An improvement over last week's DA offering. I thought 17 was maybe a bit too cute (and a somewhat dated reference for me).

Across

1

Old measure defends shows turned down (9)
MISERABLE — MILE (old measure) outside (defends) reversal (turned) of BARES (shows)

6

Rebuff infuriated Bedouin (5)
NOMAD — NO (rebuff) MAD (infuriated)

9

Exhibit describes centre of Oort Cloud’s purpose (7)
STORAGE — STAGE (exhibit) around OR (centre letters of oort)

10

Now and then, carnal love surprisingly calls for a little work? (7)
NOVELLA — anagram (surprisingly) of ANL (odd letters of carnal) LOVE

11

Romeo steals heart of joyful monster (5)
HARPY — HApPY (joyful) with p (middle letter) -> R (romeo)

13

Spirit of The Age to spot tenor swallowing drug on both occasions? (9)
ZEITGEIST — ZIT (spot) GIST (tenor) both with E (drug) inserted

14

Screen consultant pulled plug (5)
VISOR — adVISOR (consultant) without ad (plug)

16

Punk trio disrupted Poison singer (8)
BARITONE — anagram (punk) of TRIO inside BANE (poison)

19

Striker’s location to test penalty area? (8)
MATCHBOX — MATCH (test) BOX (penalty area)

20

Brad Pitt stripped, wanting a dip (5)
RAITA — RA IT (Brad Pitt, each without outside letters), around A

22

City mornings absorbed elected leader in two ways (9)
AMSTERDAM — AM AM (mornings) around ST RD (two ways) around E (first letter of elected)

24

Oddly prayer touches on an exuberant tribute (5)
PAEAN — PAE (odd letters of prayer) AN

25

First Blood influenced German director (7)
BERGMAN — B (first letter of blood) anagram (influenced) of GERMAN

26

(& 7-down) Film Spooner’s inane grind at factory, one working with loud strain (7,11)
SLUMDOG MILLIONAIRE — Spoonerism of DUMB (inane) SLOG (grind), MILL (factory) I (one) ON (working), homophone of AIR (strain)

28

Loaded boy content to rent (5)
LADEN — LAD (boy) EN (middle letters of rent)

29

Males wear one casual shoe overseas? Small world! (9)
MICROCOSM — M M (males) around I (one) CROC (casual shoe) OS (overseas)

Down

1

Jumbo’s heat way below a necessity? (4-4)
MUST-HAVE — MUSTH (jumbo's heat) AVE (way)

2

(& 24-down) Dry biscuit strangely popular amid big city (3,5)
**SAO- ** — SAO (dry biscuit) anagram (strangely) of OPULA (middle letters of popular)

3

Set book, second in syllabus (5)
READY — READ (book) Y (second letter of syllabus)

4

Worker gets regularly lazier watching over infant Nick? (9)
BEELZEBUB — BEE (worker) LZE (odd letters of lazier) BUB (infant)

5

Trade function in Abu Dhabi ends in tedium (5)
ENNUI — last letters of tradE functioN iN abU dhabI

6

Cook, perhaps to go with variant stew (9)
NAVIGATOR — anagram (stew) of GO VARIANT

8

Want d-dirt? (6)
DEARTH — D EARTH (dirt)

12

You can be certain stars use dreadful colour (4,7)
REST ASSURED — anagram (dreadful) of STARS USE, RED (colour)

15

John hit lettuce, then goes off tropical fruit (9)
ROCKETMAN — ROCKET (lettuce) MANgoes (tropical fruit) without goes

17

Outfit ferry? Vice versa (4,5)
ROXY MUSIC — cryptic def. (ferry outfit), &lit?

18

An equine sheltered by quiet tree (5,3)
MANNA GUM — AN NAG (equine) in MUM (quiet)

21

Mafia gutted in prison caper (6)
GAMBOL — MoB (mafia, without middle letter) in GAOL (prison)

23

Material I’m supplying lair (5)
DENIM — DEN (lair) IM

27

Couple cartwheeling in boudoir (3)
DUO — reversal (cartwheeling) of hidden in bOUDoir