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Home-Made IEMs - Page 8

post #106 of 2204
Thread Starter 
Quote:
Originally Posted by Billyk View Post
Have you considered any type of vacuum molding?
By this I mean placing the mold in a vacuum and drawing the plastic into it from outside the vacuum. It is fairly straightforward.
Quote:
Originally Posted by sugrhigh View Post
Vacuum molding is indeed a god send in many situations!
And, it can be done relatively cheap with a shop-vac, some scrap wood, and plastic+mold
My son, Billy (who, ironically is also known as BillyK) keeps suggesting I go that route. I'm going to have to give it another look.
post #107 of 2204
Quote:
Originally Posted by Bilavideo View Post
My son, Billy (who, ironically is also known as BillyK) keeps suggesting I go that route. I'm going to have to give it another look.
It really is a good method the only problem is if the bottom of the mold is contoured...
post #108 of 2204
Thread Starter 
Quote:
Originally Posted by sugrhigh View Post
It really is a good method the only problem is if the bottom of the mold is contoured...
I don't think that will be a problem with earphone shells.
post #109 of 2204
Thread Starter 
Okay, I'm finally home. I have to unload a van full of my sister's stuff and sell some earphones I'd advertized in the For Sale section. Then I'll be ready to start putting things together. I have the drivers, wire, filters and tubing. The only elements missing are the caps (which are coming) and the shells.
post #110 of 2204
Thread Starter 
In the "knowledge is power" department, I ran into KA's "Acoustic Interface Design Guide" online at: http://www.digikey.com/Web%20Export/...esignguide.pdf

For those trying to make sense of KA's offerings, this is a nice little guide. Here's how KA distinguishes its various driver lines:

TWFK SERIES – Dual Balanced Armature Speaker 5.00 x 2.73 x 3.86 (mm)The world’s smallest dual balanced armature speaker, the TWFK is designed for pro-audio in-ear applications. Enables customized cross-over systems to achieve target frequency response in a package size smaller than the ED Series
•Single sound port for simplified earphone design
•Extreme wideband frequency response
•Unique woofer/tweeter combination
•Enables leading-edge earphone designs for size and performance

WBFK SERIES – Wideband Balanced Armature Speaker 5.00 x 2.73 x 1.93 (mm). Same package size as FK Series, WBFK has extended high frequency response. It is recommended as a high frequency component to be combined with low/midrange speaker for music earphones.
•Lower low/mid-band sensitivity compared to FK Series
Best high frequency response of any Knowles element
•Combine with low/mid-range speaker forextended frequency response
TWFK pairs WBFK with low frequency FK

FK SERIES – Balanced Armature Speaker 5.00 x 2.73 x 1.93 (mm). The world’s smallest balanced-armature speaker, the FK Series is designed for applications where size is the most important design concern.
•114dB SPL maximum output
•Two-terminal zero-bias configuration
•Undamped, screen damped, and internally damped responses
•Wide range of coil impedances

FH SERIES – Balanced Armature Speaker 5.09 x 2.80 x 2.59 (mm). The FH speaker represents an unprecedented combination of ultra-compact size and high SPL output with efficiencies normally found only in much larger speakers. The FH speaker line brings true high-gain, high-output performance to earphone designs.
•Undamped, screen damped, internally damped, and Ferrofluid™damped responses
•Various port locations, coil impedances, damping options, termination configurations, and frequency responses available
•Maximum SPL output of 123dB at resonance peak, 109dB at midband (500Hz)*

WBHC SERIES – Balanced Armature Speaker 5.16 x 3.51 x 3.00 (mm). The advanced design of the HC Series speaker provides extended acoustic bandwidth for hi-fi in-ear speakers when paired with a low frequency speaker.
•Lower low/mid band sensitivity compared to HC series
•Combine with low/mid-range speaker for extended frequency response

HC SERIES – Balanced Armature Speaker 5.16 x 3.51 x 3.00 (mm). Knowles balanced-armature, magnetic technology to give high efficiency, stability and reliability. HC Series provides increased low frequency dynamic range in a package size equal to FC.
High-output technology provides double (+3dB) the maximum acoustic output of existing Knowles FC Series speakers
•Maximum output comparable to Knowles’ ED Series speakerin a package size only 68% as large!
•Same size and dimensions as Knowles’ EH Series
•Ideal for applications where small size and high output is required.

