Will 6 ohm tweeter work properly with 8 ohm components?

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Hello everyone -

When I asked this question:

"I was wondering if anyone could help me with the design for a 3 way sealed loudspeaker. It needs to have a curve +/- 3db from 50Hz to 18Khz, have an 8 ohm nominal impedance, and handle 100W."

in this thread, you guys recommended the following speakers:

Tweeter: Vifa D27TG-05
Mid: Vifa P13WH-00
Woofer: Peerless 850146 CSX

The problem is I wanted a nominal impedance of 8 ohms - the tweeter is 6 ohms.

Could you guys recommend me a tweeter with about 88dB sensitivity and 8 ohm nominal impedance that would work well with this combination?

-or-

Is the 6 ohm impedance ok?

Thanks
-David
 
I've been told the VIFA D19TD-05 3/4" POLY DOME TWEETER will have similar flexibility to the D27. Is this true?

Yeah, the sensitivity of the tweeter is MUCH greater than the mid and woofer. The mid and woofer are 88dB, the D27 is 92dB.

The D19 is 8 ohms and 89dB.
 
Ok I'll be more specific - I need an tweeter with an 8 ohm nominal imedpance, flat dispersion curve, and 88dB sensitivity. The "flatness" (not necessarily the frequency response) needs to begin at max 2000Hz.

The D27 had the curve I wanted but the SPL and impedance did not match.

Is there anyway to "adjust" the D27 from 6 to 8 ohms and lower the sensitivity from 92 to 88dB?
 
First, don't get too excited about the difference between a 6 ohm tweeter and an 8 ohm one. The only thing this really makes any difference to is the crossover component value calculations.

As you need to lose some signal any way to match sensititivty just put in a resistor in series with the tweeter of about 2 ohms. Make sure that any resistor you use can handle the power it will need to disapate (about 1/4 of the power going to the tweeter from the crossover). I will not comment on he sound of different resistor choices.

This will get you close. A 4 ohm may get you closer to the 4 dB of loss that you want, but now calculate the crossover components for a 10 ohm load.

One other choice, a 4.5 ohm series resistor and a 12.5 ohm parallel to the tweeter. This is a matching pad that will do the impedance transform you want but has 4.7 dB loss.

later, good luck:geezer:

Remember, you asked the question and in the world of Do It Yourself you always have choices to make.
 
dih1118 said:
Hello everyone -

When I asked this question:

"I was wondering if anyone could help me with the design for a 3 way sealed loudspeaker. It needs to have a curve +/- 3db from 50Hz to 18Khz, have an 8 ohm nominal impedance, and handle 100W."

in this thread, you guys recommended the following speakers:

Tweeter: Vifa D27TG-05
Mid: Vifa P13WH-00
Woofer: Peerless 850146 CSX

The problem is I wanted a nominal impedance of 8 ohms - the tweeter is 6 ohms.

Could you guys recommend me a tweeter with about 88dB sensitivity and 8 ohm nominal impedance that would work well with this combination?

-or-

Is the 6 ohm impedance ok?

Thanks
-David

You might want to take a look at the last project in the book Great Sounding Stereo Speaker Manual by David B. Weems and G.R. Koonce. It uses these drivers:

Vifa D27TG-45-06
Vifa P13WH-00-08
Peerless 831709

The crossover is 2nd order all 'round.
 
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