diff --git a/exmaple/react-audio-spectrum-demo/package-lock.json b/exmaple/react-audio-spectrum-demo/package-lock.json
index c6e10f5..4cc12ab 100644
--- a/exmaple/react-audio-spectrum-demo/package-lock.json
+++ b/exmaple/react-audio-spectrum-demo/package-lock.json
@@ -2112,7 +2112,8 @@
             "ansi-regex": {
               "version": "2.1.1",
               "bundled": true,
-              "dev": true
+              "dev": true,
+              "optional": true
             },
             "aproba": {
               "version": "1.2.0",
@@ -2133,12 +2134,14 @@
             "balanced-match": {
               "version": "1.0.0",
               "bundled": true,
-              "dev": true
+              "dev": true,
+              "optional": true
             },
             "brace-expansion": {
               "version": "1.1.11",
               "bundled": true,
               "dev": true,
+              "optional": true,
               "requires": {
                 "balanced-match": "^1.0.0",
                 "concat-map": "0.0.1"
@@ -2153,17 +2156,20 @@
             "code-point-at": {
               "version": "1.1.0",
               "bundled": true,
-              "dev": true
+              "dev": true,
+              "optional": true
             },
             "concat-map": {
               "version": "0.0.1",
               "bundled": true,
-              "dev": true
+              "dev": true,
+              "optional": true
             },
             "console-control-strings": {
               "version": "1.1.0",
               "bundled": true,
-              "dev": true
+              "dev": true,
+              "optional": true
             },
             "core-util-is": {
               "version": "1.0.2",
@@ -2280,7 +2286,8 @@
             "inherits": {
               "version": "2.0.3",
               "bundled": true,
-              "dev": true
+              "dev": true,
+              "optional": true
             },
             "ini": {
               "version": "1.3.5",
@@ -2292,6 +2299,7 @@
               "version": "1.0.0",
               "bundled": true,
               "dev": true,
+              "optional": true,
               "requires": {
                 "number-is-nan": "^1.0.0"
               }
@@ -2306,6 +2314,7 @@
               "version": "3.0.4",
               "bundled": true,
               "dev": true,
+              "optional": true,
               "requires": {
                 "brace-expansion": "^1.1.7"
               }
@@ -2313,12 +2322,14 @@
             "minimist": {
               "version": "0.0.8",
               "bundled": true,
-              "dev": true
+              "dev": true,
+              "optional": true
             },
             "minipass": {
               "version": "2.3.5",
               "bundled": true,
               "dev": true,
+              "optional": true,
               "requires": {
                 "safe-buffer": "^5.1.2",
                 "yallist": "^3.0.0"
@@ -2337,6 +2348,7 @@
               "version": "0.5.1",
               "bundled": true,
               "dev": true,
+              "optional": true,
               "requires": {
                 "minimist": "0.0.8"
               }
@@ -2417,7 +2429,8 @@
             "number-is-nan": {
               "version": "1.0.1",
               "bundled": true,
-              "dev": true
+              "dev": true,
+              "optional": true
             },
             "object-assign": {
               "version": "4.1.1",
@@ -2429,6 +2442,7 @@
               "version": "1.4.0",
               "bundled": true,
               "dev": true,
+              "optional": true,
               "requires": {
                 "wrappy": "1"
               }
@@ -2514,7 +2528,8 @@
             "safe-buffer": {
               "version": "5.1.2",
               "bundled": true,
-              "dev": true
+              "dev": true,
+              "optional": true
             },
             "safer-buffer": {
               "version": "2.1.2",
@@ -2550,6 +2565,7 @@
               "version": "1.0.2",
               "bundled": true,
               "dev": true,
+              "optional": true,
               "requires": {
                 "code-point-at": "^1.0.0",
                 "is-fullwidth-code-point": "^1.0.0",
@@ -2569,6 +2585,7 @@
               "version": "3.0.1",
               "bundled": true,
               "dev": true,
+              "optional": true,
               "requires": {
                 "ansi-regex": "^2.0.0"
               }
@@ -2612,12 +2629,14 @@
             "wrappy": {
               "version": "1.0.2",
               "bundled": true,
-              "dev": true
+              "dev": true,
+              "optional": true
             },
             "yallist": {
               "version": "3.0.3",
               "bundled": true,
-              "dev": true
+              "dev": true,
+              "optional": true
             }
           }
         },
@@ -3869,18 +3888,26 @@
       "dev": true
     },
     "elliptic": {
-      "version": "6.5.0",
-      "resolved": "http://rnpm.hz.netease.com/elliptic/download/elliptic-6.5.0.tgz",
-      "integrity": "sha1-K47UyJG33jIA4UQSpbgkjHr1Bco=",
+      "version": "6.5.4",
+      "resolved": "https://registry.npmjs.org/elliptic/-/elliptic-6.5.4.tgz",
+      "integrity": "sha512-iLhC6ULemrljPZb+QutR5TQGB+pdW6KGD5RSegS+8sorOZT+rdQFbsQFJgvN3eRqNALqJer4oQ16YvJHlU8hzQ==",
       "dev": true,
       "requires": {
-        "bn.js": "^4.4.0",
-        "brorand": "^1.0.1",
+        "bn.js": "^4.11.9",
+        "brorand": "^1.1.0",
         "hash.js": "^1.0.0",
-        "hmac-drbg": "^1.0.0",
-        "inherits": "^2.0.1",
-        "minimalistic-assert": "^1.0.0",
-        "minimalistic-crypto-utils": "^1.0.0"
+        "hmac-drbg": "^1.0.1",
+        "inherits": "^2.0.4",
+        "minimalistic-assert": "^1.0.1",
+        "minimalistic-crypto-utils": "^1.0.1"
+      },
+      "dependencies": {
+        "bn.js": {
+          "version": "4.12.0",
+          "resolved": "https://registry.npmjs.org/bn.js/-/bn.js-4.12.0.tgz",
+          "integrity": "sha512-c98Bf3tPniI+scsdk237ku1Dc3ujXQTSgyiPUDEOe7tRkhrqridvh8klBv0HCEso1OLOYcHuCv/cS6DNxKH+ZA==",
+          "dev": true
+        }
       }
     },
     "emoji-regex": {
@@ -4915,7 +4942,8 @@
         "ansi-regex": {
