diff --git a/src/fixed/common.cpp b/src/fixed/common.cpp
index e31efd7..c9edb5c 100644
--- a/src/fixed/common.cpp
+++ b/src/fixed/common.cpp
@@ -10,6 +10,8 @@ Matrix* matrixPtr = matrixStack;
     AABBi frustumAABB;
 #endif
 
+EWRAM_DATA Sphere gSpheres[2][MAX_SPHERES];
+
 const FloorData* gLastFloorData;
 FloorData gLastFloorSlant;
 TargetInfo tinfo;
@@ -773,6 +775,7 @@ void matrixSetBasis_c(Matrix &dst, const Matrix &src)
     dst.e12 = src.e12;
 }
 
+#ifndef IWRAM_MATRIX_LERP
 #define LERP_1_2(a, b)   a = (b + a) >> 1
 #define LERP_1_3(a, b)   a = a + (b - a) / 3
 #define LERP_2_3(a, b)   a = b - (b - a) / 3
@@ -832,6 +835,7 @@ void matrixLerp_c(const Matrix &n, int32 pmul, int32 pdiv)
         LERP_MATRIX(LERP_SLOW);
     }
 }
+#endif
 
 void matrixTranslate_c(int32 x, int32 y, int32 z)
 {
diff --git a/src/fixed/common.h b/src/fixed/common.h
index 27c341c..b40b781 100644
--- a/src/fixed/common.h
+++ b/src/fixed/common.h
@@ -350,6 +350,7 @@ extern void* osLoadLevel(const char* name);
 
 #define STATIC_MESH_FLAG_NO_COLLISION   1
 #define STATIC_MESH_FLAG_VISIBLE        2
+#define MAX_STATIC_MESH_RADIUS          (5 * 1024)
 
 extern int32 fps;
 
@@ -904,7 +905,7 @@ struct Mesh {
 struct StaticMesh {
     uint16 id;
     uint16 meshIndex;
-    uint16 flags;
+    uint32 flags;
     AABBs vbox;
     AABBs cbox;
 };
@@ -2050,6 +2051,7 @@ extern int32 gFacesCount;
     extern AABBi frustumAABB;
 #endif
 
+extern Sphere gSpheres[2][MAX_SPHERES];
 extern SaveGame gSaveGame;
 extern Settings gSettings;
 extern int32 gCurTrack;
@@ -2135,6 +2137,7 @@ vec3i boxPushOut(const AABBi &a, const AABBi &b);
         void matrixRotateYQ_asm(int32 quadrant);
         void boxTranslate_asm(AABBi &box, int32 x, int32 y, int32 z);
         void boxRotateYQ_asm(AABBi &box, int32 quadrant);
+        bool transformBoxRect_asm(const AABBs* box, RectMinMax* rect);
     }
 
     #define phd_sin                 phd_sin_asm
@@ -2147,6 +2150,7 @@ vec3i boxPushOut(const AABBi &a, const AABBi &b);
     #define matrixRotateYQ          matrixRotateYQ_asm
     #define boxTranslate            boxTranslate_asm
     #define boxRotateYQ             boxRotateYQ_asm
+    #define transformBoxRect        transformBoxRect_asm
 #else
     #define phd_sin                 phd_sin_c
     #define matrixPush              matrixPush_c
@@ -2158,6 +2162,7 @@ vec3i boxPushOut(const AABBi &a, const AABBi &b);
     #define matrixRotateYQ          matrixRotateYQ_c
     #define boxTranslate            boxTranslate_c
     #define boxRotateYQ             boxRotateYQ_c
+    #define transformBoxRect        transformBoxRect_c
 
     int32 phd_sin_c(int32 x);
     
@@ -2171,6 +2176,8 @@ vec3i boxPushOut(const AABBi &a, const AABBi &b);
 
     void boxTranslate_c(AABBi &box, int32 x, int32 y, int32 z);
     void boxRotateYQ_c(AABBi &box, int32 quadrant);
+
+    bool transformBoxRect_c(const AABBs* box, RectMinMax* rect);
 #endif
 
