902-16HF and 921-8A question

[argieX]

How does the 902-16HF sound, compared to the 8ohm version.

Can I use the same crossovers if I put a 16ohm resistor in parallel with the driver ?

Is the 921-8A worth using at home, or should I stick with the JBL 2225 I am using now ?

[LICORNE]

argieX

Can I use the same crossovers if I put a 16ohm resistor in parallel with the driver

<font size="2" face="Verdana, Helvetica, sans-serif">Examination of a simulated low frequency driver depicted in Figure 1, shows a large peak at resonance, and a relatively small section where the impedance is flat. This equates to the nominal impedance of the speaker, but as shown below, this covers a limited frequency range. The biggest problem for the crossover is not resonance (for a woofer, at least), but the rise in impedance as the voice coil inductive reactance starts to become significant relative to the nominal impedance.





Impedance Curve of "Simulated" Loudspeaker

The green line on the above graph represents the 'semi-inductance' of the voicecoil. Because the coil is surrounded by conductive metal (steel), its inductance is not linear with frequency. This creates a lossy inductor, and as such it cannot actually achieve the 6dB/ octave (20dB/ decade) impedance rise that one would normally expect. The actual rise varies from one driver to the next, and cannot be simulated in general terms - it must be measured. The real impedance rise due to voicecoil inductance (or semi-inductance) is usually between 3 and 5dB/ octave. For the range of frequencies that we need to be concerned with for a crossover network, the error introduced into the formulae that follow is minimal, and can be ignored.


So you can connect a 16 ohms to your passive 8 ohms network. If the highs are week you can tweek the EQ 8DB around 10K.

If it sounds good leave it as is . If you can find a XO with 16 ohms it would be better.

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[argieX]

Thank you.

I?ll bid on the drivers then, and if they don?t work with the normal crossover, I can tweak the values for 16ohm.