           "version": "2.1.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "aproba": {
           "version": "1.1.1",
@@ -4966,7 +4994,8 @@
         "balanced-match": {
           "version": "0.4.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "bcrypt-pbkdf": {
           "version": "1.0.1",
@@ -4981,6 +5010,7 @@
           "version": "0.0.9",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "inherits": "~2.0.0"
           }
@@ -4989,6 +5019,7 @@
           "version": "2.10.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "hoek": "2.x.x"
           }
@@ -4997,6 +5028,7 @@
           "version": "1.1.7",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "balanced-match": "^0.4.1",
             "concat-map": "0.0.1"
@@ -5005,7 +5037,8 @@
         "buffer-shims": {
           "version": "1.0.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "caseless": {
           "version": "0.12.0",
@@ -5022,12 +5055,14 @@
         "code-point-at": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "combined-stream": {
           "version": "1.0.5",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "delayed-stream": "~1.0.0"
           }
@@ -5035,17 +5070,20 @@
         "concat-map": {
           "version": "0.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "console-control-strings": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "core-util-is": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "cryptiles": {
           "version": "2.0.5",
@@ -5091,7 +5129,8 @@
         "delayed-stream": {
           "version": "1.0.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "delegates": {
           "version": "1.0.0",
@@ -5117,7 +5156,8 @@
         "extsprintf": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "forever-agent": {
           "version": "0.6.1",
@@ -5139,12 +5179,14 @@
         "fs.realpath": {
           "version": "1.0.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "fstream": {
           "version": "1.0.11",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "graceful-fs": "^4.1.2",
             "inherits": "~2.0.0",
@@ -5200,6 +5242,7 @@
           "version": "7.1.2",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "fs.realpath": "^1.0.0",
             "inflight": "^1.0.4",
@@ -5212,7 +5255,8 @@
         "graceful-fs": {
           "version": "4.1.11",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "har-schema": {
           "version": "1.0.5",
@@ -5251,7 +5295,8 @@
         "hoek": {
           "version": "2.16.3",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "http-signature": {
           "version": "1.1.1",
@@ -5268,6 +5313,7 @@
           "version": "1.0.6",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "once": "^1.3.0",
             "wrappy": "1"
@@ -5276,7 +5322,8 @@
         "inherits": {
           "version": "2.0.3",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "ini": {
           "version": "1.3.4",
@@ -5288,6 +5335,7 @@
           "version": "1.0.0",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "number-is-nan": "^1.0.0"
           }
@@ -5301,7 +5349,8 @@
         "isarray": {
           "version": "1.0.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "isstream": {
           "version": "0.1.2",
@@ -5374,12 +5423,14 @@
         "mime-db": {
           "version": "1.27.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "mime-types": {
           "version": "2.1.15",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "mime-db": "~1.27.0"
           }
@@ -5388,6 +5439,7 @@
           "version": "3.0.4",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "brace-expansion": "^1.1.7"
           }
@@ -5395,12 +5447,14 @@
         "minimist": {
           "version": "0.0.8",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "mkdirp": {
           "version": "0.5.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "minimist": "0.0.8"
           }
@@ -5453,7 +5507,8 @@
         "number-is-nan": {
           "version": "1.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "oauth-sign": {
           "version": "0.8.2",
@@ -5471,6 +5526,7 @@
           "version": "1.4.0",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "wrappy": "1"
           }
@@ -5500,7 +5556,8 @@
         "path-is-absolute": {
           "version": "1.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "performance-now": {
           "version": "0.2.0",
@@ -5511,7 +5568,8 @@
         "process-nextick-args": {
           "version": "1.0.7",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "punycode": {
           "version": "1.4.1",
@@ -5549,6 +5607,7 @@
           "version": "2.2.9",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "buffer-shims": "~1.0.0",
             "core-util-is": "~1.0.0",
@@ -5593,6 +5652,7 @@
           "version": "2.6.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "glob": "^7.0.5"
           }
@@ -5600,7 +5660,8 @@
         "safe-buffer": {
           "version": "5.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "semver": {
           "version": "5.3.0",
@@ -5658,6 +5719,7 @@
           "version": "1.0.2",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "code-point-at": "^1.0.0",
             "is-fullwidth-code-point": "^1.0.0",
@@ -5668,6 +5730,7 @@
           "version": "1.0.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "safe-buffer": "^5.0.1"
           }
@@ -5682,6 +5745,7 @@
           "version": "3.0.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "ansi-regex": "^2.0.0"
           }
@@ -5696,6 +5760,7 @@
           "version": "2.2.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "block-stream": "*",
             "fstream": "^1.0.2",
@@ -5751,7 +5816,8 @@
         "util-deprecate": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "uuid": {
           "version": "3.0.1",
@@ -5780,7 +5846,8 @@
         "wrappy": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         }
       }
     },
diff --git a/exmaple/react-audio-spectrum-demo/yarn.lock b/exmaple/react-audio-spectrum-demo/yarn.lock
index b850806..309239f 100644
--- a/exmaple/react-audio-spectrum-demo/yarn.lock
+++ b/exmaple/react-audio-spectrum-demo/yarn.lock
@@ -984,9 +984,9 @@ bluebird@^3.4.7:
   version "3.5.1"
   resolved "https://registry.yarnpkg.com/bluebird/-/bluebird-3.5.1.tgz#d9551f9de98f1fcda1e683d17ee91a0602ee2eb9"
 