 #define phd_cos(x)      phd_sin((x) + ANGLE_90)
@@ -2199,7 +2206,6 @@ void setPaletteIndex(int32 index);
 void clear();
 int32 rectIsVisible(const RectMinMax* rect);
 int32 boxIsVisible(const AABBs* box);
-bool transformBoxRect(const AABBs* box, RectMinMax* rect);
 void transformRoom(const Room* room);
 void transformMesh(const MeshVertex* vertices, int32 vCount, const uint16* vIntensity, const vec3s* vNormal);
 void faceAddQuad(uint32 flags, const Index* indices);
diff --git a/src/fixed/draw.h b/src/fixed/draw.h
index 8c40c43..e07d77a 100644
--- a/src/fixed/draw.h
+++ b/src/fixed/draw.h
@@ -771,9 +771,9 @@ void drawRoom(const Room* room, Camera* camera)
     int32 rz = info->z << 8;
 
     matrixPush();
-    matrixTranslateAbs(info->x << 8, info->yTop, info->z << 8);
+    matrixTranslateAbs(rx, info->yTop, rz);
 
-    camera->updateFrustum(info->x << 8, info->yTop, info->z << 8);
+    camera->updateFrustum(rx, info->yTop, rz);
 
     setPaletteIndex(ROOM_FLAG_WATER(info->flags) ? 1 : 0);
 
@@ -833,9 +833,9 @@ void drawRoom(const Room* room, Camera* camera)
         if (!(staticMesh->flags & STATIC_MESH_FLAG_VISIBLE)) continue; // invisible
 
         vec3i pos;
-        pos.x = mesh->pos.x + (info->x << 8);
+        pos.x = mesh->pos.x + rx;
         pos.y = mesh->pos.y;
-        pos.z = mesh->pos.z + (info->z << 8);
+        pos.z = mesh->pos.z + rz;
 
         matrixPush();
         matrixTranslateAbs(pos.x, pos.y, pos.z);
@@ -843,7 +843,7 @@ void drawRoom(const Room* room, Camera* camera)
 
         int32 vis = boxIsVisible(&staticMesh->vbox);
         if (vis != 0) {
-            enableClipping =vis < 0; // TODO wrong visibility BBox?
+            enableClipping = vis < 0; // TODO wrong visibility BBox?
 
             calcLightingStatic(mesh->intensity << 5);
             drawMesh(staticMesh->meshIndex);
@@ -899,7 +899,9 @@ void drawRooms(Camera* camera)
         }
     }
 
+#ifndef MODEHW
     flush();
+#endif
 
     setPaletteIndex(0);
     setViewport(camera->view.room->clip);
diff --git a/src/fixed/game.h b/src/fixed/game.h
index 375fb06..6c9ab51 100644
--- a/src/fixed/game.h
+++ b/src/fixed/game.h
@@ -29,6 +29,7 @@ struct Game
 
         animTexFrame = 0;
 
+        sndStop();
         sndFreeSamples();
 
         void* data = osLoadLevel(name);
diff --git a/src/fixed/item.h b/src/fixed/item.h
index 351ae2f..c202292 100644
--- a/src/fixed/item.h
+++ b/src/fixed/item.h
@@ -987,8 +987,8 @@ uint32 ItemObj::collideSpheres(Lara* lara) const
     return 0xFFFFFFFF;
 #endif
 
