So I detuned a 4 x 12" last night....

Discussion in 'Amps and Cabs' started by cryptozoo, Feb 19, 2008.

  1. cryptozoo

    cryptozoo Member

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    Thought I'd share my detuned 4 x 12" story with y'all.

    I was hopping through various speaker impedance threads yesterday and I came across some posts on detuned cabs. This sounded pretty cool to me, so I decided to do a little experiment last night with an 90s SUNN 4 x 12" B cab I've had lying around for a while. 48 hours ago the cab was loaded with Celestion 75s and sounded pretty thick, mostly due to it being oversized by an inch or two compared to Marshalls and the like. I decided I wanted to try something different, so on Sunday night I swapped out two of the 75s for V30s in a hex pattern, ala Bogner's Uberkab, and was pretty happy with the results - focused, similar low end, but seemed to cut a lot better in the mids department (I like mids). Then I read these damn threads on detuned cabs and they started to get to me. Against better judgment, I got the power screwdriver and soldering iron out again last night and yanked the two 75s, leaving both the V30s in the top position and wiring them for 8ohm operation.

    I plugged my Les Paul up to my Marshall 800 and my first indication was that it sounded rounder, looser, and in some cases, like a 4 x 12" with two big holes in it : ). It had some echo / reverb action going, but it was very subtle and pleasing. I started to wonder if I'd made a mistake and was going to have to take apart this cab for the third time. Not an easy task, especially since my power screwdriver's bit is about an inch too short to be able to get past the lip on the cab. Anyways, then I plugged the cab up to my Reinhardt Titan. Holy God. It sounded amazing. The lows were great, there were no fizzy highs, and the mids were right where I wanted them. I played that setup for about 15 minutes, then switched to a Marshall JMP 50 watt Master Volume. Normally this amp is pretty bright and takes me some time to get it dialed in where my ears are ok with it, but it paired up with this cab amazingly well. Sounded oddly 'modern,' for lack of a better word. Had a very pleasing compression to it that the cab emphasized. Also, the cab still had casters on it -- I bet I'd get even more low end if I removed those, so I'll probably try to do that today.

    I have rehearsal tonight so I'll see how the cab sits in the band situation, but a couple of things impressed me right off the bat: low end (obviously), more pleasing mids and tamed highs, and lastly, the utter NON lack of volume. Logic told me that the cab would be quieter by removing half its speakers, but this is not the case. It's still just as loud. Now the SUNN cab that's been sitting in the corner for a long time is finally getting some use, it sounds unique and is lighter (which is important, because this cab is a beast). I'm not sure I would do this with all my 4 x 12"s, but it's definitely cool to have this gigantic 2 x 12" in the cabinet arsenal!
     
  2. mmorse

    mmorse Member

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    I have done this a couple of times with my 412. In fact, right now I have two Scumback H75s in the 412 and it sounds great. Like a big, full sounding 212. I put one on top and one on the bottom and wired it for 8 ohms. And it's just as loud. Too loud in fact for home use. That's why it's for sale.
     
  3. mxr2000

    mxr2000 Member

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  4. DC1

    DC1 Member

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    It's the dumbest, damn, nonsensical thing you ever heard.


    And it absolutely sounds amazing. You will not believe it until you try it.

    DC
     
  5. michael.e

    michael.e Supporting Member

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    I pulled a couple of speakers from my old Orange cab and it sounded great at home.
    Sounded like crap at rehearsal and did not cut. I attribute it to too many transients mucking up the more direct and woody tone. Too weak for a rock band in my experience.

    Emee
     
  6. rockon1

    rockon1 Member

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    I pukked one of the speakers in my oversized 2x12 out. Immediately put it back in. Couldnt hear anything better sounding about it. Bob
     
  7. GrecoVee

    GrecoVee Member

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    What the heck does the term "Detune a cabinet" mean anyway?
    Just sounds like some speakers were exchanged or a couple of speakers were changed or taked out to create a different tonal responce?
    Enlighten me on what "Detuned" means please!:D
     
  8. DC1

    DC1 Member

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    It's from Kevin O'Conner of London Power. Simply put, taking 2 speakers out of a 4x12 or one out of a 2x12 (pay attention to your wiring and impedances!) moves the tuning of the port so low that the port (the big speaker holes) are below guitar frequencies and pass not just bass, but pretty much everything in the cabinet. Hence detuned. Combine this with the unloading of the air resistance in the cabinet (a sealed box limits the excursion of the speaker cones) so the speakers are no longer fighting that resistance to move, and the combining of the reversed polarity sound from inside the cabinet with the normal sound from the front of the cone, and you have the overall effect of detuning.

    As you can see from this thread it is not for everyone, but I think it sounds wonderful with my gear.

    DC
     
  9. cryptozoo

    cryptozoo Member

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    Alright, got the chance to try it out last night with the band. We had another guitar player who's been jamming with us off and on, and I let him use the SUNN with the Reinhardt Titan. He's played that combination before, and I didn't tell him I'd done anything beyond swapping some speakers around. He was immediately floored by the low end and volume from it, especially when I took off the grill cloth and showed him it was just two 12"s in there. In our two-guitar setup it sounded great and fit perfectly -- better than it did before, in fact.

