A pair of Yamaha NS-10 Studio speakers have just arrived in our house totally free and still in their box
Question i have is are they suitable for home stereo listening? If yes, is it just a case of hooking up to a standalone amp? As I think I have a Sony amp laying around somewhere that I could use. Plus, what cable would I use as there are none with the speakers. Apologies for dumb questions but I am pretty useless with this sort of thing.
I would not expect them to make satisfactory home stereo loudspeakers, unless you value a phase-coherent loudspeaker over one with a broad and even frequency response (especially getting down below ~100Hz). They have many notable characteristics, including uneven freq response most noticeable around the "presence" area from 1 - 4 kHz. They also have many strengths, notably their accuracy in coherent time reproduction.
I think it's fair to say their popularity grew from their small size (allowing producers and engineers to have a consistent reference source when they travelled between studios) and relatively low price, as much as their unique qualities related to their capacity for accurate audio reproduction.
The best analogy is to consider them in the same light as Shure SM57 and 58 mics. Everyone knows they have an uneven frequency response, because the original design (essentially unchanged today, even with modern Beta models that simply change the original cardioid response pattern to hypercardioid) worked well with old 1960's PA such as Vocalmaster or WEM column loudspeakers. The presence peak of a SM57/58 mic (same capsule, different filter, shield etc) benefited both human voices and commonly mic'd instruments such as snare drums. Nowadays that mic is popular because it's a known quantity, and every decent live sound tech knows what to dial down via 31-band GEQ or parametric EQ, to even out its response.
The same presence peak is easily seen on a graph of either the original Fletcher-Munson curve, or the modern generically named "equal-loudness contour". The closest equivalent loudspeaker is the old BBC LS3/5 monitor, made by many companies such as Rogers.
NS10s made their name due to the way the LF driver/woofer has an unusual stiffness, added to the normal characteristic of sealed box / infinite baffle design. The latter is inevitably superior in terms of faithful reproduction, as it avoids the phase-inverted character of bass reflex designs around their port tuning frequency, or the (relatively less intrusive, taking account of wavelength lengths) inherent delay of transmission-line loading (used in loudspeakers from acclaimed companies such as PMC, whilst the highly efficient Tom Danley designed Tapped Horn pro-audio subwoofer uses an inversion of this technique producing a remarkably efficient horn-loaded design).
There is a significant error in the linked Wikipedia article. It states the NS10 went out of production due to a lack of the specific wood pulp used to form the cones of the LF driver. The original design didn't use pulp formed into a paper cone, rather used actual formed paper to make the LF cone - hence its inherent stiffness, from which many unique qualities (both desirable and undesirable) are directly related to. The article does subsequently correctly describe the unusual manufacturer process of the LF driver.
Whilst sealed box / infinite baffle loudspeaker designs inherently contain a natural high-pass filter, the beneficial effect is that in terms of phase coherence - they behave much more accurately than similar sized bass-reflex designs in the time domain. The "group delay" characteristic of a bass-reflex design is thankfully absent in designs using infinite baffle loading.
All the best and worst characteristics can be seen with a measurement system such as Rational Acoustics Smaart
or similar programs using FFT (Fast Fourier Transform) measuring techniques - basically anything capable of measuring the loudspeaker's Transfer Function
- a simple and easily interpreted graph that plots frequency on the horizontal axis (in Hertz) with the left hand vertical axis representing amplitude (measured in deciBels/dB) and phase (represented in degrees from 0° to 360°) on the right hand vertical axis.
To use the pair you have - ensure they are orientated so as the writing under the HF driver is horizontal. Connect them to whatever amplifier you have using the thickest copper speaker cable you have. If you only have bell-wire look at online shops like CPC or Studiospares for cheap copper loudspeaker cable. NS10s don't normally need any costly termination - install-spec bare ends should suffice.
Given you state these are in new condition and still boxed - unless they are the original vertically-oriented hi-fi model, the subsequent design revision of the passive crossover network should be sufficient to tame excess treble. Obviously the grilles fitted should not be removed. The old stories about using tissue paper as a clumsy low-pass filter should be ignored - the number of reflections, secondary arrivals and other undesirable artifacts that result produce an undesirable comb-filter effect. If you find the treble too bright - add a modest HF shelf filter to reduce it if needs be; the use of toilet paper as a rudimentary HF shelving filter are old and anecdotal. Every studio I've visited with NS10s had no such filter cludges, but any adjustment to HF brightness was dealt with using accurate electrical / electronic techniques.
Once you've established the correct orientation, try and mount it on something close to the meter bridge of an old large frame analogue console. This provides half-space loading which reinforces the low and low-mid frequencies missing when this box is measured in an anechoic chamber.
To properly understand why Yamaha NS10 variants became standards in terms of near-field studio monitoring, start by reading this link, which has far more information than I can give (without sounding very dull and using many unnecessarily-complicated long words)
Further reading of this fascinating research paper
gives good insight into the true value of Yamaha NS10 loudspeakers. If you want a realistic monetary value, the 2nd gen (horizontal orientation model) with the "M" suffix go for £200 minimum on eBay. Even a less desirable model should reach close to that amount, or may exceed it - the most important thing to check is that all drivers are original and there are no faults such as cold solder joints on the passive crossover circuit. If all that checks out fine (easy to measure resistance etc with a cheap digital multimeter) you're good to go.
The more modern NS10 MT model is a significant revision of the original design. It utilizes the extended frequency response of a bass reflex design. This gives it a more conventional degree of loudspeaker bass extension, but loses the important phase coherence of the original sealed box / infinite baffle design, as the extra bass that comes from the acoustic coupling of the direct driver output summing with a 180° phase shifted port tuning output. Whilst this may be a criticism in the case of the NS10 as a high fidelity loudspeaker speaker, the bass reflex design is used on 99% of all loudspeakers marketed to both the studio monitor and hi-fi sectors (they are the same markets, but manufacturers differentiate to increase profits and give false logic to Gearslutz who are better at bickering than actually making music).
Assuming you don't have an old large format studio recording console as part of the furnishings in your house, you really should experiment with half and quarter load positioning to best bring out low frequencies (ie around 100Hz and below). Placement really does play an important factor in making these cabs sound good!