Originally Posted by Czickefoose
Okay, so I apologize if this is not the right thread to ask this question, so please direct me to the right one if it isn't. I have the PB16 Ultra and PC13 Ultra. So, for about 95 percent of the time, my PB16 ultra doesn't chuff. But when it does... boy does it. I haven't really noticed any issues until last night, I'm watching Insurgent and towards the end, holy crap. There was more chuffing than I have ever heard and it even bottomed out (had that flapping sound). It was only a couple scenes but it was really bad.
I have a small room, 10x13. PB16 is on the left PC13 on the right. Right side has a semi open wall. I have a Yamaha a3050 with the YPAO on and measured to flat. Dynamic mode is on high. I feel like on minimum it just doesn't have... well... any dynamic to the sound. Bass under sound options is set to 1 but bass boost is off. MV is set to -24.5 during this movie. Under YPAO, the PB16 is set to -7 and PC13 is set to -4.5 (it has a bass boost in that location of the room). PB16's sound on the sub is set to -2 during that scene, I then put it to -5 during that scene and the chuffing went down considerably, but was still rather bad. PC13 has a volume, on the sub itself, at -2.5 (if I recall correctly, not at home right now).
So, firstly, has anyone watched this film and experienced this? I've been plagued with chuffing from this sub but better placement and better measuring from the YPAO has helped a lot. The reason I am writing this post now is the fact that it was so bad during that movie. I also have read so many posts about people not having issues with chuffing at all at any volume.
So it makes me wonder, do these people have dynamic range turned off? Did they measure using a DSP for their subs? I can't help but wonder if the YPAO is boosting bass for this sub for say... the 20hz range. And therefore, when those scenes come up and have a ton of 20hz and below material, the sub is going to chuff due to such boosting. Which leads me to wonder if I had a better eQ device such as a DSP, would that remedy this issue? I am about to get one and I hope it will help. I have noticed that adjusting the phase to allow for better sounding bass has helped as well. I can lower the volume and get the same perceived bass output, thus minimalizing the chuffing.
Do you all think that my settings are extreme or could be leading to such chuffing. I feel like I could never find the limits of the sub for 30hz or above frequencies, but the 20 and below stuff seems to always lead to chuffing when the volume is above a certain range. Sure, if I turn the MV down or the sub's volume down, no chuffing happens. But anything above the aforementioned levels, and it does happen. The PC13 has very little to NO chuffing.
So again, to summarize my rant... would dynamic range being on cause the chuffing at these scenes. Are my sound level settings rather high? Will a DSP help by offering better equalizing? Thanks for any input and yes, I have been in contact with SVS before and they normally just give me the same answer, that chuffing will happen on any ported sub.
I don't know that I can answer all of your questions. Ideally, you should email Ed Mullen, at SVS, and let him help you troubleshoot this specific problem in detail. But, perhaps I can help to start the process. First, any ported sub can chuff, depending on the material, the sub's placement in the room, and the external EQ applied. But, you may be able to change two of those variables, while still enjoying the material that is making the sub chuff.
You can experiment with improved room placement by temporarily taking the PC13 out of your system and placing the PB16 in an optimal position in the room. You could do a reverse sub crawl by putting the PB16 on furniture sliders and moving it around. Then, you would position the PC13 after you found the optimal position for the PB16. (The PC13 should be a little more resistant to chuffing anyway--same size ports; less powerful amplifier.) You might, for instance, find that just swapping sub locations would work, or that you end up moving the PB16 to a completely new location, perhaps one that is even closer to your MLP.
Second, although I am not familiar with YPAO, I would experiment with some different combinations of settings. You mentioned Dynamic Mode. Perhaps taking it off high and increasing the internal bass boost would help. I would also consider increasing the gain on the PB16 and decreasing the trim, even below -5. I can't tell you that doing that will solve your problem, but there is going to be a certain degree of trial-and-error to find out what will help.
The third thing that you can try is to use the 20Hz mode rather than the extended mode on the PB16. Again, I don't know how much that will help, or whether you will like the resulting bass as much, but in a small room you should be getting pretty good low frequency room gain, and in theory, the 20Hz mode should reduce chuffing.
Finally, you could experiment with some of the PB16's internal DSP. For instance, you could set a high pass filter for that sub. I have never experimented with the internal DSP on my PB16's, so I can't speak to the result, but I know it's there for situations like this one.
You can certainly try a miniDSP, but to use it effectively, you will also have to use REW. Ultimately that may prove to be the best solution, but it's going to be a fairly big investment in time, with its own learning curve. To start with, I think I would just go back to square one with respect to the location of the PB16, and then systematically work my way through the suggestions listed above. Perhaps some combination of those measures will work well and please you, and if not, you can develop a Plan B.
I hope this helps!