More Clipping and Distortion Testing (D4S MM1000 and Sundown SIA-1250D)

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  • Опубликовано: 9 ноя 2024

Комментарии • 56

  • @barevids
    @barevids Год назад +34

    Hey man, great testing! 😎 I can explain a few things here!
    - The way that an internal clip light on the amplifier works is the MOST accurate by design; it simply compares the rail voltage with the peak-peak of the output sine wave, and when they touch, the LED comes on. That in itself is the definition of clipping. The reason you see it coming on before you can see a flat spot on the scope is likely two reasons: firstly the peak voltage on the sine wave IS that of the rail voltage and it has not yet been exceeded, which would give you a visible flat spot; or that the way comparator circuit works doesnt allow for a single instantaneous yes/no logic point for activation, more of a curve, so lets say the rails are at 50v, the circuit may begin activating softly at 49.8v just due to the mechanics involved. But either way when you see this light on the amp come on, you are AT the amplifier's limits, even if they have not yet officially been exceeded causing a "clip" of the sine wave.
    - The fuzziness you can see on the D4S amp at clip point is caused by how class D behaves at clipping. Inside the amplifier, the output mosfets creating the sine wave are pulsing (oscillating) at over 100,000 times a second, and the duration of those pulses determines what part of the sine wave is currently being generated, gradually making longer pulses for the top half and smaller pulses for the bottom half of the wave. The problem is, when the sine wave touches the rail voltage limit (ie clips), the mosfets stay fully ON or OFF for the entire clipped parts on the top and bottom of the wave. This sudden stopping and starting of the oscillation causes spikes and noise to make its way through the inductor filter network between the fets and the terminals, since those inductors have a bit of inertia, like trying to suddenly stop and start a heavy flywheel. This is inherently bad for the amplifier for a number of reasons especially under load. The SIA amplifier didnt exhibit this though, why? It may be because clipping is artificially induced at the preamp stage at a point just under where the amp would naturally clip at, preventing "hard clipping" from occurring and having the oscillation stop/start. This same circuit will likely also induce an even lower clip point when the amplifier is wired down to lower impedances and it detects high current draw, to maintain a fixed power output. (this part is heavily simplified)
    - Thanks for relaying that distortion and clipping are very different! Clipping CAUSES distortion, but you can have a fully distorted waveform that is not clipping. Clipping simply means the output wave the amplifier is trying to produce has reached the limits of the internal rail voltages. The DD1 doesnt detect clipping, it detects distortion. You can prove this by generating a triangle or sawtooth 40hz waveform with audacity, and playing it through a FULL RANGE amplifier into the DD1. Even at very low volumes the DD1 should light up despite the amp being miles from clipping.
    Im glad youve had a good experience with the SIA, personally from inspecting the circuit they are rushed with some design oversights especially in the power supply section, you may find that your amp gets warm to the touch after 10min+ of being powered on even without playing anything, in the ones I saw they had programmed the MCU with the incorrect switching frequency for the transformers used and the fets run hot.

    • @stereomojo
      @stereomojo  Год назад +10

      Barevids! What an honor! Thanks man!!

    • @1280spoon
      @1280spoon Год назад +11

      Man you are a genius bro with breaking things down so we can better understand how they work

    • @JohnDoe-le8fy
      @JohnDoe-le8fy Год назад +5

      Barevids, a blessing to the community! Keep up the great work sir!

    • @1ohmwrecker
      @1ohmwrecker Год назад +6

      Can't get a better answer from anyone 🤷‍♂️👏👏👏

    • @danielgreene3346
      @danielgreene3346 Год назад

      Well you definitely got it from the horses mouth great content brother I enjoy all of you videos hope it blows up for you the best is yet to come for this channel

  • @tripnit559
    @tripnit559 9 месяцев назад +1

    You sir have earned a subscriber. I am learning so much from your videos

    • @stereomojo
      @stereomojo  9 месяцев назад

      That’s awesome! Thanks a bunch!

  • @evilinside5984
    @evilinside5984 Год назад +3

    @Stereo MoJo- Yes, i did mean LPF turned down from 250 Hz( I went back and edited my question to read LPF), till the sine wave was clean. Thank you for testing my idea, and showing that, i really appreciate your time doing this❤️Yes by having to turn the LPF down so much, it started cutting the power down, show's that this amp was going past it's clean power limit's.

