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Discussion Starter #1
This has been posted many times and debated to death here. Is there a sound quality difference between amplifiers given that they are of good quality and at a reasonable price point? I was of the camp that believed that in a blind test no one could tell a difference so long as gains where set exactly equal and power range was within the amplifiers specified range (no clipping or under clipping).

So the Amplifier shootout by Matt Hall posted here gave me the idea to try and test this theory for myself as best I could in my garage with a blind listening test using my ears and my wife’s ears to be the judge, and by my modest means. My wife who is very much into music can recall any lyric to any song you can think of without stopping to think about it. She has become accustomed to good sounding systems thanks to me. I would consider her ears the best trained I have and also her hearing is better than mine. I’ve outfitting all of her vehicles over the years with some pretty nice sounding systems, including the full active system in her Toyota Sienna now.

The Test equipment consisted of some Kef C45 bookshelf speakers and a Parts Express Mean Well power supply to power the amplifiers at 14 volts. The benchmark amplifier I used to compare all my others in this test to is an Alpine 3548 2 channel 60 wpc Class AB amplifier made in Japan from the early 90’s, when Alpine made some top shelf awesome sounding stuff. I describe this amplifiers sound as dynamic, open, airy, and natural sounding, plus it’s the best one I have. Playing music through this amplifier makes the music come alive. I picked this amplifier up new back in the early nineties and it was one of the first amplifiers I owned.

The test consisted of swapping the speaker leads at the speakers to the amplifiers with quick connect banana plugs so I could swap amplifiers in less than 30 seconds. I did this by hooking up both amplifier’s to the power supply and using a banana plug for the remote turn on wire to only power one amplifier at a time so I didn’t overwhelm the power supply. So I just had to swap the speaker banana plugs to the speakers, remote turn on banana plug to power up one amp at a time, and swap the input RCA to the amplifier for the input source. I used my IPod gen 7, and played some lossless files consisting of Imagine Dragons songs with a phono to RCA adapter to feed directly into the amplifier. I used my Unik microphone and REW to set the gains on the amplifiers by matching their db output exactly to within 1/10 of each other so having one play louder than the other wouldn’t skew the result’s.

First test was against my Alpine MRP F240, which is a 4 channel 40 wpc amplifier. It served me well and I regarded it as a good sounding amplifier. This amplifier was recently swapped out for my Pioneer D8604 in my truck. The Alpine MRP F240 is a Chinese made Alpine and of class AB design. Let’s just say this one was the easiest to tell the difference. I was actually surprised that I could tell a difference at first. The 3548 by comparison sounded more open, had a wider stage, and more realistic sounding bass. Thinking it was because the MRP F240 has less power, I then bridged it for 100 wpc, and performed the test again and it didn’t seem to make a difference. Remember I set the gain to match the output of the 3548 so only dynamics should change.

Second test was against an NVX MVPA4, which is a Chinese made micro class D amplifier that many people buy for motorcycles or for tight spaces. This amplifier originally served as the main amp for the front stage in my wife’s Sienna because I had to hide it under the dash, and space was extremely tight. It is rated at 50 wpc, although Sonic Electronix's likes to claim it makes way more power, but I do not believe it makes much more power than 50 wpc, and this is based on my experience with it compared to more powerful amplifiers. There was a noticeable difference in sound quality when I swapped this amplifier for a Pioneer D9500F in my wife’s Toyota Sienna, and I’m not sure why I noticed that then but not now. Initially I did the test on this one first and had a harder time telling a difference. I had to run a few more tests for myself, and eventually I noticed that the songs seemed a little more hard edged in the upper frequencies and that the detail from the Alpine seemed to be a little better in the upper high end frequencies. I ran a couple of blind listening tests with my wife and she easily picked out the Alpine 3548 as the better sounding amplifier. Now I owe Sonic and NVX an apology because I kind of bashed this amplifier as sounding much worse than it actually does. It sounds better than the Alpine MRP F240 (class AB) and so did better in this test than I thought it would.

Third test was against my best class D I have, which is a pioneer PRSD4200 with ICE power design, for whatever that means. Holding this amplifier in my hands shows it’s made to a higher standard. The pots look and feel nice and the switches look and feel like they are of higher quality than typical for this class. When the amplifier turns on, it has a separate relay inside it that makes an audible click. This amplifier is kind of large and heavy too for a 75 wpc class D amplifier. Its specifications are some of the best I’ve seen for the price point and class D design. This amplifier was the one I swapped with that Alpine 3548 in my CX5 over three years ago, and I do not remember noticing a difference in SQ after the swap. The Pioneer is a 4 channel design rated for 75 wpc into 4 ohms and 150 wpc into 2 ohms, so this tells me it has a robust power supply. I did the first listening test and really could not tell a difference, but I also knew which one was playing so my thoughts were biased and I wanted it to win. When my wife did the test (not knowing which one was playing), she asked me to swap them back and forth one more time, but in the end she once again chose the Alpine 3548, stating that this test was the hardest for her to decipher. She said the crispness of the vocals was slightly better when listening to the Alpine 3548, but that this was the hardest for her to tell a difference. For me it’s not enough of a difference that I want to change my amplifiers for something better, but it’s an eye opening test that proves to me that there are small audible differences in sound between different amplifiers.

