[az2123]

I've been wondering a lot about this recently - in the Grado world, it seems that metal-wood hybrid > wood > metal > plastic, at least in regards to price and perceived luxury. Does this have any real correspondence with SQ?
 
String instruments are made with wood and brass instruments, metal - so there are clearly important acoustic properties. However, many expensive headphones are made with plastic (top of the line Beyers, Senns, AKG, Ultrasone), and plastic didn't exist when violins/trumpets were first created. I'm not saying that plastic violins/trumpets would be superior, but musical instruments are very different from electronic reproduction, where neutrality is preferred.
 
In my mind, the most perfect headphone would be two headphone drivers magically suspended in the air, a centimeter from my ears. However, since we can't do that and must accept coloring of some kind, what exact properties of wood/metal/plastic affect the sound?
 
I'm posting in Sound Science, because I'm hoping someone familiar with material and acoustic engineering can clarify with regards to scientific measurable effects like resonance, rigidity etc. If you're gonna tell me about the time you bought $200 lacquered exotic woodied cups and how that "totally opened up the sound"... I'm not sure what to say.

 

[az2123]

Btw, I am aware of previous similar threads, but haven't really been satisfied
 
http://www.head-fi.org/t/249081/plastic-metal-or-wood-grados
http://www.head-fi.org/t/143511/wood-metal-plastics-the-best-material-for-housing-a-driver
http://www.head-fi.org/t/174895/wood

 

[Br777]

unfortunately i dont have anything sciency to add, but i can say that in my bass playing heydays, i demo'd a LOT of bass guitars, and rarely if ever found a synthetic material to sound as good as a wood instrument.  of course some of that is personal taste, but there is certainly something to be said about the acoustic properties of wood being unique, and not easily if at all reproducable with synthetic materials. 
 
the way sound waves are bounced or absorbed, or cause resonance with any two different materials is going to make a difference, no matter if wood is involved or not. 
 
I actually wonder a lot just how much wood or, non wood contributes to the sound of headpones too.  will be interested to see where this discussion goes.

 

[Uncle Erik]

It depends on the manufacturer. Some test designs extensively and use the best material for the job.

Others tart up old designs with wood and metal to give the appearance of luxury.

And sound isn't everything in the audio world. People buy according to fashion and assume that beautiful and expensive gear sounds "better." After all, something that costs that much must sound good. Right? If it's finished so nicely, then they must have put just as much effort into the sound. Right? The manufacturer is so friendly, helpful and attentive that there is no way the product is a tarted up old design. Right?

Caveat emptor.

The audio market makes used car salesmen look like Mother Teresa.

 

[MaciekN]

Theoretically materials can be sorted by their density, stiffness, probably speed of sound in given material does also play a role. Under these criteria there are materials superior to any wood, like carbon fiber, yet they don't sound as good, or, offer a different tune. There is a reason why building a good guitar or violin is an art, it is more a matter of experience than science, the way to combine different types of materials not to mention shapes. Picking up certain material is just another way to tune the sound in a certain direction.
 
As for plastic and high-end headphones, keep in mind that many of them are open-backed, with small or no air chambers, so the impact of the material is minimal, at least compared to closed-back designs. Denon, Audio Technica and, if I remember well, top Ultrasones all use wooden chambers in their closed high-end headphones. And as for your ideal model of headphone, you've more or less described AKG K1000.

 

[Iniamyen]

The design goal is to have a certain sound at the listener's ear. This "certain sound" is different between headphones, but it's determined by the designers, and they accomplish it partially by whatever material(s) they choose to make the headphones out of. There are many design decisions and you could probably get extremely different sounds using the same materials, and likewise similar sounds using different materials. I don't think there is an end-all "inherent sound" to any type of material when there are SO many other headphone design decisions at play (transducer type/placement, headphone shape, backing, etc...)

 

[wnmnkh]

Quote:

I've been wondering a lot about this recently - in the Grado world, it seems that metal-wood hybrid > wood > metal > plastic, at least in regards to price and perceived luxury. Does this have any real correspondence with SQ?
 
String instruments are made with wood and brass instruments, metal - so there are clearly important acoustic properties. However, many expensive headphones are made with plastic (top of the line Beyers, Senns, AKG, Ultrasone), and plastic didn't exist when violins/trumpets were first created. I'm not saying that plastic violins/trumpets would be superior, but musical instruments are very different from electronic reproduction, where neutrality is preferred.
 
In my mind, the most perfect headphone would be two headphone drivers magically suspended in the air, a centimeter from my ears. However, since we can't do that and must accept coloring of some kind, what exact properties of wood/metal/plastic affect the sound?
 
