diff --git a/src/easydynamics/sample_model/components/damped_harmonic_oscillator.py b/src/easydynamics/sample_model/components/damped_harmonic_oscillator.py
index 86fd6c0b..e7ea9561 100644
--- a/src/easydynamics/sample_model/components/damped_harmonic_oscillator.py
+++ b/src/easydynamics/sample_model/components/damped_harmonic_oscillator.py
@@ -26,9 +26,9 @@ class DampedHarmonicOscillator(CreateParametersMixin, ModelComponent):
 
     def __init__(
         self,
-        area: Numeric | Parameter = 1.0,
-        center: Numeric | Parameter = 1.0,
-        width: Numeric | Parameter = 1.0,
+        area: Numeric = 1.0,
+        center: Numeric = 1.0,
+        width: Numeric = 1.0,
         unit: str | sc.Unit = 'meV',
         name: str = 'DampedHarmonicOscillator',
         display_name: str | None = None,
@@ -39,11 +39,11 @@ def __init__(
 
         Parameters
         ----------
-        area : Numeric | Parameter, default=1.0
+        area : Numeric, default=1.0
             Area under the curve.
-        center : Numeric | Parameter, default=1.0
+        center : Numeric, default=1.0
             Resonance frequency, approximately the peak position.
-        width : Numeric | Parameter, default=1.0
+        width : Numeric, default=1.0
             Damping constant, approximately the half width at half max (HWHM) of the peaks. By
             default, 1.0.
         unit : str | sc.Unit, default='meV'
diff --git a/src/easydynamics/sample_model/components/delta_function.py b/src/easydynamics/sample_model/components/delta_function.py
index d63780fa..c10e6185 100644
--- a/src/easydynamics/sample_model/components/delta_function.py
+++ b/src/easydynamics/sample_model/components/delta_function.py
@@ -30,8 +30,8 @@ class DeltaFunction(CreateParametersMixin, ModelComponent):
 
     def __init__(
         self,
-        center: Numeric | Parameter | None = None,
-        area: Numeric | Parameter = 1.0,
+        center: Numeric | None = None,
+        area: Numeric = 1.0,
         unit: str | sc.Unit = 'meV',
         name: str = 'DeltaFunction',
         display_name: str | None = None,
@@ -42,9 +42,9 @@ def __init__(
 
         Parameters
         ----------
-        center : Numeric | Parameter | None, default=None
+        center : Numeric | None, default=None
             Center of the delta function. If None, it will be centered at 0 and fixed.
-        area : Numeric | Parameter, default=1.0
+        area : Numeric, default=1.0
             Total area under the curve.
         unit : str | sc.Unit, default='meV'
             Unit of the parameters.
diff --git a/src/easydynamics/sample_model/components/exponential.py b/src/easydynamics/sample_model/components/exponential.py
index b331b162..8894a065 100644
--- a/src/easydynamics/sample_model/components/exponential.py
+++ b/src/easydynamics/sample_model/components/exponential.py
@@ -25,9 +25,9 @@ class Exponential(CreateParametersMixin, ModelComponent):
 
     def __init__(
         self,
-        amplitude: Numeric | Parameter = 1.0,
-        center: Numeric | Parameter | None = None,
-        rate: Numeric | Parameter = 1.0,
+        amplitude: Numeric = 1.0,
+        center: Numeric | None = None,
+        rate: Numeric = 1.0,
         unit: str | sc.Unit = 'meV',
         name: str = 'Exponential',
         display_name: str | None = None,
@@ -38,11 +38,11 @@ def __init__(
 