FC SERIES – Balanced Armature Speaker 5.18 x 3.55 x 3.00 (mm). FC Series receivers may be used for small radio communication earphones where ED size does meet package requirements. Rounded corners make it slightly smallercompared to EH Series speakers.
•Available in High-Output HC receiver version
•Two-terminal zero-bias and three-terminal center-tapped configurations
•Undamped, screen damped, internally damped, andFerrofluid™ damped responses
•Rounded corners for improved fit rates; 10% smaller cross-sectioncompared to EH speaker

EH SERIES – Balanced Armature Speaker 5.19 x 3.55 x 3.00 (mm). EH Series speakers are approximately 2/3 the size of ED speakers and may be used for small radio communication earphones where ED size does not meet package requirements.
•Balanced-armature, magnetic technology to give high efficiency,stability and reliability
•High sensitivity
•Various responses, including standard, damped and modified
•Low distortion
•Self-shielded for low magnetic radiation

ES SERIES – Balanced Armature Amplified Speaker 5.18 x 3.54 x 3.04 (mm). EH size speaker with integrated Class D power amplifier
•EH micro speaker, but with internal, highly-efficient, class D amplifier
•Lower current drain prolongs battery life
•Lower distortion
•Available in a range of SPL ratings

EP SERIES – Balanced Armature Amplified Speaker 6.32 x 4.29 x 2.99 (mm). Based on Knowles’ versatile and popular ED speaker, the EP series adds the benefits of an internal Class-D amplifier. Its compact size and appreciable output power make the EP speaker suitable for a variety of designs
•Class D amplified magnetic speaker
•Self-shielded to reduce magnetic radiation
•125dB SPL maximum output
•Three-terminal electrical connection

FED SERIES – Balanced Armature Speaker 6.32 x 4.31 x 2.47 (mm). The addition of ferro fluid to Knowles ED series speakers improves mechanical shock survival and provides peak damping to smooth frequency response.
•Ferrofluid damped with 2dB, 4dB, or 6dB peak amplitude
•Superior shock performance and reduced speaker vibration
•Two-terminal zero-bias and three-terminal center-tapped configurations
•Numerous port locations and coil impedances

ED SERIES – Balanced Armature Speaker 6.32 x 4.31 x 2.97 (mm). One of Knowles’ most versatile and most popular speakers, its compact size and appreciable output power make the ED speaker suitable for a variety of instruments.
•Undamped, screen damped, internally damped, and Ferrofluid™damped responses
•Numerous port locations and coil impedances
•High efficiency and low distortion

EC SERIES – Balanced Armature Speaker 7.57 x 4.31 x 3.67 (mm). EC Series receivers are commonly used in isolating earphones for radio communication.
•Similar SPL output to the BK Series
•Rounded corners on the face opposite the terminal pad
•34% smaller volume than the BK Series

TEC SERIES – Balanced Armature Speaker 7.87 x 4.09 x 2.79 (mm). The TEC combines output comparable to the larger BK speaker in an ultra-thin package. The TEC is suitable for multi-element earphone designs.
•Ultra-thin
•Wideband output
•DTEC combines two TEC elements
•Enables small multi-element designs

DTEC SERIES – Balanced Armature Speaker 7.87 x 4.09 x 5.59 (mm). The DTEC Series combines two TEC speaker elements with a single round port. Case size is equivalent to BK/EF. DTEC provides increased output and reduced vibration compared to a single speaker.
•Dual elements with single sound port
•More output than BK in equal package size
•Reduced vibration compared to BK
•Improved frequency response compared to BK

BK SERIES – Balanced Armature Speaker 7.87 x 5.59 x 4.01 (mm). BK Series speakers provide broadband performance at value pricing. They are commonly used for full range in-ear speakers and communications utilizing an earplug design
•High efficiency and low distortion
•Various port locations, coil impedances, damping options,terminal configurations, and frequency responses available.

