diff --git a/ruby/lib/jam_ruby/models/jam_track_mixdown.rb b/ruby/lib/jam_ruby/models/jam_track_mixdown.rb
index bc2ffed1f..f1841e365 100644
--- a/ruby/lib/jam_ruby/models/jam_track_mixdown.rb
+++ b/ruby/lib/jam_ruby/models/jam_track_mixdown.rb
@@ -66,6 +66,14 @@ module JamRuby
       if !tweaked
         errors.add(:settings, 'have nothing specified')
       end
+
+      if parsed["speed"] && !parsed["speed"].is_a?(Integer)
+        errors.add(:settings, 'has non-integer speed')
+      end
+
+      if parsed["pitch"] && !parsed["pitch"].is_a?(Integer)
+        errors.add(:settings, 'has non-integer pitch')
+      end
     end
 
     def self.create(name, description, user, jam_track, settings)
diff --git a/ruby/lib/jam_ruby/models/jam_track_mixdown_package.rb b/ruby/lib/jam_ruby/models/jam_track_mixdown_package.rb
index 4a73079f2..cc9714599 100644
--- a/ruby/lib/jam_ruby/models/jam_track_mixdown_package.rb
+++ b/ruby/lib/jam_ruby/models/jam_track_mixdown_package.rb
@@ -45,7 +45,7 @@ module JamRuby
       end
     end
 
-    def self.create(mixdown, file_type, sample_rate, encrypt)
+    def self.create(mixdown, file_type, sample_rate, encrypt_type)
 
       package = JamTrackMixdownPackage.new
       package.jam_track_mixdown = mixdown
@@ -53,6 +53,7 @@ module JamRuby
       package.sample_rate = sample_rate
       package.signed = false
       package.signing = false
+      package.encrypt_type = encrypt_type
       package.save
       package
     end
diff --git a/ruby/lib/jam_ruby/resque/jam_track_mixdown_packager.rb b/ruby/lib/jam_ruby/resque/jam_track_mixdown_packager.rb
index 2f9184e25..77aeb0054 100644
--- a/ruby/lib/jam_ruby/resque/jam_track_mixdown_packager.rb
+++ b/ruby/lib/jam_ruby/resque/jam_track_mixdown_packager.rb
@@ -331,8 +331,11 @@ module JamRuby
         @speed_mix_file
       else
         # otherwise we need to convert from lastly created file to correct
-        output = File.join(tmp_dir, "output.#{@mixdown_pacakge.file_type}")
-        cmd("sox \"#{@speed_mix_file}\" \"#{output}\"")
+        output = File.join(tmp_dir, "output.#{@mixdown_package.file_type}")
+
+        raise 'unknown file_type' if @mixdown_package.file_type != JamTrackMixdownPackage::FILE_TYPE_AAC
+
+        cmd("ffmpeg -i \"#{@speed_mix_file}\" -c:a libfdk_aac -b:a 128k \"#{output}\"")
         output
       end
     end
diff --git a/ruby/spec/jam_ruby/models/jam_track_mixdown_spec.rb b/ruby/spec/jam_ruby/models/jam_track_mixdown_spec.rb
index 7bd5c2557..8da940afd 100644
--- a/ruby/spec/jam_ruby/models/jam_track_mixdown_spec.rb
+++ b/ruby/spec/jam_ruby/models/jam_track_mixdown_spec.rb
@@ -33,12 +33,43 @@ describe JamTrackMixdown do
     count.should eq(1)
   end
 
-  it "validates settings" do
-    invalid = FactoryGirl.build(:jam_track_mixdown, settings: {}.to_json)
-    invalid.save
-    invalid.errors.any?.should be_true
-    invalid.errors["settings"].should eq(["have nothing specified"])
+  describe "settings" do
+    it "validates empty settings" do
+      invalid = FactoryGirl.build(:jam_track_mixdown, settings: {}.to_json)
+      invalid.save
+      invalid.errors.any?.should be_true
+      invalid.errors["settings"].should eq(["have nothing specified"])
+    end
+
+    it "validates speed numeric" do
+      invalid = FactoryGirl.build(:jam_track_mixdown, settings: {"speed": "5"}.to_json)
+      invalid.save
+      invalid.errors.any?.should be_true
+      invalid.errors["settings"].should eq(["has non-integer speed"])
+    end
+
+    it "validates pitch numeric" do
+      invalid = FactoryGirl.build(:jam_track_mixdown, settings: {"pitch": "5"}.to_json)
+      invalid.save
+      invalid.errors.any?.should be_true
+      invalid.errors["settings"].should eq(["has non-integer pitch"])
+    end
+
+    it "validates speed not-float" do
+      invalid = FactoryGirl.build(:jam_track_mixdown, settings: {"speed": 5.5}.to_json)
+      invalid.save
+      invalid.errors.any?.should be_true
+      invalid.errors["settings"].should eq(["has non-integer speed"])
+    end
+
+    it "validates pitch not-float" do
+      invalid = FactoryGirl.build(:jam_track_mixdown, settings: {"pitch": 10.5}.to_json)
+      invalid.save
+      invalid.errors.any?.should be_true
+      invalid.errors["settings"].should eq(["has non-integer pitch"])
+    end
   end
 
+
 end
 
diff --git a/web/app/assets/javascripts/react-components/PopupMediaControls.js.jsx.coffee b/web/app/assets/javascripts/react-components/PopupMediaControls.js.jsx.coffee
index a923804fb..ae0a58368 100644
--- a/web/app/assets/javascripts/react-components/PopupMediaControls.js.jsx.coffee
+++ b/web/app/assets/javascripts/react-components/PopupMediaControls.js.jsx.coffee
@@ -294,7 +294,7 @@ mixins.push(Reflux.listenTo(JamTrackStore, 'onJamTrackChanged'))
 
     mixdown = {jamTrackID: @state.jamTrack.id, name: name, settings: {speed:speed, pitch: pitch}}
 
-    package_settings = {file_type: 'ogg', encrypt_type: 'jkz'}
+    package_settings = {file_type: 'aac', encrypt_type: null}
 
     JamTrackMixdownActions.create(mixdown, package_settings, @createMixdownDone, @createMixdownFail)