         Parameters
         ----------
-        amplitude : Numeric | Parameter, default=1.0
+        amplitude : Numeric, default=1.0
             Amplitude of the Exponential.
-        center : Numeric | Parameter | None, default=None
+        center : Numeric | None, default=None
             Center of the Exponential. If None, the center is fixed at 0.
-        rate : Numeric | Parameter, default=1.0
+        rate : Numeric, default=1.0
             Decay or growth constant of the Exponential.
         unit : str | sc.Unit, default='meV'
             Unit of the parameters.
diff --git a/src/easydynamics/sample_model/components/gaussian.py b/src/easydynamics/sample_model/components/gaussian.py
index 54cfe97c..cab505b1 100644
--- a/src/easydynamics/sample_model/components/gaussian.py
+++ b/src/easydynamics/sample_model/components/gaussian.py
@@ -33,9 +33,9 @@ class Gaussian(CreateParametersMixin, ModelComponent):
 
     def __init__(
         self,
-        area: Numeric | Parameter = 1.0,
-        center: Numeric | Parameter | None = None,
-        width: Numeric | Parameter = 1.0,
+        area: Numeric = 1.0,
+        center: Numeric | None = None,
+        width: Numeric = 1.0,
         unit: str | sc.Unit = 'meV',
         name: str = 'Gaussian',
         display_name: str | None = None,
@@ -46,11 +46,11 @@ def __init__(
 
         Parameters
         ----------
-        area : Numeric | Parameter, default=1.0
+        area : Numeric, default=1.0
             Area of the Gaussian.
-        center : Numeric | Parameter | None, default=None
+        center : Numeric | None, default=None
             Center of the Gaussian. If None.
-        width : Numeric | Parameter, default=1.0
+        width : Numeric, default=1.0
             Standard deviation.
         unit : str | sc.Unit, default='meV'
             Unit of the parameters.
diff --git a/src/easydynamics/sample_model/components/lorentzian.py b/src/easydynamics/sample_model/components/lorentzian.py
index 81453fb8..88051d16 100644
--- a/src/easydynamics/sample_model/components/lorentzian.py
+++ b/src/easydynamics/sample_model/components/lorentzian.py
@@ -30,9 +30,9 @@ class Lorentzian(CreateParametersMixin, ModelComponent):
 
     def __init__(
         self,
-        area: Numeric | Parameter = 1.0,
-        center: Numeric | Parameter | None = None,
-        width: Numeric | Parameter = 1.0,
+        area: Numeric = 1.0,
+        center: Numeric | None = None,
+        width: Numeric = 1.0,
         unit: str | sc.Unit = 'meV',
         name: str = 'Lorentzian',
         display_name: str | None = None,
@@ -43,11 +43,11 @@ def __init__(
 
         Parameters
         ----------
-        area : Numeric | Parameter, default=1.0
+        area : Numeric, default=1.0
             Area of the Lorentzian.
-        center : Numeric | Parameter | None, default=None
+        center : Numeric | None, default=None
             Center of the Lorentzian. If None, defaults to 0 and is fixed.
-        width : Numeric | Parameter, default=1.0
+        width : Numeric, default=1.0
             Half width at half maximum (HWHM).
         unit : str | sc.Unit, default='meV'
             Unit of the parameters.
diff --git a/src/easydynamics/sample_model/components/mixins.py b/src/easydynamics/sample_model/components/mixins.py
index 0d760865..22ef7bc5 100644
--- a/src/easydynamics/sample_model/components/mixins.py
+++ b/src/easydynamics/sample_model/components/mixins.py
@@ -24,7 +24,7 @@ class CreateParametersMixin:
 
     def _create_area_parameter(
         self,
-        area: Numeric | Parameter,
+        area: Numeric,
         name: str,
         unit: str | sc.Unit = 'meV',
         minimum_area: float = MINIMUM_AREA,
@@ -37,11 +37,11 @@ def _create_area_parameter(
 
         Parameters
         ----------
-        area : Numeric | Parameter
-            The area value or Parameter.
+        area : Numeric
+            The area value.
         name : str
             The name of the model component.
-        unit : str | sc.Unit, default='meV'
+        unit : str | sc.Unit, default="meV"
             The unit of the area Parameter.
         minimum_area : float, default=MINIMUM_AREA
             The minimum allowed area.
@@ -49,39 +49,36 @@ def _create_area_parameter(
         Raises
         ------
         TypeError
-            If area is not a number or a Parameter.
+            If area is not a number.
         ValueError
-            If area is not a finite number or if the area Parameter has a non-finite value.
+            If area is not a finite number.
 
         Returns
         -------
         Parameter
             The validated area Parameter.
         """
-        if not isinstance(area, (Parameter, Numeric)):
-            raise TypeError('area must be a number or a Parameter.')
+        if not isinstance(area, Numeric):
+            raise TypeError('area must be a number.')
 
