I was cash poor once. Where do you live? there is a MMA-8150t today for $50 in Connecticut. $50 freight for me, less if you are closer to CT. 150 w into 4 ohms, dual output transistor pairs. Mono amp. https://www.ebay.com/itm/265725222025?hash=item3dde751c89:g:B1wAAOSwU3pinhdl
I've gotten these for as low as $40 + 25 freight. Mono mixer amps aren't high on anybody's want list, except people in a cash short position. Right after the burglar carried off $4000 in sound equipment, I bought an MMA-875t for $20 + $25 freight. 75 watts into 4 ohms. Worked! Still use it on my HDTV with a toslink converter. $5 the pair 3 way speakers with 6.5" woofers wasn't bad, either. Salvation Army resale shop.
First, a 240-120V transformer isn't what you want, as the amplifier would then "see" 16 ohms, not 8.
Second, an inductor is most certainly NOT a solution.
Third, most amplifiers are not going to be embarrassed by a 4 ohm load.
Fourth, the described noisy symptoms are not at all what you'd expect from such an embarrassed amplifier (I favour the aforementioned speaker over-excursion as an explanation for that).
Fifth, forget the idea of series resistors. Waste of power and damping factor. And time and money and heat.
I'd suggest a high-pass filter to protect the bass driver from over-excursion. Easiest might be to connect in series with the woofer series back-to-back electrolytic capacitors of value approximately 1000uF (at least 35V, connect positive to positive).
By the way is the woofer in a ported box (seems likely)?
Second, an inductor is most certainly NOT a solution.
Third, most amplifiers are not going to be embarrassed by a 4 ohm load.
Fourth, the described noisy symptoms are not at all what you'd expect from such an embarrassed amplifier (I favour the aforementioned speaker over-excursion as an explanation for that).
Fifth, forget the idea of series resistors. Waste of power and damping factor. And time and money and heat.
I'd suggest a high-pass filter to protect the bass driver from over-excursion. Easiest might be to connect in series with the woofer series back-to-back electrolytic capacitors of value approximately 1000uF (at least 35V, connect positive to positive).
By the way is the woofer in a ported box (seems likely)?