Detuned cab ?

Discussion in 'Amps and Cabs' started by scottcw, Nov 18, 2005.

  1. scottcw

    scottcw Low rent hobbyist Silver Supporting Member

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    My understanding of a detuned cab is that you use a 2-12" or 2-10" cab, but only load one speaker. Can you do this with just any cab or is there some special design involved?

    Examples:

    Could I load THIS CABINET with a single 10" on top and essentially have a detuned cab?

    Is THIS CABINET an example of a detuned cab, but using a reflex horn?

    Thanks.
     
  2. Distortion

    Distortion Member

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    Your links are not working.
     
  3. mmorse

    mmorse Member

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    A detuned cab (at least what is typically refered to a s detuned cab) is to remove half the speakers and leave the holes in the baffle empty. That's 1 speaker in a 212 and 2 speakers in a 412. I don't think orientation matters technically but may affect tone. I've tried it with a closed back 412. Speakers project out the back as well as the front. Detuning allows the speakers back wave to escape out the front of the cab instead of out the back in an open back design.

    Tonal results vary depending on cabinet size, speakers used etc. I tried it with a pair of RI Greenbacks in a 1960 cab. The detuned cab exhibited more bottom than with 4 GBs in the cab and was just as loud. Overall, I thought it sounded better with 2 than 4 GBs. I don't have enough experience with detuned cabs to know if my results are typical. I did it to see if it would be more quiet and it wasn't.
     
  4. lhallam

    lhallam Member

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    The short answer is yes.

    mmorse's findings are correct that a 2x12 detuned is as loud as a 4x12. Kevin O'Connor stated that he used a db meter and found the same results.

    In O'Connor's design, the biggest thing that makes his cabs different is the depth which is 16". The width of most gtr cabs are 13.5" or less. Although he suggests 16" he says that anything over 12" deep is acceptable. I've noticed that even without the detuned design, deep cabinets have a very full sound.

    Here's a 1x12 I made using O'Connor's specs, bulky but light:

    [​IMG]
     
  5. rockon1

    rockon1 Member

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    As loud with say 1 wattat 1 meter or as loud with as many watts as they each can take? I find it hard to believe that 1x12 speaker would be capable of producing the same volume as say a 4x12 with a 100 watt head driving it.
     
  6. drbob1

    drbob1 Silver Supporting Member

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    This is just a variation on a ported cab, no? Which means that the speaker moves more easily, so you get more volume from the same watts, but if the "port" is in the correct position, you don't get the bass cancellation you tend to get with open back cabs?
     
  7. mmorse

    mmorse Member

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    I don't think it's a question of bass cancelation so much as that in an open back design, the speakers back wave is directed away from your ears and in a detuned cab the back wave is redirected back out the front to your ears.

    I don't know about a detuned 212 being a loud as a full 412 cab but a detuned 412 IS as loud as a full 412.
     
  8. rockon1

    rockon1 Member

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    Still cant see it. Four speakers have to be capable of moving more air than two. Yeah this detuned cab may be more efficient but given enough power I still think 4 speakers will be louder than two.;)
     
  9. mmorse

    mmorse Member

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    Think about it. Half a speaker's output radiates behind it. In a closed cab it has no place to go. 4 speakers with half their output being absorbed in the cab or 2 speakers with all their output being directed out the front of the cab. Don't take my word for it. Give it a try. I couldn't believe how loud the cab was when I removed 2 speakers. I tried it because I honestly thought the cab would be more quiet. I was VERY wrong.
     
  10. rockon1

    rockon1 Member

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    Well Im getting a 4-12 soon for the first time in years. I'll give it a try for grins. I like experimenting.Unfortunately I dont have anything to measure the SPL but my ears.
     
  11. lhallam

    lhallam Member

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    I never said a detuned 1x12 = a standed 4x12 in db's. A detuned 1x12 = closed back 2x12.

    "...drivers contained will produce the most sound from the least electrical power. The detuned port has a broader frequency response than a critically tuned port, so the port acts like second driver over a good portion of the audio range.

    ...and the de-tuned single driver cabinet is as least as loud as the same size sealed cabinet with two drivers...

    (When testing 2x15 against a 1x15 detuned) -
    At the same input power and measure from the same distance in front of the cabinet, there was no difference in the sensitivity of the cabinet nor was their a difference in the maximum SPL achieved."

    --- Kevin 'Connor - "London Power Speaker Cabinets for Musical Instrument Application"

    Yes it's technically ported BUT most amps use small ports for bass frequencies. The idea here is the larger port allows for more of the gtr friendly frequencies (mids & hi's) to be heard.

    Open back cabs sound different depending upon the environment especially in it's relation to a wall. The detuned is supposed to sound consisent no matter the room and where it is placed.
     
  12. rockon1

    rockon1 Member

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    OK I can definately see that. "Same power input" sure. Now go ahead and push the same type 2x12's with more power and Im sure they are probaly going to be louder.
     
  13. lhallam

    lhallam Member

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    I'm not clear what you are saying, equal is equal. Turn the 2x12 up and not the detuned 1x12, yes the 2x12 will be louder. O'Connor is saying if you turn them both up, they both measure the same SPL.

    I haven't measured with a meter but I can tell you that my 1x12 is plenty loud. I think part of it has to do with quality of the sound.

    Application is a consideration, this is not a compressed metal crunch sound, it has a very open and "airy" quality to it that fills the room. I use my Marshall 4x12 for more aggressive crunchy tones.
     
  14. rockon1

    rockon1 Member

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    Well Im saying that 2x12's will have twice the power handling capabilites of a single 12. By giving the 2x12 cab that extra power that it can handle,it will be louder,thats all. The detuned 112 cab is probably more efficient but 2x12's (with more power added to them) will be louder.
     
  15. rwe333

    rwe333 Supporting Member

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    There are variables like speaker sensitivity and speaker/cab 'throw' - I've heard some 4x12s that pale in comparison to well-designed 1x12s (at least in their ability to project live), for example...

    The detuned cabs do work as O'Connor describes - that said, while nice for live stage projection, they are not the easiest to mic and/or record...

    I've found the happiest medium w/ thoughtfully-designed cabs like the Tone-Tools 1x12s, the old Rivera TAC112 (works best w/ an EV), the THD 2x12...
     
  16. scottcw

    scottcw Low rent hobbyist Silver Supporting Member

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  17. drbob1

    drbob1 Silver Supporting Member

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    How deep is it?
     
  18. scottcw

    scottcw Low rent hobbyist Silver Supporting Member

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    So are we talking width or depth 16"? You interchange them in the above paragraph.

    Also, does the 16" deep apply to 12" speakers or any speaker? I would imagine that a 10" cab could be less deep.
     
  19. zoooombiex

    zoooombiex Member

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    Stupid question incoming: why do they call it "detuned"?
     
  20. aman74

    aman74 Supporting Member

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    That's not a dumb question. I often wondered myself.

    What it means is that it's not "critally tuned" like a thiele port or some other ports that may take very exact cab dimension, driver choice and would most likely be designed to affect a narrow area of the frequency spectrum.

    So it's basically untuned, not tuned, "de" tuned, etc...
     

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