-        if isinstance(area, Numeric):
-            if not np.isfinite(area):
-                raise ValueError('area must be a finite number or a Parameter')
+        if not np.isfinite(area):
+            raise ValueError('area must be a finite number.')
+        area_param = Parameter(name=name + ' area', value=float(area), unit=unit)
 
-            area = Parameter(name=name + ' area', value=float(area), unit=unit)
-
-        if area.value < 0:
+        if area_param.value < 0:
             warnings.warn(
                 f'The area of {name} is negative, which may not be physically meaningful.',
                 UserWarning,
                 stacklevel=3,
             )
         else:
-            if area.min < minimum_area:
-                area.min = minimum_area
+            area_param.min = minimum_area
 
-        return area
+        return area_param
 
     def _create_center_parameter(
         self,
-        center: Numeric | Parameter | None,
+        center: Numeric | None,
         name: str,
         fix_if_none: bool,
         unit: str | sc.Unit = 'meV',
@@ -92,13 +89,13 @@ def _create_center_parameter(
 
         Parameters
         ----------
-        center : Numeric | Parameter | None
-            The center value or Parameter.
+        center : Numeric | None
+            The center value.
         name : str
             The name of the model component.
         fix_if_none : bool
             Whether to fix the center Parameter if center is None.
-        unit : str | sc.Unit, default='meV'
+        unit : str | sc.Unit, default="meV"
             The unit of the center Parameter.
         enforce_minimum_center : bool, default=False
             Whether to enforce a minimum center value to avoid zero center in DHO.
@@ -106,38 +103,37 @@ def _create_center_parameter(
         Raises
         ------
         TypeError
-            If center is not None, a number, or a Parameter.
+            If center is not None or a number.
         ValueError
-            If center is a number but not finite, or if center is a Parameter but has a non-finite
-            value.
+            If center is a number but not finite.
 
         Returns
         -------
         Parameter
             The validated center Parameter.
         """
-        if center is not None and not isinstance(center, (Numeric, Parameter)):
-            raise TypeError('center must be None, a number, or a Parameter.')
+        if center is not None and not isinstance(center, Numeric):
+            raise TypeError('center must be None or a number.')
 
         if center is None:
-            center = Parameter(
+            center_param = Parameter(
                 name=name + ' center',
                 value=0.0,
                 unit=unit,
                 fixed=fix_if_none,
             )
-        elif isinstance(center, Numeric):
+        else:
             if not np.isfinite(center):
-                raise ValueError('center must be None, a finite number or a Parameter')
+                raise ValueError('center must be None or a finite number.')
 
-            center = Parameter(name=name + ' center', value=float(center), unit=unit)
-        if enforce_minimum_center and center.min < DHO_MINIMUM_CENTER:
-            center.min = DHO_MINIMUM_CENTER
-        return center
+            center_param = Parameter(name=name + ' center', value=float(center), unit=unit)
+        if enforce_minimum_center and center_param.min < DHO_MINIMUM_CENTER:
+            center_param.min = DHO_MINIMUM_CENTER
+        return center_param
 
     def _create_width_parameter(
         self,
-        width: Numeric | Parameter,
+        width: Numeric,
         name: str,
         param_name: str = 'width',
         unit: str | sc.Unit = 'meV',
@@ -148,13 +144,13 @@ def _create_width_parameter(
 
         Parameters
         ----------
-        width : Numeric | Parameter
-            The width value or Parameter.
+        width : Numeric
+            The width value.
         name : str
             The name of the model component.
-        param_name : str, default='width'
+        param_name : str, default="width"
             The name of the width parameter.
-        unit : str | sc.Unit, default='meV'
+        unit : str | sc.Unit, default="meV"
             The unit of the width Parameter.
         minimum_width : float, default=MINIMUM_WIDTH
             The minimum allowed width.
@@ -162,7 +158,7 @@ def _create_width_parameter(
         Raises
         ------
         TypeError
-            If width is not a number or a Parameter.
+            If width is not a number.
         ValueError
             If width is non-positive.
 
