OK. Big help needed here.

[mlwarriner]

Wiring a cabinet. I have sixteen 8ohm drivers, I would like to end up with a 4ohm cabinet.

Or, if that's impossible, I'd like to end up with two 8ohm loads in the same cabinet.


HELP!

 

[projectMalamute]

Your two goals are equivalent, if you can wire up two independent 8 ohm sections you could then wire those sections in parallel and have a 4 ohm box. Sadly, you cannot. 2, 8, and 32 are doable. That's gotta be a big box.

 

[4Mal]

Your two goals are equivalent, if you can wire up two independent 8 ohm sections you could then wire those sections in parallel and have a 4 ohm box. Sadly, you cannot. 2, 8, and 32 are doable. That's gotta be a big box.

Guess he'll have to do two of them at 8 and put them in parallel...

 

[mlwarriner]

Your two goals are equivalent, if you can wire up two independent 8 ohm sections you could then wire those sections in parallel and have a 4 ohm box. Sadly, you cannot. 2, 8, and 32 are doable. That's gotta be a big box.

it's a pseudo-phil jones cab.

16x5

 

[mlwarriner]

ok, so 4 won't work. it's all good... i've been convinced that the difference between 4ohms and 8ohms with this cab on my amp won't really be audible anyhow.

 

[Johnny Mack]

it could be up to +3dB... but as said, you can only do 2ohms or 8ohms.

 

[mlwarriner]

it could be up to +3dB... but as said, you can only do 2ohms or 8ohms.

the difference between 500 and 700 watts running through identical speaker arrangements isn't likely to be enough to be noticeable.

 

[Johnny Mack]

1dB could be noticable, that doesnt mean it will be significant, but it could also give you more head room for cleaner power.

 

[billfitzmaurice]

1dB could be noticable, that doesnt mean it will be significant, but it could also give you more head room for cleaner power.

When the bel and decibel were originally quantified literally hundreds of people were tested to determine the smallest level variation that they could detect, and that average value was used to define the decibel. Thus by definition it is so slight as to be insignificant. While the centibel exists it's never used, as no one can hear even a 50 centibel level change.

 

[mlwarriner]

early picture - needs loaded, covered and grilled.

 

[billfitzmaurice]

early picture - needs loaded, covered and grilled.

Critique: you need a lot of panel to panel bracing or it's going to vibrate like mad. The drivers are spaced too far apart for the wavefronts to properly integrate, they should be literally touching each other, so you're going to have combing issues. You can get around that if you have only the center row (vertically speaking) of drivers running full range, with the outer rows low-passed no higher than where their center to center spacing is one wavelength. All things considered a single vertical array would be better, done in two or three boxes for ease of transport.

 

[mlwarriner]

Critique: you need a lot of panel to panel bracing or it's going to vibrate like mad. The drivers are spaced too far apart for the wavefronts to properly integrate, they should be literally touching each other, so you're going to have combing issues. You can get around that if you have only the center row (vertically speaking) of drivers running full range, with the outer rows low-passed no higher than where their center to center spacing is one wavelength. All things considered a single vertical array would be better, done in two or three boxes for ease of transport.

when the drivers are loaded, there will be less than .125 inches between flanges.

and a single vertical array (if i understand the term correctly) would be less than 1 foot wide, and over 9 feet tall. real-world stability comes into play there...

 

[will33]

The bracing is of extreme importance. You need them from baffle to back to stabilze the baffle, some horizontally across the back and sides should be added too as well as a couple added to the top and bottom. The large expanses of unbraced panels you have there will vibrate like crazy cancelling out frequencies leaving you wondering why this huge cab sounds so quiet and hollow. No need for disgust yet, you can add all this now before covering, padding and drivers.

 

[billfitzmaurice]

when the drivers are loaded, there will be less than .125 inches between flanges.

It doesn't appear that way in the photo, assuming you're front loading them. If you're rear loading them diffraction could be a major concern.

and a single vertical array (if i understand the term correctly) would be less than 1 foot wide, and over 9 feet tall. real-world stability comes into play there...

I agree, nine feet is stretching it a bit, though I'd think you should be able to fit sixteen fives in a seven foot high box, so two x 3 1/2 feet to haul about.

 

[mlwarriner]

It doesn't appear that way in the photo, assuming you're front loading them. If you're rear loading them diffraction could be a major concern.

according to my builder, there will be approximately .125 inches between the flanges when the cabinet is loaded.

 

[billfitzmaurice]

according to my builder, there will be approximately .125 inches between the flanges when the cabinet is loaded.

The holes don't appear large enough to accept five inch drivers loaded from the front of the baffle and have only an eighth of an inch between the frames. They could be, it just doesn't appear that way in the pic. If OTOH they are as small as they appear to be because he's mounting them to the rear of the baffle that would be a mistake.

 

[-Kramer-]

The only problem I see with this set up


Diet Dr. Pepper does not taste more like regular Dr. Pepper.

IMO

 

[mlwarriner]

the build begins tonight. stay tuned for pics and/or reviews...