Hello,

I just switched the amp on my subwoofer and was quite surprised at the
results. I had a Lanzar OptiDrive 500 w/ch stereo amp ( one of the old
original ones ) bridged to mono. I am driving a single 4ohm JL Audio 12W0.
I switched to a JL Audio 250/1 today. The bass is stronger, deeper, and
cleaner with the 250/1. My gains are equal or slightly lower on the 250/1
than where they were set on the OptiDrive as well.

This leads me to question whether class A/B watts are somehow less
meaningful than class D watts for a subwoofer application. I was also
surprised at the quality of the bass. I always believed that Class A
amplification provided the best quality sound and Class A/B slightly lower
quality sound. I thought that Class D may have been unaccepatable in sound
quality. Man was I wrong.

Can anyone provide an explanation for the bass performance with less power?

Thank you,
Steve.

I just switched the amp on my subwoofer and was quite surprised at the
results. I had a Lanzar OptiDrive 500 w/ch stereo amp ( one of the old
original ones ) bridged to mono. I am driving a single 4ohm JL Audio
12W0.
I switched to a JL Audio 250/1 today. The bass is stronger, deeper, and
cleaner with the 250/1. My gains are equal or slightly lower on the 250/1
than where they were set on the OptiDrive as well.

This leads me to question whether class A/B watts are somehow less
meaningful than class D watts for a subwoofer application. I was also
surprised at the quality of the bass. I always believed that Class A
amplification provided the best quality sound and Class A/B slightly lower
quality sound. I thought that Class D may have been unaccepatable in
sound
quality. Man was I wrong.

Can anyone provide an explanation for the bass performance with less
power?

What you've witnessed here is a disparity between power ratings and *real
world* power output.

In article ,
"Steve" wrote:

Hello,

I just switched the amp on my subwoofer and was quite surprised at the
results. I had a Lanzar OptiDrive 500 w/ch stereo amp ( one of the old
original ones ) bridged to mono. I am driving a single 4ohm JL Audio 12W0.
I switched to a JL Audio 250/1 today. The bass is stronger, deeper, and
cleaner with the 250/1. My gains are equal or slightly lower on the 250/1
than where they were set on the OptiDrive as well.

This leads me to question whether class A/B watts are somehow less
meaningful than class D watts for a subwoofer application. I was also
surprised at the quality of the bass. I always believed that Class A
amplification provided the best quality sound and Class A/B slightly lower
quality sound. I thought that Class D may have been unaccepatable in sound
quality. Man was I wrong.

Can anyone provide an explanation for the bass performance with less power?

Thank you,
Steve.

It's normal for car audio equipment to grossly overstate or outright lie
about power ratings. "Peak output power" is a common claim, which is a
clipped pulse output reaching 2x to 4x the continuous power. I've seen
"peak-to-peak output power," which is a nonsense rating 4x to 12x of the
continuous RMS output. (The term peak-to-peak applies to voltage
deltas, not signal power.) Still another cheating trick, which Kenwood
always uses on their home equipment, is to measure channels one at a
time so that the power supply does not droop (or blow a fuse).

So now you can see that the "500W x 2" amp that you were using could
have really been one of those dime-a-dozen 65W RMS x 2 amps.

Class D is more efficient so it doesn't consume as much power and
produce as much heat. Class D also has a lower quality/price ratio at
higher frequencies. That's why Class D is common for subwoofer amps but
a bit pricey for quality full range amps.