@@ -171,29 +167,19 @@ def _create_width_parameter(
         Parameter
             The validated width Parameter.
         """
-        if not isinstance(width, (Numeric, Parameter)):
-            raise TypeError(f'{param_name} must be a number or a Parameter.')
-
-        if isinstance(width, Numeric):
-            if not np.isfinite(width):
-                raise ValueError(f'{param_name} must be a finite number or a Parameter')
-
-            if float(width) < minimum_width:
-                raise ValueError(
-                    f'The {param_name} of a {self.__class__.__name__} must be greater than zero.'
-                )
-            width = Parameter(
-                name=name + ' ' + param_name,
-                value=float(width),
-                unit=unit,
-                min=minimum_width,
+        if not isinstance(width, Numeric):
+            raise TypeError(f'{param_name} must be a number.')
+
+        if not np.isfinite(width):
+            raise ValueError(f'{param_name} must be a finite number')
+
+        if float(width) < minimum_width:
+            raise ValueError(
+                f'The {param_name} of a {self.__class__.__name__} must be greater than zero.'
             )
-        else:
-            if width.value <= 0:
-                raise ValueError(
-                    f'The {param_name} of a {self.__class__.__name__} must be greater than zero.'
-                )
-            if width.min < minimum_width:
-                width.min = minimum_width
-
-        return width
+        return Parameter(
+            name=name + ' ' + param_name,
+            value=float(width),
+            unit=unit,
+            min=minimum_width,
+        )
diff --git a/src/easydynamics/sample_model/diffusion_model/delta_lorentz.py b/src/easydynamics/sample_model/diffusion_model/delta_lorentz.py
index 0a96ee59..150015a7 100644
--- a/src/easydynamics/sample_model/diffusion_model/delta_lorentz.py
+++ b/src/easydynamics/sample_model/diffusion_model/delta_lorentz.py
@@ -486,16 +486,13 @@ def create_component_collections(
             # ------------------------------#
             # Create Lorentzian
             # ------------------------------#
-            if self._allow_Q_variation['lorentzian_width'] is True:
-                width = self._lorentzian_width_list[i]
-            else:
-                width = 1.0
             lorentzian_component = Lorentzian(
                 name=self.lorentzian_name,
                 display_name=self.lorentzian_display_name,
                 unit=self.unit,
-                width=width,
             )
+            if self._allow_Q_variation['lorentzian_width'] is True:
+                lorentzian_component._width = self._lorentzian_width_list[i]  # noqa: SLF001
 
             # If the width is allowed to vary with Q it is independent.
             # If the width is not allowed to vary with Q it must be made
diff --git a/tests/unit/easydynamics/sample_model/components/test_damped_harmonic_oscillator.py b/tests/unit/easydynamics/sample_model/components/test_damped_harmonic_oscillator.py
index a420fa40..87f9556c 100644
--- a/tests/unit/easydynamics/sample_model/components/test_damped_harmonic_oscillator.py
+++ b/tests/unit/easydynamics/sample_model/components/test_damped_harmonic_oscillator.py
@@ -42,28 +42,6 @@ def test_initialization(self, dho: DampedHarmonicOscillator):
         assert dho.width.value == pytest.approx(0.3)
         assert dho.unit == 'meV'
 
-    def test_init_with_parameters(self):
-        # WHEN
-        area_param = Parameter(name='area_param', value=3.0, unit='meV')
-        center_param = Parameter(name='center_param', value=1.0, unit='meV')
-        width_param = Parameter(name='width_param', value=0.8, unit='meV')
-
-        # THEN
-        dho = DampedHarmonicOscillator(
-            display_name='Paramdho',
-            area=area_param,
-            center=center_param,
-            width=width_param,
-            unit='meV',
-        )
-
-        # EXPECT
-        assert dho.display_name == 'Paramdho'
-        assert dho.area is area_param
-        assert dho.center is center_param
-        assert dho.width is width_param
-        assert dho.unit == 'meV'
-
     @pytest.mark.parametrize(
         'kwargs, expected_message',
         [
diff --git a/tests/unit/easydynamics/sample_model/components/test_exponential.py b/tests/unit/easydynamics/sample_model/components/test_exponential.py
index 97df632e..6c2a1c50 100644
--- a/tests/unit/easydynamics/sample_model/components/test_exponential.py
+++ b/tests/unit/easydynamics/sample_model/components/test_exponential.py
@@ -42,28 +42,6 @@ def test_initialization(self, exponential: Exponential):
         assert exponential.rate.value == pytest.approx(1.2)
         assert exponential.unit == 'meV'
 
