Car Audio Midrange Explained: Location, Airspace and Tune
The midrange plays the vocal range, so it shapes how clear voices sound and how high the stage (the apparent position of the band in front of you) sits. Peter Steinbacher of Pssound calls it "the most important part of the system". His core idea is to give it its own driver, mount it high with nothing in its path and free air behind it, and make sure it plays low enough to hand over cleanly to the midbass (the driver below it).
The short version
The midrange plays most of the vocal range, so it belongs up high at ear height, not low in the door.
Peter's favourite spot is on top of the dash near the windscreen, though good pillar builds also work.
Every cone midrange needs open airspace behind it and a very rigid mount.
A dash midrange can't play much below about 100–120 Hz, so a 4" is enough for most cars.
The lower the midbass sits, the lower and more capable the midrange must be.
Set the crossover by how loud you listen, and use EQ (turning frequencies up or down) to cut the 200–500 Hz bump.
Skip dome midranges, and fix location and airspace before buying a dearer driver.
Why the midrange belongs up high
Voices sound clear when the midrange sits near ear height with nothing in its way. Think of a cinema or TV: the sound comes from eye level, not the floor.
The usual 2-way puts a midbass low in the door and a tweeter in the A-pillar (the post beside the windscreen) or sail panel (the small trim panel by the wing mirror), and Peter says the midrange gets sacrificed. A mid low in the door is playing onto your leg: move your leg and the balance and image shift. The stage also sits low, with dips and gaps in the response. No tuning or EQ makes it as good as a mid placed high, where nothing is in its path (watch).
Low mids can still give a high centre image, but left and right sag a little (the rainbow effect).
Stereo assumes about 60° of spread, not 120°, so pillar and dash positions give enough width.
To stay 2-way, put a wideband (one driver covering midrange and treble) up top instead of the usual tweeter, played from 200–400 Hz upward. The alternative, a door midbass stretching up to 2–3 kHz or higher, is full of compromises (watch).
Dash or pillar: where Peter puts the midrange
Peter's preferred spot is on top of the dash, close to the windscreen, using the glass reflection to your advantage. It gives the mid a controlled environment and a stable, realistic stage. His advice is to make the windscreen work: if your car has a mid location up there, try it first (watch).
The usual objection is that the windscreen will ruin the sound. Peter replies that pillar mids cause even more problems, harder to fix, while a properly tuned and measured dash mid can sound fantastic. He has said he would always put a midrange, especially a larger one, on the dash over a pillar build. The stage may feel narrower, but the extra distance makes the image more believable (watch).
His practical choice has shifted. In 2020 he called a dash build one of the easiest jobs once you have done a few. By 2024 he chose pillars for a BMW G21 3 Series, because a dash midrange is a much bigger modification and pillars are easy to change back to factory (watch).
Pillars still work when pulling the dash isn't worth it, but check the space behind the trim first: Peter rejected them in a Vectra with under an inch of depth and an airbag behind.
Getting a dash midrange to work
A dash mid reaches you twice: direct, and bounced off the windscreen. Where the two meet you get comb filtering (a pattern of peaks and dips in the response). With a good location and aim it plays well up to about 1.5–2 kHz; above that, sometimes from 1 kHz, it gets messy unless you measure, tune and EQ well.
Distance matters more than aim. Peter says aiming a dash mid doesn't make a big difference; the gap between windscreen and speaker centre does. Push it as far into the corner as you can, though one dropped in flat will work fine (watch).
The Amarok lesson. Steg MSS3 mids in a simple trim ring on a VW Amarok's dash were a struggle to tune because of comb filtering. Peter spent a day measuring, then 3D-printed a temporary mount that put them much closer to the windscreen, and that alone fixed it (watch).
Width. Dash mids can give a narrow stage, especially on the driver's side, because the A-pillar line runs to about the middle of the mid. In a BMW X3 the pillar trim was redesigned to disappear there, putting each mid roughly 2" further out (watch).
No sealed box needed. Peter says dash mids don't need a sealed enclosure (a Steg MSS3 plays under the dash with no box at all), and if you build one it must be big enough not to suffocate the driver.
Building pillar mids: airspace, rigidity and aim
Pillars can be a very solid mounting for a midrange, as long as the driver gets room to breathe. Leave the back open so it vents down behind the trim into the cavity under the dash, with plenty of room all round and no long tube behind it.
The classic mistake is building onto the trim and leaving only a small hole for the speaker cable. A 3–4" mid then breathes into roughly 0.3–0.4 L, is suffocated, won't play low and shows a big peak from about 300 to 600 Hz (watch).
Chamfer (bevel) the back of the mounting ring (watch). A basket sits 10–15 mm behind the mounting face, so a thick baffle (about ¾", or 19 mm) wraps around it and restricts airflow, and no EQ fixes that.
Build it rigid. Clean lower midrange comes from solid mounting, not just equipment. Pssound's pillars are thick, deadened on the back and about 1.5 kg each, because a mid playing down to 200 Hz feeds vibration into the pillar (watch).
