Same watts at 8 and 4 ohms?


I'm in the market for an integrated amp and trying to sort through tech specs. My understanding of the tech aspects of hi-fi gear is limited. Looking for some clarity in regard to watts-per-channel specs.

It is my understanding that wpc at 4 ohms is typically 1.5x -2x the wpc at 8 ohms.

But I'm seeing a number of respectable mid-fi integrateds with the same wpc for both 8 and 4 ohms. The NAD 388 is one and I think this is true for several of the Cambridge Audio units at a similar price point ($1500-$2000).

The NAD features make a point of saying " 4-ohm stable for use with a wide range of speakers". 

Would appreciate any insight to what these specs mean and what 4 ohm stable really means to me. My speakers are 4 ohm speakers.

Thanks,

George
n80
Every time a question like this comes up it reminds me what a good decision I made way back in the 1970’s to avoid hard to drive speakers with low sensitivity. It just makes life so much easier. Doesn’t hurt that every hard to drive low sensitivity speaker I ever heard never sounded that good to me. Maybe because they were never used with an amp that could make them sound good? That could be it. But whatever, who cares, not my problem!

It was only much later on that I discovered tube watts and solid state watts are nowhere near the same. People can howl all they want, throw all the technical mumbo jumbo they want, when you hear 50 tube watts have more authority than 200 SS watts you have to admit all the words in the world can’t change the fact tubes just plain sound way more powerful than they measure.

Put it all together and you blew it once, and are blowing it again. Just not by as much this time. But its no hallucination. If anything stands a chance of making those speakers sound good its a good tube amp. I drove Talon Khorus for 15 years with 50-60 watt tube amps, and they went a lot louder than you're talking. So you will probably be fine.
Well, in my defense (as if speaker choice needs defending) I got both sets of my speakers for free and driven properly they both sound amazing to my far-from-golden ears. 
Baconboy you can take it for what it's  worth, I’ve read reviews of the NAD C388 driving maggies and other hard to drive speakers. I used the C388 with some Ohm Walsh 2000 and it handled them with ease. You should probably check some maggie threads and see what others use.
If you're ready to consider a serious setup - amp and not integrated - I would recommend the H2O Audio S250 Signature.

Old school linear power supply, dual big transformers, B&O Class-D. Puts out 250/500W into 8/4-ohms. Handles 1-ohm Apogee Scintillas with ease.

It will easily run any of your speakers. You can leave it on all day and it doesn't get warm. A solid piece of gear, I had it for a while with Scintillas and Duetta Signatures and it was a great match.

Read a review or two and check it out...
The Aerial speakers are not that hard to find an amp for, your criteria limits your choices but you should find something appropriate. If memory serves Crutchfield paid return shipping on a preamp I tried about a year and half ago. I hate doing returns but the with no B&M stores close I've resorted to it a couple of times.