pre-amp input circuitry
• Bass Remote Control
• Direct-connect integrated Speaker and Power wire Terminals
• Illuminated Logo
• Class A/B
• RCA Line Outputs for easy Daisy chain configuration
• frequency response: 20-28KHz
• (2) 60A Fuses
• THD: .05 %
• S/N Ratio: Greater than  95 dB
• DC Short Circuit Protection
• Input voltage: 11 - 14.4 volts
• Adjustable Input sensitivity: .2 MV - 5V
• Dimensions: 19.68" x 2" x 10.5" inches