-    Sphere a[MAX_SPHERES];
-    Sphere b[MAX_SPHERES];
+    Sphere *a = gSpheres[0];
+    Sphere *b = gSpheres[1];
 
     int32 aCount = getSpheres(a, true);
     int32 bCount = lara->getSpheres(b, true);
diff --git a/src/fixed/lara.h b/src/fixed/lara.h
index 0d45a7b..2fe0825 100644
--- a/src/fixed/lara.h
+++ b/src/fixed/lara.h
@@ -3121,12 +3121,12 @@ struct Lara : ItemObj
 
             if (arm->target && arm->target->health > 0)
             {
-                Sphere spheres[MAX_SPHERES];
+                Sphere* spheres = gSpheres[0];
                 int32 spheresCount = arm->target->getSpheres(spheres, false);
 
                 for (int32 i = 0; i < spheresCount; i++)
                 {
-                    Sphere &s = spheres[i];
+                    const Sphere &s = spheres[i];
 
                     if (abs(s.center.x) >= s.radius)
                         continue;
diff --git a/src/fixed/room.h b/src/fixed/room.h
index 2c2e17c..8c9d0ac 100644
--- a/src/fixed/room.h
+++ b/src/fixed/room.h
@@ -300,6 +300,10 @@ bool Room::collideStatic(CollisionInfo &cinfo, const vec3i &p, int32 height)
     {
         const Room* room = *nearRoom++;
 
+        int32 rx = p.x - (room->info->x << 8);
+        int32 ry = p.y;
+        int32 rz = p.z - (room->info->z << 8);
+
         for (int i = 0; i < room->info->meshesCount; i++)
         {
             const RoomMesh* mesh = room->data.meshes + i;
@@ -314,10 +318,12 @@ bool Room::collideStatic(CollisionInfo &cinfo, const vec3i &p, int32 height)
             if (staticMesh->flags & STATIC_MESH_FLAG_NO_COLLISION)
                 continue;
 
-        // TODO align RoomInfo::Mesh (room relative int16?)
-            int32 x = mesh->pos.x - p.x + (room->info->x << 8);
-            int32 y = mesh->pos.y - p.y;
-            int32 z = mesh->pos.z - p.z + (room->info->z << 8);
+            int32 x = mesh->pos.x - rx;
+            int32 y = mesh->pos.y - ry;
+            int32 z = mesh->pos.z - rz;
+
+            if (abs(x) > MAX_STATIC_MESH_RADIUS || abs(z) > MAX_STATIC_MESH_RADIUS || abs(y) > MAX_STATIC_MESH_RADIUS)
+                continue;
 
             AABBi meshBox(staticMesh->cbox);
             boxRotateYQ(meshBox, STATIC_MESH_QUADRANT(mesh->flags));
diff --git a/src/platform/3do/common_asm.inc b/src/platform/3do/common_asm.inc
index f430591..842befc 100644
--- a/src/platform/3do/common_asm.inc
+++ b/src/platform/3do/common_asm.inc
@@ -32,6 +32,7 @@ FRAME_WIDTH     EQU 320
 FRAME_HEIGHT    EQU 240
 
 FIXED_SHIFT     EQU 14
+F16_SHIFT       EQU (16 - FIXED_SHIFT)
 PROJ_SHIFT      EQU 4
 LVL_TEX_OFFSET  EQU (23 * 4)
 
diff --git a/src/platform/3do/render_cel.cpp b/src/platform/3do/render_cel.cpp
index 51af3e0..597d868 100644
--- a/src/platform/3do/render_cel.cpp
+++ b/src/platform/3do/render_cel.cpp
@@ -143,30 +143,6 @@ void setPaletteIndex(int32 index)
     gPalette = (uint16*)(intptr_t(RAM_TEX) + paletteOffset + index * level.tilesCount * sizeof(uint16) * 16);
 }
 
-int32 rectIsVisible(const RectMinMax* rect)
-{
-    if (rect->x0 > rect->x1 ||
-        rect->x0 > viewport.x1 ||
-        rect->x1 < viewport.x0 ||
-        rect->y0 > viewport.y1 ||
-        rect->y1 < viewport.y0) return 0; // not visible
-
-    if (rect->x0 < viewport.x0 ||
-        rect->x1 > viewport.x1 ||
-        rect->y0 < viewport.y0 ||
-        rect->y1 > viewport.y1) return -1; // clipped
-
-    return 1; // fully visible
-}
-
-int32 boxIsVisible(const AABBs* box)
-{
-    RectMinMax rect;
-    if (!transformBoxRect(box, &rect))
-        return 0; // not visible
-    return rectIsVisible(&rect);
-}
-
 X_INLINE int32 cross(const Vertex *a, const Vertex *b, const Vertex *c)
 {
     return (b->x - a->x) * (c->y - a->y) -
@@ -710,9 +686,8 @@ void faceAddMeshTrianglesFlat_c(const MeshTriangle* polys, int32 count, uint32 s
         ccbMap3(f, v0, v1, v2, 20 | (16 << 8));
     }
 }
-#endif
 