    • @stereomojo
      @stereomojo  Год назад +1

      Thanks Evil! I’ve had a lot of fun messing with this one!

  • @BeatsByGRIMM
    @BeatsByGRIMM Год назад +1

    Any overlap is pushing an amplifier limits but seeing the clipping and distortion between the amp and DD1 so far apart is something new to me.. Great Video once again and a big thanks to @barevids for clearing that up!!👍👍

    • @stereomojo
      @stereomojo  Год назад

      An overlap is needed to reach 1% THD and clipping. The owner’s manual for the AD-1 says to use “at least a -5db overlap”. This can be seen on the D’more Engineering website.

    • @BeatsByGRIMM
      @BeatsByGRIMM Год назад +1

      @@stereomojo I have the DD-1 and I read that.. The RP150.4 bridged @ 4Ohm doesn't like any overlap at all.. even @ -5 it heats up and cuts out during demos with extra fans and open space.. Could just be the RP line from Skar.. Thanks for the reply

    • @stereomojo
      @stereomojo  Год назад

      @@BeatsByGRIMM yeah, there’s definitely a difference in how different amps respond to different amounts of overlap.

  • @BDauto86
    @BDauto86 Год назад +1

    It is signal noise, both of those amps clip lights are sensitive so they're both starting to flicker immediately at prob .1-.2% thd which is fairly impressive.
    On the MM it's allowing a slight bit of signal noise thru the output filtering, the amp is catching it and flickering the clip light. At that point it's still under 1%thd is why the dd1 isn't picking up.
    Like Jason mentioned above I doubt that would harm a subwoofer and most likely couldn't hear it so the amp and sub would be fine with alil bit of clip light flickering just don't want it on solid.

  • @SwishaMane420
    @SwishaMane420 Год назад +1

    I just bought an A/B amp from D4S recently, about to hook it up and will be putting my oscope on it for sure after seeing that weird signal output.

    • @stereomojo
      @stereomojo  Год назад

      I’m sure it’ll be nice and clean.

    • @JasonWW2000
      @JasonWW2000 Год назад +1

      That class of amp should not have any high frequency noise. You might look close to where the sign wave crosses the zero point. Thats where one fet stops and the other starts. Any issue there is called crossover distortion. Its highly unlikely you will see anything, though.

  • @alconyers2003
    @alconyers2003 Год назад

    Cheap amps usually clip before doing rated power. You get what you pay for

  • @Silentroller93
    @Silentroller93 8 месяцев назад +1

    I bet the clip light on the amp is dummy proof so people don’t push the amp too far. I think those weird waves you see on the scope are from switching happening in the amp.

    • @stereomojo
      @stereomojo  8 месяцев назад +1

      You’re probably right

  • @lsohweldfab6575
    @lsohweldfab6575 Год назад

    Did you try any other frequencies

  • @D1aNdOnLyNiCkx3
    @D1aNdOnLyNiCkx3 9 месяцев назад

    Have you tested or are you gonna test the jp234 distortion level? I have it and I just feel it just puts out dirty power would love to see the data

  • @JasonWW2000
    @JasonWW2000 Год назад +3

    Your MM1000 is half bridge. Only the bigger MM1500 is full bridge. According to D4S.

  • @JasonWW2000
    @JasonWW2000 Год назад +1

    Keep in mind that the DD1 is a $200 device. It's built to a high standard of precision.
    The clip light circuitry in an amp can't cost any where near that. They have to keeps costs down as much as possible. It's probably an extra $5 or $10 worth of circuitry so it's not gonna be perfect, it just needs to be somewhat usable. No telling how it works or what it's actually detecting.
    We would need an amp designer to give details on a clip light circuit.
    Tony DeAmore designs amps and the DD1. He would be the perfect person to ask if you can get a hold of him.

    • @MacNifty
      @MacNifty Год назад +1

      I doubt it's $5 worth of circuit bro you are reaching super far he is using the cheapest components and it's very easy to make these boards and it's very easy to pay someone to make the shell any of us can make these amplifiers. Mister price is a thief he wants to be low budget and low quality and he'll never get my respect I will say cool bro you want to be like Pyramid in boss that's cool he's all about sales and he will sell out and not be Made in the USA for sales he's a salesman and that's what I don't like about him he's not about precision and power he's not about being the best but just selling the most. He's like Sam Walton of Walmart everybody loves him but for the wrong reasons because he gave you a good deal that's like the reason why China is still a problem it was for the good deal and now that country has greater power because of the great deal what kind of deal is that. I like that he's doing his thing but I wish he wouldn't look so cheap it's like I Want To have pride for American products but it's kind of hard when it looks like a 1992 piece of junk. When it looks like it came out of a 25 cent gunball box. It is what it is I'm looking for an GH class right now and I don't want Di want real power.

