Sony MDR-CD900ST Japan Headphone Review

[bejeweledman]

As a monitor , for people with small pinnae almost flat to the head, I can fully understand this headphone to be the choice over the MDR7506.
It isolates the mids nicely which is handy for singers and instrumentalists. Yes, even bass players.

I am quite certain no mixing is done on these headphones though and if someone did that I am sure they know how to translate the sound they hear to a good end product.
It could well lead to recordings with lots of deep bass in it and some brilliance and clarity.

Voices would sound very good and at somewhat louder levels not 'harsh' when using it as a monitor and the ST stands for STudio. It is a purpose made tool. A hifi headphone it is not.

Yup, the CD900ST is designed for a specific purpose - monitoring in a recording studio.
I always say that only buy this pair of headphone if you know what you are going to use it for, and you understand its unique characteristics.

 

[IAtaman]

I got a pair some time ago based on a suggestion from @GXAlan. I am quite happy with them. I think they are a nice collectible headphones - they have a nice story associated with them. They are not the most accurate when it comes to tonality, but they sound good when EQed.

When I got them, I think I measured them on my own head with in-ear mics and matched their treble response to that of HD600 and lower end to Harman bass. Here they are in case anyone is interested.

Preamp: -6 dB
Filter 1: ON PK Fc 169 Hz Gain 3 dB Q 1
Filter 2: ON PK Fc 335 Hz Gain -2 dB Q 3
Filter 3: ON PK Fc 3000 Hz Gain -1 dB Q 2
Filter 4: ON PK Fc 3400 Hz Gain -1.5 dB Q 3
Filter 5: ON PK Fc 5000 Hz Gain 11 dB Q 3
Filter 6: ON LSC Fc 50 Hz Gain 6 dB Q 0.7
Filter 7: ON PK Fc 802 Hz Gain -1 dB Q 0.7
Filter 8: ON PK Fc 1680 Hz Gain 5 dB Q 0.9
Filter 9: ON PK Fc 1800 Hz Gain 2 dB Q 3

 

[solderdude]

What bothered me with the MDR7506 (CD900 has the same construction/pads) was not the sound but rather the comfort.
Pad depth (new pads) is just 14mm. That became quite unpleasant to wear after an hour. I need minimal 19mm to not touch my pinnae.
No EQ can save discomfort.

 

[teched58]

Here is Sean Olive on the MDR-7506:

"It does very well.. It sort of falls in between an AE and and OE headphone-- until you have small pinna. It's extremely good value... It's a little bright for some people but overall good balance. . . It's reassuring that a Pro headphone used for decades has good balance. Looks pretty good for a $80 Pro headphone. Put to shame many models costing hundreds more." (Source: an exchange on Twitter in Nov. 2021.)

 

[Robbo99999]

Here is Sean Olive on the MDR-7506:

"It does very well.. It sort of falls in between an AE and and OE headphone-- until you have small pinna. It's extremely good value... It's a little bright for some people but overall good balance. . . It's reassuring that a Pro headphone used for decades has good balance. Looks pretty good for a $80 Pro headphone. Put to shame many models costing hundreds more." (Source: an exchange on Twitter in Nov. 2021.)

I'm not sure what's up with some of his measurements. One notable one was a K702 that was almost completely hugging the Harman Curve over the whole range. Everything I've seen with the K702 being measured on other sources is not showing smooth hugging of Harman for K702 (Oratory / Crinacle / & subjectively myself with owning 4 units of K702). Yeah, I don't know how to explain some of the peculiarities I see with Sean's measurements he's been publishing off his own back......albeit some of his measurements of some other headphones marry up with what you would expect vs other published measurements out there.

 

[solderdude]

The secret lies mostly in the scaling, smoothing and presenting.

There is very little difference between Amir's and Sean's measurement other than the dB scale, smoothing and FR/dB ratio of the plot and thicker traces.
10dB/div on a 70dB scale, smoothed and thick trace single channel vs 2.5dB/div on a 48dB scale with a different FR/dB ratio and no smoothing, thin traces and 2 channel.

If I needed to sell something I would pick Sean's plots, if I wanted to scrutinize it I would choose Amir's plots.

 

[IAtaman]

What bothered me with the MDR7506 (CD900 has the same construction/pads) was not the sound but rather the comfort.
Pad depth (new pads) is just 14mm. That became quite unpleasant to wear after an hour. I need minimal 19mm to not touch my pinnae.
No EQ can save discomfort.

What do you mean they touch my pinnae? Being on ears, they rest on the pinna don't they. Or does your outer ears fit inside the pads?

 

[IAtaman]

The secret lies mostly in the scaling, smoothing and presenting.

