This is what I know so far to look for.

Frequency responce= Looking for a wide range 20Hz or lower to how ever high It goes.

Sensitivity= How loud you can get before distortion

RMS Watts!! How much can I really put into the speaker at all times


This is what I need help on.

Voice coil = what kind how many watts for a decent speaker. By saying decent I want something loud that you cant talk over. Loud that makes old people stare at you when you drive down the street thinking <i><font color=blue>What is he thinking? He is going to blow a ear drum!</i></font>

Type of Box= everyone I beleive wants loud, clear, deep, bass. What kind of box is the best? Bad pass? Sealed? Ported? What kinda wood. The heavy stuff right? None of that particle board that you find at a flea market.

Can you judge a speaker by the magnett?= Got a air hole this must be good for cooling the voice coil.

<font color=red>Come on if you technical and you know a bit about what makes a good speaker post you thoughts cause just there are probably alot of people wondering the same things I do. Well I do now that I thought I had a good speaker but it turned out to be a rip and not what I was really looking for. Oh yeah lets just say price doesnt mater for now I just want the specs......


:rockon:
<i><font color =blue>Take that lady!!
<img src=http://www.cerwinvega.com/products/images/corner1.gif>

 

use MDF for the sub box

 

I am going to assume these questions are about subwoofers, so I will answer in that vein, but this information will apply to most other drivers as well. First of all, most high end drivers will operate in a certain frequency range, subs usually from below 20hz to about 80-100hz, where higher frequencies are filtered out by a low pass crossover. In all cases, it is most desirable to have a flat frequency response across the range of frequencies the driver will handle and quality crossovers to prevent drop outs and phase problems. Generally for subs, the higher order of crossover, the better, such as a 12dB/octave or even 24dB/octave, 2nd and 4th order crossovers, respectively. Steep 4th order crossovers for midbass/tweeter component speakers often cause phase problems, so a 1st order (6dB/octave) or 2nd order should be used.

Loudspeaker sensitivity is a measure of how much sound the driver will produce for a stated amount of amplifier power, usually expressed as the decibel level of a speaker from one meter away, driven by one watt of amplifier power, eg. 88dB 1W/1m. This says the driver in question will play at an SPL of 88dB one meter away from the speaker when it is driven by one watt. This is a very important spec, since a speaker rated at 80dB 1W/1m will require about 100W of power to play at an SPL level of 100dB, while a speaker rated at 95dB would require only 3W of power to achieve the same SPL.

RMS power ratings are often mistakenly given too much weight in one's speaker purchase decision. Power handling specs are a meaningful spec, but not nearly as important as sensitivity, or making sure the speaker has lots of good, clean power. More often than not, square wave distortion from an overdriven amp is what causes speaker destruction, not a mis match of amplifier power and speaker RMS ratings. The simple fact to remember here is if loudness is what you seek, you get a gain of 6dB SPL by adding another driver, while you will get a net gain of 3dB by doubling amplifier power, provided your amps can do it, and your speakers can handle it. Do the math, and the choice is easy.

Dual voice coil sub designs allow for creative wiring to accomidate multiple sub set ups, or to take advantage of an amp that can drive low impedance loads. By wiring dual 4ohm voice coils in parallel, the speaker now presents the amp with a 2ohm load, and theoretically, doubles power output. Conversely, dual 4ohm coils wired in series will present the amp with an 8ohm load. Before fiddling with these configurations, make sure your amp is capable of driving low ohm loads with high current capability.

There are many types of boxes, all should be built with a minimum of 3/4"MDF, and each box will do different things. The type of enclosure that is right for you involves many factors such as what kind of music you listen to, what kind of drivers you own, and whether you want just loud, or loud and SQ, to name just a few. In very general terms, sealed enclosures generally sound very good, with a flat system frequency response, and a gentle 12dB/ovtave roll off at the low end. Seraled enclosures also require more amplifier power to play louder. Reflex enclosures, or "ported" boxes, roll off at a much steeper 24dB/octave, but require less power to produce loud volumes, and the enclosure, or volume is usually less than that of a sealed enclosure, meaning a smaller box. What you gain with all of this, you lose some with a somewhat more boomy sound, and less defined bass, especially in transient response, or the "attack" of bass notes.

Magnet size and such is much less an indicator of a good sub than the information above. In general, look for quality fit and finish in the connectors and basket (stamped or cast?). The bottom line is quality drivers in a well built box, driven by good amps is what equals good sound, and lots of it. Take your time, listen to lots of equipment, read up, and talk to experienced people who have systems you like, and remember, great is never cheap.