Hi,
the speaker is nominally 8 ohms so if your Aiwa amp can drive 4 ohms :
The 9db peaking can be reduced somewhat crudely :
Wire a resistor in parallel with the speaker say 10R (10watt).
This will drastically reduce the impedance variation the capacitor
will have to deal with.
It will reduce the peak of ~ 30 ohm at 130Hz to ~ 9ohm.
A guesstimate is the peaking will be reduced to ~ 3dB.
This should be safe for the driver, and not cause too much distortion.
By definition a 3dB bass peak will half power handling.
The 9dB peak reduces power handling to 1/8 of normal value.
/sreten.
the speaker is nominally 8 ohms so if your Aiwa amp can drive 4 ohms :
The 9db peaking can be reduced somewhat crudely :
Wire a resistor in parallel with the speaker say 10R (10watt).
This will drastically reduce the impedance variation the capacitor
will have to deal with.
It will reduce the peak of ~ 30 ohm at 130Hz to ~ 9ohm.
A guesstimate is the peaking will be reduced to ~ 3dB.
This should be safe for the driver, and not cause too much distortion.
By definition a 3dB bass peak will half power handling.
The 9dB peak reduces power handling to 1/8 of normal value.
/sreten.i think i may try that sreten...thanks for the help
although im not quite sure if the aiwa system will appreciate that 4 ohm load....one time i hooked up another bookshelf to the same channel and at high volumes it eventually shut off....
yessir, i did CRAZY things bak in the day
however, zaph helped me understand precisely why using a simple cap could damage the speakers, so i think i now know what needs to be done....
i cant seem to find a bennic poly cap for the 100uF amount....i sure hope bennic electrolytic caps work ok
although im not quite sure if the aiwa system will appreciate that 4 ohm load....one time i hooked up another bookshelf to the same channel and at high volumes it eventually shut off....
yessir, i did CRAZY things bak in the day
however, zaph helped me understand precisely why using a simple cap could damage the speakers, so i think i now know what needs to be done....
i cant seem to find a bennic poly cap for the 100uF amount....i sure hope bennic electrolytic caps work ok
Zaph said:
i apologize for being difficult, but it was not my intention to create trouble, or criticize your design...
my intentions are to LEARN why this project was designed the way it is, and why taking shortcuts in designing (such as, say, ignoring the need for an impedence flattening circuit) would be not only harmful to sound but also harmful to the speaker (according to you and the xmax comment)....
i am not tryint to be a stingy cheapskate, but i want to know WHY i am doing what i am doing.....your "use an active subwoofer crossover" section did metion, but not in detial, the effects of being a cheapskate in this instance...
i want you to know that i do appreciate u posting the information that you did because it has helped me to decide how i am going to handle it...you told me exactly what i wanted to know about bad sound quality, overexcursion, harmonic distortion, and why to prevent it: so i thank you for your time
jaygeorge1979 said:
Hi,
the subamp you buy / have will have 2 x ~ 100uF capacitors.
They will be reversible electrolytics, you could bypass
them with a polyester cap of any reasonable value.
100uF poly caps are very rare - but are available
- usually surplus ex from a speaker manafacturer.
If you have spare inductors lying around add them in series
with the 10R resistor, will reduce loading on the amplifier.
/sreten.- Status
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