-    def test_init_with_parameters(self):
-        # WHEN
-        amplitude_param = Parameter(name='amp_param', value=3.0, unit='meV')
-        center_param = Parameter(name='center_param', value=1.0, unit='meV')
-        rate_param = Parameter(name='rate_param', value=0.5, unit='1/meV')
-
-        # THEN
-        exponential = Exponential(
-            display_name='ParamExponential',
-            amplitude=amplitude_param,
-            center=center_param,
-            rate=rate_param,
-            unit='meV',
-        )
-
-        # EXPECT
-        assert exponential.display_name == 'ParamExponential'
-        assert exponential.amplitude is amplitude_param
-        assert exponential.center is center_param
-        assert exponential.rate is rate_param
-        assert exponential.unit == 'meV'
-
     @pytest.mark.parametrize(
         'kwargs, expected_message',
         [
@@ -73,11 +51,11 @@ def test_init_with_parameters(self):
             ),
             (
                 {'amplitude': 2.0, 'center': 'invalid', 'rate': 1.0, 'unit': 'meV'},
-                'center must be None, a number',
+                'center must be None or a number',
             ),
             (
                 {'amplitude': 2.0, 'center': 0.5, 'rate': 'invalid', 'unit': 'meV'},
-                'rate must be a number or a Parameter',
+                'rate must be a number',
             ),
         ],
     )
diff --git a/tests/unit/easydynamics/sample_model/components/test_gaussian.py b/tests/unit/easydynamics/sample_model/components/test_gaussian.py
index 9bf0b13d..f5acf10c 100644
--- a/tests/unit/easydynamics/sample_model/components/test_gaussian.py
+++ b/tests/unit/easydynamics/sample_model/components/test_gaussian.py
@@ -43,28 +43,6 @@ def test_initialization(self, gaussian: Gaussian):
         assert gaussian.width.value == pytest.approx(0.6)
         assert gaussian.unit == 'meV'
 
-    def test_init_with_parameters(self):
-        # WHEN
-        area_param = Parameter(name='area_param', value=3.0, unit='meV')
-        center_param = Parameter(name='center_param', value=1.0, unit='meV')
-        width_param = Parameter(name='width_param', value=0.8, unit='meV')
-
-        # THEN
-        gaussian = Gaussian(
-            display_name='ParamGaussian',
-            area=area_param,
-            center=center_param,
-            width=width_param,
-            unit='meV',
-        )
-
-        # EXPECT
-        assert gaussian.display_name == 'ParamGaussian'
-        assert gaussian.area is area_param
-        assert gaussian.center is center_param
-        assert gaussian.width is width_param
-        assert gaussian.unit == 'meV'
-
     @pytest.mark.parametrize(
         'kwargs, expected_message',
         [
@@ -74,7 +52,7 @@ def test_init_with_parameters(self):
             ),
             (
                 {'area': 2.0, 'center': 'invalid', 'width': 0.6, 'unit': 'meV'},
-                'center must be None, a number',
+                'center must be None or a number',
             ),
             (
                 {'area': 2.0, 'center': 0.5, 'width': 'invalid', 'unit': 'meV'},
@@ -85,6 +63,12 @@ def test_init_with_parameters(self):
                 'unit must be None',
             ),
         ],
+        ids=[
+            'invalid area',
+            'invalid center',
+            'invalid width',
+            'invalid unit',
+        ],
     )
     def test_input_type_validation_raises(self, kwargs, expected_message):
         with pytest.raises(TypeError, match=expected_message):
diff --git a/tests/unit/easydynamics/sample_model/components/test_lorentzian.py b/tests/unit/easydynamics/sample_model/components/test_lorentzian.py
index 3c7809c6..6056bab9 100644
--- a/tests/unit/easydynamics/sample_model/components/test_lorentzian.py
+++ b/tests/unit/easydynamics/sample_model/components/test_lorentzian.py
@@ -43,28 +43,6 @@ def test_initialization(self, lorentzian: Lorentzian):
         assert lorentzian.width.value == pytest.approx(0.6)
         assert lorentzian.unit == 'meV'
 
