Sonic Studios Monitor/Audiophile/Field Headphone Page

Subject: Re: Higher sensitivity = higher volume?

>Subject: Higher sensitivity = higher volume?
>Date: Sat, 06 Jan 2001 04:17:57 GMT

>I am choosing headphones for my MZR70 and wonder if higher sensitivity
>translates to higher volume? Sony MDR-EX70's sensitivity is 100, while
>MDR-E888 is 108.
>Does this mean that the latter is louder than the former?
>>Sent via



GuySonic@aol replies:

The sensitivity rating is usually for 1 milliwatt POWER input to the phones and a corresponding sound pressure level (SPL) output (USUALLY 102 to 106 dB SPL output for moderate to high sensitivity rated phones).

However, connecting different sets of phones with the same 1 milliwatt to SPL output sensitivity rating to the same headphones amplifier output may, or may not give corresponding equal or loud enough SPL operation!

The impedance (the ohms rating of the phones voice coil) determines how much audio 'voltage' needs be applied to get that '1 milliwatt' or more power into the phone's motor circuit.

For example: A low 16 to 45 ohm headphone (low ohms impedance that's typical for Sony headphones) will easily get to operate for many milliwatts for providing close to live loudness on battery powered portable equipment that typically output only .5-1.5 volts RMS volts output.

A 65 to 600 ohms phones set impedance (higher ohms typical of Sennheiser, Beyer, & AKG headphones). will require a higher headphones amplifier output voltage signal to get the same milliwatts into the phones voice coil for providing equal loudness.

Most of these higher impedance phones require connection to a headphone amp circuit that has ability to drive at least 2-6 Volts RMS to get reasonable loudness for phones listening. Not the type of headphone to use on most portable powered deck's with low voltage phones outputs. These high ohms phones really need a an AC powered amplifier's headphone jack or even direct connection to 10 watt or more power amp's speaker outputs for realistic (loud) listening. There are headphone amps available for this purpose and some are battery powered with at least (1 or 2) 9 volt batteries, the minimum supply needed for higher impedance phones to work at reasonable loudness.

Bottom line: Phones sensitivity is only a measure of the ability to play loud enough only if comparing phones with about the same ohms impedance that are being driven by the same headphone amplifier.

Best before buying is to try out the phones on the exact equipment you to use while playing typical sounds of interest.

My current choices for best natural sound and loud enough (for most) listening ability with portable mini-decks is the Sony MDR-CD2000 and MDR-F1.

Both models of phones are large and comfortable with the MDR-F1 being extremely comfortable with best audiophile speaker-like imaging and pleasurable sound. Alternately, the MDR-CD2000 is a tad bit heavier, work nicely as warm and cozy ear muffs for working in cold windy places, and couples very low bass better. The CD2000 seems most suitable for mastering where best resolution for hearing high and low frequency detail is most important.




SONY MDR-F1 & CD2000 Monitoring/Mastering Stereo Headphones
MDR-F1 Stereo Headphones Introduction

>>--- (edited from Pro Audio Mail Response)--<<

My site has 'too high a quality for streaming' but file downloadable .mp3 encoded sound/music selections.


These samples were recorded with an HRTF baffled omni mic method I pioneered & patented in the mid 80's and now offer as product on my site via Mail Order.


These are stereo 'psycho-acoustical' recordings that are NOT binaural, but are naturally 3-D Stereo encoded and Dolby 'pro logic' decodeable for full surround speaker playback.


Headphone listening with full 'outside the head perceived' ambient is only fully accomplished using headphones like Sony's MDR-F1 with drivers 'floating in space' forward of the ears and angled to firing back into the ears.


The MDR-F1  the only 'stock' phones that seem to give seamless surround sound with none of the hard left/right and weak middle sounds common with all other headphone designs.

MDR-F1 Bass Lens Design

Sony has a few other models with similar designs with the same comfort and imaging ability, but these are rather inexpensive and "dark" sounding and found to be not very good for critical listening of details.


While the MDR-F1 may not be the ideal phone for binaural (where closed or in-ear inserted types might be far more suited, it now seems the perfect phone for 3-D or VR type ambient stereo recordings where isolation from outside ambient sounds is not demanded for playback listening.


This model also seems fully suitable to substitute for using nearfield speakers and with audible perception advantage of more consistent stereo image QA monitoring.

