diff --git a/configs/mainnet.yaml b/configs/mainnet.yaml
index 1a65084e2..1a2e1ea83 100644
--- a/configs/mainnet.yaml
+++ b/configs/mainnet.yaml
@@ -9,8 +9,8 @@
 MAX_COMMITTEES_PER_SLOT: 64
 # 2**7 (= 128)
 TARGET_COMMITTEE_SIZE: 128
-# 2**10 (= 1,024)
-MAX_VALIDATORS_PER_COMMITTEE: 1024
+# 2**11 (= 2,048)
+MAX_VALIDATORS_PER_COMMITTEE: 2048
 # 2**2 (= 4)
 MIN_PER_EPOCH_CHURN_LIMIT: 4
 # 2**16 (= 65,536)
@@ -51,12 +51,12 @@ BLS_WITHDRAWAL_PREFIX: 0x00
 
 # Time parameters
 # ---------------------------------------------------------------
-# 6 seconds 6 seconds
-SECONDS_PER_SLOT: 6
+# 12 seconds
+SECONDS_PER_SLOT: 12
 # 2**0 (= 1) slots 6 seconds
 MIN_ATTESTATION_INCLUSION_DELAY: 1
-# 2**6 (= 64) slots 6.4 minutes
-SLOTS_PER_EPOCH: 64
+# 2**6 (= 32) slots 6.4 minutes
+SLOTS_PER_EPOCH: 32
 # 2**0 (= 1) epochs 6.4 minutes
 MIN_SEED_LOOKAHEAD: 1
 # 2**2 (= 4) epochs 25.6 minutes
diff --git a/configs/minimal.yaml b/configs/minimal.yaml
index f9eb5c4fe..75b93f66a 100644
--- a/configs/minimal.yaml
+++ b/configs/minimal.yaml
@@ -8,8 +8,8 @@
 MAX_COMMITTEES_PER_SLOT: 4
 # [customized] unsecure, but fast
 TARGET_COMMITTEE_SIZE: 4
-# 2**10 (= 1,024)
-MAX_VALIDATORS_PER_COMMITTEE: 1024
+# 2**11 (= 2,048)
+MAX_VALIDATORS_PER_COMMITTEE: 2048
 # 2**2 (= 4)
 MIN_PER_EPOCH_CHURN_LIMIT: 4
 # 2**16 (= 65,536)
@@ -50,7 +50,7 @@ BLS_WITHDRAWAL_PREFIX: 0x00
 
 # Time parameters
 # ---------------------------------------------------------------
-# 6 seconds 6 seconds
+# [customized] Faster for testing purposes
 SECONDS_PER_SLOT: 6
 # 2**0 (= 1) slots 6 seconds
 MIN_ATTESTATION_INCLUSION_DELAY: 1
diff --git a/specs/core/0_beacon-chain.md b/specs/core/0_beacon-chain.md
index ca968713d..9be1f07d8 100644
--- a/specs/core/0_beacon-chain.md
+++ b/specs/core/0_beacon-chain.md
@@ -154,7 +154,7 @@ The following values are (non-configurable) constants used throughout the specif
 | Name | Value |
 | - | - |
 | `FAR_FUTURE_EPOCH` | `Epoch(2**64 - 1)` |
-| `BASE_REWARDS_PER_EPOCH` | `5` |
+| `BASE_REWARDS_PER_EPOCH` | `4` |
 | `DEPOSIT_CONTRACT_TREE_DEPTH` | `2**5` (= 32) |
 | `SECONDS_PER_DAY` | `86400` |
 | `JUSTIFICATION_BITS_LENGTH` | `4` |
@@ -170,7 +170,7 @@ The following values are (non-configurable) constants used throughout the specif
 | - | - |
 | `MAX_COMMITTEES_PER_SLOT` | `2**6` (= 64) |
 | `TARGET_COMMITTEE_SIZE` | `2**7` (= 128) |
-| `MAX_VALIDATORS_PER_COMMITTEE` | `2**10` (= 1,024) |
+| `MAX_VALIDATORS_PER_COMMITTEE` | `2**11` (= 2,048) |
 | `MIN_PER_EPOCH_CHURN_LIMIT` | `2**2` (= 4) |
 | `CHURN_LIMIT_QUOTIENT` | `2**16` (= 65,536) |
 | `SHUFFLE_ROUND_COUNT` | `90` |
@@ -200,9 +200,9 @@ The following values are (non-configurable) constants used throughout the specif
 
 | Name | Value | Unit | Duration |
 | - | - | :-: | :-: |
-| `SECONDS_PER_SLOT` | `6` | seconds | 6 seconds |
-| `MIN_ATTESTATION_INCLUSION_DELAY` | `2**0` (= 1) | slots | 6 seconds |
-| `SLOTS_PER_EPOCH` | `2**6` (= 64) | slots | 6.4 minutes |
+| `SECONDS_PER_SLOT` | `12` | seconds | 12 seconds |
+| `MIN_ATTESTATION_INCLUSION_DELAY` | `2**0` (= 1) | slots | 12 seconds |
+| `SLOTS_PER_EPOCH` | `2**5` (= 32) | slots | 6.4 minutes |
 | `MIN_SEED_LOOKAHEAD` | `2**0` (= 1) | epochs | 6.4 minutes |
 | `MAX_SEED_LOOKAHEAD` | `2**2` (= 4) | epochs | 25.6 minutes |
 | `SLOTS_PER_ETH1_VOTING_PERIOD` | `2**10` (= 1,024) | slots | ~1.7 hours |