-bool transformBoxRect(const AABBs* box, RectMinMax* rect)
+bool transformBoxRect_c(const AABBs* box, RectMinMax* rect)
 {
     Matrix &m = matrixGet();
 
@@ -720,12 +695,14 @@ bool transformBoxRect(const AABBs* box, RectMinMax* rect)
         return false;
     }
 
-    int32 minX = box->minX << F16_SHIFT;
-    int32 maxX = box->maxX << F16_SHIFT;
-    int32 minY = box->minY << F16_SHIFT;
-    int32 maxY = box->maxY << F16_SHIFT;
-    int32 minZ = box->minZ << F16_SHIFT;
-    int32 maxZ = box->maxZ << F16_SHIFT;
+    const int32* ptr = (int32*)box;
+
+    int32 minX = ptr[0] >> 16 << F16_SHIFT;
+    int32 maxX = ptr[0] << 16 >> (16 - F16_SHIFT);
+    int32 minY = ptr[1] >> 16 << F16_SHIFT;
+    int32 maxY = ptr[1] << 16 >> (16 - F16_SHIFT);
+    int32 minZ = ptr[2] >> 16 << F16_SHIFT;
+    int32 maxZ = ptr[2] << 16 >> (16 - F16_SHIFT);
 
     gVertices[0].x = minX; gVertices[0].y = minY; gVertices[0].z = minZ;
     gVertices[1].x = maxX; gVertices[1].y = minY; gVertices[1].z = minZ;
@@ -738,7 +715,10 @@ bool transformBoxRect(const AABBs* box, RectMinMax* rect)
 
     projectVertices(8);
 
-    *rect = RectMinMax( INT_MAX, INT_MAX, INT_MIN, INT_MIN );
+    int32 x0 = INT_MAX;
+    int32 y0 = INT_MAX;
+    int32 x1 = INT_MIN;
+    int32 y1 = INT_MIN;
 
     const Vertex* v = gVertices;
 
@@ -748,22 +728,47 @@ bool transformBoxRect(const AABBs* box, RectMinMax* rect)
         int32 y = v->y;
         int32 z = v->z;
 
-        if ((z & CLIP_MASK) & (CLIP_NEAR | CLIP_FAR))
+        if (z & (CLIP_NEAR | CLIP_FAR))
             continue;
 
-        if (x < rect->x0) rect->x0 = x;
-        if (x > rect->x1) rect->x1 = x;
-        if (y < rect->y0) rect->y0 = y;
-        if (y > rect->y1) rect->y1 = y;
+        if (x < x0) x0 = x;
+        if (y < y0) y0 = y;
+        if (x > x1) x1 = x;
+        if (y > y1) y1 = y;
     }
 
-    rect->x0 += (FRAME_WIDTH  / 2);
-    rect->y0 += (FRAME_HEIGHT / 2);
-    rect->x1 += (FRAME_WIDTH  / 2);
-    rect->y1 += (FRAME_HEIGHT / 2);
+    rect->x0 = x0 + (FRAME_WIDTH  / 2);
+    rect->y0 = y0 + (FRAME_HEIGHT / 2);
+    rect->x1 = x1 + (FRAME_WIDTH  / 2);
+    rect->y1 = y1 + (FRAME_HEIGHT / 2);
 
