Originally Posted by bulls
im not. i was doing some CEA bursts last night ~90dB... cone was moving, i was feeling pressure and uncomfortable in the ear... but i dont think i heard it... 12 hz seemed audible to me...
ill have to test this weekend during the day to make sure
i'm just concerned now i might have limited hearing :P
ok... i did it again. i turned it up. if umik correct 103 db @ 10hz... mostly pressure ... 105db @ 11 hz i hear more, 12 definitely
... wife sleeping. dont wanna wake her up with more testing
Sorry for making sure your F18s were so low in distortion.
High distortion products at 20 Hz & 30 Hz are much more audible if playing simple sine waves. When I'm testing a subwoofer, a great indicator is when you can move a good deal of air with the woofers but you feel more effect than hear sound. Playing a tone it really should be rather quiet to the ear, especially at moderate levels.
The purpose of having extension to 10Hz isn't to listen to sine waves or bursts. The benefit is to enhance the scale, weight, excitement, and realism of the soundtrack or music. I've played with the Thigpen Rotary woofer a few times, and having that energy present is certainly a desirable addition. The lowest range is not subjectively loud though. For most soundtracks, subjectively low & loud drums, explosions, and effects gain that quality from energy in the 25-35Hz range. You need the entire range to make it sound real and impactful with detail, but the very low frequency energy is much more like strong punctuation on the soundtrack, not the primary content.
When it comes to dialing in the exact level and energy from your subwoofer, be sure to start with dynamic EQ and dynamic volume off, and listen at the higher range of where you will be listening. Soundtracks with a range of percussive sounds and instruments like drums, bass guitar, gunfire, explosions, and other heavy shuddering give you a mix covering most of the subwoofer spectrum. The F18 has an LF Adjust knob which you can tinker with back and forth with the level, and then even making some adjustments to the LCR speaker crossover in your surround processor.
Broken into simple terms, the gain/level give you more overall intensity. Increase this until the bass starts to slightly cloud the dialog, and then back down slightly from there. Next play with the LF Adjust, starting by making changes of ~2 notches on the dial at a time. Clockwise will give more heft, weight, and shuddering effects, but too much will loose detail in the bass and deliver to much rumbling or shaking, and not enough impact and detail. You can even turn the dial down 1-2 notches while increasing the gain/level to shift the balance back some. The best setting will depend on your room's acoustic qualities, the in-room response, general listening level, what any auto-EQ did to the response, capability of the main speakers, and of course your overall preference. You can see some graphs demonstrating how the same control works on the SubMersive here on our forum
. Finally, before settling on a final level, if raising the subwoofer level any further negatively impacts male voices and overall detail, try lowering the crossover frequency to your main speakers by one increment, or 5-15Hz. After lowering the crossover frequency, go back and listen while increasing the level again and going up/down 1-2 notches on the LF Adjust dial as well.
Be sure to make one adjustment at a time, starting with more significant changes and then honing in on the balance that you like best. For me, How to Train Your Dragon's opening and ending battle works wonderfully to cover all the bases with clear dialog, sharp explosions, on to heavy beating wings of dragons, and big rumbling explosions.
I have yet to calibrate a system with measurements that I didn't decide to make subtle or even not so subtle adjustments when I do final listening. It's your system and be sure to make yourself happy with the result.