My own Amplifier Sound Quality Shootout

[JCsAudio]

I've got the Zapco ST-2X SQ strapped up, level matched, and ready to go. See how it compares in the attached REW graph playing pink noise. I also measured the DB level while I was performing the listening tests with the judges and the DB level was only around 78 db at about six feet from the speakers.

Zapco ST-2X SQ is green and DLS CCi-44 is red

[JCsAudio]

Okay, I was able to get my daughter to do the judging but I seem to have lost the notes I took from her on Saturday. I'm not having much luck with time and the wife isn't very receptive to doing one more test so it might be a little longer, plus my son has three games this week. My daughter auditioned the Zapco ST 2X SQ three times with one song and then two times with another song before making a decision. She liked both for slightly different reasons but in the end chose the DLS over the Zapco mainly because of the very slight increased clarity in vocals during demanding levels within the song, which I'm attributing to the DLS for having more power. It was really close and there is no clear winner here so far. Remember this test is blind and she did not know which amplifier she was listening to; only that there are two and one is #1 and the other is #2.

Some of the things I’m starting to think are that within the distortion and clipping limits of the amplifiers they basically sound the same. Some differences could be attributed to phase differences as well although I don’t fully understand how yet. With these contenders in this price group it doesn’t seem to matter whether they are class A/B or Class D and the Pioneer D8604 Class D surprised me. Some of the things you do get with more expensive amplifiers are higher quality components and features and less noise floor. With the DLS for example, the switches and pots seem to be of higher quality and on the RF Power, the terminal clamps are nice. The winners in this group seem to be attributed to just having more power vs anything else I can attribute it to, although without objective testing I’m only guessing. Still the subjective blind listening tests show there isn’t much difference in sound among these amplifiers and it certainly wouldn’t be a factor in the noisy environment of a vehicle in my opinion.

In the first shootout I used a power supply that was barely adequate for the amplifiers I was testing. Still the power hungry Alpine Class A/B 3548 sounded noticeably better than the others, especially over the Alpine MRP F240, and even I could hear that difference. In this group of testing I’m using the equivalent of 110 amps of power supply (two APS 55 ganged together) at 14.2 volts so I’d like to strap up that Alpine MRP F240 to these power supplies and test it against the DLS to see if I can again clearly hear a difference. If I can’t repeat those results than I’m going to attribute the MRP F240 losing to the lesser power supply not supplying enough power in the first test.

[JCsAudio]

Well, finally got my wife to finish the listening test between the Zapco ST 2X SQ and the DLS CCI-44 and she pretty much easily picked out the DLS over the Zapco after going back and forth three times as the better sounding amplifier.

For the Zapco (amplifier #1) she said the vocals seemed brighter but not as crisp. She said things got a little muddy when the singer was singing and all the instruments were playing all at once. The song was Believer by Imagine Dragons in lossless file format.

She said about the DLS (amplifier #2) that she liked the separation of sound when everything was playing at once. She said everything in the song is very definite and well defined and that there is more detail in the small differences when everything is playing together. She explained it in many different ways but basically kept saying how well the music was well defined, that she could hear all the little tiny details especially when everything was playing together during demanding passages within the song.

Honestly I thought the Zapco would have been closer but she pretty much zeroed in on it pretty quickly. I think the Pioneer D8604 class D was more of a challenge than anything else in this testing.

I also noticed how much hotter than DLS gets than the Zapco or any other class A/B in this test. I think its more class A biased maybe. It was 99 degrees within 20 minutes of standing by when the Zapco was 79 degrees and the air temperature was 69 degrees.

I will hook up the Alpine MRP F240, which was the class A/B that had the worst sound in the first test and see how well that does this time. If it loses horribly like it did before than I'll know the tests are repeatable. If it becomes a situation where its hard to tell than I have some explaining to do.

[JCsAudio]

MRP F240 vs DLS level matched to within .2 db in favor of the Alpine. We shall see what happens soon.
Attached Thumbnails

[JCsAudio]

This test consisted of an Alpine MRP F240 bridged for 100 wpc (amplifier #1) vs DLS CCi-44 (amplifier #2) using two channels at 85 wpc.

Well, the Alpine MRP lost big time to the DLS so much so that I even noticed it from standing behind the speakers. It was a noticeable difference. I even bridged the MRP F240 so that it was giving 100 watts per channel so that the power would be in the Alpines favor but that obviously didn’t help and the Alpine is a class A/B so no blaming class D on this test. My wife told me to turn it off after just one play on each one and said amplifier #1 was garbage, which was again the Alpine MRP F240. She stuck her tongue out and said she didn’t even want to listen to it again, it was so bad by comparison to the DLS (amplifier # 2).

So that concludes this testing. I’m out of amplifiers and money that I want to spend on this testing. Is there a difference in sound between amplifiers, yes but with newer modern amplifiers the differences are very small when played within their limits. Does class A/B sound noticeably better than class D; I don’t think so at this price point. All my class D amplifiers actually did very well in this testing. What makes one amplifier sound better than another; too many things to say. Differences in sound could be attributable to phase differences, power differences, or the quality of the power supply within the amplifier itself. I think today’s amplifier technology, whether class A/B or class D, is very good and it really depends on the design of the amplifier more than the class itself. I also am starting to think the Zapco SQ series is a bit over rated myself. It must be that SQ marketing thing they played up bid time. It’s not bad by any means but it’s not up there with the less known DLS as far as I’m concerned.

