String quartet no. 1 
36:43
among my earliest compositions, the first quartet has a distinctive atmosphere which my wife nicknamed “The Russian”
1. moderato
2. adagio 13’12”
3. scherzo – coda adagio 24’43”
String quartet no. 2 
30:27
a rather volatile work quite strongly influenced by Janacek. It ends uncharacteristically with a scherzo which quotes the opening of the work near the end.
1. appassionata con moto
2. adagio 11'58"
3. scherzo 21'58"
String quartet no. 3 
28:34
the final work in my early heavily influenced by Janacek string quartet phase. As with the 3rd and 4th symphonies, the contrast in mood between these two quartets, written around 4 years apart, could not be greater.
appassionata 0'00"
scherzo 11'01"
lento lamentoso 15'49"
String quartet no. 4 
41:22
perhaps the most relaxed, classical and "lieblich" of the string quartets, despite one or two strange byways in the slow movement.
allegretto 0'00"
andante 14'52"
scherzo 24'22"
tema con variazioni 32'59"
String quartet no. 5 
30:30
after early quartets often influenced by Janacek, this has for the first time a somewhat more modern harmonic style and language in places, esp.in the intermezzo. 
1st movement moderato
2nd movement intermezzo 10’58”
3rd movement adagio 17’14”
String quartet no. 6 
30:24
like a number of the quartets, this is in three movements, ending with an slow movement after a short scherzo. The first movement is unusual in the recapitulation including an “offset” passage and doesn’t at all repeat the exposition. In general it’s one of the most unbalanced and strange of the chamber works. 
1st moderato 
2nd scherzo – presto 13’08”
3rd lento 15’43” 
String quartet no. 7 
31:07
a fairly typical "middle period" quartet with a somewhat melancholic general character culminating in an impassioned climax.
1. moderato
2. scherzo 12'36"
3. adagio 15'52"
String quartet no. 8 
38:47
Among the most classically orientated of the quartets and also among the longest with five movements including a "cavatina" for reasons which should be obvious.
1. andante
2. mysterioso    8'59"
3. scherzo    14'11"
4. cavatina    16'55"
5. tema con variazioni  26'44"
String quartet no. 9 
21:49
in a rather slow post-romantic style, it is also relatively unusual for its length of having two short scherzos in what's the most compact of all my chamber works.
String quartet no. 10 
31:10
There is a mixture of styles including quite a bit of Janacek whose influence strongly permeated the early quartets.
1. allegretto molto espressivo
2. pastorale     10'56"
3. allegro con brio   22'05"
String quartet no. 11 
33:04
my newest quartet is largely chromatically contrapuntal in character, though the final "tema con variazioni" often looks back to the classical masters in spirit if not necessarily in language. The movement timings are as follows:
1. largo -- piu mosso
2. scherzo 12'18"
3. tema con variazioni 18' 27"
String quartet no.12 
28:54
the 12th quartet is something of a reflection of the times with a doleful opening adagio which frames a faster central section. The scherzo is somewhat shadowy and mysterious in character. In the last movement, the shadows are banished into a song of hope and longing.
dolente
scherzo 12'23"
dolce a molto espressivo 18' 51"
String quartet no. 13 
38:45
the 13th quartet is one of my longest chamber works and has effectively two scherzos, one rather shadowy and one fast and furious. An adagio to end with a somewhat sentimental/nostalgic Russian character. It's also the first with the rendering split equally between VSL and Chris Hein libraries.
molto agitato
intermezzo 15' 00"
molto vivace 22'57"
adagio 26'02"
String quartet no.14 
30:00
A reversion to a somewhat more neo-classical approach with a superficially high-spirited finale in C major though there is a darker side.
1. con moto
2. moderato 11'29"
3. molto vivace 21' 59"
String quartet no.15 
15:10
two of the greatest composers of the string quartet, Beethoven and Shostakovich both wrote 15 so my answer was in some ways a sort of anti 15th -- a rather short work in one movement with a somewhat enigmatic character.