Is it OK? Replaced a passive subwoofer with a bigger speaker

Audiolab 6000A Amplifier

sunilp

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Had an old Onkyo SL 107, active sub woofer which was not working.

It has 8" speaker, with 150 w amplifier,

Specs says Input impedance 1.2 kΩ (for SPEAKER LEVEL INPUT terminals) 65 kΩ (for LINE INPUT jacks) Sensitivity Speaker-Level 1.6 V Line 230 mV
On the 8" speaker, 4ohm is printed.

Have a cheap Philips sound bar with Passive subwoofer (specs: 5.25", 60 W, impedence 3.6)

I simply ripped apart all internal components from Onkyo and replace it with Philips subwoofer.

Sound is better. But is it safe for the circuits inside philips sound bar?
 

kapvin

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Hi. Welcome to the exciting and sometimes scary world of DIY.

the first issue is of electrical stability. will the circuits be stressed? There is not too much difference between 3.6 oh, and 4 ohm, so you should be okay there.

the second issue is driver capability. If it’s a genuine 150w and this is a 5.25” woofer, you way run into excursion problem, ie the cone of the woofer may get pushed out beyond its design limits by the higher power amp. Luckily we can hear excursion problems immediately and it might not happen unless you listen to it loud. So if you are careful, you should be okay

the third issue Is thermal stability of the woofer coil. Will The higher power Of the onkyo amp burn The 60w sub woofer.
if it is Rated 60w max, you may need to be a bit careful, but chances are you will run out excursion before the coil heats. if it is rated 60w nominal, again, there should be no problem . Again excursion issues are likely to come before thermal issues.

ideally, get a 8” subwooferdriver to replace the one in your onkyo box. Or build a new box. But for now enjoy, carefully


edit, I might have got it completely the other way round. If you are running the onkyo 8” sub passively using the sound bar electricals I don’t think there will be any problems. You are well within safety envelopes.
 

sunilp

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Yeah you got it reverse. Your last statement gives me relief. Didnt feel like junking 10" speaker from onkyo just because something was wrong with electricals. So connected speaker directly to philips 60W output
thanks for responding...
 
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