Best sound from a 4x12 the way speakers are loaded?

[Slobrain]

Well I know there are lots of folks here who probably have tried what I wanted to ask.

I see different speaker cabinets with the speakers front loaded and other cabs with the speakers loaded from the inside. This could be a closed back cab or a open back so my question is, what gives the best tone and low end?

I see marshalls with the speakers loaded from the inside with the front of the speaker bolted direct to the bafflem, but cabs like a Randall warhead or Peavey 4x12 that has the speakers loaded to the cab from the front with the back rims of the speaker bolted to the baffle.

I know this has to effect the sound by how the speaker is bolted to the cab.

Thanks

SLO

[tubetonez]

In my experience it matters little whether the speakers are front loaded instead of rear loaded. There might be a slight difference if measured, but not noticable. FWIW, I've been using just one half of a 4x12, and I like the tone and dispersion better from just two vertical drivers.

[Arthur B.]

In my experience it matters little whether the speakers are front loaded instead of rear loaded. There might be a slight difference if measured, but not noticable. FWIW, I've been using just one half of a 4x12, and I like the tone and dispersion better from just two vertical drivers.

What do you mean by 1/2 of a 4x12?

[tubetonez]

What do you mean by 1/2 of a 4x12?

I have a 4x12 cab wired in stereo, and use one side for my clean amp and one side for dirty.

[Joe L]

I see marshalls with the speakers loaded from the inside with the front of the speaker bolted direct to the bafflem, but cabs like a Randall warhead or Peavey 4x12 that has the speakers loaded to the cab from the front with the back rims of the speaker bolted to the baffle.

I know this has to effect the sound by how the speaker is bolted to the cab.

Thanks

SLO

If you check out some of the stereo enthusiast forums, you'll find that they prefer the speaker mounted even with the front of the baffle due to wave interference between the edge of the cone and the edge of the hole which makes a chamber, small as it is, caused by rear mounting to the baffle. Taken to the extreme, think of a speaker mounted to the back of a 12" deep hole. That would definately affect the sound.

They even recommend using a 45º chamfer bit with a router on the back of the hole of a front mounted speaker to reduce any back wave interference. When I built my subwoofer for my home system, I took the couple of minutes
it required to put a 3/8" wide chamfer on the rear of the cutout but it required using a Forstner bit to make a flat area for the tee nut to sit level and they required a little epoxy to help hold them in.

Marshall cabinets use thinner plywood which is metric sized ~5/8" thick and it would be less of a problem if you used the same thing they use. It would be lighter also. I think you ask for "cabinet grade appleply" at a specialized lumberyard which is void free and comes in 5' X 5' sheets. The edges look so nice you can make whachamadingies like magazine racks and just clear coat the whole thing.

As usual, I ramble on and overanalyse so let me go order some new tubes while I'm thinking about it.

Joe L

[Slobrain]

Hey Joe, Thanks for that info and ramble away man, no problemo.

I figure that using a 4x12 enclosed cab there has to be those little differences to make them sound great instead of just good.

On the other hand, say an open back 2x12, the way the speakers are mounted in it would maybe increase or decrease the amounts of hi's, mids and lows. Mostly trying to increase lows is a big factor on the open back amps. Also the grade of wood will also make a difference.

I wonder if using plywood, pine or MDF (I think they call it) which would get the best tone without the harsh hi's and smoother mids, lower lows in an open back design? Seems there has to be a happy medium somewhere in there without going nutz on speaker simulations.

BTW, have you talked to Jeff S. in a long time? I wonder if he is still trying to get that ULTIMATE tone


SLO...

[Joe L]

Watch your back! Don't leave it open.

On the other hand, say an open back 2x12, the way the speakers are mounted in it would maybe increase or decrease the amounts of hi's, mids and lows. Mostly trying to increase lows is a big factor on the open back amps. Also the grade of wood will also make a difference.

I've built a cabinet for a single 12" to fit my Bassman heads and used 3/4" particleboard glued in place with Pine for the rest of the construction. The amp sounded bigger than it was but doesn't sound good for distorted tones. It sounded the best with a brownface Vibroverb circuit as long as you didn't push the volume much past 5. When I run the speaker plug into one of my other amps, it's the same story, it sounds good until I hit the distortion then I run and plug into the 1977 Marshall cab with original G12H30s which is pure heaven. I've tried first a first production run V30 (bought at a trade show in New Orleans in the 80's - it doesn't even have a label), a G12-75T and a Mesa/Celestion 80 watt all with mixed results. I have a 2-12 Marshal JCM800 Combo that doesn't fair much better with distorted tones.

I wonder if using plywood, pine or MDF (I think they call it) which would get the best tone without the harsh hi's and smoother mids, lower lows in an open back design? Seems there has to be a happy medium somewhere in there without going nutz on speaker simulations.

I still think Baltic Birch plywood or "appleply" is the best compromise in strength, tone and weight. But then again, I think a 4X10 5F6a Bassman uses a really thin plywood baffle around 5/16" thick and attaches it at the top and bottom and lets the middle float. That has gotta affect the sound drastically. An open back cabinet is subject to a lot of variables depending on placement, speakers and how many beers you've had. But they sure are nice for dispersion compared to a closed back cab which with Celestions are almost guaranteed to beam like a laser.

BTW, Trace always mentioned that you need to mike the rear of an open back cab with an out-of-phase or switchable phase mike to really get a good tone. And I've read that besides the speaker its good to mike the cab on a Marshall (placement can be really finicky and hard to dial in) to get the thump we expect to hear(listen to the right channel of "For Those About To Rock, We Salute You" for an example - you can hear the wood).

BTW, have you talked to Jeff S. in a long time? I wonder if he is still trying to get that ULTIMATE tone

No, it has been a while. I'm still happy with my SLO running a pair of Philips 7581A in the outputs with the impedance switch at 8 ohms on my 16 ohm Marshall cab. I've got a quad of EL34EHs and a pair of the new EL34 Mullards ordered to try and I'm going to build up an amp in a Komet chassis I got from Hogy up the road in Baton Rouge. Don't know what it will be, probably a test bed amp with lots of turrents to play with.

[Stone]

Well I know there are lots of folks here who probably have tried what I wanted to ask.

I see different speaker cabinets with the speakers front loaded and other cabs with the speakers loaded from the inside. This could be a closed back cab or a open back so my question is, what gives the best tone and low end?

I see marshalls with the speakers loaded from the inside with the front of the speaker bolted direct to the bafflem, but cabs like a Randall warhead or Peavey 4x12 that has the speakers loaded to the cab from the front with the back rims of the speaker bolted to the baffle.

I know this has to effect the sound by how the speaker is bolted to the cab.

Thanks

SLO

In a guitar amp situation, the tone produced by the way the speaker is mounted, probably can't be detected with your ears. 99.5% comes from the cab construction and speaker(s) used.

And, a great cab/speaker won't make a crappy amp sound good.