Originally Posted by pbc
Yeah, tons of room gain for sure. Given the subs are right in a corner (within 3 to 4" each side) I've got the floor, side and back walls and ceiling boundary gains with one sub, and the same (minus one side wall) with the other, plus whatever the room itself is doing. I am surprised at the amount of gain though.
The only issue with comparing the PB13 is trying to get the FR as flat as possible with both the PB13 and the two AV15Hs, otherwise I don't see much point in trying to compare them if the FR's are very different.
Bosso - how do you combine the FR graphs from those jpg's I posed of the Ultra? I didn't save those in REW but wanted to lay them onto the same graph as the Ultra to see how close the "non-EQ'd" FR's are?
Is anyone else not surprised by the dip on the FR of the AV15's? For some reason I thought based on the WINISD models that they response would be flat out to the x-over of 150hz, or for that matter continue to rise up to the x-over vs. dropping so much? I.e., I thought the low-pass x-over would start to slope after the x-over point, not before (or do I have that wrong?).
How do I do it? Very tediously.
First, the PB Ultra is EQ'd in the plate amp, so you're comparing an EQ'd anechoic response to an un-EQ'd response, which you can see in the attached graph.
The roll off caused by the 150Hz 4th order LP looks quite normal. The 'drop off' is actually just a fairly normal in-room mountain-valley response seen between 100-300Hz.
YES, the peak is skewing the calibration. That peak is +15dB and will certainly get the meters attention when setting the SW level. So, if the movie clip you're watching has less content at 40Hz and more content below that, it will sound attenuated... because it is.
The pods emerge scene, for example, has content from 4Hz to 90Hz with the strongest content at 25-30Hz, where you subs would be 6-12dB lower than the Ultra, depending on the tune, when both are calibrated the same.
This is a testament to proper calibration.
The graph is labeled, so it should be simple enough to see what is being compared. The Ultra in sealed mode shows a 6dB boosted response, which is what I would recommend for your 15Hs for flat to single digits response.