One more Common misconception is a High Power Rated Speaker is always a better. And Most of them dont even care to see beyond Rated Power and Rated Impedance. Yes, they may be enough for a layman, But when it comes to ICE brotherhood in GH, we love to dig it into details. Simply becasue its more of an obession to us. This T/S Paramters will help you understand a lot more things on speakers than mere Power values. This is Applicable to all Cone Based Drivers (Component speakers, Midbass drivers, Coaxials, Sub Woofers and Mid Range Drivers). I ve put things in a simple way, so that all of us can understand. However, pls feel free to add / question anything in this regard.
The Thiele/Small parameters, shortly called T/S parameters, were brought about in a bid to standardize and bring meaning to the behavior of a cone loudspeaker. They were first published as research papers by A.N. Thiele and R. Small (and hence T/S). I am not going to cover the entire T/S params' but only the few which are of greater significance.
fs/fo - Free air resonance of the Driver / SpeakerThe point at which all the moving parts of the driver achieve a Balance or in another words resonate. Generally a Drivers Resonance freq is one below which the driver will not be too comfortable playing.
So a driver with an fs of 50 Hz will not produce say, 35 Hz very well. However a driver with an fs of 30 Hz will produce 35 Hz, very comfortably.
Morel Hybrid Ovation Midbass fs: 56 Hz
DynAudio MW 162 Midbass fs: 55 Hz
HAT L6SE Midbass fs: 50 Hz
Morel Ultimo Subwoofer fs: 18 Hz
JL Audio 12W6 Subwoofer fs: 25 Hz
DD 1012b Subwoofer fs: 42 Hz
Qms - Mechanical Q of a Driver
Qms is the mechanical Q of the speaker and only takes the speaker's mechanical properties into consideration. It is a measurement of the control coming from the speaker's mechanical suspension, which is made up of the surround and spider. Hence the Nautre and type of Surround, Number of Spiders all make up for the overal Qms value
Drivers with a very high mechanical Q can sound more open and have better dynamic freq range. The surround is also more flexible, the spider is better constructed, and hence they have also better air flow, making them Cool drivers.
Morel Hybrid Ovation Midbass Qms: 2.4
DynAudio MW 162 Midbass Qms: 2.2
HAT L6SE Midbass Qms: 1.94
Morel Ultimo Subwoofer Qms: 1.72
JL Audio 12W6 Subwoofer Qms: 7.1
DD 1012b Subwoofer Qms: 6.9
Qes - Electrical Q of the driver
Qes is a measurement of the control coming from the speaker's electrical suspension system - which is the Voice coil and Magnet. The Significance of Surround and Spider in Qmes is comparale to that of VC and Magnet in Qes.
The higher value of Electical Q of a driver denotes a much larger Voice Coil capable of handling lot more Power as well as Heat. They also result in higher value of Magnetic Flux density as well as the Magnetic Motor Structure also indicates the authority or control they have over thier mechanical counterparts.
Hence Drivers with higher Q can handle lot more power and thermal absue for extended periods. They also exhibit much better control thereby earning adjectives like precise and accurate apart from exhibiting better sensitivity figures.
Morel Hybrid Ovation Midbass Qes: 0.55
DynAudio MW 162 Midbass Qes: 0.57
HAT L6SE Midbass Qes: 0.62
Morel Ultimo Subwoofer Qms: 0.46
JL Audio 12W6 Subwoofer Qms: 0.48
DD 1012b Subwoofer Qms: 0.92
Qts - Total Q of the Driver
Q is basically a used to describe a quality or characteristic about the electrical or mechanical part of the driver. Qts is the overall Q of the driver, both electrical(Qes) and mechanical(Qms) put together.
Qts is defined as 1/Qts = 1/Qes + 1/Qms
Qts reflects how strong the motor and magnet system of a driver are.
A driver with a low Qts of around 0.20 would have a large magnet and be able to move the cone with a lot of force. This makes for a very tight driver which plays low Bass very powerfully. A driver with a Qts of 0.45 would have a smaller magnet and less control over its cone making it more tight and Punchy. So low values of Qts give a tight and punchy sound but with little weight or low bass and high Qts values give a slow and heavy sound that will give you lots of low frequency output.
Higher Q values suggest the need for large volume of enclosures for them to sound accurate. Few have Q values more than 0.7 indicating the need for very large enclosures, or even to be mounted on the rear parcel shelf, so that they can take the entire Boot volume as enclosure.
Qts provides an understanding of influence of a Drivers Mechanical and Electrical Components. Qts, Qms and Qes form integragal part of Speaker designing itself. They are quite important values to be considerd when designing Enclosures or using them in infinite baffle applications
Morel Hybrid Ovation Midbass Q: 0.46
DynAudio MW 162 Midbass Q: 0.45
HAT L6SE Midbass Q: 0.46
Morel Ultimo Subwoofer Q: 0.34
JL Audio 12W6 Subwoofer Q: 0.45
DD 1012b Subwoofer Q: 0.8
Vas - Volume of air equal to the driver compliance
This can be thought of as how stiff the movement of the cone is. The value is given in litres or cu inches. There are a lot of variables that determine the Vas, so you canít really say that high values of Vas mean a certain thing or are better. A single or double suspension spider will affect Vas, so does the size of the cone. The temperature of the air and also the humidity will affect Vas and so it is one of the hardest parameters to evaluate. However Vas, along with Qts and Fs is quite important when designing perfect enclsoures for Subwoofers
Xmax - The amount of voice coil overhang
This is usually in mm and it represents the distance over which the coil can travel in one direction and maintain a constant number of turns in the gap. So a driver with an xmax of 10 mm can move is cone twice as far as one with an xmax of only 5 mm.
Do note that, Xmax is not maximum excursion. Maximum excursion is how far the cone will travel before the coil hits the back plate or the cone moves so far that it is restricted by its suspension.
Xmax is how far the cone can travel with the coil still in the magnetic gap. More xmax means the cone can move in and out further while still being under control.
Note that the xmax figure is for one direction only, so an xmax figure of 5 mm means the cone can travel 5 mm outwards and 5 mm inwards past itís resting place whilst still being under the control of the motor system.
Morel Hybrid Ovation Midbass X, one way: 7 mm
DynAudio MW 162 Midbass X, one way: 6 mm
HAT L6SE Midbass X, one way: 9 mm
Morel Ultimo Subwoofer X, one way: 12.5 mm
JL Audio 12W6 Subwoofer X, one way: 17 mm
DD 1012b Subwoofer X, one way: 19 mm
Apart from this there are few other Non T/S paramters one should look before deciding on a Speaker or a Subwoofer
Sensitivity: Sensitivty is simply how loud will a speaker go. It is denoted in db and is mostly measured at 1watt / 1metre length. Higher the better.
Morel Hybrid Ovation Midbass: 90 db
DynAudio MW 162 Midbass: 91 db
HAT L6SE Midbass: 92.5 db
Morel Ultimo Subwoofer: 85 db
JL Audio 12W6 Subwoofer: 86 db
DD 1012b Subwoofer: 85 db
Frequency range: Frequency Range which the driver can play without losing out on more than -3db loudness. Higher the Better
Peak Power: Peak power values determine the max power before which the Voice Coil gives up. Higher the better
Hope you enjoyed reading this.
- Please note that all paramters given above only indicate characteristics of different drivers, the ultimate sound is determined by many parameters including the Source, amplifications enclosure etc..
- Comparison of Drivers are made for better understanding. Choice purely based ease of info availability
- If you need more understanding on technical front, suggest you to read this -> http://www.the12volt.com/caraudio/thiele.asp i found it very nice.