Speaker Cabinet Jack Plates ?

[Logan5000]

Hey there fellow metro amp builders. I have a custom made 4x12 with a single speaker jack input. I would like to wire the cab so I can have one jack that goes to two of my diagonal speakers (50w head) and the other two diagonal speakers will be wired separately in stereo. The stereo speakers will be a stereo wet signal from a small power amp.

What is the best way to go about this so that the conversions looks clean. Can anyone recommend a speaker jack plate that has at least three inputs?

Any help would be greatly appreciated.
Chuck

[demonufo]

Hmmm. I'm not sure I would bother. Unless you seperate the speakers into different enclosures, they will be greater influenced by the cabinet as a whole than the signal you individually feed to the speakers in my experience. All speakers will reproduce frequencies passively (by influence of the air behind them) as well as actively (signal fed to voice coil).

It certainly won't give anything like the clarity of seperate enclosures within the cab, or better still, seperate cabs.

[Logan5000]

Thank you for the note. I have head a cabinet wired this way with the stereo wet signals on the diagonal speakers and it sounded really cool. I understand it would be ideal to have a cab for each signal but for now I don't want to do that.
Plus my speakers are 30's and I want my head to drive only two speakers.

I was hoping someone had a suggestion that would be constructive and actually helpful ?

Thank you

[demonufo]

Well, it was supposed to be constructive. The other downside of a cab in this configuration is it would be much more unpredictable when mic-ing. The results would invariably be much different to what you can hear in the room, and phasing problems will most likely occur. That's the biggest problem of running a true stereo set-up in the same cab. The phase of the speakers will be fighting against each other, and you'll be missing part of the signal.

I can only apologize, but I figured out pointing out the drawbacks and issues would actually be constructive and helpful. Apparantly I was wrong.

[908ssp]

It can be done but you will need to add a divider in the cab. I made one like this with the divider running vertically so that I get the best horizontal spread of sound. Diagonal would be a no go in any case for me as it sets up conflicting wave patterns which will alter the sound in unpredictable ways. There are numerous pre-made speaker jack plates available many have two holes like the ones Avatar uses. They are typically wired in parallel so you can daisy chain speaker cabs but you can wire each jack to separate pair of speaker. Use plastic jacks so you don't get ground faults from grounding the jacks on the metal plate.

[Logan5000]

Thank you for the help it sounds like the cab I heard may have had the divider as you indicated and most likely it was vertical. I think what I better do is wire it temporarily and run the wires out of the single hole and then use something to plug the hole temporarily. And if it sounds wonky then I can return it to normal.

With that in mind i could buy two single 12 cab's and take two speakers out of the cab. I would sell the custom made 4x12 and buy a empty 2x12 but there just does not seem to be much of a market for 4x12's.

Question: what would be the best way to plug of the 12" holes . . Does anyone sell round blanks that can be bolted in ?

Thank you again for your help and offering something constructive.

[908ssp]

You can put one speaker in each upper hole and leave the lower holes open. There is enough room in the 4x12 that the sound coming out of the lower holes is more or less in phase with the sound off the upper holes so it acts as a kind of short echo and can be quiet pleasant sounding. Cabs are often built like this and referred to as detuned cabs. I have one with a pair of evm12l in the top and the bottoms open and it along with my SLO clone makes a terrific metal modern rock noise. I don't use this as a stereo or wet/dry setup for that I always use a second cab.

[demonufo]

I used my 1960TV a cab as a detuned cab for a while, with 2X Heritage H30's. That setup kicked arse. The only thing you can't do with a detuned cab is jack it up away from the floor (any more than the height of castors) as your bottom end disappears altogether.

I did have to put in a partial shelf below two speakers at the top, attached to the baffle board, approx just over half the depth of the cab to avoid too much loss of bass via phase cancellation though, but that was a 10 minute job.

[Logan5000]

Thank you, that is a really interesting option. So to make sure I understand this concept, what we are talking about is totally removing the bottom speakers and leaving them open ? And using the 50 to drive the top two speakers rated at 30w each.

If I did that I could take the two speakers I removed, and mount them in two single 1x12 cabinets ?

I never thought of that . . Thank you . . also I guess if I removed the lower speakers I could mount a round wooden plates where the speakers would normally be if it needed to be closed ?

[demonufo]

Yep exactly that. There are a few people who specialize in detuned cabinets. Whilst they don't necessarily have speaker shaped holes, the holes have the same area, and are underneath where the speaker sits.

Two speakers closed off (sealed) in a 4X12 might be a little undamped though depending on the speaker, and a little loose in the bottom.

[908ssp]

....
Two speakers closed off (sealed) in a 4X12 might be a little undamped though depending on the speaker, and a little loose in the bottom.

That same can be said for any open cabinet detuned or back open...so I wouldn't worry about that go by your ears.