    I don't think I'd use it as my primary cab in a live situation (I play heavier rock'n'roll), but it sounds so damn unique and cool that I'd recommend anyone with an extra 4 x 12" B cab lying around should try it. I'm interested to see how it sounds in the studio because I can walk a few feet from the cab and move from side to side and get varying degrees of insane, round low freq. I love it, and it's kept me from selling the SUNN. What's weird is that I've got those two V30s in there, and I didn't care much for those speakers before. I wonder how this would sound with Greenbacks... hmm...
     
  10. kurtsstuff

    kurtsstuff Member

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    Oh man...I hate coming across these type of theads when I'm home all day with nothing to do!!! Ok........Where's my power screw driver...lol!!:Spank:crazyguy
     
  11. JubileeMan 2555

    JubileeMan 2555 Member

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    One thing I noticed in your posting is you went from 4 x celestion 75s to 2 x V30s.

    I may be crazy, but couldn't a good portion of what you are hearing be the fact that you changed the speakers you were using? I understand the open ports do change the sound, but I think a proper test of an A/B situation would be 4 x75s, and then 2 x75s.

    right?
     
  12. cryptozoo

    cryptozoo Member

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    Actually I went from four 75s to two 75s and two V30s in a hex pattern before finally ending up with the two V30s. I agree, speakers have a big part in this sound. I guess you just have to hear it to believe it, the frequencies I'm talking about weren't really there before, or if they were, I couldn't hear them. I've had a 2 x12" before with V30s in it and it definitely didn't sound the same as this detuned cab.
     
  13. pgissi

    pgissi Member

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    Anyone that works with pro Sound Systems understands the increased efficiency a ported or horn loaded cab has over sealed enclosures and "detuning" your cab provides some of the benefits of a ported and/or horn loaded enclosure .

    All things being equal, the ported or horn enclosure will always be louder and deliver a fuller bandwidth response with the same input power.

    Guitar players are just now applying what pro sound engineers have known and relied on more so in the early days and using large horns and ports were absolutley necessary in the old days of low wattage handling drivers and power amplification.

    Have you even been in an movie theater in the 60's with huge horn loaded driver boxes flush in the wall? That was so you could fill the theatre with sound using the low wattage amps and drivers of the day

    Detuned cabs are replicating some of this magic but its less about increasing efficiency for increased spl's and more about altering the freq response you previosuly got from a totally sealed enclosure, your minimizing response anomalies of the sealed box by detuning.

    You get "smoothed" highs not because they are actually smoothed but because the harshness is now masked by the increased lows and mids since the cab/port/drivers combination is delivering a fuller tonal range overall since the empyt hole('s) in the cab are not tuned to any resonant freq, its acting more like a wide bandwidth port.

    With a horn loaded enclosure, the mouth of the horn provides an improved acoustic impedance match which improves the coupling of air to the surface of the driver and with a detuned cab this aspect is in play to some degree also although its the rear of the drivers in the cab seeing this improved coupling.

    Your right to some degree, the freq's you are now hearing were there before but were just being masked and now have been set free

    Where some may not like detuned is those who may want a tighter percussive sound, the detuned loosens it up some, especially the lows.
     
  14. bosstone

    bosstone Member

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    I agree with all above and have made single 10, single 12, single 15 and 2 X 10" detuned cabs. I would just add that the lows can go even lower and they sound more natural and not "bumped" as compared to closed back cabs.
     
  15. cpsdawg

    cpsdawg Member

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    same principle as using the sound enhancer stands on an open back combo. it is rediculous how much it fattens up ANY combo.
     
  16. pgissi

    pgissi Member

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    Absolutely, the sound enhancer stand is IMO necessary, I stopped using combos due to their lack of adequate cabinet volume, its uninspiring for me and I have been spoiled since I abandoned using combos. When I play one, which is rarely now I am reaching for the eq to add whats missing and all that does is mud things up.

    Combo cabinet volume is designed for convenience, weight and practicality, not tone.

    My next experiment is to load 2 of the 4 V30's I bought 2 years ago and ended up hating and throwing back into their boxes, into a detuned cab to see if it tames the mid spike and high end harshness.
     
  17. theidiit

    theidiit Member

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    I just detuned a Marshall 4x12, and to tell you the truth, by the time I opened it up, took out speakers, and got the back all sealed up again, I totally forgot how it sounded beforehand. Still, it sounds good now, so I'll probably leave it detuned.
     
  18. JimmyR

    JimmyR Member

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    I guess this is kinda why I just like oversized open-back 2x12 cabs. I like the cab to have about 1/3 of the back open. With the right amp and speakers they can sound huge. I have found that I prefer open back 2x12s over quads. Apart from the fact that a quad is too bloody big for me and my car (!) I prefer the tones of the 2x12. They're just as loud as a regular quad and can actually have more low-end; and the low-end that's there is less "tacked-on" sounding as someone else noted.

    How you build a combo can have a dramatic affect on the tone also. I once built a fairly compact open back 2x12 combo with a 50W Marshall style amp in it and it almost sounds like a stack. The trick was to use 18mm ply for all of the cab, including the baffle. I used thinner ply for the back panels but the cab is very solid. Using such a thick baffle gives you a tighter low-end with a much more solid sound to it. The amp had more low-end than a typical 50W Marshall and the two things together have made a pretty tough, big sounding amp.
     
  19. bosstone

    bosstone Member

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    No way an open back has as much bass as a closed back and certainly not a detuned cab. I am sure you would find this is true as long as you are using the same speakers. That is not to say that it can't sound great because it can. They can also be louder and disperse the sound more widely. Changing the cab thickness and material can make the cab more resonant but it won't have much effect on the frequency.
     

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