     return true;
 }
+#endif
+
+int32 rectIsVisible(const RectMinMax* rect)
+{
+    if (rect->x0 > rect->x1 ||
+        rect->x0 > viewport.x1 ||
+        rect->x1 < viewport.x0 ||
+        rect->y0 > viewport.y1 ||
+        rect->y1 < viewport.y0) return 0; // not visible
+
+    if (rect->x0 < viewport.x0 ||
+        rect->x1 > viewport.x1 ||
+        rect->y0 < viewport.y0 ||
+        rect->y1 > viewport.y1) return -1; // clipped
+
+    return 1; // fully visible
+}
+
+int32 boxIsVisible(const AABBs* box)
+{
+    RectMinMax rect;
+    if (!transformBoxRect(box, &rect))
+        return 0; // not visible
+    return rectIsVisible(&rect);
+}
 
 void transformRoom(const Room* room)
 {
diff --git a/src/platform/3do/sound.cpp b/src/platform/3do/sound.cpp
index 5bde0db..e851ee6 100644
--- a/src/platform/3do/sound.cpp
+++ b/src/platform/3do/sound.cpp
@@ -147,7 +147,7 @@ void sndInit()
 
     StartInstrument(sndMixer, NULL);
 
-    musicThread = CreateThread("music", 180, musicProc, 4096);
+    musicThread = CreateThread("music", 180, musicProc, 2048);
 }
 
 void sndInitSamples()
@@ -272,10 +272,9 @@ void* sndPlaySample(int32 index, int32 volume, int32 pitch, int32 mode)
 // stop a longest playing sample
     if (maxPosIndex != -1)
     {
-        Channel* ch = channels + maxPosIndex;
+        sndStopSample(maxPosIndex);
 
-        StopInstrument(ch->sampler, NULL);
-        DetachSample(ch->attach);
+        Channel* ch = channels + maxPosIndex;
 
         ch->setVolume(volume);
         ch->setPitch(pitch);
@@ -312,10 +311,21 @@ bool sndTrackIsPlaying()
 
 void sndStopSample(int32 index)
 {
+    Channel* ch = channels + index;
+    if (!ch->playing)
+        return;
 
+    StopInstrument(ch->sampler, NULL);
+    DetachSample(ch->attach);
+    ch->index = -1;
+    ch->playing = false;
 }
 
