My first GOOD sub...Outlaw LFM-1+ ! How hard can i push this beast?

[blzntnt]

So I am coming from an 8" yamaha sub from a package system bought about 8 years ago. I have a pioneer sc-61, just upgraded that also from a pioneer vsx-818....my questions is how hard can I push the outlaw?

My room is 12'x16' with the sub in the corner behind the entertainment center. Now since I have very little to compare it to based on my past sub and little audiophile experience ....but all i can say is WOW, I have been missing out!!

Now I want more....and I'm pretty sure it can give it out, but just nervous about over doing it....is there a possibility of actually blowing the sub. I know porting and chuffing is bad...just looking for some reference on how to proceed without going overboard....

Calibration on gain/vol on sub along with associated speaker levels:

Sub has one port plugged and set at max extension, Xover(set on AVR) 100

Auto MCACC
1st run: gain set to 5...Auto MCACC spl: -12, obviously came out to high

2nd run: gain set to 4...Auto MCACC spl: -10, still to high

3rd run: gain set to 3.25 or so...Auto MCACC spl: -8, still felt it was to high but didnt want to run it again....so I set the sub spl a little hot at -5....This has been my settings thus far, and so far so great! I plan to adjust the gain and run mcacc again tomorrow with the intention of getting MCACC to calibrate the sub to around -5 and then running it hot by 3-5db with the understanding that you dont want to put the sub spl on the avr to anything greater then 0.

So...
Is this a good approach?

Is there any danger of damaging the sub at these levels? I usually listen at around -15 to -12 on the avr volume when watching movies.

Is there any advantage to adjusting the gain vs adjusting the avr spl when your going to run your sub hot?

Thanks

 

[shadyJ]

You can push the beast as hard as you want, it does have protection, but I would recommend you be aware of a few things. First, do NOT run the sub in maximum extension mode with no ports plugged, the driver will be flying around too freely in that configuration and could bottom out easily on low frequency material. Also, running constant tones or sounds really loudly on the sub is causing heat on the voice coil. If you get that voice coil hot enough, it can melt. If you are playing something that is constantly pushing the sub hard, like a dubstep or drum'n'bass mix, you might give it a break every once in awhile for a cool down. That would probably be a good idea for your hearing as well. Movies should be ok to crank since they tend not have constant bass, although there are exceptions. Also, if you blast stuff with very strong low frequencies, you can over ride the limiter and bottom out your sub. Bottoming out the sub has potential of destroying the driver. Here is a list of movies with strong deep bass, I would be careful of running your sub on full throttle anything with strong bass below 18 hz.

 

[blzntnt]

So when u say "crank it" and assuming my reference level volume is at 0 db on my avr and i have my sub lets say 4 db hot then 'technically' i should be good to "crank it" to -5 db on my avr volume w/out having to worry about bottoming out the sub, is the correct train of thought or approach to take? Like I said I tipically only go as low as -12 on the avr...max so far.

BTW, I do have one port plugged with max extension...Im 60% home theater, 40% music so I want to feel it just as much as hear it! will probably even set up 2 different MCACC memories where I run the sub flat for music and hot for movies.

 

[shadyJ]

The gain on both your sub and your receiver isn't what is going to bottom out the sub, its combining that high output with a deep frequency. You can turn the sub channel up all the way and not bottom out the sub as long as it isn't playing deep frequencies. I wouldn't want it cranked all the way on some kind of sustained bass sound though, that will get the voice coil very hot. Note when you do turn crank the sub and push it to its limits, distortion is going to be much higher than normal also.

 

[fuzz092888]

Max extension is probably fine with music (except with the genres noted), but for movies I like max output mode (I have an LFM-1 EX) I just don't get enough slam in max extension for movies. In max output I only have the gain at about a 1/3 of a turn. I can run reference level movies no problem from there. In max extension, I lost that visceral feel and it heated up much faster.

 

[Jeff R.]

Just don't blow you main speakers while testing out your sub!!!!

Those may very well be your weak point for damage being introduced.

 

[blzntnt]

Thanks for all the responses...i just started running the auto MCACC and got it to -4.5 on the avr with the gain at aprox. 2.5....I am going to go through the entire MCACC setup to re-cal the rest of the system and then fiddle with some hot settings.

Now i have a new question to add...I have my sub in the corner...I thought I might be able to get some better response from the sub pushing it 3" from each wall, I had it about 5 -6' from each wall before...now in the speaker distance that MCACC calibrated for the sub it went from 11.5' to 15', just by moving it 2 or so inches closer to the wall. Is it telling me that I had it better placed before? I have done a sub crawl and found the corner to be the best place to put the sub.

Is there any rule of thumb on how far the sub should be from the wall...tried to find some threads talking about it and the only one i could find was based on the 1/3 wavelength rule which states it should be within 53cm