I'm only new to these forums, infact this is my first ever post, so not sure how it's going to go.
I just spent a heap of hours coming up with a fix for the new ix8 and Savox SC1267 servo I'm running in my DEX408. After about a million brown outs and testing during the brown out to confirm that it was the case I decided I needed to sort it out. After upgrading from a Mamba Monster, I was a little disappointed that the ix8 could not keep up with the demands of the servo even with a capacitor. I managed to sort the problem out however and the car is now super reliable. I contemplated running an external BEC, but room in the DEX is at a minimum and I didn't particularly want another component fitted to the car due to weight issues and having another component that can fail.

So here's the fix. Guaranteed to work....(this will only work if the car is running 1 or more 2S packs...we need 7.4V and not sure if it will work on any other ESC. Also disregard anything else you have heard as this only screwed me over in my testing)

Remove plug from receiver that controls ESC and from that remove ONLY the power wire (red or middle). This leaves only the signal and earth in the plug. Then solder a wire onto the first +ve terminal in the circuit starting from the -ve terminal of the ESC. (This is a must!!! ie. if running 2x2S packs in series to have 14.4V you have 2 +ve terminals. So starting at the -ve terminal of the ESC we follow the wiring to the -ve of one battery, the +ve of this battery is the one we need to solder to to power our receiver, if you solder onto the +ve of the other battery, you will supply our receiver with 14.4V and the servo will last about 3 seconds.)
Once soldering a wire onto the correct battery terminal, the wire needs to be run in place of the one removed earlier. The receiver uses the original earth through the ESC which is the bit that had me buggered.
Once you have done this thats it. You are now supplying your servo with unregulated 2S power, which the majority now handle, and don't have to worry about capacitors. The ESC runs cooler and the servo works at its optimum. Don't worry about 1 battery being drawn down more than the other if only one is powering the servo, the draw is minimal and over numerous
25 min runs flat out around a track (i dont bash) on 6900 mah packs for testing purposes, the differences over 3 separate occasions was only .15V between both packs and between cells of that pack not worth mentioning.

I know this is a long post, but I hope it can save people the headache which it gave me. If anyone has any dramas feel free to PM me

Im having this same problem with my ix8 and am very dissapointed in LRP! This is a speed control advertised to run 2s lipos and LRP cant fix this issue even with the two updates that helped but just aint cutting it. LRP fix this dahm speed control please!

wow for a $300 speed control you would think it shouldn't have any kind of issues.
I hear the duratrax DE10 is very reliable. a lot of guys are using it at the tracks around here I heard.