Sony MDR-F1 Assembly

This MDR-F1 also seems ideal for headphones playback of recordings made with the DSM microphone method and . . . perhaps those ambient type recordings made with the Soundfield mic (I haven't as yet listened to any Soundfield recordings to check this out for sure).

NOTE: Listen to DSM recordings: MP3 Page


I've searched and continue searching for very high quality headphones that meet professional monitoring requirements for natural ambient and synthetic stereo recordings.

So far, the stock Jecklin 'Float-Phone' electrostatic (is actually the best imaging with driver angle modification) and the even better imaging (as stock) Sony MDR-F1 remain the only phones found suitable for this purpose.

Sony MDR-F1 Motor & Impedance System

>>---(More edited E-mail posts)---

Subject: Re: Nothing is easy! (headphone help anyone?)

From: GuySonic


Date: 9/15/99

Ever hear of the Sony MDR-F1??

I've tried all the other phones discussed and they (sigh) all fall short of giving full unbiased details of the whole audio range, do not allow accurate stereo imaging perception, have various impedance difficulty being driven by the majority of available phones outputs, and most are not comfortable after just a few hours or less.


The F1 is a very different design with a completely open frame construction (note: zero ambient noise isolation) with the usual 10-30,000 cycle bandwidth, but it delivers it with large 50 mm open, semi-ported drivers placed away from the ear; actually angled forward facing back.

Stereo imaging is more identical to the best nearfield monitors (image with a solid center for a change) and are not at all like what phones normally do to stereo image perception (wide & hard in_the_head "left - NO MID. - right").

Sony MDR-F1 Headphones Features

I've been for over a year searching for a better replacement for the now discontinued MDR-D77 models which were very suitable for accurate mastering, was completely driveable by any phones output, and was (as a bonus) very fold-up pocketable, but lacked the true stereo imaging and absolute comfort of this F1 model.

In Summary:

Very accurate sound suitable for monitoring very critical projects, and comfortable after 10 hours continuous use!! The MDR-F1 is well worth considering as one of the best choices for monitoring/mastering where isolation isn't a requirement when working in a quiet ambient, but unbiased resolution of the full audio spectrum for speaker reproduction is of prime interest. Easily driven, provides excellent sound and adequate output on all equipment tested from smallest lo-power MiniDISC portable to a Mackie board.

What I'd wish better with the F1 is to have be a more compact folding design as these are physically very large phones. The bass is very deep, even, and extended sounding, but is not nearly as 'gut-thumping' powerful as with V600, 7506, and similar more close coupled (nearer the ear) phones.

Sony MDR-F1 Headphones Specifications

Sidenote: Finding the MDR-F1 in-stock anywhere remains a real challenge.   If you can find one or two sets, I'd suggest a quick adoption you'll never regret.


For those not so lucky in finding a set and are still interested in this headphone, please E-Mail me with the word "MDR-F1" in the subject line for news of availability and price as I'm hot on the trail to land some of these here (almost at any cost) before Sony again discontinues another "dark horse" obscure headphones model of exceptional usefulness and value.



NOTE: Impedance Measured at 17.5 ohms (DC) indicates a  higher  value than the 12 ohms (AC) specified .  1 kHz AC impedance should be a bit higher  than 17.5 ohms (DC) if I remember my engineering correctly.


Bottom Line:  There's been NO problem  noticed with getting more than adequate volume with being driven even by small MD and DAT portables.

The MDR-CD2000 model seems an excellent monitor quality headphones, and is one of the only (sensitive/low ohms enough) choice if also wanting dynamic listening levels with battery powered portable equipment.






Ever since Sony's excellent (but costly) fold-up 40 mm driven MDR-D77 became unavailable, I have searched for an equivalent performance 'pocket-size' quality headphones for remote location uses. While I have yet to try out the intriguing MDR-D66SL model that looks and costs similar to the D77, the G74SL model has good field purpose potential at a small fraction of D77 or D66 cost.

Make no mistake, Sony's 'street-style' 30 mm MDR-G74SL is NO substitute for D77's incredible crystal clear, detailed sound, and rock solid bass. However, this even more compact 'neck-worn' model (see diagram at right) does have OK full natural sound, and is ONE OF THE BEST pocket-size, field worthy (break resistant-rugged when folded) light weight phones that's currently available at many places.


Other good news is MDR-G73SL is almost comfortable enough for day-long wearing.