[JCsAudio]

I started this thread over on DIYMA before that place went to the new platform and I became a member here. I still have it going over there but decided to duplicate it here as well.

Ok this time around I have the above mentioned Kenwood XR 400-4 to put up against the still on top DLS cci44. This is Kenwood‘s attempt at an amplifier marketed as a SQ oriented class D amplifier with audiophile grade components. It’s also a very small but good looking amplifier. I got my wife and daughter to be the judges but my son wants no part of this anymore so he is out I guess. I also asked them each the same question after they gave me their comments like before and that question was: Do you think #1 sounds better, #2 sounds better, or do you think it is a tie? I also switched up which one they started with first so #1 could be either one and they would have no clue.


Amplifier #1 was the DLS CCi-44.
Amplifier #2 was the Kenwood XR 400-4 Class D


Wife
#1 (DLS) Vocals louder and stood out more from the background music. Nuances of sound blended well.


#2 (Kenwood) I could hear every separate part, was very crisp and clean. Vocals didn’t seem to stand out as much compared to #1.


Answer to question: Both sounded very good and very similar. I say it’s a tie.


Amplifier #1 was the Kenwood XR 400-4 Class D this time
Amplifier #2 was the DLC CCi-44.


Daughter
#1 (Kenwood) background music more pronounced. Bass didn’t have as much reverberation or echo. Bass sound stopped more abruptly, bass was more concise. More echo/reverberation in voices.


#2 (DLS) background music not as loud. Bass less concise (bass not as much of a complete stop) better balance of sound.


Question: These were easier to tell apart. Both sound very good but I liked the balance of #2 better.


So I think these are very close. I copied their notes basically word for word even though they may not make as much sense this time. I think I will run this test again later on. I have a Masconi amplifier and a Kicker amplifier that I will be putting to the test next so stay tuned.

[soundstreamer]

Nice thanks for the review. I have the Kenwood XR 900-5 and have been very happy with it powering my tweeters and midranges. I did have an Alpine F4 power them and didnt notice much difference at all when I switched.

[JCsAudio]

In my testing I’ve found that once you get to a certain level of qaulity that the difference between amplifiers are so small that even in a blind A/B test such as this one it’s very hard to tell. It doesn’t seem to matter much wether they are class D or class A/B. My best sounding amplifier is a class A/B but so was my worse sounding amplifier too, which by the way was an Alpine MRP f240.

[Hillbilly SQ]

I see you like the Pioneer digital amp a lot. Later this year I'm thinking about trying the 5ch and 4ch out to be able to get everything on my amp rack where it's fully protected. Much as I love my Helix G-Five that thing is a cow. Right now my dsp is under the passenger seat. It's mostly protected but with the way I throw crap in the truck sometimes after trout fishing anything can happen. No telling what might happen with wet chest waders in the passenger floor, wet rain suit, etc.

[JCsAudio]

Ok, So I re-ran the test again against the Kenwood vs DLS but this time with the Imagine Dragons song Natural because that song seems to help bring out the best and worst of most amplifiers with its quiet passages and demanding reproduction during the main body of the song. I could only get my wife to be the judge this time but that's OK because she has the most experienced ears and loves music more than I do.

Kedwood vs DLS retest:

Amplifier #2 (DLS CCi44), Vocals are so very clear and everything is playing on an even plain.

Amplifier #1 (Kenwood),Vocals sound a little echoy and instrumentation doesn’t feel as powerful as the vocals.

When asked which one she preferred she said amplifier #2.

Test #2

Amplifier #1 (Masoni Pico 2)
Amplifier #2 (DLS CCi44)

Amplifier #1 (Masconi), didn’t seem to have a lot of depth to it. Seemed like vocals and instruments are kind of flat, like Meh, compared to the other one. Not terrible but just ok. Very flat lined sound to it like in a heart monitor when someone died. When I asked her if she thinks is was worse than the one in the previous test (Kenwwod) she said yes.

Amplifier #2 (DLS) A lot of richness to the sound that the other one seemed to be lacking. Vocals seemed much more realistic and didn’t have a fake produced shallow sound. Had a lot of depth and richness to the sound comparatively speaking.

When asked which one she preferred she said amplifier #2

Test #3

Amplifier #1 (Kicker PX 100.2)
Amplifier #2 (DLS CCi44)

Amplifier #1 (Kicker PX 100.2), after the part in the first chorus, the music felt loud, messy, and overpowering comparatively to the other one (DLS) and louder than vocals or in other words it didn’t balance as well with the vocals. Vocals were a little bit harder to differentiate or sounded a lot closer in quality at first but then once you played the other one I know it wasn’t as good. I asked her how she thought it compared to the loser in the other test (PICo 2) and she said the vocals compared to the other one in the first test (PICO 2) I could pick out right away.

Amplifier # 2 (DLS) These two amplifiers are closer in this test, just sounded really clean and just sounded like it was like everything just went together volume wise. It has a very balanced sound.

When asked which one she preferred she said amplifier #2