What exactly is clipping, and DDT?

Discussion in 'Amps and Cabs [BG]' started by Wxp4759cb, Nov 25, 2001.

  1. Wxp4759cb


    Nov 23, 2000
    Kansas City, MO
    Question one, I know what clipping is, but can someone give me a good definition, and how to prevent it.

    2. Does Peavey DDT speaker protection really protect your speakers if you do clip?

    3. If you do clip does it damage your speakers?

    4. Is damage done to your speakers all or nothing? Or just does a little each time you clip?
    Does it blow your speakers or do nothing, or does it just do a little damage that you wouldn't notice unless you do it alot?

    Help me!
  2. embellisher

    embellisher Holy Ghost filled Bass Player Staff Member Supporting Member

    1. Clipping is when the peaks are clipped off of a signal, resulting in a more compressed tone with less dynamics. Mild tube amp clipping can sound very musical, but very hard clipping, i.e. square waves, sounds very unpleasant, especially with transistor based amps.

    2. DDT is a built in compression circuit that Peavey invented and patented back in the 1970's. It differs from a standard compressor in that it only compresses your signal when you drive the power amp to clipping. And if it is working properly, it can indeed protect your speakers from being damaged by square waves.

    3. Extended square wave power amp clipping is the most damaging thing to loudspeakers, especially at high volume, which is of course when it usually occurs.

    4. I beleive that the answer is that clipping can cause some damage to your speakers every time it happens for an extended amount of time at high power levels. Of course, it can blow them or warp the voice coil the first time it happens, if you have a very hot signal, the speaker is overpowered, and you turn everything all the way to 11.

    MikeyD, Joris or one of the other speaker gurus can correct any mistakes that I made.
  3. Embellisher, great explanation.

    BassMasterG, you could do a search on this site to look further into matters. There's been said a lot about clipping.

    Attached you'll find a (quite technical) article about clipping from the Rane website. I zipped it, cause the max file size is 102400 bytes.
  4. Nino Valenti

    Nino Valenti Supporting Member Commercial User

    Feb 2, 2001
    Staten Island NYC
    Builder: Valenti Basses
    I thought The DDT was Jake "The Snake" Roberts signature move.:p

    Embellisher sid it it all so I didn't have anything intellegent to say. LOL
  5. Joris - That pdf was great! awesome info to know. Where'd you get it?
  6. Bgavin mentioned it. Rane has a whole load of articles on sound reinforcement worth reading. Check www.rane.com (IIRC).
  7. embellisher

    embellisher Holy Ghost filled Bass Player Staff Member Supporting Member

    Thanks, Joris. I learned it all from guys like you, bgavin, MikeyD, throbbinut, etc.
  8. :: crashes head down on 'Bellisher's shoulder, sobbing ::

    "Ain't Talkbass a great place?"

    :: 'Bellisher patting Joris on back ::

    "Hush now, don't you cry, we all go through this some time or another"

  9. MikeyD


    Sep 9, 2000
    :D Thanks, M-bellisher! I'm glad my posts are providing useful information, if not entertainment. ;)
    - Mike
  10. Wxp4759cb


    Nov 23, 2000
    Kansas City, MO
    So is the amp sending to much power that damages the speakers, or is it just square waves in general? Basically what I'm getting at is sometimes when I slap, I clip my amp, but I never turn the volume past 5, so is this doing damage?
  11. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Gold Supporting Member Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    Hi BMG,

    It's excessive power that destroys speakers.

    A speaker doesn't care if the signal is a square wave, sine wave, sawtooth wave, random noise, or whatever, as long as the overall power dissipation is within its limits and as long as you don't exceed its Xmax (maximum cone excursion limits).

    If you're clipping your amp just briefly when you slap, you probably aren't in danger of damaging your speaker(s).

  12. Besides that, you won't even hear it. I know I wouldn't.
  13. Wxp4759cb


    Nov 23, 2000
    Kansas City, MO
    Does clipping your input have any negative effect, other than killing your tone?

    Also why do amps clip when you slap them at low volumes, but not clip plucking them at 11!
  14. CrawlingEye

    CrawlingEye Member

    Mar 20, 2001
    Easton, Pennsylvania

    Because if you're playing softly at 11, you're putting a lower input into your amp, than
    if you pick very hard, at a low volume. You can clip your preamp, as well as other things (speakers, etc). Regardless of the volume, you will begin to clip, if you start slapping and popping really harshly, or if you start picking harshly. :)