philz, on Apr 30 2007, 07:01 AM, said:
But I would like to the know the technical side, I mean the Sound Quality, does it blend in easy with the front stage, easy to work with/tune, not picky with its enclosure, hits low, can play high, accurate, etc.
All of these points depend a lot on how you build your box, how you tune the system and what power is fed to the driver.
Things like 'does it blend easily with the front stage', is highly dependant on whether you have the ears to detect whether it doesnt. Most people use leveling to 'blend', so that when subbass and midbass are both operating at around the same levels, they seem to 'form' a single note. Some people go as far as using tonality and colour changes between mid and sub bass to determine the difference, which makes selecting a woofer tougher. Personally, I find it difficult to detect tonality changes unless the woofers are totally different to the front stage (say a dry woofer coupled with warm fronts) so its easier to fool by blending well. Other challenge here is system resonance and vibrations. The sub will always vibrate your car more then your midbass, so unless the car is deadened well, the vibrations can assist in breaking up the blend.
Subs that are 'not picky' with their enclosures usually are aimed at sealed-dependant units, as there is a higher degree of latitude with design and building. These are subs with a lower Vas, Higher Qts and preferably a higher efficiency. Being underdamped helps here (Qtc greater then .707), as you can modify the box to allow greater damping.
Any speaker can hit low. Its whether the driver can do it in a fairly linear fashion and in a transient manner. This will depend on the drivers Fs, its Qts (and obviously Qtc when the box is built), efficiency and power handling, Bl, Le and linear Xmax. Two things to remember when driving low, one is you move twice as much air as the higher octave and hence require twice the Xmax, the other is because you are moving more air the driver strength needs to be greater to ensure it has the capability to do it. This leads to more power being needed, hence higher power handling, lower inductance to allow transient signal changes and a fairly flat impedance curve so the amplifier doesnt struggle.
If you want it to play high, lower inductance is the key (Le) as its this factor that most greatly influences rapid changes in signal reproduction (higher frequencies). Sounding accurate is again a bevy of a few specs, namely Le, Hg (and hence Linear Xmax) and Qes.
The IDMax is by no means the best woofer on the market, but when done properly can pull off an accurate reproduction fairly well. The reason so many people love it, is its power handling capabilities (to account for low efficiency), fairly decent Le and Qes to give it a good response and the small box requirements (making it easy to use). That, and amplifiers available these days to power one are freely available, cheapish, good damping properties and good slew rates. With an IDMax, its like you cant lose almost. Also, since almost no music has signals below 25Hz, the impedance curve wont peak until below this, so your amplifier wont struggle or clip.
In the end, its the properties of the final system, and the skill of the building/tuner, that will bring a sub like this out into the open.
Edited by thematt, 30 April 2007 - 12:34 PM.
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......cors
