Speaker test for bottom end (10-200 Hz)

Hi. Just found this, seems very useful but I’d like to hear what others think before rushing to judgement. For me, the revealing thing about it is how you can hear the room booming at particular frequencies - precisely where the holes in all our mixes are, no doubt…

http://www.cheaplaptopspeakers.info/low-frequency-response-and-subwoofer-test.html

Oh cool, I’m gonna try that. I already know that the wooden covers on the backside of my room resonate at 46Hz, I tried that a while ago :sunglasses:

The problem with the test in the OP is that you don’t know exactly where you’re at. I would be better to have a sine generator app with a sweepable knob and frequency read out. I’ve just had a look but surprisingly no luck so does anyone know of anything?

My physics teacher used to have one, no idea where you’d get that from. I’m sure you can download single frequency samples though, that’d do the trick.

-edit- After some googling I found this: Function Generator
I haven’t tried it though, if it’s malware don’t blame me :wink:

-edit2- works a charm :sunglasses:

:open_mouth: Judging by the ear-bashing I’ve just given myself I’d say that my room is tuned to A. That’s not so good for recording a guitar in. Plenty of resonance around 300 too, which is also nsg. Might be time to move house.

Thanks for the link, Strophoid.

Hi, Folks!

In the bass frequencies being discussed (10-200Hz), it is very likely that room resonances are the primary culprit formed by the distances between floor, ceiling, and walls. Getting much of anything solid below about 50 Hz is rare indeed, without doing what I did: built a basement room with sand filled concrete block walls, reinforced poured concrete floor, and very dense ceiling (lead sheet with 2 layers of wallboard on “floating” joists with no other connections to the floor above).

However, as you go up in frequencies above 100 Hz, sometimes moving about just a few feet, even in a small room, can make a big difference as the room resonances generally produce what are referred to as “standing waves” where peaks and dips are created at specific locations within the room. If you don’t have the tools to sort it all out, experimentation is the general alternative. However, if you have WL or some tool that has a pink noise generator and spectrum analyzer along with a reasonably decent condenser microphone and preamplifier, you can run a relatively moderate volume of pink noise through your playback system from a CD, and by moving the mic around and watching the spectrum analyzer, you can find locations that are reasonably flat (probably about +/- 6 to 10 dB at best). Smooth out the peaks and dips in the low end as best you can, and you just may be able to find a “happy medium” for frequency balance without resorting to sound panels, heavy draperies, bass traps, or playing in a quiet, vacant field outdoors! :open_mouth:

If you have the time and a bit of patience, you may find several “sweet spots” which sound pretty decent for various instruments and vocals. Mark 'em off with gaffer’s tape or something that will provide an “X” mark for the various spots.

Hope this helps!

Dear Southae, thank you for this very learned treatment. My room is 5m sq x 3 high, which puts it right in bass territory, so not much I can do without moving. Even moving about is a bit of a problem (furniture). And I don’t think my landlord would approve of your remedy (or my bank manager for that matter)!

I’ve also got this horrible, clangy echo, which I could probably deal with using drapes or strategically-places foam pads but never have as I’ve been intending to move for years now…

Did you try those utilities mentioned above? Do you think they’ll give a fair assessment?

Thanks for the mic tip, I’ll give that a try sometime.

Cheers,
Crotchety

PS: Sounds like you’ve built yourself a Bridgewater Hall there, mate!

This VST FX package includes also test generator capable of creating frequency sweeps: http://mda.smartelectronix.com/effects.htm

I’ve already got those but overlooked the TestTone so thanks, Jarno.