-bn.js@^4.0.0, bn.js@^4.1.0, bn.js@^4.1.1, bn.js@^4.4.0:
-  version "4.11.8"
-  resolved "https://registry.yarnpkg.com/bn.js/-/bn.js-4.11.8.tgz#2cde09eb5ee341f484746bb0309b3253b1b1442f"
+bn.js@^4.0.0, bn.js@^4.1.0, bn.js@^4.1.1, bn.js@^4.11.9:
+  version "4.12.0"
+  resolved "https://registry.yarnpkg.com/bn.js/-/bn.js-4.12.0.tgz#775b3f278efbb9718eec7361f483fb36fbbfea88"
 
 body-parser@1.18.2:
   version "1.18.2"
@@ -1053,7 +1053,7 @@ braces@^1.8.2:
     preserve "^0.2.0"
     repeat-element "^1.1.2"
 
-brorand@^1.0.1:
+brorand@^1.0.1, brorand@^1.1.0:
   version "1.1.0"
   resolved "https://registry.yarnpkg.com/brorand/-/brorand-1.1.0.tgz#12c25efe40a45e3c323eb8675a0a0ce57b22371f"
 
@@ -1952,16 +1952,16 @@ electron-to-chromium@^1.2.7, electron-to-chromium@^1.3.27:
   resolved "https://registry.yarnpkg.com/electron-to-chromium/-/electron-to-chromium-1.3.27.tgz#78ecb8a399066187bb374eede35d9c70565a803d"
 
 elliptic@^6.0.0:
-  version "6.4.0"
-  resolved "https://registry.yarnpkg.com/elliptic/-/elliptic-6.4.0.tgz#cac9af8762c85836187003c8dfe193e5e2eae5df"
+  version "6.5.4"
+  resolved "https://registry.yarnpkg.com/elliptic/-/elliptic-6.5.4.tgz#da37cebd31e79a1367e941b592ed1fbebd58abbb"
   dependencies:
-    bn.js "^4.4.0"
-    brorand "^1.0.1"
+    bn.js "^4.11.9"
+    brorand "^1.1.0"
     hash.js "^1.0.0"
-    hmac-drbg "^1.0.0"
-    inherits "^2.0.1"
-    minimalistic-assert "^1.0.0"
-    minimalistic-crypto-utils "^1.0.0"
+    hmac-drbg "^1.0.1"
+    inherits "^2.0.4"
+    minimalistic-assert "^1.0.1"
+    minimalistic-crypto-utils "^1.0.1"
 
