Thursday, November 21, 2024
BassGuitar Tips & Hacks

Tips and Tricks – Understand Impedance – Ampeg Heads and Cabs


OHM my God, this stuff can be confusing. Let Dino tell you all about impedance, the pesky little bit of math that could save your head or cabs.

What cabs can you plug into what heads? What happens when you run an 8 ohm and 4 ohm cab in parallel? Will plugging this cab up set my head on fire?

These are all valid questions. Just watch the video already.

http://www.ampeg.com

#Tips #Tricks #Understand #Impedance #Ampeg #Heads #Cabs

Originally posted by UCzDELDW7YezbUyDp_6OjEWA at https://www.youtube.com/watch?v=bTcx-f1PIJU

33 thoughts on “Tips and Tricks – Understand Impedance – Ampeg Heads and Cabs

  • Ok. So I just bought an EVH 5150 iconic 40 watt 112 combo. I put a Vintage 30 8 ohm speaker in it. I want to also hook up another 112 Vintage 30 cab also 8 ohm to the second speaker out. So would this be correct for me to switch the ohms on my amp to 4 ohms because technically I am running 2 separate cabs, one being the actual speaker on my combo amp the other being the second 112 cab.

    Reply
  • I emailed Marshall with this situation/question: "I have a Marshall Origin 212 cabinet that I want to pair my DSL1H with. The potential problem is the Origin 212 cabinet has two 16 ohm speakers wired in parallel making it 8 Ohms. I wired it in series making it a 32-Ohm unit. Will this be an issue for the 16-Ohm DSL1 head? Can I use a 32-Ohm cabinet with the 16-Ohm DSL1H?"

    Marshall's response:

    "The DSL-1 is a valve amplifier and therefor the Impedance must be correctly matched to avoid damage to the output transformer.

    I guess the only way you could use the Origin cab safely would be to disconnect one of the speakers.

    If you need it to be an 8 Ohm cab for other amps, maybe switch one of the speakers so 8 & 16 can be selected?

    Not what I wanted to hear lol.

    Reply
  • I do want to combine 2 Cabs my ampeg 8×10 and my ampeg 1×15 how should I go about this? If anyone knows or if it’s even safe im using a Mark Bass Big Bang 500watt. If anyone knows please let me know… but im gonna try it anyways lol ???? but I don’t want too pay the ohms lol

    Reply
  • ..good explanation…..so, if i may, can i use two svt 8×10 standard cabs with a 300 watt svt head? is that 2 ohm load? i have a black line 70's head and i always wondered if two cabs wiold be a good thing 🙂

    Reply
  • Piece of cake. For the SVT, if using two 8-ohm cabs, set the amp impedance to 4 ohms. If using two 4-ohm cabs, set the amp impedance to 2 ohms. If using three cabs where two cabs are 8 ohms each and the third cab is 4 ohms, set the amp impedance to 2 ohms. If using four 8-ohm cabs, set the amp impedance to 2 ohms.

    Reply
  • Can I connect two cabinets one with speakon cable and the other with a 1/4” cable? SVT at two ohms and both cabs 4 ohms

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  • Damn!!! I still don’t know the math!!! Make it simple, does the Micro-VR Head compatible with SVT-112AV? Please advise… ????????

    Reply
  • My Ampeg B25B head was designed to play through a 2X15 cab in series at 16 Ohms. I run it with two 15" ~ 8 ohm cabinets, so that would be a 4 ohm load. My tech obtained a schematic of the head, and he told me that if I plugged an 8 ohm cab in one speaker outlet and another 8 ohm in the other speaker jack, that there is a switching jack (or something, I forget) that shows a 16 ohm load.

    Reply
  • This is like a high school video about safe sex but for bass players – thx Dr. Monoxelos!

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  • I'm a guitar player, not bass player, but I found this very straight forward and helpful. Thanks for posting.

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  • How about the power? What if I have 400W@4ohms amp an want to plug 2×8 Ohm cabitents pararelly? What should be the wattage of each of it?

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  • Awesome video! Helped me a lot!
    But I still have one question:
    I have a marshall mg100dfx turned in a head.. and this amp has 100w. At the loudspeaker output it only says (use minimum 4ohms) so my question is: I own a marshall 1936 2×12 running in parallel so each speaker has 8ohms and 75w each (celestions g12-75)… Can I plug my mg100dfx in stereo (in only one speaker) with my joyo bluejay bantamp on another?
    The higher resistence (8ohms) of the cabinet will low the voltage of 100w and I won't blow my 75w celestion? Thank you very much!!

    Reply
  • At 2:40, you say that the power ratings for cabinets never change. So does this mean that if two identical cabinets rated for 200 watts @ 8 ohms are hooked up parallel, they will still each receive 8 ohms, even though the amp is putting out 4 ohms?

    Reply
  • I’ve always heard that it was ok to plug a head into a cabinet with a higher impedance than the amp is rated for, but NOT okay to plug a amp into a cabinet with a lower impedance than the head is rated for. Is that accurate?

    Although it seems like there are so many output options on modern amps that there’s no real reason to not match it exactly anyway.

    Reply
  • What happens if I wire two separate 4ohm speakers to the same output terminal of an amplifier?

    Example: I’m using 1 amp capable of doing 2ohm or 4ohm. Sometime I only need one speaker and sometimes for more Power I need 2 speakers. So if I take the same amp output and send out 4 wires (or 2 wires to each cabinet. Left and right/ positive and negative) will that be 2ohms final impedance?

    Reply
  • Very helpful video. I was particularly inspired by the idea for a "wall of DOOM". Good idea. I'll get on it.

    Reply
  • Oh snap! Don't ever run without a cab?!!! I was tracking direct. If no cab is 2ohms, then why is the VST Classic rated at 2 & 4 ohms? If 2 x 4 ohms equals 2.67 ohms and you advise to avoid that situation, then… well…. is that a cab on the planet earth that matches the SVT classic?

    Reply
  • Yes or No. answer!

    1. Solid state 750w amp 4ohm head. running with 410hlf 500w Rms 4ohm speaker cab.

    Yes or No?

    2. 750w Amp 4ohm head. Running with One 12” speaker at 8ohm rated 200w power

    Yes or No?

    3. 750w Amp 4ohm head. Running with two 10” speaker 8ohm rated 400w power.

    Yes or No?

    If No, please explain. Thanks!

    Reply
  • hey buddy, ive got a marshall mg15 fx, that im going to convert into a head. im going to build a cabinet, but im unsure what ohms the speakers need to be? think the one in the marshall is 8 ohms. id like to fit two 50w speakers to the cab. do they both need to be 8 ohms.
    thanx

    Reply

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