Each person's voice is unique, with its on nasality, tone. It'd be real tough to find two people sounding exactly the same.
Regarding speakers from different speaker's designers and manufacturers...
...Speakers that are the same with less than 0.25dB tolerance value between them in their frequency response and power response.
In different rooms the same speaker will sound different.
I posted few good links yesterday on some of the driver's designs and materials used.
Each speaker's designer use his own experience, knowledge and a set of guides to tune the sound he's after from his babies.
The tools he uses for his measurements are is guiding light, his computerized controlled world in helping for his designs,.
Other tools are anechoic chamber rooms, listener blind tests preforming, etc. ...Dunlavy, PSB, Genelec, Paradigm, B&W, Energy, Mirage, Tannoy, KEF, Revel, etc.
A trumpet, a grand piano, a saxophone, a violin, a cello, a church organ, an acoustic standing bass, a Gibson acoustic guitar, a Martin acoustic guitar, a Jean-Claude Larrivee acoustic guitar, a full classical orchestra with 88 musicians plus two tenors (female and male), ...the entire music world with all the musical instruments and all singer's voices in it; to design and build a speaker that can reproduce all those distinctive tones accurately is the ultimate audio nirvana goal.
And two different amplifiers will impregnate their own tonal characteristic powering that same ultimate speaker. So the speaker designer is tuning using a series of amplifiers to match his design goal, "his sound signature".
The volume control in a pre-amp will add its own signature sound touch, ever so slightly it might be.
And I won't go there today (tomorrow maybe...), but some fine ears can distinctively hear variations in different cable's compositions and designs. ...Their geometry, solid core vs twisted braided wires and up to ultra flat wires a la Nordost. But those tones are for another thread (she's probably already there...in the form of when 12AWG is truly 12AWG, some' like that).
Speaker drivers, from the top driver makers, with vast experience, solid engineering, durability, longevity...always a good place to start building the ultimate loudspeaker with the tone YOU want, for the customers YOU think they'd like like YOU. ...With measurements in anechoic room chambers and all...NRC and HK and Dunlavy and Magico and Vandersteen and Genelec and ATC and Salk and Sonus Faber rooms. ...With all the coherence required and time domain perfectly executed from the phase-tuned active separate crossover, or internal passive with one single set of speaker 6-way binding posts.
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♦ Bonus link (just for knowledge fun):
http://www.coolpolymers.com/heattrans.html
