|You can use your C-weighted SPL meter to create a house curve. Just EQ it flat, but don't use any correction factors. You'll end up with a nice house curve.
Well, the RS meter doesnâ€™t start with drastic deviations until about 40 Hz. Above that point itâ€™s pretty consistently off only a dB or two. If your house curve doesnâ€™t start until 40, it will indeed sound boomy and inaccurate.
|It originates from a psycho-acoustic phenomenon which makes a flat frequency response sound too bright in a large space like a movie theater.
Actually, thatâ€™s 100% backwards. Larger rooms need
flatter response than small rooms in order to sound correct. I found this out the first time I RTAâ€™d a large church and right off the bat tried to dial in the same house cure I had at home. It was extremely
The phenomenon is explained in the â€œLarge room equalizationâ€ section of most Ashly equalizer manuals: â€œAs sound travels long distances through the air, high frequencies are attenuated more [rapidly] than low frequencies. In general large rooms benefit from some low frequency roll-off [and] high frequency boost...â€
|How much of a no-no is it to add boost filters in addition to those that are taming peaks? I know it's not ideal because of the extra demand on the amp, but I'm having a hard time getting a flat curve w/o them.
That â€œdonâ€™t boostâ€ thing is one of those myths that just wonâ€™t die. For EQing subs, boosting or cutting is largely academic.
For instance, letâ€™s say you have a couple of considerable dips in your response, down 10 dB or more at 22 and 63 Hz. If you followed the â€œcut onlyâ€ rule, equalizing, your overall gain will down a substantial 10-12 dB or more. Of course, you will have to recover probably that full 10-12 dB to get the output back up to where you had it.
So you have to boost the sub right back up. Thus it would appear that you are now driving your sub as hard as before, right? Nope. The situation now is that you have much flatter response. This means the frequencies that were underrepresented before ( ~22Hz and 63Hz in your case) are now being driven harder
than they were before equalizing. Thatâ€™s right â€“ youâ€™ve succeeded in boosting those low areas
, whether you intended to or not.
So â€“ anyway you cut it, subwoofer equalizing places increased demands on the amp and driver. Itâ€™s unavoidable, so you just have to make sure you have enough headroom going in. So donâ€™t worry about setting filters for boost if itâ€™s a more efficient way to flatten your response (i.e., using fewer filters).
The only thing to look out for is a true null. Not all under-represented areas in the response curve are nulls. A true null you canâ€™t boost â€“ it wonâ€™t respond to equalization. So itâ€™s best not to try to boost a null. No sense â€œburningâ€ headroom when you donâ€™t get anything in return.
|but I don't see anyone defining it or explaining how to get a house curve. Anyone care to enlighten me? Much appreciated
Basically a house curve is perceived
flat response as opposed to measured
flat response. As noted earlier in this post, small rooms donâ€™t typically sound good with measured flat response â€“ they generally sound overly bright with anemic bass. Thus a house curve will have response gradually rising as it descends to the lower frequencies.
Dialing in the right curve is the tricky part. Rooms of different sizes need different slopes; smaller rooms need steeper slopes than larger rooms. A bedroom theater set-up compared to one set up in a family room open to other areas in the house is a couple of typical small vs. large home scenarios.
Hereâ€™s a method that worked well for me in the place I used to live (havenâ€™t had time to tweak my system yet in our new place). It was very musical (i.e, sounded balanced and accurate) yet gave enough impact for movies to vibrate the sofa. :D Other people have told me they like this method, too. Try it and see if works for you.
What you need do is first get your sub response reasonably flat. Then play a couple of sine wave test tones, one at 100 Hz, the other at 32 Hz. With measured flat response, the 100 Hz tone will sound louder than 32 Hz. Boost the 32 Hz tone until it sounds
like itâ€™s the same volume level as the 100 Hz tone. Then as much as possible, EQ for a straight line between the two. I prefer to shelve response below 32 Hz. I tried keeping the slope going below that point, but everything sounded unnaturally boomy.
Itâ€™s not a bad idea to take the Fletcher-Munson phenomenon into consideration, in that you want to dial in your house curve at your usual listening volume. If you set it for a higher volume than you normally listen too, then it will probably sound bass-shy when you turn things down. The inverse is true if you house-curve for too low a level.
Wayne A. Pflughaupt