CM SERIES – Balanced Armature Speaker 8.38 x 16.64 DIA (mm). The CM Series delivers the benefits of balanced armature technology in a compact finishedpackage. The CM is ideal for use in situations where a non-contacting headset is required, but signal voltage is limited – as is common for radios and wireless telephones. The CM also conserves battery power, and provides static shock protection for the user.
•Balanced-armature, magnetic technology to give high efficiency,stability and reliability
•High acoustic efficiency enables sufficient sound output even when limited power is available
•In-built static protection
•Lightweight, matt-black, plastic housing
•Ergonomically designed with rounded edge to fit the concha
•High-quality sound output
•Tailored bandwidth for superb speech intelligibility

SR SERIES – Balanced Armature Speaker 8.84 DIA x 5.00 (mm)At 8.8mm diameter, the SR is the first round balanced armature speaker in the marketplace. SR offers output equivalent to the BK series and maximizes bass performance.
•Round package facilitates earphone designs
Drop-in upgrade for moving coil dynamic speakers
•Designed for high volume production
•Balanced armature technology

CI SERIES – Balanced Armature Speaker 9.47 x 7.18 x 4.10 (mm). Knowles’ largest and most powerful speaker, the CI series is the speaker of choice. With its high efficiency and a 143dB SPL maximum output, the CI speaker provides optimal low frequency performance.
•Two-terminal zero-bias and three-terminalcenter-tapped configurations
•Various port locations, coil impedances, termination configurations, and frequencyresponses available

MR SERIES – Waterproof Speaker 22.12 DIA x 9.3 (mm). The MR Series Assemblies consist of a speaker element attached to a waterproof bellows assembly. They may be panel mounted, and are suitable for outdoor use or repeated submersion.
•Highly waterproof – no loss of performance after immersion in 15m water
•Corrosion resistant
•Withstands explosive decompression
•Design proven in rugged environments
•Leads attached
•High resistance to mechanical shock
•Acoustically transparent bellows
•Resists effects of mud, sand, and salt encrustation

CB SERIES – Balanced Armature Speaker 25.15 x 25.15 x 9.65 (mm). The CB Series Transceiver offers high electro-acoustic efficiency to conserve power in push-to-talk radio handsets and other battery operated equipment. The CB is available with mounting pins to facilitate assembly to a PC board. Model CB-23817-000 is designed to survive submersion in water.
•Excellent sound quality
•High speech intelligibility, stability, and reliability
•Suitable for PCB mounting
•Can function as a microphone or beeper
•Various impedances
•Face and edge port locations available
post #111 of 2204
Thread Starter 
BILL'S PICKS OF THE LITTER

TWFK SERIES – Dual Balanced Armature Speaker 5.00 x 2.73 x 3.86 (mm)The world’s smallest dual balanced armature speaker, the TWFK is designed for pro-audio in-ear applications. Enables customized cross-over systems to achieve target frequency response in a package size smaller than the ED Series
•Single sound port for simplified earphone design
•Extreme wideband frequency response
•Unique woofer/tweeter combination
•Enables leading-edge earphone designs for size and performance

WBFK SERIES – Wideband Balanced Armature Speaker 5.00 x 2.73 x 1.93 (mm). Same package size as FK Series, WBFK has extended high frequency response. It is recommended as a high frequency component to be combined with low/midrange speaker for music earphones.
•Lower low/mid-band sensitivity compared to FK Series
Best high frequency response of any Knowles element
•Combine with low/mid-range speaker forextended frequency response
TWFK pairs WBFK with low frequency FK

SR SERIES – Balanced Armature Speaker 8.84 DIA x 5.00 (mm)At 8.8mm diameter, the SR is the first round balanced armature speaker in the marketplace. SR offers output equivalent to the BK series and maximizes bass performance.
•Round package facilitates earphone designs
Drop-in upgrade for moving coil dynamic speakers
•Designed for high volume production
•Balanced armature technology

CI SERIES – Balanced Armature Speaker 9.47 x 7.18 x 4.10 (mm). Knowles’ largest and most powerful speaker, the CI series is the speaker of choice. With its high efficiency and a 143dB SPL maximum output, the CI speaker provides optimal low frequency performance.
•Two-terminal zero-bias and three-terminalcenter-tapped configurations
•Various port locations, coil impedances, termination configurations, and frequencyresponses available
post #112 of 2204
So basically it would make sense to use the WBFK series as tweeter, SR, CI or HC series for Woofers. And the mids...
post #113 of 2204
Thread Starter 
If I were building a single driver, I'd use the CI-22955. When I tried them out as prototypes, without filters or crossovers, I was impressed by the sound. They have a very wide range. The HF was fine and the bass was rocking.

If I were building a dual driver, I would grab the TWFK by itself or match the WBFK to the CI (for the best quality bass), or the SR (for the best quantity of bass). The HC also works as a bass driver - and has that 3 dB output advantage - but if I were going dual from a pair of single drivers, my first choice in woofers would be the CI, then the SR, then the HC. Because of its duality, the TWFK is the best value, even if it's the most expensive driver. At $52 per driver, it beats a WBFK ($40) and a CI ($28).

