I have a set of cerwin vega 15 towers. This is why I'm asking I know that Vegas are power hungry
The problem is that if one search for Cerwin Vega 15, one will find all sorts of variety such as LS-15, XS, LV-17, AT-15 and possible more.. So which model do you have exactly? Does the speaker have a name plate that can identify the exact model number?
If you can't identify it exactly, then I guess based on the other models we can find and assume they all have similar impedance and sensitivity specs, and then would be: 4 ohms or 8 ohms, 102 dB/W/M.
Edit: Thanks to HD, now I know it is the VE-15, only 95 dB/1W/1M, still very easily to drive unless it has some nasty dips to say between 2-3 ohms.
In that case unless you listen to very extremely loud level, your receiver should be able to power it without shutting down. So how loud was it at 1/4 volume just before the receiver shut down? If it was very loud, then turn the volume down a little and see what happens.
You cannot go by this 1/4, 1/2 volume thing because it depends on the input level and that could be dependent on the source/contents you listen to, though in most cases, it shouldn't shut down at 1/4 but could still be normal for your case.
Do you have another pairs of speakers you can try just to prove your old Vega 15? is not the problem?