-    def test_init_with_parameters(self):
-        # WHEN
-        area_param = Parameter(name='area_param', value=3.0, unit='meV')
-        center_param = Parameter(name='center_param', value=1.0, unit='meV')
-        width_param = Parameter(name='width_param', value=0.8, unit='meV')
-
-        # THEN
-        lorentzian = Lorentzian(
-            display_name='ParamLorentzian',
-            area=area_param,
-            center=center_param,
-            width=width_param,
-            unit='meV',
-        )
-
-        # EXPECT
-        assert lorentzian.display_name == 'ParamLorentzian'
-        assert lorentzian.area is area_param
-        assert lorentzian.center is center_param
-        assert lorentzian.width is width_param
-        assert lorentzian.unit == 'meV'
-
     @pytest.mark.parametrize(
         'kwargs, expected_message',
         [
diff --git a/tests/unit/easydynamics/sample_model/components/test_mixins.py b/tests/unit/easydynamics/sample_model/components/test_mixins.py
index 4989f76e..e30f4bdd 100644
--- a/tests/unit/easydynamics/sample_model/components/test_mixins.py
+++ b/tests/unit/easydynamics/sample_model/components/test_mixins.py
@@ -28,20 +28,9 @@ def test_create_area_parameter_from_numeric(self, dummy_model, area_input, unit)
         assert not area_param.fixed
         assert area_param.min == pytest.approx(0.0)
 
-    def test_create_area_parameter_from_parameter(self, dummy_model):
-        # WHEN
-        area_input = Parameter(name='input_area', value=3.0, unit='meV', fixed=True)
-
-        # THEN
-        area_param = dummy_model._create_area_parameter(area_input, 'TestModel')
-
-        # EXPECT
-        assert area_param is area_input  # Should be the same object
-        assert area_param.min == pytest.approx(0.0)
-
     def test_create_area_parameter_invalid_type_raises(self, dummy_model):
         # WHEN THEN EXPECT
-        with pytest.raises(TypeError, match='area must be a number or a Parameter'):
+        with pytest.raises(TypeError, match='area must be a number'):
             dummy_model._create_area_parameter('invalid', 'TestModel')
 
     @pytest.mark.parametrize(
@@ -54,7 +43,7 @@ def test_create_area_parameter_invalid_type_raises(self, dummy_model):
     )
     def test_create_area_parameter_invalid_numeric_raises(self, dummy_model, non_finite_area):
         # WHEN THEN EXPECT
-        with pytest.raises(ValueError, match='area must be a finite number or a Parameter'):
+        with pytest.raises(ValueError, match='area must be a finite number'):
             dummy_model._create_area_parameter(non_finite_area, 'TestModel')
 
     def test_negative_area_warns(self, dummy_model):
@@ -92,21 +81,9 @@ def test_create_center_parameter_from_None(self, dummy_model, fix_if_none):
         assert center_param.unit == 'meV'
         assert center_param.fixed == fix_if_none
 
-    def test_create_center_parameter_from_parameter(self, dummy_model):
-        # WHEN
-        center_input = Parameter(name='input_center', value=1.0, unit='meV', fixed=True)
-
-        # THEN
-        center_param = dummy_model._create_center_parameter(
-            center_input, 'TestModel', fix_if_none=False
-        )
-
-        # EXPECT
-        assert center_param is center_input  # Should be the same object
-
     def test_create_center_parameter_invalid_type_raises(self, dummy_model):
         # WHEN THEN EXPECT
-        with pytest.raises(TypeError, match='center must be None, a number, or a Parameter'):
+        with pytest.raises(TypeError, match='center must be None or a number'):
             dummy_model._create_center_parameter('invalid', 'TestModel', fix_if_none=False)
 
