[SaazerSpalt]

Hello! I’m new here, but it seemed like a great place to potentially educate myself on a complicated topic I’m curious about. Recently, I’ve been trying to decide between the new ThieAudio Hype 4 and the Xenns Mangird Top. Taking a look at the frequency response graphs, they’re extremely similar, almost identical until the upper mids and treble and even there it’s not exactly a dramatic difference: https://squig.link/?share=Harman_Adjusted_Target,Xenns_Mangird_Top,ThieAudio_Hype_4



Yet despite how similar they are, no one is claiming they sound the same, even in frequency ranges where they appear almost identical. The consensus seems to be that the Hype 4, for example, has a more controlled, better quality bass than the Top. That’s the most prominent example where the language is the most consistent, I’m having trouble pinning down as definitively how they compare in other ranges (and opinions seem outright contradictory in some cases), but my point is I wonder if these differences come down to driver types and amounts, that perhaps when frequency response is so similar the individual qualities of the drivers used becomes more apparent.



The Hype 4 has two dynamic drivers and four balanced armatures, while the Top has a single DD and 8 BAs. While I’m happy to take any subjective personal experience with either of these IEMs to help me make a decision, the primary motivation for me posting this wall of text is to possibly learn more about drivers and how they might affect sound. What’s the benefit of having a whopping 8 BAs compared to 4 or 2? Using these two sets as examples, how, theoretically or actually, might the Top’s 8 BAs have an advantage over the Hype’s 4? Does the double DD in the Hype affect more than just the bass, or do they literally only produce sound for specific frequencies? Neither of these sets have electrostatic drivers, but their more expensive counterparts the Monarch Mk3 and the Xenns UP do, what qualities to they contribute to the sound profile?



Apologies for the huge amount of text, brevity is not my strong suit but I appreciate your patience with me. I’m just trying to learn about something I find fascinating, and as well as satisfying my curiosity I suspect it may help me become a better informed consumer when I get stuck between deciding between products like I am now. I don’t have anyplace near me where I can demo products in person, so all my purchases have been blind buys based on weeks of reading reviews and hearing opinions. So far it hasn’t bit me, but this is my first foray into this price bracket so details they didn’t matter as much when I was spending $40 are feeling more important now.

 

[Waxletter]

Alright! Finally something up my alley!

So, the likely reason for this trend in your research is due to the limitations behind driver tech, particularly BA drivers. BA drivers are pretty old tech, and were used a lot back in the old old days of headphones and speakers, but they had some serious frequency limitations, and couldn't cover the whole range of sound you expect to get out of audio tech today. This is why IEMs need a LOT of BAs to cover the full frequency range (although there are a few models that use very little iirc). Dynamic drivers are much better at presenting bass, and that's probably the reason why the Hype 4 is being rated higher in that category. So the difference here is likely that while there are enough drivers to fill out the frequency range in the Top, they might not be replicating the bass at the same resolution. It could also have something to do with their location in the IEM housing. Maybe the sound isn't getting in as well as it could?

Anyways, to sum it up, dynamic drivers tend to be better with bass than BAs, which need to compensate for their issues with high quantity.

As for electrostatic drivers, they're just generally more precise and "even" compared to other drivers. Dynamics can push out sound pretty well, but they still have issues mixing both high and low frequencies out of a curved diaphragm. Electrostats (or "condenser") drivers have a level of sensitivity and precision that nothing short of the best planar-magnetics can hope to replicate, but are very expensive, which explains why only higher-end models would have that tech.

Here's a Handy List of Drivers:

• Moving Iron (OLD / OBSOLETE) - Moves a thin ferrous disc using magnets. Seriously lacking in detail and range, and only used in headphones designed for high impedance radios.
• Balanced Armature - Moves a rod using a compact mechanism. Lacks range, and only used in IEMs nowadays.
• Inductor (OLD / OBSOLETE) Uses a complicated self-entangled mechanism to move a rod. Made to compensate for issues with Moving Iron and Balanced Armature, but lacked treble, producing a very distinct vintage sound. The salt to Piezoelectric's pepper.
• Dynamic / Moving Coil - Most common type. Pulls on a curved diaphragm using a magnet and coil. Produces a clear, natural sound, especially when using biocellulose.
• Electrostatic - Moves an incredibly thin mylar sheet between two stators. Arguably the best driver, but incredibly expensive and mostly locked to dedicated home setups.
• Orthodynamic (OLD) - A replication of electrostatic tech made in the 70s and 80s using magnets and thin metallic sheets. Uses a circular, porous, wafer shape for its stators. The contemporary equivalent to this is typically square, so I count it as a separate type. Not made anymore, but definitely holds up to current standards.
• Planar-Magnetic / Isodynamic - The contemporary successor to orthodynamic, typically used in larger, more open housings with a square sheet and bar-shaped stators.
• Piezoelectric (OLD / OBSOLETE? ) - Shocks an electric-sensitive crystal to produce sound. Incredibly high impedance, and sees little contemporary use. Not completely obsolete though, every once in a while some rogue company will release a headphone or IEM incorporating this driver. Primary issue other than impedance is an intense, unamendable bass dropoff. The pepper to Inductor's salt.
• Air Motion Transformer (AMT) - Uses a magnetic, accordion-esque sheet with vertical folds.
• Ribbon - Uses a magnetic, accordion-esque sheet with horizontal folds.

The only ones with key weaknesses here are Moving Iron, BA, Inductor, and Piezoelectric. The other drivers on this list can handle a full frequency range pretty well.

 

[SaazerSpalt]

Alright! Finally something up my alley!

