Harmonica Construction

Harmonica Construction and its Effects on Sound and Feel

Harmonica Construction and its Effects on Sound and Feel

The harmonica isn’t a particularly complicated instrument, especially in diatonic form: essentially it’s not much more than two sets of vibrating reeds, a comb and a pair of metal cover plates. This apparent simplicity does, however, belie a wealth of differences between specific models and manufacturers. Let’s take a look at some of these differences and their effects on the sound and feel of the instrument.

Recessed or Sandwiched Comb

Take a look at Hohner’s current Marine Band 1896 Classic and compare it to a Marine Band from 50 or 75 years ago. They don’t look very different, do they? Sure, there are small variations in the the type of wood used for the comb (peachwood was eventually replaced with pearwood) and the cover plate material (nickel plated mild steel versus stainless steel), but the overall design, with two reed plates sandwiching a wood comb, with the edges of the plates exposed, is essentially identical. And this is the way all diatonic harmonicas were constructed for many years. Then, along came the Hohner Special 20, and everything changed.

The main innovation featured on the Special 20 is the injection moulded comb. This makes it completely swell resistant, but, perhaps more importantly, allows for greater manipulation of the shape of the comb than can be achieved with wood. This opened up the possibility of recessing the reed plates into the comb itself, resulting in a much smoother mouthpiece than traditional sandwich style harmonicas. In practical terms, this makes it easier to move quickly around the harmonica, with less irritation of the lips and, as a beneficial side effect, allows the harmonica to be more beard-friendly.

Of course, some players dispute the validity of these benefits; a quick search on any of the main harmonica forums will yield plenty of comments from players extolling the virtues of sandwich harps, and decrying those who claim that they’re harder or less comfortable to play. From a personal point of view, I do find the smooth surface of a Special 20 or Session Steel to be much quicker than, say, a Marine Band, but this can be partially obviated by disassembly of the harp, followed by careful positioning of the reed plates so that they are more flush with the comb. As ever, you pay your money and…you know the rest.

Vents or no Vents

Side vents on the cover plates are a feature of many harmonicas, including the Hohner Marine Band and Big River and the Suzuki Manji. In theory, they should allow more acoustic volume, but this is somewhat debatable; a quick, and wholly unscientific test with a Fender Blues Deville, a noise meter and some tape to block the side vents, revealed that there was very little difference in volume with them blocked or open. However, it does appear to have a small influence on tone: with the vents open the harmonica was brighter; with closed the vents it had a more muted, darker tone.

Of course, it’s possible to block and unblock the vents with your hands whilst playing, which you could argue makes a vented harmonica more appealing, as it provides the player with more potential to add colour to their performance. However, some players – especially those with smaller hands – may find this technique difficult or impossible. My advice is to try both types and see whether you have a preference.

Comb Material

I’ve already covered comb material in a previous post, which you can find here, but it’s worth summarising some of the findings from that article. In short, alloy combs are brighter, unsealed pearwood combs have what many players would describe as the ‘best’ sound, albeit with the attendant disadvantages of the wood swelling, and plastic sits somewhere in the middle.

Ultimately, comb material has a fairly small influence on overall tone; the reeds, and, most significantly, the player, will have a far greater effect on the final sound than whether it is fitted with a wood, alloy or plastic comb.


Unlike combs and cover plates, there’s a fairly small range of materials that are suitable for producing reeds with. Most manufacturers use brass, although Suzuki, and some of the more expensive harps from Chinese manufacturers such as Easttop, use phosphor bronze, and Seydel uses stainless steel for all but a small number of its harmonicas.

There is plenty of (often conflicting) anecdotal evidence about the relative advantages and disadvantages of specific reed materials, but few hard facts. In my experience, having sold thousands of harmonicas from all of the major players, phosphor bronze and stainless steel reeds usually last longer than brass reeds. I say ‘usually’, because there will always be a story on the harp forums of one player who blew out a stainless steel or phosphor bronze reed in the first two minutes of using their new harp. The moral here, is that some players just ask too much of their instrument too quickly, and no currently available material will be a panacea for that sort of abuse.

Tone differences are less debatable; stainless steel reeds are usually brighter sounding than brass, with phosphor bronze sitting somewhere in the middle.

As ever, try a few harps out and see which ones best fit your own personal preferences.

Jonathan Prestidge


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