     @pytest.mark.parametrize(
@@ -119,9 +96,7 @@ def test_create_center_parameter_invalid_type_raises(self, dummy_model):
     )
     def test_create_center_parameter_invalid_numeric_raises(self, dummy_model, non_finite_center):
         # WHEN THEN EXPECT
-        with pytest.raises(
-            ValueError, match='center must be None, a finite number or a Parameter'
-        ):
+        with pytest.raises(ValueError, match='center must be None or a finite number'):
             dummy_model._create_center_parameter(non_finite_center, 'TestModel', fix_if_none=False)
 
     @pytest.mark.parametrize('unit', ['meV', 'eV'])
@@ -138,29 +113,9 @@ def test_create_width_parameter_from_numeric(self, dummy_model, width_input, uni
         assert width_param.unit == unit
         assert not width_param.fixed
 
-    def test_create_width_parameter_from_parameter(self, dummy_model):
-        # WHEN
-        width_input = Parameter(name='input_width', value=3.0, unit='meV', fixed=True)
-
-        # THEN
-        width_param = dummy_model._create_width_parameter(
-            width_input, 'TestModel', param_name='width'
-        )
-
-        # EXPECT
-        assert width_param is width_input  # Should be the same object
-
-    def test_create_width_parameter_from_parameter_negative_raises(self, dummy_model):
-        # WHEN
-        width_input = Parameter(name='input_width', value=-1.0, unit='meV', fixed=True)
-
-        # THEN EXPECT
-        with pytest.raises(ValueError, match=' must be greater than zero'):
-            dummy_model._create_width_parameter(width_input, 'TestModel', param_name='width')
-
     def test_create_width_parameter_invalid_type_raises(self, dummy_model):
         # WHEN THEN EXPECT
-        with pytest.raises(TypeError, match='width must be a number or a Parameter'):
+        with pytest.raises(TypeError, match='width must be a number'):
             dummy_model._create_width_parameter('invalid', 'TestModel', param_name='width')
 
     def test_create_width_parameter_negative_raises(self, dummy_model):
@@ -178,5 +133,5 @@ def test_create_width_parameter_negative_raises(self, dummy_model):
     )
     def test_create_width_parameter_invalid_numeric_raises(self, dummy_model, non_finite_center):
         # WHEN THEN EXPECT
-        with pytest.raises(ValueError, match='width must be a finite number or a Parameter'):
+        with pytest.raises(ValueError, match='width must be a finite number'):
             dummy_model._create_width_parameter(non_finite_center, 'TestModel')
diff --git a/tests/unit/easydynamics/sample_model/components/test_voigt.py b/tests/unit/easydynamics/sample_model/components/test_voigt.py
index 4d28c73a..5f42704d 100644
--- a/tests/unit/easydynamics/sample_model/components/test_voigt.py
+++ b/tests/unit/easydynamics/sample_model/components/test_voigt.py
@@ -47,31 +47,6 @@ def test_initialization(self, voigt: Voigt):
         assert voigt.lorentzian_width.value == pytest.approx(0.7)
         assert voigt.unit == 'meV'
 
-    def test_init_with_parameters(self):
-        # WHEN
-        area_param = Parameter(name='area_param', value=3.0, unit='meV')
-        center_param = Parameter(name='center_param', value=1.0, unit='meV')
-        gaussian_width_param = Parameter(name='gaussian_width_param', value=0.8, unit='meV')
-        lorentzian_width_param = Parameter(name='lorentzian_width_param', value=0.9, unit='meV')
-
-        # THEN
-        voigt = Voigt(
-            display_name='ParamVoigt',
-            area=area_param,
-            center=center_param,
-            gaussian_width=gaussian_width_param,
-            lorentzian_width=lorentzian_width_param,
-            unit='meV',
-        )
-
-        # EXPECT
-        assert voigt.display_name == 'ParamVoigt'
-        assert voigt.area is area_param
-        assert voigt.center is center_param
-        assert voigt.gaussian_width is gaussian_width_param
-        assert voigt.lorentzian_width is lorentzian_width_param
-        assert voigt.unit == 'meV'
-
     @pytest.mark.parametrize(
         'kwargs, expected_message',
         [