Speaker/Cabinet Resonance

[BbAltered]

My studio monitors are an old pair of m-Audio 6" powered speakers. Most of what happens in the studio is me practicing my digital keyboard (Roland rd-2k); less frequently I work on original projects and more rarely still I am recording someone.

 

As I practice, I am noticing the notes around high-Bb to high-high C sound louder and more prominent than surrounding notes. This seems to be true regardless of what patch I am playing. I suspect this occurs because those notes excite resonant frequencies in the speaker cabinet, and so stand out more.

 

Question: is there something else that might be going on to make those particular notes stand out? I don't think it is a problem of the audio samples in the keyboard - I hear the same notes standing out regardless of what patch I am playing.

 

The speakers themselves are positioned about 18 inches from a wall, and about 7 feet from the nearest room corner. The room itself is about 30 feet square with a fairly low 8 foot ceiling. When playing the keyboard, I am positioned a little off the center of the room.

 

More importantly, is there anything I can do to tame the loud notes? I would prefer not to have to buy new speakers or buy a lot of room treatments. Because this is bothering me mostly when playing the keyboard - and not when doing critical mixing duties (I don't have a whole lot of critical mixing duties to do) - my inclination is to not spend a lot on this particular problem and just live with it if the fix is expensive or complicated.

 

So I guess I am asking if anyone has any inexpensive and easy things I can do to temper notes I hear standing out. Thanks

[Mike Rivers]

Well, not all musical instruments are perfect. Guitarists and Bassists learn where notes stick out and play them a little softer.

 

It's indeed possible, though, that the frequency response of your speakers makes them more sensitive to that range so they come out louder. It's not out of the question that there's something acoustic going on due to the positioning of the speakers. You could try relocating them temporarily and see if those notes still bloom. Don't look too hard for the spec sheet for your speakers. If it has a frequency response plot at all, it probably looks very flat.

[KuruPrionz]

First, plug in some decent headphones and listen to your keyboard directly. No peaks? Then it probably isn't the keyboard. Peaks but in a different frequency? Both your headphones and your speakers/room have problems.

 

I added the room because 2 things can happen in a room. The bass notes can be uneven and peak or they can be uneven and null out with the notes that are not nulling out being louder.

 

If the speakers are the problem then you should notice peaks in the same frequencies playing any music that has those frequencies.

 

You could also try a different keyboard and see if you get the same results.

 

I didn't learn much from algebra but "remove the variables" has served me well time and time again.

[BbAltered]

Thanks guys - you have provided some useful inexpensive and easy things to try: re-position the speakers; re-position my playing position in the room; try using headphones; try some other playback audio. Now I'm excited to try these things out.

[Chip McDonald]

Does the keyboard have a master eq section on it?

 

I also think you can modify the tone of each note individually on that keyboard. And Roland may have baked-in a curve to "make sure it cuts through the mix" on the lower registers.

[Anderton]

Depending on how loud you're playing the speakers, they could be exciting resonances in the room, not just the cabs. Play some recorded material through the speakers, and move around the room...see if the peaks remain.

 

If the problem is indeed the speakers, then you can insert a filter to flatten things in your master out. I use the Sonarworks Reference ID system, and it makes a difference. It's a little pricey if you don't have a reference mic, but if you have an iPhone, download a sound level meter program, like SPLnFFT (unfortunately, Android phones vary sufficiently that sound level meter apps aren't as accurate). Run some pink noise through your speakers, see if there are some peaks, and EQ to compensate. It's not an ideal solution if the problem is the room, because if you change your position in the room, the EQ won't be as effective.

 

Even if the problem is the speakers, anything you can do to the room will be advantageous. I don't think 18 inches from the wall is far enough, unless the materials are really dead behind the speakers. I have my speakers set up at about the 1/3 point of the room, so there's plenty of space behind them. They're also equidistant from the right and left sides, which helps. I need to get some bass traps, but otherwise, it's not bad.

[The Real MC]

No one mentioned the composition of the speaker cabinet? Wood? Polymer?

 

Polymer cabinets can have weird resonances that vary with volume. Polymer gets weaker with age, more resonance problems.

 

Wood is less vulnerable but not 100% free of resonances.

 

You mention these are old monitors. The foam surrounds on the speakers can degrade over time, that also contributes to frequency problems. I had to replace the speakers on my JBL Control-5 monitors after 20 years.

 

Cloth-impregnated foam surrounds last a lot longer.