 void sndStop()
 {
-    sndStopTrack();
+    //sndStopTrack(); // TODO wait for signal?
+    for (int32 i = 0; i < SND_CHANNELS - 1; i++)
+    {
+        sndStopSample(i);
+    }
 }
\ No newline at end of file
diff --git a/src/platform/3do/transformBoxRect.s b/src/platform/3do/transformBoxRect.s
new file mode 100644
index 0000000..8becaa9
--- /dev/null
+++ b/src/platform/3do/transformBoxRect.s
@@ -0,0 +1,123 @@
+    AREA |C$$code|, CODE, READONLY
+|x$codeseg|
+
+    INCLUDE common_asm.inc
+
+    IMPORT projectVertices_asm
+
+    EXPORT transformBoxRect_asm
+
+boxArg  RN r0
+rectArg RN r1
+m       RN r2
+vert    RN r3
+vptr    RN r4
+rect    RN r5   ; must be in r4-r6
+minX    RN boxArg
+maxX    RN rectArg
+minY    RN m
+maxY    RN r6
+minZ    RN r12
+maxZ    RN lr
+
+xx      RN maxX
+yy      RN maxY
+zz      RN maxZ
+rMinX   RN boxArg
+rMinY   RN rectArg
+rMaxX   RN m
+rMaxY   RN maxY
+vx      RN vptr
+vy      RN minZ
+vz      RN maxZ
+
+INT_MIN EQU 0x80000000
+INT_MAX EQU 0x7FFFFFFF
+
+    MACRO
+$index  check
+        ldmia vert!, {vx, vy, vz}
+        tst vz, #(CLIP_NEAR | CLIP_FAR)
+        bne $index.skip
+        cmp vx, rMinX
+        movlt rMinX, vx
+        cmp vy, rMinY
+        movlt rMinY, vy
+        cmp vx, rMaxX
+        movgt rMaxX, vx
+        cmp vy, rMaxY
+        movgt rMaxY, vy
+$index.skip
+    MEND
+
+transformBoxRect_asm
+        ldr m, =matrixPtr
+        ldr m, [m]
+        ldr m, [m, #(11 * 4)]
+        cmp m, #VIEW_MIN_F
+        movlt r0, #0
+        movlt pc, lr
+        cmp m, #VIEW_MAX_F
+        movge r0, #0
+        movge pc, lr
+
+        stmfd sp!, {r4-r6, lr}
+
+        mov rect, rectArg   ; to use after projectVertices_asm call
+        ldmia boxArg, {xx, yy, zz}
+
+        mov minX, xx, asr #16
+        mov maxX, xx, lsl #16
+        mov maxX, maxX, asr #(16 - F16_SHIFT)
+        mov minX, minX, lsl #2
+
+        mov minY, yy, asr #16
+        mov maxY, yy, lsl #16
+        mov maxY, maxY, asr #(16 - F16_SHIFT)
+        mov minY, minY, lsl #2
+
+        mov minZ, zz, asr #16
+        mov maxZ, zz, lsl #16
+        mov maxZ, maxZ, asr #(16 - F16_SHIFT)
+        mov minZ, minZ, lsl #2
+
+        ldr vptr, =gVertices
+
+        mov vert, vptr
+        stmia vert!, {minX, minY, minZ}
+        stmia vert!, {maxX, minY, minZ}
+        stmia vert!, {minX, maxY, minZ}
+        stmia vert!, {maxX, maxY, minZ}
+        stmia vert!, {minX, minY, maxZ}
+        stmia vert!, {maxX, minY, maxZ}
+        stmia vert!, {minX, maxY, maxZ}
+        stmia vert!, {maxX, maxY, maxZ}
+
+        mov r0, #8
+        bl projectVertices_asm  ; TODO compare with non-SWI version
+
+        mov rMinX, #INT_MAX
+        mov rMinY, #INT_MAX
+        mov rMaxX, #INT_MIN
+        mov rMaxY, #INT_MIN
+
+        mov vert, vptr
+_0      check
+_1      check
+_2      check
+_3      check
+_4      check
+_5      check
+_6      check
+_7      check
+
+_done   add rMinX, rMinX, #(FRAME_WIDTH >> 1)
+        add rMinY, rMinY, #(FRAME_HEIGHT >> 1)
+        add rMaxX, rMaxX, #(FRAME_WIDTH >> 1)
+        add rMaxY, rMaxY, #(FRAME_HEIGHT >> 1)
+
+        stmia rect, {rMinX, rMinY, rMaxX, rMaxY}
+
+        mov r0, #1
+        ldmfd sp!, {r4-r6, pc}
+    END
diff --git a/src/platform/gba/packer/main.cpp b/src/platform/gba/packer/main.cpp
index c0162e7..1a9b961 100644
--- a/src/platform/gba/packer/main.cpp
+++ b/src/platform/gba/packer/main.cpp
@@ -1319,7 +1319,7 @@ struct LevelPC
     {
         uint16 id;
         uint16 meshIndex;
-        uint16 flags;
+        uint32 flags;
         MinMax vbox;
         MinMax cbox;
 
@@ -2771,8 +2771,6 @@ struct LevelPC
 
         header.frameData = f.align4();
         f.write(frameData, frameDataSize);
-        
-        static int32 maxMeshes = 0;
 
         header.models = f.align4();
         for (int32 i = 0; i < modelsCount; i++)
@@ -4175,8 +4173,6 @@ struct LevelPC
 
         header.frameData = f.align4();
         f.write(frameData, frameDataSize);
-        
-        static int32 maxMeshes = 0;
 
         header.models = f.align4();
         for (int32 i = 0; i < modelsCount; i++)