Number of drivers in IEM: Is more better? - Page 2

I think that more drivers CAN equal better sound, but they don't always. Take the JH-13s and JH-16s, who are highly favored by many people. I believe that iems with large numbers of drivers are, in fact, held back by their passive crossovers. We will see if this is true once the JH-3A arrives.

Quote:

Originally Posted by roy_jones 

 

I am very curious to hear why we've seen a steady movement to more drivers if there isn't an associated improvement.  

 

Someone should mention the 800-pound gorilla in the room: MARKETING.

It's much easier to sell features like "more drivers" when, to all intents and purposes, there is no spec-driven way to differentiate among most acrylic-shell BA designs other than sensitivity.

[Edit: LOL@xpost...]

I think anything more than 3 drivers is just overkill - in fact, 3 drivers is plenty. Lows, mids, highs - what more could you ask for?

For example, many people consider the EM3 to be among the best IEMs out there. Sleek Audio did an excellent parody of this on April Fools' Day, as I'm sure we're all aware. (Rhyme not intended.)

Marketing is huge.

But, in terms of performance, the 3-driver UE IERM has been very well reviewed. It definitely seems to not only compete, but to beat 6 and 8 driver designs in its stated use as a professional reference monitor.

Shigzeo, a longtime reviewer, really liked the ACS T1, a 3 driver design.

Many who have compared the 5-driver ES5 like it better than the 6 driver jh13 and 8 driver jh16.

I found the dynamic driver (that's a single moving coil driver) FS MG6Pro did far better than an 8-driver JH16 demo in terms of realistic production of sound--something which likely won't really be improved by eliminating phase problems.

Of course, at this level custom, personal preference and intended use should play an important role. Number of drivers definitely don't seem to give better sound, although there is plenty of hype.

Quote:

Originally Posted by Kunlun 

I found the dynamic driver (that's a single moving coil driver) FS MG6Pro did far better than an 8-driver JH16 demo in terms of realistic production of sound--something which likely won't really be improved by eliminating phase problems.

 

Of course, at this level custom, personal preference and intended use should play an important role. Number of drivers definitely don't seem to give better sound, although there is plenty of hype.

On a tangential point, moving coil drivers require more space than BA's, right? It's my understanding that this requirement resulted in the IE8 having a vented design, which allows for a natural sound when left open, and oddly sterile when closed (e.g. with my fingers). 

If my understanding is correct, then more BAs might be necessary to approximate/emulate the natural sound of a dynamic driver?

Quote:

Originally Posted by Eric_C 

On a tangential point, moving coil drivers require more space than BA's, right? It's my understanding that this requirement resulted in the IE8 having a vented design, which allows for a natural sound when left open, and oddly sterile when closed (e.g. with my fingers). 

 

If my understanding is correct, then more BAs might be necessary to approximate/emulate the natural sound of a dynamic driver?

No, it's not about size. I'm not an expert, so take this a grain of salt. However, it's not the space that leads to a vented design. Rather, all dynamics are vented in one way or another and for the same reason that low frequency speakers are usually vented. This has to do with the air pressure wave generated as the diaphragm of the dynamic vibrates. A vent ends up allowing for better low frequency response. In fact, this is true even for a BA to some degree as some manufacturers are using vented BA's in vented housing designs for slightly better while others are strangely using a vented BA in a closed off housing for reasons that don't really make much sense.

Hopefully an engineer can explain it better, but it's NOT that you need to have lots of little BAs to make the same size as a dynamic and it won't all fit so they have to have a hole in the housing... hope that helps at least inspire you to ask someone more knowledgeable than me about it!

Quote:

Originally Posted by Uncle Erik 

Roy, a big reason more drivers are used is marketing. To most consumers, more equals better. It's like Gillette and their razor blades. What are they up to now, five? I just use one, and it's better. Don't fall for marketing gimmicks.

Of course, razors are not headphones. But the marketing trick is the same. This is also why car manufacturers can sell a 4x4 to someone who only drives it on asphalt.

IEMs aside, there's been a longstanding discussion of multiple drivers in speakers. A good 50 years.

