Here is one of the main threads that has a lot of info on our products...
How many arms do I need?
Here is the lowdown as best as I can explain it without you having the earphone models in your ears.... Before I explain how many armatures you need. Let's go over some terms first:
IEM or IE = In Ear Monitor - this is usually a professional level earphone that is customized to fit your ear canals. The performer will use these to minimize stage volumes, so they can work for more than 10 years without losing your hearing. With lower volumes it is easier for them to control what they want to hear in the monitor mix thus saving their hearing. Now the performer can stay on pitch and keep good timing.
PM = Personal Monitors, earphones with armatures
Headphones or HP = General description for all types
Earbuds = Similar to the Apple headphones with Moving coil transducers inside
Entry Level PM's.......... use a simple balanced armature. The challenge the engineer has primarily rests in the balance armature design itself, the damper and the nozzle design. This is a very difficult task to make full range since the transducer will work well in the LF or the HF but not generally wideband. Typically the Bass, Vocals or Drums suffer the most with this design, sounding slightly harsh or not having any output that is audible in that range. In other words the vocal sounds throaty or scratchy depending on the model. There is also limited SPL with this design due to being a single arm design. Even with these disadvantages it sounds better than any moving coil design that I have heard since the mass of the diaphragm is much less the HF is much more accurate than a standard earbud with a moving coil. Custom 1 has been optimized to give the best balance of LF and HF. This design uses a KG332 armature.
Mid Level PM's............ use either premium single armatures that are usually smaller or dual armatures with minimal or no EQ. Each product has its limitations.
For Klipsch's IMAGE PM a premium armature is used which is a proprietary KG926 driver. The KG926 is ultra compact. Less weight generally means more comfort because there is less force on the ear canal. This model has "special sauce" which I can't go into, due to its proprietary nature, but it is very full range with delicate high's and smooth deep bass. The sound is very accurate due to its light weight diaphragm and the multiple levels of treatment to the design. Generally speaking people will have a hard time complaining about this design. It is easy to use and sounds very accurate. Vocals are silky smooth and drums have a nice snap to them. You can not believe your ears...a product this size sounding this full! The primary limitation is that it is small so you must have a good air seal or you will loose bass. The way we have minimized this problem is by making the chassis micro small with a thin aluminum extruded body or chassis. This small diameter allows the armature to get closer to your eardrum than all of the others models out there. Precision machining is required to make this model, and the design is complicated to get correct due to its size. The patent pending eartip also insures a better seal since it is similar to the shape of your ear.
Another type of mid level design is using dual armatures similar to our Custom 2. In the Custom 2 design we have partnered with Sonion and have applied for a patent on this armature, so I can talk about some of the details. The KG534 driver is really two drivers i.e. two motors two armatures and two diaphragms that are tandem (back to back). The benefit of this design is that the diaphragms pump air in opposing directions so any vibration modes are minimized. Think of this similar to dual air bellows on your fireplace with a single nozzle. When you have dual diaphragms your SPL increases by 3 dB and your distortion goes down because it is not working as hard. Part of our applied patent evolves around the low pass acoustic filter that is built into one of the two armatures. This give Klipsch greater control over the EQ since we can have two pistons, one optimized for bass and one optimized for full range. This baby rocks! Musicians will love this product because it is portable yet very efficient. Your vocals will stand out in the mix as an IEM application.
High Level PM's...............use two or three armatures and a passive crossover. Our Custom 3 goes much further. Not only does it have two different types of drivers and a passive crossover it also has a patent pending low pass acoustic filter. The Custom 3 utilizes a Klipsch KG723 for the HF tweeter which is a premium armature. This allows the vocals to be ultra silky and very low in distortion. The LF is implemented by a KG732 armature for the LF woofer. The Custom 3 has TWO low pass filters the armature has an internal LP filter plus an additional.... you guessed.... patent pending LP filter on the outside which is optimized for a very low crossover point in such a small chassis without sacrificing sensitivity in the low region of the response. This bad boy has it all! Looks! Comfort! And Concert Level Sound! The passive crossover has 5 components more than any other in its league. With the two acoustic filters and a second order crossover, the LF has a 24 dB per octave rolled off at 1 kHz. Why so low? Everyone else seems to crossover above the vocal region but we wanted to eliminate Intermodulation Distortion (IMD) so we have removed the kick drum and bass tones from the tweeter so the diaphragm can concentrate on silky highs without movement from the LF signal. This also allows us to take advantage of the shape of the crossover for additional EQ in the midrange. The vocals are so natural that this high end IEM won't fatigue your ears like most designs can. But my favorite part is the BASS. I use to have a regional touring pro sound system for live performance applications. I had eight 18 inch 1000 watt drivers just for the subs, so I don't have to tell you how much I can appreciate good clean bass. Image hearing headphones flat BELOW the musical bandwidth. There is no limitation to the bass. I just wish it would shake my pant legs like my pro system did. I encourage everyone to try this product before the buy any other. You will find that the money was well spent.
So what type of HP do you need? You will have to be the judge, but you will need to keep in mind that there is a reason why there is large range of prices. The number of arms does make a difference for the IE headphone family.
Why don't you stick it in your ears!