Road King cab with fader control between V30 - C90

[THE TUBENATOR]

I was just presented with an unexpected opportunity to purchase a Road King 4x12 Straight cab. I wasn't in the market to purchase another 4x12 cab at the moment. I was planning to purchase a Rectifier 4x12 straight cab as a Christmas present to myself.....because I'm such a good boy. A friend called me last night to let me know that another friend of his is planning to sell a two year old 4x12 RK cab. Not what I was planning at the moment and not the cab that I had in mind but this does open opportunities. The only thing I have ever thought of doing with a Road King cab since they are half open with C90's and half closed with V30's is to install a speaker fader control knob so I can dial in the amount of V30 ~ C90 combination I desire. Now, someone please tell me if this is possible? I currently have a 5:50 head sitting on a Stiletto Traditional Slant 4x12 cab. If I put that cab on one of the 4 Ohm outputs and put the RK cab on the other 4 ohm output what would happen if I installed a speaker fader pot on the RK cab? Will it let me dial in the sweet spot sound between the V30's and the C90's with the fader control? I'm hoping this would work. Please let me know if I'm completely off base here so I don't do something damaging to both my amp and the cab I might purchase. Thank you for any information!

 

[J.J]

From what I can tell the Road King cab is a 4Ohm cab and the Stilleto is 8Ohm. You would have a mismatch from the start.

Also, if I understand what you want to do, you will have a ratio of 6 V30 to 2 C90. I'm Not sure if you will even know the C90 are there

From an electrical point of view you could certainly rig up a fader to fade between the V30 and C90 in the RK cab. That would also have an effect on the interaction between the amp and speakers. You would have to try it to find out if that is good thing or bad. If I had an RK cab I would add say 4Ohms in series with the V30 side for a quick test to see if the idea could work, but I wouldn't buy one to test the theory :mrgreen:

 

[giorikas81]

I don't understand exactly what you are saying but I don't think it is possible. This isn't only signal you are passing to the speakers, it is power. Juice!!! Even if there is a way to give 80 watts to the V30 and 20 watts (for example) to the c90's then all you will have left is the V30's blasting about 10-15 db's more than the c90's. Maybe I don't understand your concept...

 

[ifailedshapes]

I like this idea, but I have the same concern since you'll be sending an amplified signal. Radial makes a cabinet switcher pedal which would allow you to use the Road King cab in stereo and have either the C90s or the V30s in use at any given time. I don't know how possible it will be to blend the two, though. Also, I agree with the above poster who voiced concerns about using the Road King can AND the Stiletto Cab together. That one just doesn't make any sense to me. Four V30s on at all times? That will drown out the C90s in the Road King cab, plus the cabs are different dimensions, so the stack would look weird.

 

[THE TUBENATOR]

Again, I want to add that this opportunity to purchase a used RK 4x12 S presented itself to me quite unexpectedly. I'm not in the market for it. I really prefer the Rectifier cab. I have played through the Recto 4x12 and Stiletto 4x12 combined with a 5:50 driving them and I loved it! I prefer closed back speakers. The RK 4x12 has three speaker connection options; A - 8 Ohms closed back, B - 8 Ohms open back, or 4 Ohms combined A & B. I thought of making a fader control that would just plug into the A & B inputs and dial in the sound I wanted and not alter the internal wiring of the RK. But on second thought as J.J. posted; with 6 - V30's and only 2 - C90's what could I possibly achieve? I guess this would work better if it was just the single cab with A & B and not the Stiletto thrown into the mix to completely over power the equation with its four V30's. My original plan was to purchase a Rectifier 4x12 Straight cab to perch my 4x12 Stiletto Slant and 5:50 Long Head on it. Yes there is a size difference but it looks great; it's like a pyramid! The Recto cab is slightly wider than the Stiletto cab and the Stiletto cab is slightly wider than the 5:50 LH. I also like the tonal range that the Recto & Stiletto combined offers. Enhanced mids from the Stiletto and thunderous bass from the Recto. I think I'm just scrapping the RK purchase idea. Thank you for the input. Very helpful and insightful. Nice to get different points of view. I still think the fader control would offer added range to those who have just the single cab with open & closed back configuration.

 

[J.J]

If the price is good it couldn't hurt to have 3 4x12 cabs :shock:

I think the idea to power fade between the two halves is good as I have a V30 and C90 and think they work well together, but would still like to tame down the V30 a bit more. Find the sweet point as tubenator mentioned.

Power fading in speakers is not unusual and can be seen on many older hifi speakers where there is a control the adjusts the tweeter level. The control is generally called an L-Pad and is a simple resistor network. In Hifi, the tweeter is normally a higher efficiency than the other drivers so it makes sence to remove power from it as the easiest solution.

The L-pad really is an attenuator and can be as simple as a single series resistor or more complicated with multiple resistors and switching or even a variable resistor setup.

The more sophisticated setups will keep the impedance constant so an 8 ohm cab for instance would remain as an 8ohm cab to the amp.

For my V30 C90 setup I would just add 4 Ohms in series with the V30 (making that speaker effectively 12Ohm) and plug each speaker in to one of the 4Ohm outlets on the amp. This will not cause any problems and the V30 output would be dropped on average by about 2 or 3db. It would probably need to be adjusted to taste after that.

For people who are less inclined to go the DIY way there are any number of attenuators available like the Hot plate or Power brake.

 

[cherbst]

You could use the speaker pairs on separate jacks and bi-amp. Would need 2 power amps, then turn each side's master up or down.