There is very little difference between Amir's and Sean's measurement other than the dB scale, smoothing and FR/dB ratio of the plot and thicker traces.
10dB/div on a 70dB scale, smoothed and thick trace single channel vs 2.5dB/div on a 48dB scale with a different FR/dB ratio and no smoothing, thin traces and 2 channel.

If I needed to sell something I would pick Sean's plots, if I wanted to scrutinize it I would choose Amir's plots.

I think the difference is not just smoothing and scaling. I suspect the underlying data is significantly different. Look at 2K for example. Amir measured -7.5dB below target while Sean Olive's measurements are a few dBs above the target. Same for 100-200Hz range - Amir's measurements show deficiency, Sean's show overshoot.

 

[solderdude]

We seem to have a different definition of over- and on-ear.
Granted some headphones can be kind of both (partial on ear) for different people.

The internal dimensions are 50 x 38 x 14 so for most people over-ear except for the depth.
People with larger pinnae will find their ear-lobes may be trapped under the pads (possibly breaking the seal).

I suspect the underlying data is significantly different.

You are comparing CD900ST vs 7506.... I was comparing Amirs 'regular' 7506 vs Sean's 7506 and take into account that there are also small differences in fixtures.

 

[IAtaman]

We seem to have a different definition of over- and on-ear.

The internal dimensions are 50 x 38 x 14 so for most people over ear.
People with larger pinnae will find their ear-lobes may be trapped under the pads (possibly breaking the seal).

Yea, I guess I have gigantic ears, among other things. For me these are strictly on ears. What you are describing for these cans seems to be similar with my experience with K371.

You are comparing CD900ST vs 7506.... I was comparing Amirs 'regular' 7506 vs Sean's 7506.

Right. Figured it out after I clicked post. 7506 measurements seem very similar indeed as you pointed out, and you are most likely right.

 

[solderdude]

What you are describing for these cans seems to be similar with my experience with K371.

Yep, and considering the K371 has much more space for the ears; H=60mm, W=40mm, D=20mm you must have big ears.

 

[IAtaman]

Yep, and considering the K371 has much more space for the ears; H=60mm, W=40mm, D=20mm you must have big ears.

Technical term is gigantic I believe.

I heard these pads being recommended for 7506 and CD900 - might give them a try sometime. They seem to be relatively larger / deeper and might make them over ear for me as well.

Amazon.com

 

[teched58]

I heard these pads being recommended for 7506 and CD900 - might give them a try sometime. They seem to be relatively larger / deeper and might make them over ear for me as well.

Amazon.com

I use the Wicked Cushions aftermarket pads. Only $20. FYI, the manufacturer's link is here.

 

[IAtaman]

I use the Wicked Cushions aftermarket pads. Only $20. FYI, the manufacturer's link is here.

Those are same dimensions as the originals I take it?

 

[Mr Vinyl]

These are very much like the Yamaha NS-10. They measure poorly yet are widely used even to this day in Asia for music production decisions. They are still in production!

【インタビュー】SONY”MDR-CD900STを創った男”投野耕治氏インタビュー！​

e☆イヤホンのはまちゃんです！2017年も、もう少しですね！今年のクリスマスの予定は決まっていますか？僕のクリスマスの予定は、バンドでレコーディングです！最高です！ 本日は！

e--earphone-blog.translate.goog

“The consumer MDR-CD900 was released in 1985 and production ended in 1990. MDR-CD900 has a folding mechanism and is a curl cord. Overseas, it is sold under the model number "MDR-V6" with slightly different specifications.

At the time, the monitor headphones used at the CBS/Sony studio in Shinanomachi had a fairly round sound, and although voices could be heard well, I felt it was lacking. After all, I learned that the voice has a very high priority in the studio, and that the timbre is what matters, so I started creating the sound of monitor headphones for the studio based on the MDR-CD900. During development, digital recording was also just beginning, and we wanted to find new sounds.

Three years after the MDR-CD900, we developed a new headphone called the MDR-CD900CBS (1988) for use only within CBS/Sony's Shinanomachi and Roppongi studios. The sound is different from the original MDR-CD900, but I think it's more advanced than the studio headphones of the time.

While we were creating the sound in the studio, we talked about how we were concerned about the sharpness of the low range, and while we were talking about it, we even poked holes in the headphones with a pencil to make fine adjustments.

After completion, the sound of the CBS/Sony Studio headphones gradually became popular with musicians, and the headphones were not only used at the CBS/Sony studios, but were also sold to other studios. At that time, you decided to name it MDR-CD900ST.

The NS-10s started as a cheap budget pair of home speakers. Then some people in the US discovered that mixing with them 'accidentally' gave them what was to become the V shape - by boosting both extremeties and lowering the midrange without intentionally doing so. Thus was born the early funk and disco sound used in budget studios at the time. It's a mixing philosophy that is divisive. The European school favoured a more balanced sound, using the BBC specs like Rogers, Spendor, etc.