 emoji-regex@^6.1.0:
   version "6.5.1"
@@ -2839,11 +2839,11 @@ hash-base@^3.0.0:
     safe-buffer "^5.0.1"
 
 hash.js@^1.0.0, hash.js@^1.0.3:
-  version "1.1.3"
-  resolved "https://registry.yarnpkg.com/hash.js/-/hash.js-1.1.3.tgz#340dedbe6290187151c1ea1d777a3448935df846"
+  version "1.1.7"
+  resolved "https://registry.yarnpkg.com/hash.js/-/hash.js-1.1.7.tgz#0babca538e8d4ee4a0f8988d68866537a003cf42"
   dependencies:
     inherits "^2.0.3"
-    minimalistic-assert "^1.0.0"
+    minimalistic-assert "^1.0.1"
 
 hawk@3.1.3, hawk@~3.1.3:
   version "3.1.3"
@@ -2858,7 +2858,7 @@ he@1.1.x:
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/he/-/he-1.1.1.tgz#93410fd21b009735151f8868c2f271f3427e23fd"
 
-hmac-drbg@^1.0.0:
+hmac-drbg@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/hmac-drbg/-/hmac-drbg-1.0.1.tgz#d2745701025a6c775a6c545793ed502fc0c649a1"
   dependencies:
@@ -3042,14 +3042,18 @@ inflight@^1.0.4:
     once "^1.3.0"
     wrappy "1"
 
-inherits@2, inherits@2.0.3, inherits@^2.0.1, inherits@^2.0.3, inherits@~2.0.0, inherits@~2.0.1, inherits@~2.0.3:
-  version "2.0.3"
-  resolved "https://registry.yarnpkg.com/inherits/-/inherits-2.0.3.tgz#633c2c83e3da42a502f52466022480f4208261de"
+inherits@2, inherits@^2.0.1, inherits@^2.0.3, inherits@^2.0.4, inherits@~2.0.0, inherits@~2.0.1, inherits@~2.0.3:
+  version "2.0.4"
+  resolved "https://registry.yarnpkg.com/inherits/-/inherits-2.0.4.tgz#0fa2c64f932917c3433a0ded55363aae37416b7c"
 
 inherits@2.0.1:
   version "2.0.1"
   resolved "https://registry.yarnpkg.com/inherits/-/inherits-2.0.1.tgz#b17d08d326b4423e568eff719f91b0b1cbdf69f1"
 
+inherits@2.0.3:
+  version "2.0.3"
+  resolved "https://registry.yarnpkg.com/inherits/-/inherits-2.0.3.tgz#633c2c83e3da42a502f52466022480f4208261de"
+
 ini@^1.3.4, ini@~1.3.0:
   version "1.3.4"
   resolved "https://registry.yarnpkg.com/ini/-/ini-1.3.4.tgz#0537cb79daf59b59a1a517dff706c86ec039162e"
@@ -4031,11 +4035,11 @@ mimic-fn@^1.0.0:
   version "1.1.0"
   resolved "https://registry.yarnpkg.com/mimic-fn/-/mimic-fn-1.1.0.tgz#e667783d92e89dbd342818b5230b9d62a672ad18"
 
-minimalistic-assert@^1.0.0:
-  version "1.0.0"
-  resolved "https://registry.yarnpkg.com/minimalistic-assert/-/minimalistic-assert-1.0.0.tgz#702be2dda6b37f4836bcb3f5db56641b64a1d3d3"
+minimalistic-assert@^1.0.0, minimalistic-assert@^1.0.1:
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/minimalistic-assert/-/minimalistic-assert-1.0.1.tgz#2e194de044626d4a10e7f7fbc00ce73e83e4d5c7"
 
-minimalistic-crypto-utils@^1.0.0, minimalistic-crypto-utils@^1.0.1:
+minimalistic-crypto-utils@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/minimalistic-crypto-utils/-/minimalistic-crypto-utils-1.0.1.tgz#f6c00c1c0b082246e5c4d99dfb8c7c083b2b582a"
 
@@ -5014,9 +5018,9 @@ rc@^1.0.1, rc@^1.1.6, rc@^1.1.7:
     minimist "^1.2.0"
     strip-json-comments "~2.0.1"
 
-react-audio-spectrum@^0.0.4:
-  version "0.0.4"
-  resolved "https://registry.yarnpkg.com/react-audio-spectrum/-/react-audio-spectrum-0.0.4.tgz#8b81dcbc578fcac31ac4d414230f7bd8db2d7e4f"
+react-audio-spectrum@^0.1.0:
+  version "0.1.0"
+  resolved "https://registry.yarnpkg.com/react-audio-spectrum/-/react-audio-spectrum-0.1.0.tgz#286c883aac7513b4b44fab26dc5e53f77c037730"
   dependencies:
     prop-types "^15.6.0"
     react "^16.1.0"