Speakers

Sealed versus ported#

Some people think I hate ported speakers. I don't. I love ported speakers. Just not in the studio. In a sub they are fantastic because you get extremely powerful bass and the time domain drawbacks are totally dwarfed by the large reverberant rooms.

In a studio, time domain is more critical.

A sealed speaker with a gentle, low-Q roll-off is generally more accurate in the time domain than a ported one, but at the cost of naturally less powerful bass.

A passive radiator is a port in disguise: an unpowered cone wobbling in sympathy with the box. Some shops even list those as sealed monitors but they have more or less the same effect on the sound.

You can easily see the time domain issues on waterfall plots. Something sealed like an NS10 is fast across its whole range. Small ported monitors often show significant resonances below 100 Hz. In some of the worst cases the ringing at 50 Hz could last half a second or even longer, which is hilariously bad for studio use.

You can hear the port in an ordinary room#

The usual objection is that port ringing is too short to hear and the room dominates anyway. This is correct in a club but I would argue not the case in a well treated studio room when some small ported speakers can ring in the bass for half a second.

So I recorded speakers in a normal studio room: same room, same mic, same position, no EQ. Radiohead's "Feral" has a short, precise kick/bass groove. Through my sealed speakers it goes "boom-b". Through a ruler-flat ported speaker it goes "boom boom". At least to my ears, it's a different groove. To me the severity of this colouration is on par with that of a low bit-rate MP3 VS the original.

Hearing time-domain faults takes ear training, and as a mastering engineer I'm especially sensitive to it.

A flat chart does not mean clean timing#

Frequency and time are two sides of the same coin. Anything you do in one has knock-on effects in the other. The manufacturer's published frequency response chart is performed at one SPL in an anechoic chamber. With ports and passive radiators the linearity depends on SPL, so it changes when you turn the monitor knob, with the dynamics of every note. Correcting the frequency response to become ruler flat with DSP doesn't give you a clean time domain.

Small speakers are compromised by physics#

Cabinet size is inversely related to the Q of the low-frequency resonance, so a big, well-damped box tends to roll off smoothly and a smaller one can ring.

Pretty much every trick for getting bass out of a small box trades accuracy for extension. Ports ring. High-excursion drivers add suspension, harmonic and intermodulation distortion, which is why high-end designers tend to want low excursion. EQ just makes the sweep look flat. So the market is full of small ported speakers. It's not necessarily nefarious, it's just not optimal.

Small boxes are cheaper to build, ship and warehouse, and buyers tend to pick the speaker which sounds more bassy. The manufacturers understand the cost, physics and buyer psychology extremely well.

NS10s and Auratones are not bad speakers#

Many professionals use them because their midrange timing and distortion are excellent, and hearing less low end makes them less dependent on the room. Amateurs often dismiss them because there's not much bass. In my personal opinion a speaker that rolls off naturally and focuses on the mids may even have the edge over a ruler-flat one for mixing. A good sealed speaker works for any genre, from post-hardcore to vomit step, although electronic sub-bass heavy music may still need a sub or pair of headphones along side them.

"Nearfield" is a listening position, not a type of speaker. An NS10 can work as a midfield.

All good studio monitors sound the same#

Two flat, sealed speakers sound essentially the same. The mid-dome version of my DIY three-way was near-identical to a Neumann KH310, the industry-standard sealed three-way, without being EQ-matched to it. Both were just designed flat. (Neumann lent me a demo pair.)

The only fair comparison is level-matched recordings from the same position. Otherwise you can't separate the speaker from the room. Placement matters hugely too: a desk can add comb filtering and resonances, and on stands in a decent room good speakers come very close to the digital source.

DIY speakers#

Commercial prices carry shipping and distribution. With DSP plate amps the crossover is software, and specialist driver shops have the rest, so mastering-grade speakers are possible for under two grand. That's a cheat code when it replaces 80 grand mastering speakers, but not necessarily a hack when you could just buy a four-grand pair of KH310s. This is why I didn't make an online course for my Hypex + mid dome version of my 3-way speakers, and I only promoted the 500 euro - 700 dollar per pair passive version which requires a bit more effort to solder the crossover.

Cheap, well-measuring Class D amps drive passive speakers fine. More information on my approach and specific speaker builds can be found in my Speaker Building courses.