    • @JasonWW2000
      @JasonWW2000 Год назад

      ​@@MacNiftySorry, I have no idea what or who you are talking about.

    • @JasonWW2000
      @JasonWW2000 Год назад

      I did find out that Tony's partner, Juan Rodriguez, designed the DD1.

    • @barevids
      @barevids Год назад +2

      The internal clip light is more accurate because it has the rail voltage as reference. This is like having the question and answer right in front of you. The DD1 doesnt have the question, only the answer. So lots of complicated electronics and code are required to analyse the answer to determine the question.

    • @evilinside5984
      @evilinside5984 Год назад

      @@MacNiftyI love our Jp95- (5 ch.) amp, that's been loaded down, with ALL 5 chs. driven, for over a year and a half now! The component's sound great on the high's, and the 5th= sub ch. Is wired down to 1 ohm, on a pair of 12's

  • @JasonWW2000
    @JasonWW2000 Год назад +1

    At 5:30 it looks like high frequency noise. I don't believe it has any effect on the subwoofer. The circuit in the amp seems to be picking it up. It might be too sensitive.
    At 4:32 it looks like the wave is starting to clip. Thats when the DD-1 lights up. The flat spot on the top and bottom of each wave IS going to affect your subwoofer.
    I wish we could get Bare Vids over here to look at it.

    • @onesikm3
      @onesikm3 26 дней назад

      Your wish is my command d sir Come back and read the comments he has gotten in on this 😊

    • @JasonWW2000
      @JasonWW2000 26 дней назад

      ​@@onesikm3I actually got a hold of Sam and got him to comment on it. 👍

  • @lsohweldfab6575
    @lsohweldfab6575 Год назад

    What is your count and voltage settings on your oscilloscope

  • @suazzz3070
    @suazzz3070 Год назад +1

    How do people feel about the D4s amps? I’m gonna start designing a new system for my car and was looking at them

    • @chefbgordon8892
      @chefbgordon8892 Год назад +1

      I like my jp23 thinking of getting one of their door speaker amps to go with my d4s mids

    • @alconyers2003
      @alconyers2003 Год назад +2

      You get what you pay for. If you want quality, go with a brand that’s been around for awhile. They will last longer and give better sound quality. And d4s get hot, they draw a lot of power due to cheap power supplies. And they blow quite a bit more than comparable amps.

    • @alconyers2003
      @alconyers2003 Год назад

      @@chefbgordon8892why? You every look at amp specs. Dampening factor and all that? Hell did you even pay any attention to this video

    • @onesikm3
      @onesikm3 26 дней назад

      I didn’t like two of their amps jp84 and 23v2 gave me nothing but overpriced problems

  • @JayTR_10
    @JayTR_10 7 месяцев назад

    Will you post the outputs at 4,2,1 ohm for each of these?

    • @stereomojo
      @stereomojo  7 месяцев назад +1

      I have videos that show the output of each amp

    • @JayTR_10
      @JayTR_10 7 месяцев назад

      @@stereomojo thank you

  • @curbysmith3081
    @curbysmith3081 10 месяцев назад

    That thing is made for just old school amps not nothing new😂😂😂

    • @stereomojo
      @stereomojo  10 месяцев назад +1

      Goofy comment #2

  • @Acestrex
    @Acestrex 3 месяца назад +1

    man why are you smacking your lips constantly?
    god it makes watching your videos super difficult with that major annoyance!!!
    I appreciate what your video is about but i cant keep watching.

    • @stereomojo
      @stereomojo  3 месяца назад

      @@Acestrex it’s all for you! You’re welcome!

  • @curbysmith3081
    @curbysmith3081 10 месяцев назад

    😂😂😂😂😂😅😅😅 get a real Dino machine something that's up-to-date not from the 1960s or the 1970

    • @stereomojo
      @stereomojo  10 месяцев назад +1

      Goofy comment #1