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Is this why JBL 2245 was discontinued ? [message #38154] Tue, 03 September 2002 16:45 Go to next message
Anonymous

Is this one of the reasons why JBL 2245 is history?

WinISD says for ported box;

2245 = 7.7 cubic feet, 30hz, 95db
2241 = 10.6 cubic feet, 35hz, 98db

but, in a sealed box, both have the same box
size for q = 0.7 and 2245 f3's 10hz lower
while 2241 has 3db more sensitivity.

Differences between 2241 and 2245? [message #38155 is a reply to message #38154] Tue, 03 September 2002 17:28 Go to previous messageGo to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 18787
Registered: January 2001
Illuminati (33rd Degree)

The 2245 is tuned lower but isn't as efficient as the 2241. Both are pretty good parts. The 2245 (like the 2235) is tuned deep and offers more extension. The 2241 (like the 2226) is tuned higher and is more efficient.

Re: Differences between 2241 and 2245? [message #38156 is a reply to message #38155] Tue, 03 September 2002 17:46 Go to previous messageGo to next message
Anonymous
three things on my mind - lol

#1 Is there a correlation between a woofers x-max rating and
"tight bass" ? if you know what I mean (loose suspension and tight
suspension). Do "tight coned" woofers sound better than "subwoofers",
or is this just a myth?

#2 Is there a correlation between a woofers voice coil diameter and
"tight bass" and/or sound quality assuming similar woofers?
or is the voice coil just a function of power handling,
not sound quality ? ie, if JBL made a woofer with a 2" voice
coil would it sound as good/bad as the same one using a a 4" dia
voice coil ?

#3 What factors do you look at when trying to find a woofer
with a strong motor ?



Motor strength [message #38158 is a reply to message #38156] Tue, 03 September 2002 18:11 Go to previous message
Wayne Parham is currently offline  Wayne Parham
Messages: 18787
Registered: January 2001
Illuminati (33rd Degree)

This is a balancing act, and the parameters are set according to the intended application. But here is a generalized description of the interrelationships.

Motor strength is set by magnetic flux, number of voice coil turns and amount of current passing through it. To make the motor stronger, you need the most amount of magnetic energy, the most number of turns, and the highest amount of current in the smallest space.

Mass and stiffness of the moving assembly combines with motor strength to set the electro-mechanical parameters like resonant frequency and Q.

Radiator size and excursion set displacement, which affect overall maximum power levels. Even if the motor is very powerful, if the Xmax is limited, then the total power output is limited. Making Xmax larger means making a longer coil and spreading the magnetic energy over a larger area. This tends to make the motor less efficient, but it allows it to move the diaphragm further.

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