I'm posting in Sound Science, because I'm hoping someone familiar with material and acoustic engineering can clarify with regards to scientific measurable effects like resonance, rigidity etc. If you're gonna tell me about the time you bought $200 lacquered exotic woodied cups and how that "totally opened up the sound"... I'm not sure what to say.

 
God, this post remind me one member here whined about HD800 being plastic. It was so sad and embarrassing enough that made my face red.
 
 
The purpose of materials used in instruments (which 'produce' sound) and those used in audio playback devices (which 'reproduce' sound) are different.
 
 
 
Please pay attention to bold words. "Produce" and "Reproduce" have rather completely different meanings. You see, wood, brass and some other chosen materials are selected in instruments because they react to various physical forces (from vibration, airflow friction, brute force, etc) and make interesting sound based on their properties.
 
 
But for playback devices, the main purpose of materials containing transducers is prevent unwanted sound from the transducers (because they cannot physically perfectly transfer electronic signal into physical sound wave.) So, for speakers and headphones, we have to deal with enclosures/damping materials. For the purpose, materials with good acoustic absorption and highly resonance-resistant are highly desired for the job.
 
 
Now, the trick is "good acoustic absorption and highly resonance-resistant" materials do not have to be super expensive and super hard-to-find materials (and of course, super pretty materials like wood.) If what those 'hi-fi' audio makers' claims are true, then we should see those top studio monitor makers using various exotic woods for their products for the best accurate sound. But they still use plain boring black plastic (for a good reason, of course.)
 
 
Really, simply put, makers use wood/leather/-insert super expensive material here- because they are quite pretty and attract customers. Regardless of what those folks claim, there are few reasons to use such materials to make proper audio playback devices.
 
 
 
Plus : Not to mention, due to the nature of physics, no materials absorb all sound energy and stop resonance completely. Thus, using fewer materials possible is usually ideal because fewer the materials used, less coloration introduced by the materials. This is why open headphones are usually much better sounding ones compared to closed headphones at same price.
 

 

[dhruvmeena96]

Ok....it depends on psychoacoustic effects, reflection and action reaction of certain material...


Wood is not so great thats why its great....due to irregular pore design, density etc.. It colours the sound, but in a way that it sounds tonal to people plus fue to pores have large surface area increasing soundstage and sub bass.


Metal on other hand avoid colouration on mids and bass, but deeply colour treble....because metal density is high so it avoids shaking colouration....but it reflects thing back to your driver....where treble goes harsh


Plastic is perfect balance between these two


If you want best sound, buddy start modding

Dynamat extreme and paxmate are your best buddy

 

[Koei]

I don't know how it is for headphones, but for speakers it does matter. You don't want material that resonates. That's why most speakers are made from MDF covered with something to make it look pretty (pure wood isn't as good). There are also some speakers made from concrete because of this reason. The main disadvantage of those? They weigh a fuxkton. Plastic isn't solid enough and it would be hard to make a speaker that way. Metal would resonate at certain frequencies (not to sure), would have internal reflections and it would be incredibly hard to make.

 

[Digitalis]

   
String instruments are made with wood and brass instruments, metal - so there are clearly important acoustic properties. However, many expensive headphones are made with plastic (top of the line Beyers, Senns, AKG, Ultrasone), and plastic didn't exist when violins/trumpets were first created. I'm not saying that plastic violins/trumpets would be superior, but musical instruments are very different from electronic reproduction, where neutrality is preferred.

As a musician I'll take the opportunity to elaborate on this - Musical instruments have changed a lot over the past 500 years. For instance: the Violin body construction used today is made to pretty exacting standards. In fact: pretty much all modern violins are carbon copies of Antonio Stradivarius instruments. But none of them sound quite like original instruments made by him due the to composition of the varnish and resins he used - the materials he used have been lost in time, also as the varnish ages the degree of polymerization interactions between the varnish fixes to the wood affects sound. The strings used for older instruments were different from modern materials - Violin strings used to be made of catgut, now they are made of nylon and silver. Carbon fibre is also becoming popular body material for cellos and double bass instruments due to its light weight and strength.
 