Another option is to use two CIs. This would improve the efficiency of each, lowering its resonance issues.

If I were building a triple, I'd pick the TWFK + CI. The TWFK gives you a WBFK tweeter plus an FK woofer, which can be used, either as a woofer or as a midrange. The CI gives you the best quality bass. There are alternatives but this is both the best choice and the best value, due to the TWFK's dual drivers.

If I were building a quad, I'd be tempted to go with two TWFKs. One of the qualities about the TWFK that KA didn't put into its sales pitch, but is visible from the frequency response graph, is its amazingly flat performance. It's not perfectly flat but it's definitely a lot flatter than any of its rivals. A pair of these would be an awesome configuration.

An alternative would be the TWFK + CI + SR. The TWFK + CI would give you a triple. The SR could be used as a subwoofer. This is pretty much what the UE11 appears to be doing, though it's always anyone's guess.

For a quint, you could use 2 TWFKs plus a CI.

For 6 drivers, you could use 3 TWFKs OR 2 TWFKs plus a CI plus an SR.

I'm not sure how far you can go with this, nor am I sure how necessary it is to have a zillion drivers, but for the price of a custom-made IEM, you could certainly build the IEM of your dreams. That's what has me pulling away from the IEM market to build my own.
post #114 of 2204
Quote:
Originally Posted by Bilavideo View Post
If I were building a single driver, I'd use the CI-22955. When I tried them out as prototypes, without filters or crossovers, I was impressed by the sound. They have a very wide range. The HF was fine and the bass was rocking.

If I were building a dual driver, I would grab the TWFK by itself or match the WBFK to the CI (for the best quality bass), or the SR (for the best quantity of bass). The HC also works as a bass driver - and has that 3 dB output advantage - but if I were going dual from a pair of single drivers, my first choice in woofers would be the CI, then the SR, then the HC. Because of its duality, the TWFK is the best value, even if it's the most expensive driver. At $52 per driver, it beats a WBFK ($40) and a CI ($28).

Another option is to use two CIs. This would improve the efficiency of each, lowering its resonance issues.

If I were building a triple, I'd pick the TWFK + CI. The TWFK gives you a WBFK tweeter plus an FK woofer, which can be used, either as a woofer or as a midrange. The CI gives you the best quality bass. There are alternatives but this is both the best choice and the best value, due to the TWFK's dual drivers.

If I were building a quad, I'd be tempted to go with two TWFKs. One of the qualities about the TWFK that KA didn't put into its sales pitch, but is visible from the frequency response graph, is its amazingly flat performance. It's not perfectly flat but it's definitely a lot flatter than any of its rivals. A pair of these would be an awesome configuration.

An alternative would be the TWFK + CI + SR. The TWFK + CI would give you a triple. The SR could be used as a subwoofer. This is pretty much what the UE11 appears to be doing, though it's always anyone's guess.

For a quint, you could use 2 TWFKs plus a CI.

For 6 drivers, you could use 3 TWFKs OR 2 TWFKs plus a CI plus an SR.

I'm not sure how far you can go with this, nor am I sure how necessary it is to have a zillion drivers, but for the price of a custom-made IEM, you could certainly build the IEM of your dreams. That's what has me pulling away from the IEM market to build my own.
'
Very very true, maybe one day you can have your own company, price them at a super reasonable price. And everyone in this thread can be proto-testers =D what a great idea!
post #115 of 2204
Thread Starter 
I expect to have the first prototypes available for testing by August 1st.
post #116 of 2204
Quote:
Originally Posted by Bilavideo View Post
I expect to have the first prototypes available for testing by August 1st.
I'll be in for that
post #117 of 2204
looking forward to it.

Hope you end up making a comprehensive guide, so that others can reproduce your work.

