When making a good speaker, you need to pay attention to many details. Today we are going to discuss a key parameter of the speaker: Thiele-Small parameters (t/s parameters for short). These parameters are a series of indicators used to describe the performance of the speaker, which are crucial for speaker design and application. First of all, we should understand the meaning of t/s parameters: such as Fs, Qes, Qms, Qts, Vas, etc.
1.Fs (Free-air Resonant Frequency): This is the resonant frequency of the speaker in free air, that is, the frequency at which the speaker has the largest amplitude. Lower Fs values ​​generally mean that the speaker can respond better to low frequencies, which is suitable for woofers. Higher Fs values ​​may limit the low-frequency response, but help improve the performance of mid-range and high frequencies.
2.Q parameters: These parameters are related to the control ability of the speaker at the resonant frequency (Fs).
Qms (Mechanical Q): Mechanical control ability provided by the spider and periphery.
Qes (Electrical Q): Electrical control ability provided by the voice coil and magnet.
Qts (Total Q): Calculated by multiplying Qms by Qes and dividing by the sum of the two, it reflects the quality factor of the total system. Generally, speakers with lower Qts values ​​are suitable for use in vented cabinets, while speakers with higher Qts values ​​are suitable for sealed cabinets or infinite baffle (IB) configurations.
3.Re (DC Resistance): The DC resistance of the speaker, not to be confused with impedance.
4.Le (Voice Coil Inductance): The inductance of the speaker voice coil, usually measured at 1kHz.
5.Cms (Compliance of the Mechanical System): The compliance of the mechanical system, that is, the degree of response of the system to force.
6.Vas (Volume of Air): When air is compressed to 1 cubic meter, it exerts a force equal to Cms.
7.Mms (Mass of the Moving System): The total mass of the moving part of the speaker, including the diaphragm, voice coil and other moving parts and the air resistance caused by the movement.
8.Mmd (Mass of the Moving System without Air Resistance): Same as Mms, but does not include the effects of air resistance.
9.Sd (Surface Area of ​​the Cone): Surface area of ​​the diaphragm.
10.Xmax (Maximum Usable Linear Excursion): Maximum usable linear excursion of the speaker, calculated by subtracting the voice coil height from the magnetic gap height and dividing by 2.
11.Xlim (Physical Limit of Excursion): Physical excursion limit of the speaker, exceeding this limit may cause the voice coil to leave he magnetic gap, output nonlinearity, or even damage the speaker.
Understanding and applying these t/s parameters are critical for speaker designers because they directly affect the performance and sound quality of the speaker. By accurately measuring and optimizing these parameters, designers can ensure that the speaker can provide the best performance in a variety of applications. Whether in home theater systems, music production or professional audio, t/s parameters are key to ensuring the best sound quality and reliability of the speaker. As technology continues to advance, a deeper understanding and application of these parameters will drive speaker technology to higher sound quality and a wider range of applications. Let us look forward to more innovations and breakthroughs in speaker technology in the future.