Now Brass instruments - a lot of them aren't made of actual brass anymore, cheaper instruments are nickel, and plated with either brass, gold or silver. Some professional instruments are made of solid brass with heavy gold plate - some components are even solid gold. Flutes are also made of exotic materials, Silver, Brittania silver, aumurite, 9K Gold ~ 24K gold, Titanium, Aluminium,Tin, Platinum, Iridium, Carbon Fibre, exotic dalbergia hardwoods - there is considerable debate among musicians over whether these materials actually make any difference to the sound. Oboes, Clarinets and Bassoons have changed over the years, clarinettists use crystal reeds, oboists and bassoonists are using crystal reeds too. Though many prefer to make hand made reeds from cane that can be customized for their instrument and bring out its character. Oboes like other woodwind instruments have been made of different materials, solid silver, thermoplastics,various hardwoods, and even glass. But for various and assorted reasons Grenadilla hardwood remains the most common material used.
 
Pianos have changed too, in the time of Beethoven the piano had a softer sound - you could play the Moonlight sonata without using the sustain pedal - you can't do that on a modern piano without having dissonances from each chord shatter the atmosphere of the work. This is due to the fact the modern piano are so well designed acoustically the strings remain vibrating for much longer than they did on classical era instruments. Strings of the piano are also under more tension, modern tuning has seen to that: there is about 20 tons of pressure exerted by the strings on the frame of a modern piano.  Also Classical era pianos had wood frames: modern pianos have cast iron frames. The design of the piano key action is more precise and efficient..pitch has changed: in the time of Bach, musicians used to tune to the A from the towns pipe organ: which could be anywhere between A=405 to A=433. Modern pitch is A=440 cycles per second - though even this "standard" is creeping upwards, the last flute I bought was built to A=444.
 
In my subjective opinion:  metal speaker drivers are the best material for speaker driver design - since instruments from guitars to the thunderous tone of a 32' pedal note on a pipe organ to the crash of a cymbal all have, at some point metal involved in creating/shaping the sound. In order to reproduce that sound with any degree of authenticity, paper driver cones or composite plastics and paper/silk dome tweeters are going to colour sound drastically compared to metal coned woofers and metal tweeters.

 

[Roseval]

Those old Strads are horrible
http://www.thestrad.com/blind-tested-soloists-unable-to-tell-stradivarius-violins-from-modern-instruments/

 

[Digitalis]

As an Addendum to my post I will point out that recordings of the human voice are still subject to the qualities of metal, gold sputtered Mylar diaphragms are commonly used in microphones - ribbon mics with microscopically thin metal elements are seeing a resurgence in popularity. I personally use a ribbon mic as the pickup pattern and high frequency rolloff are desirable with higher pitched woodwind instruments.

 

[gregorio]

@Digitalis - Unfortunately, you are confusing the acoustic properties of metal with it's electrical/conductance properties. Furthermore, the subjective opinion part of your first post makes no sense. According to your logic, in order to reproduce the sound of say wood instruments "with any degree of authenticity" then shouldn't the drivers be made of wood?

G

 

[Digitalis]

I made no mention of the electrical properties of metal,and that isn't what I'm saying at all here.

I'm suggesting that a sound wave created through metal/and interactions with metal will be reproduced with greater fidelity by a metal driver cone - as the acoustic properties, and harmonic frequency distribution is likely to be a better match than non-metallic materials.

There are speaker drivers that are made of wood: albeit in a refined form known as Alpha cellulose, or paper, has been commonly used for driver cones for decades. However paper has issues with mechanical rigidity* and sonic non-linearity and outright phase inversions when used for high frequency reproduction over 3Khz - Metals such as Beryllium and Titanium have superior acoustic characteristics in this range**.

I am inclined to agree that well designed paper driver cones have properties that are more favorable at lower frequencies [ 1.5khz~150hz] to metal ones regarding cone break up and driver resonance characteristics - to counter this argument: a properly designed speaker cabinet and crossover network can mitigate these issues with the appropriate crossover order and driver specific crossover point. At lower frequencies [150~20hz] paper has rigidity issues and is outperformed by lighter and structurally stronger materials such as polymers and metals. Most of the subwoofers I have heard with paper cones tended to sound rather dull and flabby.

*polymer dopants have been used to improve mechanical rigidity, the problem is that use of these add mass to the driver and reduce its capacity to produce higher frequencies and can interfere with the linearity of the driver.
** AFAIK neither metals are used in ribbon tweeters, and are a bit outside my experience. The ribbon Microphone i use is fitted with a machined corrugated aluminum element in it, I can only assume similar materials are used in ribbon tweeters.

 

[bigshot]

Acoustically, there shouldn't be much difference at all between materials as long as they are hard and reflect sound roughly the same. In antique phonos with horns, a metal horn sounds pretty much identical to a wood horn. The shape of the horn is more important than what it's made of.