The problem is that crossovers are very, very tricky to get right. So is driver matching, phasing, delivering sufficient power to each driver, and many other difficult engineering problems. There's a huge amount of research and testing behind these issues, as well. Jack (above) is completely right.

Minaturization is also a huge problem. One of my projects is a Linkwitz Orion3. It's a 3-way speaker, but Dr. Linkwitz really tackled the crossover and power problem. It requires an outboard active crossover in a standard case. Then the crossover feeds eight amplifier channels which are directly connected to the drivers. Not your typical solution, but it solves the issues of having multiple drivers and is one of the best-regarded systems available at any price.

If you have anything that demonstrates that more is always better, go ahead and post it. Just how do you keep all those drivers in phase? How do you design a crossover network so the drivers work together seamlessly without smearing into each other and keeping volume at a consistent level? How do you make sure that each driver receives sufficient power to operate through it's entire range? These, and many others, are real engineering problems. Adding more drivers only makes the engineering more complex. The more complex something is, the more unintended consequences appear.

Finally, Jack's point about points of failure is excellent. Reliability is everything.

There's no question that marketing plays a significant role.  I think it's important to do a better job of outlining the terms of the argument.  For example, obviously the presumption is that we're restricting the conversation to balanced armatures.  Also, if you read Kunlun's post, you'll see that counterexamples are being offered to suggest that not always does more drivers translate into better sound.  I have no problem with the softer form of that argument. 

The problem, though, is that in general, over a period of many years, we've seen a movement towards an increased number of drivers.  While some of these counterexamples, like the UERM, do seem to offer competitive performance with fewer drivers, the problem is that they still use more than one driver.  Why doesn't the UERM use a single driver, if there isn't any inherent advantage to more than one?  It's a reductio ad absurdum argument. 

I've got no problem with people applying skepticism to audio claims- I'm very much a skeptic myself.  This doesn't appear to me to be a convincing case of audio hype, though.  We've seen a clear progression over a period of many years that seems to confirm that performance has been increased by higher numbers of drivers. 

Quote:

Originally Posted by roy_jones 

There's no question that marketing plays a significant role.  I think it's important to do a better job of outlining the terms of the argument.  For example, obviously the presumption is that we're restricting the conversation to balanced armatures.  Also, if you read Kunlun's post, you'll see that counterexamples are being offered to suggest that not always does more drivers translate into better sound.  I have no problem with the softer form of that argument. 

 

The problem, though, is that in general, over a period of many years, we've seen a movement towards an increased number of drivers.  While some of these counterexamples, like the UERM, do seem to offer competitive performance with fewer drivers, the problem is that they still use more than one driver.  Why doesn't the UERM use a single driver, if there isn't any inherent advantage to more than one?  It's a reductio ad absurdum argument. 

 

I've got no problem with people applying skepticism to audio claims- I'm very much a skeptic myself.  This doesn't appear to me to be a convincing case of audio hype, though.  We've seen a clear progression over a period of many years that seems to confirm that performance has been increased by higher numbers of drivers. 

 

Yes, it's good to outline the terms of the discussion. In terms of saying that there is a clear progression for BA customs, could you help me understand that a bit better? As I understand it three driver customs have been around quite a while. Maybe they were two way crossover designs, now they are three way. Still, look at ASC T1, the UE IERM, Sensaphonics (I think these might even be 2 way crossovers still), these are still top tier. So, maybe in the past we've gone from early two driver designs to three driver to....today's three driver top tier designs? Of course, I'm not saying that more than 3 can't be good or any such thing, just that the three driver models compete and have evolved from three driver models which have been around quite a while. So, I'm not sure about a progression in terms of performance, however, I'm interested in your thoughts on it.

 

The customs world seems to be advancing.  There are 2 8 BA customs, the well known 3-way JH16 and the LS8, which is 4-way.  The theory, from what I have gathered from the manufactures is that 2 drivers covering the same frequency spectrum allows each driver to move less, improving the performance.  Why even use more than one BA?  I am sure everyone on this thread knows that a single BA can usually doesn't reproduce the entire spectrum at the same time very well.  The ER4 is an example of that not being true, but there are more examples where it is true, at least at this time.