Lastly I ran a few pink noise tests and sweeps using my microphone and REW to see if I could measure any differences between all amplifiers. The pink noise testing revealed no real differences nor did the sweeps except for maybe the NVX in a small area. I then just played Imagine Dragons Believer (lossless ripped from a CD) and measured the song in Rew up to 100 averages. This revealed some slight differences of 1 db or less in the upper ranges and I also graphically it looked like there were softer edges to the peaks and valleys in the graph for the Alpine 3548 vs the others. I need to re-measure these though just to make sure that what I’m looking at is accurate.
 

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Where and why they are different would be a different test to answer the same general question of are "they different".
 

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Yeah thanks for posting. Interesting to read.
I've often wondered if I'm giving up something running the Pioneer DRSP800 mini-amps. They also feel very high quality and are probably fairly well related to the newer 4 channel amp you tested. I'm installing a new system now and planning to use an older RF 4 channel A/B amplifier for the front stage, and I'll have to do compare to using 3 of the mini pioneer amps (1 for midrange/high, and 1 each bridged for the woofers).
 

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Discussion Starter #5
I’m tempted to pull out my Pioneer D8604 from my truck and do the same test. I’d pull the D9500F from the van too, but that one requires taking apart the Toyota dash to get to it so it’s kind of too much work and the wife won’t like it either.

If anyone in the area has a 2 or 4 channel amplifier they’ed like to try in this listening test, than just let me know and maybe we can set up a test. I would love to test something higher end to judge just how much of a difference there may or may not be.
 

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I am not sure it is worth te bother.

I put a special set of test tones used for distortion into the tubes amps and out the nice speakers.
Then I took the Mrs old transistor unit and the bookshelf speakers, which sound a bit dry.

And their distortion was lower that the system that sounded better and 10x the money.

Feelings are better than truth, so subjective and non repeatable tests in my view are problematic. But they are interesting to read.
 

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Discussion Starter #7
It’s all totally subjective Holmz, measuring with test tones and measuring distortion plots is great and helpful in understanding what might sound good but in the end we use this equipment for recreating music and so using our ears in subjective testing is in my opinion the best test. The more people who listen and agree for any given blind test, the better and more believable the results. Because it’s all subjective, there will always be those who do not agree with the group/majority but we all have to start some place, especially those of us like me with modest means who cannot go out and buy $1000 amplifiers like it’s just another cable bill, lol. ;)
 

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Good luck. They are good reads and some truth comes out.
All the best!
 

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2011 Prius rsx gs9>apl1 >helix dsp ultra>2 brax mx4’s &jl Audio 600/1> full focal Utopia m
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It’s funny but this morning I went in my garage to look for a ring for a 556u “only alarm guys knows what this is” and walked pass 6 new kenwood reference amplifiers, 2 arc xdiv2 a Zed leviathan, not sure how many jl hd amps at least 6 about the same amount of Rockford fosgate plus more before I got to the alarm section and I said to myself “ how stupid can u be to think that all amps sounds the same?” I’m using McIntosh amps and had a really hard time finding something more transparent till I heard bill’s fj cruiser and Josh’s versa. don’t tell me that they would’ve sounded the same with any other amp cuz I’ve worked with jl, amps all my car audio career and in any blind fold test with any speaker and radio you use, I will tell you exactly what series of jl amp is being used 100% of the time.
 

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That versa is something else for sure

Sent from my SM-G950U1 using Tapatalk
 

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i know someone with a giant table of amps to shootout too, but that guys busy....
he may have been messing with some of them in his spare time
 

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Discussion Starter #13
i know someone with a giant table of amps to shootout too, but that guys busy....
I’m guessing he is a young guy who lives 3 hours from me and has a cat for an avatar. :D. Since he is so young, I’m betting he has no kids and tons of free time as a result. :D
 

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I’m guessing he is a young guy who lives 3 hours from me and has a cat for an avatar. :D. Since he is so young, I’m betting he has no kids and tons of free time as a result. :D
hes probably a kid trying to figure out life while balance starting a business, expanding said business, hiring an employee who may or may not be active in this very thread and generate work for said employee, getting jobs done, and make time for a nagging girlfriend. There will have to be a full on man hunt to find free time
 
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hes probably a kid trying to figure out life while balance starting a business, expanding said business, hiring an employee who may or may not be active in this very thread and generate work for said employee, getting jobs done, and make time for a nagging girlfriend. There will have to be a full on man hunt to find free time
Not to mention chatting on diyma... :p
 

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Lol... Me too
 

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?, I wonder who’s that person.
 

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