Originally Posted by audiovideoholic
There isn't need for any filters as the amps run out of juice before the subs get close to xmax. That is y. I said that if could. Run these at 4ohms bridged i would have thought about a different amp/amps. Oh well. I might try bridging them and see what happens even though a different amp would have been better like boso said tho, i could lower the switch from 150v to next lower setting to help protect the drivers id want to try around 3000 watts n see how they handle it instead of the 5000 claimed per side.
They clip rather easily with music but haven't really tested movies as the amps aren't in the same room.
What are you all thoughts on 4 ohms bridged. I really don't even know why im thinking about it since so many including myself have advised against it. I don't remember boso coming in on it until now either. But he did post a lot back in the beginning of the FP thread about lots of different stuff.
I was the one who posted the test result during which the clone crapped out. It was a stereo 2 ohm sine wave torture test (that is, a sine wave input driving the amp to clipping). The comment was "inadequate protection", IIRC. That test happened in April 2010. It was an FP10000Q clone, but I don't know from which agent it was purchased. The test was done in England, which I believe is 230V-50 Hz. The tested amp met output specs in 4 ohm stereo, 8 ohm stereo and 8 ohm bridged. It "buggered out" in 2 ohm stereo.
That's pretty much all I said on the subject because that's pretty much all I know on the subject. The rest is conjecture, hearsay, recommendation, etc., based on zero experiences or facts as they would relate to JT's version of the clones, as far as I'm aware.
I've never used a 4 channel version. I tested several amps of a similar platform from different Asian factories that did not blatantly copy Lab's case design. The Lab clone amps I bought from Sanway were FP9K and the original K12K, which is what I suspect you all are using, re-badged as the FP14K. I bought them in July 2010, around a year before the clone thread. I suggested Sanway to not, who was looking at a couple of other agents that I was aware of as not being trustworthy.
Those back door factories can and will, without notice or disclaimer, use counterfeit parts. Important parts, like, for one example, the output transistors. I've seen output transistors that are warped like a banana (instead of perfectly flat as they should be) and obviously would not be able to make proper contact with the heat sink. That's the sort of thing that can lead to failure regardless of heat sink design and/or fans used or mode of operation, but can be blamed on many other things without a thorough investigation.
Math tells me that the FP9k is only about -2dB less rated output than the FP14K, so it was a simple choice for me. I've used 2 of them extensively. I used one to run 8x15. I had a couple of them arrive with defective VPL, but since then have learned how they work and affected a fairly simple repair.
Again, I'm not familiar with the Quad channel versions. Are you (or anyone else) running them in dual 8 ohm bridged vs quad single channel? Mainly I ask to remind you that the VPL dip switch settings values double when in bridged mode. So, 150V becomes 300V, which is essentially equal to disabling the VPL.
I'm always a bit stunned at folks who purchase such serious hardware, hook it up and let it rip without understanding the operational nuances. When I read posts with "easily clipped" and "easily bottomed" with no AC/settings/connections details, It all sounds pretty crazy to me. LMS Ultras and FP14K clones are not easily bottomed or clipped in any circumstance, so those situations need to be immediately investigated in detail.
Ilkka poured 3600W of long term sine wave into a single LMS-U in 3.5 cubes. There was no bottoming or clipping to 10 Hz. Below 10 Hz, folks who claim reproduction with no problem need to post the entire chain of hardware up to and including the sub, but short of that (because I doubt it will ever become the norm), they are not seeing much below 10 Hz from the typical system, which is down as much as -20dB by 5 Hz and the hardware does not perform the same at 5 Hz as it does at 20 Hz (that's why the benchmark for specs begins at 20 Hz). L/T and/or Audyssey boost is another wrinkle most don't fully grasp the mechanics of. Looking at a WinISD "prediction" is useless. Modeling software crunches the math. It assumes signal integrity to DC amplified by an alien amp that gives unlimited power with no changes in waveform to DC into a driver that keeps its T/S parameters intact at any level with any input source.
Sorry I'm cramming too much into a single post, but i won't likely be able to follow up post, so trying to cover a lot of bases at once. All of which is just my take, YMMV, etc.