Speaking of crossovers, there are 1st order and 2nd order, with a 1st order rolling off at 6 dB per octave while a 2nd order rolls off at 12 dB per octave.  Both have their strengths and weaknesses.  

I will be posting my experiences with a breadth of customs, including the JH16 and LS8 among many others, including my 2-way 3 BA EM3 Pro.

I would have to agree that, at least at this point, more drivers don't necessarily mean better above a certain point.  

Quote:

Originally Posted by freealloc 

My theory: there's no room for inductors and no power (or room) for active components. So, you're stuck with RC filters for the crossovers. Additionally, the driver impedance it pretty small (not compared to drivers-- just small in general). Therefore, there are tight restrictions on the magnitude of resistors that can be used to prevent excessive loading. As a result, you're stuck with really crappy, low order filters. The more drivers involved, the smaller of a section of the spectrum each filter will need to cover. Since you can't increase the order of the filters much, they'll just interfere more.

End result-- a pretty crappy overall system. I would imagine going from one to two driver is beneficial. Two to three, maybe. Beyond that, you're probably just shooting yourself in the foot.

Agree with this 100%.

I can see some benefit from one to two, as having one driver to handle bass and another to do the mids and highs makes sense to me. Most single driver BAs are bass deficient, with only the X10 really standing out to me as a good single driver BA with lovely bass. 

Two to three I am not so sure, even the Triple.Fi 10 which I liked uses just one driver for mids and highs and two for bass, I don't really see the need. Four and up, I honestly don't see the point. 
 

damn joe.. how is the wife handling all that expenditure?

Quote:

Originally Posted by roy_jones 

The problem, though, is that in general, over a period of many years, we've seen a movement towards an increased number of drivers.  While some of these counterexamples, like the UERM, do seem to offer competitive performance with fewer drivers, the problem is that they still use more than one driver.  Why doesn't the UERM use a single driver, if there isn't any inherent advantage to more than one?  It's a reductio ad absurdum argument. 

 

 

Quote:

Originally Posted by average_joe 

The theory, from what I have gathered from the manufactures is that 2 drivers covering the same frequency spectrum allows each driver to move less, improving the performance.  Why even use more than one BA?  I am sure everyone on this thread knows that a single BA can usually doesn't reproduce the entire spectrum at the same time very well.  The ER4 is an example of that not being true, but there are more examples where it is true, at least at this time.

 

roy_jones: My understanding of BA's mirrors what average_joe has said here. A single BA cannot as efficiently cover the full frequency range, so sharing the load helps--up to a point.

Quote:

Originally Posted by Kunlun 

 

No, it's not about size. I'm not an expert, so take this a grain of salt. However, it's not the space that leads to a vented design. Rather, all dynamics are vented in one way or another and for the same reason that low frequency speakers are usually vented. This has to do with the air pressure wave generated as the diaphragm of the dynamic vibrates. A vent ends up allowing for better low frequency response. In fact, this is true even for a BA to some degree as some manufacturers are using vented BA's in vented housing designs for slightly better while others are strangely using a vented BA in a closed off housing for reasons that don't really make much sense.

 

Hopefully an engineer can explain it better, but it's NOT that you need to have lots of little BAs to make the same size as a dynamic and it won't all fit so they have to have a hole in the housing... hope that helps at least inspire you to ask someone more knowledgeable than me about it!

 

Thanks for explaining, Kunlun. However, I think you misunderstood me slightly: I wasn't comparing the size of BA drivers to dynamic drivers at all. When I mentioned "space requirements", I was referring to the chamber where the driver is housed, and whether a dynamic driver needed a larger chamber than a BA to recreate a natural sound. Nonetheless your explanation has helped dispel some of the mystery around drivers, thanks.

I used to a huge proponent to a single driver, such as the ER4P

But now after listening to different multi-driver designs....  the ER4P is no longer "top shelf" choice for me.