So, the likely reason for this trend in your research is due to the limitations behind driver tech, particularly BA drivers. BA drivers are pretty old tech, and were used a lot back in the old old days of headphones and speakers, but they had some serious frequency limitations, and couldn't cover the whole range of sound you expect to get out of audio tech today. This is why IEMs need a LOT of BAs to cover the full frequency range (although there are a few models that use very little iirc). Dynamic drivers are much better at presenting bass, and that's probably the reason why the Hype 4 is being rated higher in that category. So the difference here is likely that while there are enough drivers to fill out the frequency range in the Top, they might not be replicating the bass at the same resolution. It could also have something to do with their location in the IEM housing. Maybe the sound isn't getting in as well as it could?

Anyways, to sum it up, dynamic drivers tend to be better with bass than BAs, which need to compensate for their issues with high quantity.

As for electrostatic drivers, they're just generally more precise and "even" compared to other drivers. Dynamics can push out sound pretty well, but they still have issues mixing both high and low frequencies out of a curved diaphragm. Electrostats (or "condenser") drivers have a level of sensitivity and precision that nothing short of the best planar-magnetics can hope to replicate, but are very expensive, which explains why only higher-end models would have that tech.

Here's a Handy List of Drivers:

• Moving Iron (OLD / OBSOLETE) - Moves a thin ferrous disc using magnets. Seriously lacking in detail and range, and only used in headphones designed for high impedance radios.
• Balanced Armature - Moves a rod using a compact mechanism. Lacks range, and only used in IEMs nowadays.
• Inductor (OLD / OBSOLETE) Uses a complicated self-entangled mechanism to move a rod. Made to compensate for issues with Moving Iron and Balanced Armature, but lacked treble, producing a very distinct vintage sound. The salt to Piezoelectric's pepper.
• Dynamic / Moving Coil - Most common type. Produces a clear, natural sound, especially when using biocellulose.
• Electrostatic - Moves an incredibly thin mylar sheet between two stators. Arguably the best driver, but incredibly expensive and mostly locked to dedicated home setups.
• Orthodynamic (OLD) - A replication of electrostatic tech made in the 70s and 80s using magnets and thin metallic sheets. Uses a circular, porous, wafer shape for its stators. The contemporary equivalent to this is typically square, so I count it as a separate type. Not made anymore, but definitely holds up to current standards.
• Planar-Magnetic / Isodynamic - The contemporary successor to orthodynamic, typically used in larger, more open housings with a square sheet and bar-shaped stators.
• Piezoelectric (OLD / OBSOLETE? ) - Shocks an electric-sensitive crystal to produce sound. Incredibly high impedance, and sees little contemporary use. Not completely obsolete though, every once in a while some rogue company will release a headphone or IEM incorporating this driver. Primary issue other than impedance is an intense, unamendable bass dropoff. The pepper to Inductor's salt.
• Air Motion Transformer (AMT) - Uses a magnetic, accordion-esque sheet with vertical folds.
• Ribbon - Uses a magnetic, accordion-esque sheet with horizontal folds.

The only ones with key weaknesses here are Moving Iron, BA, Inductor, and Piezoelectric. The other drivers on this list can handle a full frequency range pretty well.

Oh wow thanks so much for all the info! I sincerely find this stuff so interesting, and I appreciate you listing out the driver types and how they work. I hear so much of these terms and had so little context for what it actually meant. It sounds almost as if BA drivers are sort of a “yeah it’s old tech but we don’t have better options for this application” when it comes to IEMs. Do they have strengths compared to dynamic drivers or is it more of a cost or size thing that keeps them in use?

A sort of side question that might sound sort of dumb, but I’ve noticed in IEMs that use exclusively BA drivers they are often “unvented”, something that form my experience is never the case when any other driver type is involved. Do some drivers not work properly if there’s pressure changes inside the ear canal?

Thanks again for all the info, I love learning new things and I appreciate you taking the time to write that response!

 

[Waxletter]

Oh wow thanks so much for all the info! I sincerely find this stuff so interesting, and I appreciate you listing out the driver types and how they work. I hear so much of these terms and had so little context for what it actually meant. It sounds almost as if BA drivers are sort of a “yeah it’s old tech but we don’t have better options for this application” when it comes to IEMs. Do they have strengths compared to dynamic drivers or is it more of a cost or size thing that keeps them in use?

A sort of side question that might sound sort of dumb, but I’ve noticed in IEMs that use exclusively BA drivers they are often “unvented”, something that form my experience is never the case when any other driver type is involved. Do some drivers not work properly if there’s pressure changes inside the ear canal?

Thanks again for all the info, I love learning new things and I appreciate you taking the time to write that response!

No problem! I've been wanting to make a post about driver types for a while now, and this was the perfect opportunity!

As for your questions, I believe the reason for their high use in IEMS is mostly due to size and efficiency. They can cover a lot of different frequencies if you have enough, and are much smaller than other options. And I found a post on the hybrid IEM thread that could explain the "vent" question.

My understanding is all hybrids are ported somehow. Or, at least I haven't seen a hybrid that isn't ported (my experience is limited though). All the ones I've seen tend to have the port on the front face of the IEM. It's not for pressure relief AFAIK; that's the concept behind stuff like the ADEL and APEX modules by companies like 64 Audio. The ports on hybrid IEMs are usually there because of the dynamic driver. Dynamic drivers need more air to move in order to work better because of how they function. BA units are much more self-contained; they don't need ports because they work differently from a standard dynamic driver. Dynamic drivers are cones and the whole cone moves in order to push and pull air to make sound waves. BA units have a very small piece of material that vibrate over a hole to cause the movements in air and as such, they need a lot less air to create sound compared to dynamic drivers.

Read up on basic working structures of dynamic drivers and balanced armature drivers written by people way smarter than I am. You'll get a better understanding of why dynamic and hybrid IEMs have ports for the dynamic driver, no matter how unnoticeable.