Fairy Tale CEA Ratings, Why?

[Bass911 10+ year member]

This girl I know wanted to get a Kenwood KAC-9104d because she saw it on a display board. She was going to get it online, but I told her to wait so I could check out the reviews. CEA rates it at 900rms @ 1 and 2 ohms. Come to find out it only does 565 @ 12.5v and 644 @ 14.4v, done by a Car audio magazine. Why is CEA so far off? Are companies paying them under the table to inflate rms ratings?

I didn't use the search and someone has probably already brought this up. I thought we could at least trust CEA ratings! Any thoughts?

Click to read more...

 

[newusername 10+ year member]

They gave CEA ratings to all the RF hybrid amps that don't make that power continuous, either. Great intentions...sub-par execution.

 

[gunz4me 10+ year member]

IIRC, that particular Kenwood is only CEA rated at 4 ohms! Read the fine print...

ETA: The biggest give away should be its fusing. 60 amps worth of fusing will have a hard time making 900 watts RMS!

 

[Haunz 10+ year member]

They gave CEA ratings to all the RF hybrid amps that don't make that power continuous, either. Great intentions...sub-par execution.

It dosen't necasarilly make sense to rate the RF 'hybrid' amps continuosly because they capitalize on the fact that music is not continuous...

Amplifier ratings are often bogus.. and certain standards existed long before CAE..

CAE attempts to put car amps on a somewhat level playing field.. However, if manufactures are posting 'CAE specs' only at 4ohms with some bogus number still stamped on the front of the amp as gunz4me suggests then thier really isn't much point at all..

 

[AZsound 10+ year member]

Rated Power Output (CEA-2006)

On May 28, 2003, the Consumer Electronics Association published standard CEA-2006, "Testing & Measurement Methods for Mobile Audio Amplifiers." This "voluntary" standard advocates a uniform method for determining an amplifier's RMS power and signal-to-noise ratio. Using 14.4 volts, RMS watts are measured into a 4-ohm impedance load at 1 percent Total Harmonic Distortion (THD) plus noise, at a frequency range (for general purpose amplifiers) of 20 Hz to 20,000 Hz. Signal-to-Noise ratio is measured in weighted absolute decibels (dBA) at a reference of 1 watt into 4 ohms. This applies to both external amplifiers and the amplifiers within in-dash receivers.

So there is no any CEA standarts for 2 ohm load or 1 Ohm load. So, Kenwood KAC-9104d does over 500Wt at 4 Ohm according to CEA-2006 standart. Kenwood has a right to publish any numbers how many watts it's does at 2 or 1 Ohm, even if it doesn't. Just few lines from specifications.

Amplifier-Specifications (manufacturer spec.)

Maximum Power Output (4Ω) 1800W x 1

Rated Power Output (4Ω, 14,4V) 500W x 1 (20Hz ~ 200Hz, 0.5%THD)

Rated Power Output (2Ω, 14,4V) 900W x 1 (100Hz, 1.1%THD)

Rated Power Output (1Ω, 14,4V) 900W x 1 (100Hz, 1%THD)

Rated Power Output (CEA-2006) 500Watts RMS x 1 at 4 ohms and 1% THD

Low-pass Filter 50~200Hz (24dB/oct)(B-Channel)

Bass Boost Circuit 0~18dB (Variable)

Bass Boost Frequency 40Hz

Infrasonic filter 15/25Hz (18dB/oct)

Input Sensitivity 0.2 ~ 5V

Input Impedance 10kΩ

Signal to Noise Ratio 100dB

Signal To Noise Ratio (CEA-2006) 75dBa (Reference: 1 Watt into 4 Ohms)

Frequency response (+0dB, -3dB) 5Hz ~ 200Hz

Operating voltage 14.4V (11V ～ 16V allowable)

Dimensions (WxHxD) 350 x 59 x 238(mm),

Weight 3.4kg

Current Consumption 55A

http://www.caraudiomag.com/reviews/caep_0811_kenwood_kac_9104d_review/output_power_distortion_etc.html

 

[Bass911 10+ year member]

That Kenwood did not even bench test at 500 @ 4 ohm at 14.4v. Google kac-9104d magazine test and you'll see what it benched at. It is 1 ohm stable regulated to stay at an imaginary 900 rms. I'm not trippin, I just found this out about these ratings. Salesmen will try to always use this as a selling point, making it seem like the other brand is not as good because they don't volunteer to this CEA testing. I think she is going to go for a zx750.1 refurb or the BXi1208d?

 

[gunz4me 10+ year member]

That Kenwood did not even bench test at 500 @ 4 ohm at 14.4v. Google kac-9104d magazine test and you'll see what it benched at. It is 1 ohm stable regulated to stay at an imaginary 900 rms. I'm not trippin, I just found this out about these ratings. Salesmen will try to always use this as a selling point, making it seem like the other brand is not as good because they don't volunteer to this CEA testing. I think she is going to go for a zx750.1 refurb or the BXi1208d?

Uh, it made 506 watts @ 14.4 volts: http://www.caraudiomag.com/reviews/caep_0811_kenwood_kac_9104d_review/output_power_distortion_etc.html

ETA: When going with the BXi, make sure you account for about 15% less than what Hifonics rates them at because they are a tad bit overrated too! The 1208 should give you about 750 RMS @ 2 ohms and 900 to 1,000 @ 1 ohm.

 

[Bass911 10+ year member]

You're right, it did 506. I just looked at the test again. My Badd!

 

[Bass911 10+ year member]

I guess I misunderstood the whole meaning of this rating system. I didn't know it was just at 4 ohms. I should have did more research. I jumped the gun on this one. I was just stuck on how is it making 900 with only 2x30 fuses. I still didn't expect a company like Kenwood to lie that much on their rms. I guess if everyone was a Diehard like me, they wouldn't sell any amps?

 

[Bass911 10+ year member]

Yeah, I already know the Hifonics is overrated. I use to run a bxi2006d and my Mtx 81001 seems a little stronger.

 

[Haunz 10+ year member]

I still didn't expect a company like Kenwood to lie that much on their rms.

//content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif:laugh://content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

 

[GAM3OVR 5,000+ posts]

Kenwood is //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

I never trusted those amps to do 900 RMS.

Figured it might do 600 @ 2 ohm.

Guess I was right

 

[Bass911 10+ year member]

I could care less about Kenwood and never plan on running one in the future. I might get a Dnx8120 though, but that's not an amp. The amp wasn't for me anyway. The last time I ran a Kenwood amp was 1996 and I think it did rated. I just assumed the 900 rating was from CEA. I never really cared about it because I already know who makes good equipment. I was wrong about this issue, but still learned something new today. I rarely run amps at 4 ohms so CEA ratings are useless for me. A birthsheet is good enough for me and even some of those are not accurate.

 

[maddskillzz 10+ year member]

you get what you pay for with kenwood...do really expect an amp to do 900rms that you can buy for $129???? I have a 9103d and its a nice little amp..but its a nice little cheap amp..

 

[jmanpc 5,000+ posts]

Uh, it made 506 watts @ 14.4 volts: http://www.caraudiomag.com/reviews/caep_0811_kenwood_kac_9104d_review/output_power_distortion_etc.html
ETA: When going with the BXi, make sure you account for about 15% less than what Hifonics rates them at because they are a tad bit overrated too! The 1208 should give you about 750 RMS @ 2 ohms and 900 to 1,000 @ 1 ohm.

//content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif The newest line of Brutus amps does rated power. A team maxxsonics member came in and posted that they ditched chrome and fancy lights in favor of spending that money on beefing up their amps' boards //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif