A completely transparent power-soak?

[Joe L]

Has anyone thought of this?

Take a cheap high wattage speaker of 4 ohms such as this, and put it in a closet/dressing room/truck or even inside another speaker cab. Wire your 4 X 12 cab all in series to be 48 ohms. Plug both speakers in parallel into your amp and set the impedance to 4 ohms.

With ten volts output, the 4 ohm speaker will receive 25 watts. The 4 X 12 will get 2 watts.

I know the Weber Mass is similar but also a lot more expensive.

[R.G.]

Whatever else it may be, it's not completely transparent. The electrical and mechanical properties of the cheap, high wattage speaker and it's acoustic load appear in parallel with the speaker cap you're listening to. Since the cheap speaker you're not listening to is eating most of the power, it's also got a disproportionate electrical effect on what the "good" speakers are getting. And wiring your 4x12 in series may make it sound quite different from series-parallel or parallel.

[The Dude]

Certainly all true R.G., and there's nothing you posted one could argue with, but is the tone you get acceptable? You can only know if you try it.

[R.G.]

Yep. Motherhood is good, and so is apple pie. Everyone who is suitably equipped ought to at least consider doing both, either singly or in combinations, because you can only know if you try it.

If the title of the post had been something like "Is this a new way to make a power soak?" I'd never have commented. The title indicates that the author does think it's "transparent", whatever that actually means, and it isn't.

No harm, no foul, just commenting. Messing with stuff to get a tone you like is something musicians have been doing ever since there were musicians. In fact, "transparency" has only become a holy grail recently. It reminds me of wine being served "a chambre" (at room temperature) and the cavil I heard in a comedy about the wine being TOO a chambre.

And yes, only you can prevent forest... er, only you can tell if you like the tone. Cool. Worth experimenting. Heck, it might even BE transparent for some combinations of values of 4x12 and cheap high power speakers.

Just sayin'.

[Joe L]

The are a couple of reasons for coming up with this idea.

I built an 18 watt Marshall for a friend at work and the output waveform was unusable for testing purposes as compared to running it on a cabinet. It had a lot of "fizz" when pushed hard due to bias excursion which just didn't show up the same with a resistive load. To get around this and save what little hearing I have left, I wired a speaker with cat 5 cable to a speaker in my bedroom closet. It worked great. I added Zeners to limit the excursion and changed the output transformer to get it sounding like I wanted.

Secondly, I have a '77 Marshall cab with original cone 30 watt greenbacks. I'm really cautious about pushing it too hard because I love the tone of those speakers. I have the matching 2203 head, a '74 1959 and a homebrew SLO that I like to occasionally let rip when I've had just a bit too much tequila .

I hate the sound of the power soak and it is limited for troubleshooting on the bench and was thinking this would be a good compromise. Good enough to throw it out here in case someone else could use the info.

I am going to order that speaker I linked above and see how it works.

[R.G.]

Let me be really, really clear: I did not mean that I think it's necessarily a bad idea at all.

It's just not necessarily going to be "transparent" because the rewiring of the speakers in the 4x12 and the electrical reactions caused by the acoustic electrical loading on the cheap high power speaker can and probably will change the frequency response and damping (which amounts to time response, which is different).

That doesn't make it bad, just not necessarily transparent. It may even please you more than the stock sound. "Better" isn't "transparent" either. Could be better, could be worse. Might sometimes be the same, but that's not guaranteed. IF you try it and like the sound, great!

[Joe L]

Let me be really, really clear: I did not mean that I think it's necessarily a bad idea at all.

No need to clarify RG! Honest and informed discussion was the reason I posted this here.

[dmartn149]

What if you also cut some big holes in the cone, and maybe reinforce what's left of the cone so that it doesn't move as much air? You don't want to hear this one, right?

[oc disorder]

What if you also cut some big holes in the cone, and maybe reinforce what's left of the cone so that it doesn't move as much air? You don't want to hear this one, right?

Yes well that will reduce its efficiency by not moving as much air but as the integrity of the cone has been altered so the tone will be somewhat different !
It was rumored that the speakers were slashed for that intro in the Kinks "You Really Got Me" so I guess what I'm trying to point out is you can try anything to get the sound you like....
I also wonder if any one has any experience with this ?

FluxTone Speakers reduce speaker volume without tone destruction

This makes so much sense technically and practically but I wonder what it really sounds like?

There is also some discussion here

The Boogie Board ? View topic - Fluxtone Variable Efficiency Speakers

[dmartn149]

[QUOTE=oc disorder;310302]Yes well that will reduce its efficiency by not moving as much air but as the integrity of the cone has been altered so the tone will be somewhat different !/QUOTE]

I thought that this extra speaker was ONLY to soak up some power, and be isolated and not heard at all.

[Leo_Gnardo]

Joe L would you be willing to settle for "a lot more clear" as opposed to "completely transparent"? Maybe you've already tried this but worth a mention : wire a "brightening" cap from the hot to the wiper of your attenuator's ww pot or switch. THD does this, no reason you can't too. Figure on 1 to 5 uF, 200V or more, film cap.

One thing that also works against you when the atten's dialed down is Fletcher-Munson, those clever guys who figured out so much about hearing in the 1920's. At lower volumes, your ear (mine too, everybody's) is less sensitive to high and low frequencies. That's why there's a "Loudness" button on some stereos, to try & make up for that. You can add a brightening cap that will get your ears happy at low volumes. Sure beats hinky wiring your speaker cabs. Cheap too.

[Joe L]

I have gotten the speaker in and when I have time, I'm going to try it. And no need to cut any holes in it, I only want it as a reactive load. I actually am pretty impressed at the build quality for $19.95 to the door.

And yes Leo, I'm familiar with old Fletcher-Munson My goal is to have a fraction of the wattage going to the cab but still be a reactive load. Transparency isn't high on the list. One of the main reasons to do this, is for trying out new builds and experiments that at the same time, won't draw the attention of local law enforcement. Plus, my hearing is on the edge of needing some kind of aid.

And if I had thought of it in the '70s, I could have kept my Ampeg V4 from going thru a set of greenbacks every 3 months.

[J M Fahey]

Ampeg V4 and 4 Greenbacks are not to be even mentioned in the same phrase, let alone connected to each other.

That said, while they lasted, sound must have been killer

[Joe L]

Ampeg V4 and 4 Greenbacks are not to be even mentioned in the same phrase, let alone connected to each other.

That said, while they lasted, sound must have been killer

It was killer. We wondered what the fuss was about with Marshalls because our Ampegs sounded so huge. I borrowed a MK 2 Superlead for a few weeks when my V4 blew a tube/screen resistor and didn't like it. Now, I realize it was the 6550s that I didn't like.

But yes, the original cones lasted almost a year. The voice coils were just a charred mess. A local shop in Baton Rouge did reconeing services and used a supposedly higher wattage coil but they would blow like a fuse within a month. I sure wish I would have known I could have pulled two power tubes or put an EVM in an isolation cab to help with the V4 thunder.

My ears are still ringing.