MDR-G74SL seems an excellent value.

Suggest always carrying a folded set in a jacket pocket or recording equipment pack.

Purchase at (or one of their many affiliates), or for about ~$30-$40 USD (after shipping cost)

MDR-G74SL is VERY sensitive (specifications above) so monitoring at high loudness levels with low voltage battery powered equipment is guaranteed.




While available in several models including an external noise canceling version, and essentially a closed phones design, the Bluetooth/Wired model shown at left is my next headphones to try and review.

Might be almost as good as the no longer made previous Sony reviewed open phones I prefer, and loved by critical audiophiles/professional audio engineers & sound designers


Type Closed Supra-Aural, Dynamic
Drivers 1.5" (40 mm) Dome-Type (HD, OFC Voice Coil) Liquid Crystal Polymer Diaphragm High-Energy Neodymium Magnet (360 kJ/m³)
Frequency Response 4 Hz to 80 kHz (Effective Range)
Impedance 24 O @ 1 kHz
Sensitivity 105 dB/mW

Wireless Bluetooth: Version 3.0+EDR1, 2.4 GHz band (2.4000 to 2.4835 GHz FHSS)Network Transport Protocol: A2DP (Sampling Frequency: 44.1 kHz)Transmission Range: 20 Hz to 20 kHzLine of Sight: 30' (10 m) (Approximate)
Microphone Type: Omnidirectional Electret Condenser Frequency Range: 100 Hz to 4 kHz
Remote Control Play, Stop, Pause, Fast Forward, Fast Rewind

Power Battery Charging: 6 Hours (Approximate)Battery Life: Playback: Up to 30 Hours Playback or Communication (Approximate)Standby: Up to 200 Hours
Battery Type DC 3.6 V Built-In Lithium Ion Rechargeable

Power Handling 1500 mW
Connector Gold-plated L-Shaped Stereo Mini-Plug
Cable Length 47.25" (1.2 m) (Approximate)
Weight 10.48 oz (297.00 g) (Approximate)

In a message dated 2/8/04 4:38:28 AM Pacific Standard Time, writes:


I've read most of your site with great interest having just come in possession of a Sony PCM M1.

Sonic Arts is my thing and I'm looking to collect ambient rural/nature and urban sounds. 


Headphones are also an issue.  Are there any cans that have recently been introduced that will do the job as well as those mentioned on your site.  It seems the Sony pair are not readily available over here.

Many Thanks
Rob Nxxxx


Hello Rob,
While I do not know if MDR-F1 is easily available for you, I have found natural sounding headphones that also image well (sounds can be heard all around seamlessly, especially with 3-D recordings like DSM) have similar DESIGN characteristics or traits.

NOTE: These design traits are ONLY indications that a particular headphone is worth trying out. Phones with these (see below) same features are MOSTLY NOT good enough quality to use for critical professional and/or audiophile entertainment purposes. You still need to try each model to see if satisfactory natural sound and with 3-D spatial imaging ability is present in sufficient measure.


All natural sounding phones are OPEN-BACK (also called OPEN-AIR, and Aura-Nomic) design (NOT closed back 'can' types), have larger 40-50 mm sized transducers inside (for good bass), AND the transducers (the inside speaker elements) ARE NOT FLAT positioned close against and/or parallel to the ear, but instead are positioned ANGLED at a distance slightly IN FRONT of the ear; like is shown clearly in diagrams of MDR-F1.

While not so obvious, the 'angled-in-front-the ear headphone design is found in MDR-CD2000 model. Although not yet common, also now found designed into 'more-or-lesser' quality headphones models from Sony, Sennheiser, AKG,  Beyerdynamic, Panasonic, Koss, and more.  Sometimes looking and/or feeling (with a gentle probing/sliding finger) the inside 'ear-cup' area may help determine if the transducers are front-angle positioned if this not already stated in the manufacturer's literature.
ALSO important (for field recording use) is LOW <40 ohms impedance, and high >103 dB/1 mW sensitivity rating. These two additional design issues are important for adequate listening loudness when driven by compact battery powered portable equipment. 

Wearing comfort is another consideration sometimes important depending on intended use.
Suggestion: Copy some DSM (MP3 encoded) recordings to CD for playing at stores to find suitable headphones(for your purposes) before buying.



Suggesting Headphone models is like asking people opinions on the best available shoe to purchase. Everyone walks a bit differently and over ever-changing terrain suited to personal interests and comfort fit requirements.

