diff --git a/Detector/DetEcalMatrix/compact/det.xml b/Detector/DetEcalMatrix/compact/det.xml
index ef4c0ed9e590b4eb9b8116e40f7215dc309ce285..bb4f486360a1c5bee3176f9ca2214653ddda0cf7 100644
--- a/Detector/DetEcalMatrix/compact/det.xml
+++ b/Detector/DetEcalMatrix/compact/det.xml
@@ -32,13 +32,18 @@
 
   <detectors>
     <detector id="1" name="CaloDetector" type="EcalMatrix" readout="CaloHitsCollection" vis="VisibleGreen" sensitive="true">
-      <position x="0"  y="0"  z="1800*mm"/>
+      <position x="0"  y="0"  z="1835*mm+30*cm"/>
+      <dimensions dx="30*cm"  dy="30*cm"  dz="30*cm"/>
     </detector>
   </detectors>
   
   <readouts>
     <readout name="CaloHitsCollection">
-      <id>system:8</id>
+      <segmentation type="CartesianGridXYZ" 
+                    grid_size_x="1*cm" 
+                    grid_size_y="1*cm" 
+                    grid_size_z="1*cm"/>
+      <id>system:8,x:32:-6,y:-6,z:-6</id>
     </readout>
   </readouts>
 
diff --git a/Detector/DetEcalMatrix/src/calorimeter/EcalMatrix.cpp b/Detector/DetEcalMatrix/src/calorimeter/EcalMatrix.cpp
index 0869850674d7555030ff1c31715a9f5641350721..274330ba63acddec63b9c15abcdea8e8b3ac6d37 100644
--- a/Detector/DetEcalMatrix/src/calorimeter/EcalMatrix.cpp
+++ b/Detector/DetEcalMatrix/src/calorimeter/EcalMatrix.cpp
@@ -27,6 +27,7 @@ static dd4hep::Ref_t create_detector(dd4hep::Detector& theDetector,
     MYDEBUGVAL(det_name);
     MYDEBUGVAL(det_type);
     xml_dim_t   pos    (x_det.child(_U(position)));
+    xml_dim_t   dim    (x_det.child(_U(dimensions)));
 
 
     dd4hep::DetElement sdet(det_name, x_det.id());
@@ -34,7 +35,7 @@ static dd4hep::Ref_t create_detector(dd4hep::Detector& theDetector,
     dd4hep::Volume motherVol = theDetector.pickMotherVolume(sdet);
 
     dd4hep::Material det_mat(theDetector.material("G4_BGO"));
-    dd4hep::Volume det_vol(det_name+"_vol", dd4hep::Box(60, 60, 60), det_mat);
+    dd4hep::Volume det_vol(det_name+"_vol", dd4hep::Box(dim.dx(), dim.dy(), dim.dz()), det_mat);
 
     dd4hep::Transform3D transform(dd4hep::Rotation3D(),
                                   dd4hep::Position(pos.x(),pos.y(),pos.z()));