Mind the size. A 4" vanishes on a dash but looks extortionately big in most pillars once you add the ring and airspace, and a 6.5" in an A-pillar is pointless because a 4" does the same job.
Aim matters less than for tweeters. A mid only has to play up to where the tweeter takes over, so crossed well below its beaming point (where high notes narrow into a tight beam) it can sit well off axis. A Golf Mk8's pillar mids, crossed at around 3–4 kHz, do exactly that (watch). A tweeterless wideband is different: keep it within about 20° of on-axis.
How big a midrange, and how low it must play
In 2017–18 Peter built 12.5 L enclosures on his Honda's dash for 6.5" drivers, hoping to play midbass up there. From that corner you can't really play below about 100 Hz, while the same driver low in a door or a box plays down to 30–40 Hz (watch). Enclosing them didn't help, so a dash mid stops at about 100–120 Hz whatever its size and needs a separate midbass or front woofer below it (see our midbass guide).
Bigger doesn't buy bass: a 3–5" dash mid rolls off below about 150–200 Hz, where the target response (the curve you tune towards) should keep rising, and more EQ can't rescue a struggling driver.
Keep dash mids to 4", or 5" at most. Peter says a 4" does pretty much everything you need in a car, especially if you don't compete (watch).
The lower the midbass sits, the lower and more capable the mid must be. Under-seat midbass can't be played high, so small mids can't integrate with it, which is why BMW fits a 4" in the door (watch).
His view moved here. In 2022 he told a 3 Series owner a 3" pillar mid can't meet under-seat midbass, but the 2024 G21 got 4" pillar mids, which should play low enough.
Crossovers and EQ for the midrange
Set the crossover (the filter that decides which notes each driver plays) by how loud you listen, not by where the driver comes alive. At competition levels (85–90 dB) a low crossover does no harm. At about 95 dB maximum, or 100 dB peaks, you could cross a small 3" as low as about 250 Hz. For 110–115 dB peaks with electronic or rock music played full tilt, cross it higher (watch).
Not every wideband can go low. Micro Precision 5-series mids and some Stegs can be crossed at 170–200 Hz at loud sound-quality levels, but the Scan-Speak 10F wants nothing below about 250 Hz, preferably 300 Hz.
Expect a lower-midrange hump. Speakers up on the pillars or dash get a lot of boost between 200 and 500 Hz, so a peak of about 9 dB on pillar mids is normal and worth cutting with EQ (watch). Once that boost is cut by 6–8 dB, a 3" crossed at about 200 Hz (24 dB/oct slope) hardly sees any power between 150 and 300 Hz.
A narrow cancellation (here 520–600 Hz) can't be fixed with DSP but is acceptable; a full-octave hole (400–800 Hz) would be a huge issue. For the general rules, see our crossover, EQ and time alignment guide.
Widebands, domes and choosing a driver
A wideband is one driver that covers the midrange and the top end, in sizes from 2" to 7". Peter says it often covers the top as well as a tweeter does, and some of the best competition cars run them tweeterless, including a European who has won the Euro Finals six or seven times with widebands in the dash corners. Even so, he says it is always better to have a tweeter.
Know where a wideband breaks up (where the cone stops moving as one piece and the top end turns ragged). The Steg MS30 3" breaks up at about 19 kHz, essentially out of the audible range, since most people can't hear above 16–17 kHz. Most widebands break up at about 14–15 kHz, which gives a fake-sounding top end (watch). It matters less when a tweeter takes over.
Skip dome midranges. They are very dynamic from 700–800 Hz to 4–5 kHz, but can't play low enough, and a door midbass falls apart from about 300 Hz up, so a dome leaves a gap you can't really sort out (watch).
Location and tune beat price. Peter says a midrange needs only to be installed right, put in the right location and tuned until it plays its range without distortion, so don't assume a dearer driver is the fix.
The Steg MSS3 (4") is Pssound's usual choice for the dash. It plays low, takes a lot of power and, he says, not one has ever failed (watch). Pssound's shop lists it at £599. His favourite midrange is the Accuton C100 AM, a 91 dB reference he calls very musical.
Common mistakes to avoid
Leaving the midrange low in the door and hoping EQ will make up for it.
Building a pillar pod with only a small hole behind it, which suffocates the driver.
Using a thick baffle, a long tube behind the driver or a tiny sealed box, or mounting the mid on something flimsy.
Expecting a bigger driver on the dash to give you more bass.
Pairing a small mid with a midbass that can't play high, or choosing a dome mid.
Crossing the mid as low as it will go without thinking about how loud you listen.
Buying a dearer driver before you have fixed the location, airspace and tune.
Watch Peter explain it
This is an independent, plain-English summary of Peter Steinbacher's public YouTube videos, written by VA3 Car Studio. It is not affiliated with or endorsed by Pssound. The links jump to the moment in each video where he makes the point.
Part of our series: Car audio lessons from Pssound, start here
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