General considerations and exceptions

1) Most natural sound/imaging are from open types, best isolation/bass is from closed 'can' and sealed in-ear type phones.

EXCEPTIONS: In my experience the most natural sounding 'closed' phone is the long departed Sony MDR-D77. A folding 40mm closed/ported design with very strong tight bass sound, and sense of exceptional wide bandwidth detail; with usual lousy imaging and a pain to put on. An excellent quality/compact-monitoring field phone. Been out of production for 10 years, and I still get e-mail from people wanting a set as there is NO close feature/performance equivalent as yet. Best sounding bass I've yet to hear is from open type MDR-SA3000.

2) Best sound mostly from 40 - 50mm size diaphragms for closed and open dynamic type

3) 24-to-70 ohm/>100dB SPL output for 1 milliwatt input sensitivity is desirable for good performance/loudness with battery/computer powered headphone outputs.

4) Most all headphones WILL more or less sound differently with EACH headphone amplifier that's driving it. Long cords are most usable feature, but present design challenges for lowest distortion phones performance.

5) Model numbers do NOT change, but materials/components to make these models DO CHANGE.

Example is my experience with original V6 purchased mid-to early 80's. I loved the natural sounding excellent detail of those phones, especially if driven with a good amplifier. 10 years later, wanted a second set but every V6 purchased, also tried V600, V7506 Grado SR60, sounded noticeably inferior, at least compared to the definition/clarity still heard on the original V6.

Figured that different V6 components were being used, and it all added up to NOT being a V6 I could live with. Settled for V900 as judged best available, but found this set limited and most useful for having long cord, good isolation sound check purpose, and being much easier to put on/take off than most favored D77 with a bit too short a cord for some purposes.

Later tried and liked very accurate Jecklin electrostatic float phones with 4x4 inch diaphragms, Sony MDR-D77, MDR-F1, MDR-CD2000 in order of acquiring, and currently (in production) MDR-SA3000 as likely one THE best performing open dynamic phones AND the best dollar value ever found.

The SA3000 are now my personal 'fully usable for recording mastering' favorites.

One of the most comfortable headphones ever made. Only complaint is this model's ear pad was changed from synthetic leather over soft foam to proven more durable synthetic woven poly-fabric over fairly stiff foam; or the reverse as there seems two descriptions of either leather or fabric SA3000 in the marketplace.

I think NOT to like the fully synthetic fabric with longer lasting stiff foam pad design as this makes LOUD RUBBING SOUNDS with head movement. So you got to be still otherwise, its like rubbing a rubber balloon next to your ears and is disturbing until learning to ignore the noise with every movement of the head.

Would like to sometime try the twice as costly SA5000 model (with real leather pads) as the SA1000 model's sound (at ~60% of SA3000 cost) was noticeably weak in the midrange and not the most natural sounding, even after break-in period, especially in comparison to the SA3000 that needed little or no break-in time.

So I naturally wonder what the SA5000 might be like.


MDR-SA1000,SA3000, SA5000 model series seems more or less based on original MDR-F1's open frame design and retains the outstanding imaging ability of the F1.

Refinements make reviewed SA3000 model sound nothing like the weaker bass/softer detail experienced of F1 or weak mid-bass of SA1000 with having astonishing-natural sounding high frequency detail, strong solid bass, and wearing comfort improvements over already extremely comfortable F1.

Credit for transparent high frequency detail, natural sound, and strong extended bass likely in part due to evolved refinement of the original F1 design with new 50mm transducer materials, and effective acoustic lens technology





Sensitivity --- 100dB/mW

Impedance --- 70 ohms at 1kHz

Frequency Response --- 8-100,000Hz


Type --- Open air, dynamic

Headphones --- Circum aural

Headphones --- Urethane Texture type and Low Dispersion

  Driver Unit --- 50mm diameter, dome type

Diaphragm --- Nano composite HD

Magnet --- Neodymium (360kJ/m3)

Cord --- Single sided, 3.5m texture type cord (6N-OFC)

Plug --- Straight stereo unimatch plug (gold) screw type

Headband --- Wire frame with adjusting mechanism

Headband --- CFRP Frame

Power Handling Capacity --- 1,500mW (IEC)

Supplied Accessories

Unimatch plug adapter (gold) screw type

Carrying pouch

Warranty card
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