Might not be a bad idea to start thinking of a name for them either =)


EDIT: Also, contacting ClieOS to see if he is game for a review of them wouldn't be a bad idea.
post #118 of 2204
Come to think of it, I think the biggest part of making custom iems with cross overs may actually be the cross over moreso than which drivers you use. If you can find the right frequency cutoffs for each driver, and the right amount of cross over from one driver to the other, you may end up with the perfect mix. I can see that as being a major contributor to overall sound signature (not quality) and could potentially be the number one cost and differences say between the W3, UM3x, SE530, TFT Pro, etc... and ofcourse the same should apply to even higher end iems. And if that's the case, it might support current listening theories about how a 4 driver custom from JH Audio or from UE can compare to their 6 driver line up. They simply use the same cross over frequencies between models giving them similar sound signatures. Well just a theory, and I might very well be dreaming since it is 3 in the morning. I hate insomnia
post #119 of 2204
Quote:
Originally Posted by pdupiano View Post
Come to think of it, I think the biggest part of making custom iems with cross overs may actually be the cross over moreso than which drivers you use. If you can find the right frequency cutoffs for each driver, and the right amount of cross over from one driver to the other, you may end up with the perfect mix. I can see that as being a major contributor to overall sound signature (not quality) and could potentially be the number one cost and differences say between the W3, UM3x, SE530, TFT Pro, etc... and ofcourse the same should apply to even higher end iems. And if that's the case, it might support current listening theories about how a 4 driver custom from JH Audio or from UE can compare to their 6 driver line up. They simply use the same cross over frequencies between models giving them similar sound signatures. Well just a theory, and I might very well be dreaming since it is 3 in the morning. I hate insomnia
You're theory in a way is correct. A Crossover is (in my opinion) the most important part, even if you gather the highest quality drivers, you'll render them useless if you don't give each driver their "party piece" frequency range, then the driver configuration won't sound to it's best.But sound signature wise, i think it's more to the drivers than to the crossover.
post #120 of 2204
Thread Starter 
Just a few thoughts about crossovers.

1. In a loudspeaker system, crossovers serve two functions: (1) to protect specialized components (mostly tweeters) from signals they're not designed for; and (2) to maximize the efficiency of those specialized components by limiting output to their optimal frequency range (as opposed to letting them hit their resonant frequency).

2. Except for a handful of drivers - like the WBFK and the SR - the vast majority of BAs are wide-rangers. They're not specialized transducers, limited to a narrow band of frequencies. You can blast bass, midrange and treble through the same driver - which is why there are single-driver IEMS out there that sound pretty amazing.

3. Absent specialized transducers, the real reason to sell multi-driver phones is marketing. Can you improve the sound presentation with multiple drivers? Yes, if only to lower the load on each driver, thereby lowering distortion. But there's a big difference between a real three-way system and three drivers singing in unison.

4. It gets worse. When IEM manufacturers advertise their use of an "integrated passive crossover" - and it turns out the XO is only wired to one driver (usually the tweeter) - they're selling mystique, not performance. These same manufacturers are actually relying on something much less high-tech: mechanical filters. Shove this filter in this pipe, that filter in that pipe (and usually that's it, since the second driver is usually a "dual" driver - even if it only has one lead and only one sound outlet).

5. The "crossover circuit" - typically wired to a single driver - is just a capacitor, providing (at best) a first-order crossover (6 dB per octave). Because the advertised "crossover" is more form than function, it doesn't even matter whether the cap is of the right value. It's window dressing to sell cool-looking pieces of plastic.

6. I found this interesting little tidbit at Hearing Review http://www.hearingreview.com/issues/...002-01_99.asp:

Quote:
Microminiature Leaded Tantalum Capacitor
BREL International, Sarasota, Fla, has released the Type CLT-Microminiature Leaded Tantalum Capacitor, the latest addition to the BREL Precision Components Inc product line. The Type CLT tantalum capacitor is one of the smallest on the market. Primarily supplied to the hearing aid industry, it is suitable for other medical and industrial applications.

The Type CLT tantalum capacitor is available in three popular case sizes, with axial or radial leads. These precision microminiature polarized capacitors are especially suitable for general filtering, decoupling, bypassing, and RC timing application. The CLT series operates to +85C without derating and up to +125C with derating. The favorable capacitance to volume ratio makes this series perfect for such high-density applications as hearing aids.

The Type CLT leaded tantalum capacitor was designed in cooperation with a major supplier of electronic components. Additional features include digital marking of capacitance value, color-coded tolerance marking, and robust pure nickel leads with solder coating that is suitable for soldering or welding. Units are priced to $1.69 each, depending on quantity, with up to 6 weeks stock delivery.

BREL Precision is part of the BREL International group of companies, which includes BREL International Components Inc. (800) 237-4564; BREL International, Inc. ~ Home Page.
7. In the world of audio, tantalum caps are considered the worst. They leak. They change their values with heat. They smear. Their real virtue is their cost and size. They can provide a lot of capacitance for a very tiny space. And at a whole $1.69 apiece, who wouldn't want to put one in their $500 triple?
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