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
An ideal amp maintains the voltage output regardless of speaker impedance, which is synonymous with saying it doubles the wattage as the impedance is cut in half.


This isa good post.
Which is why I always ck the weight ofa  amp 1st, this tells me the size/quality of the transformer. 
Bigger the better,,up to say 80 lbs,, after that i can't lift the thing and not interested. 
Big hefty well built trans is what you want to consider,,I recall Marantz had some respectable power in certain models,, Then came along Rotel, NAD, Nacimichi,, Onkyo,, Onkyo and nac has a few amps with some solid power, Rotel, NAD were so over rated Sherwood , Snasui, Luxman, all so over rated on watts. So many ss amps sound anemic to me, I can lift most **100Watt* amps with 1  hand, completely ridiculous. 
 In hifi there are 2 types of amps
Real watts and fake watts. 
Its how beefy and well constructed are the trans. 
btw not only do i hate ss amplification,,I also hate as much low wattage SET amps. . best sounding speakers are all under 90bd, 4 ohm. Driven with real wattage  power. 
@n80 Have you contacted Aerial and asked for their recommendation?? They know more than anyone here about what might fit your use scenario and excel in doing so...

https://aerialacoustics.com/contact-us/
I have talked with the owner about other things but not this. I feel like the limitations I am up against (budget, size, room limits, intended use, etc) make it unlikely that he will be able to recommend something adequate for these speakers.

I have heard that he imports Gato amps. I cannot afford one of those. I have heard he endorses the Peachtree products. One of those is one the short list.

I'm waffling all over the place between going all out (makes no sense as I will not be using these often) and just getting rid of the speakers since there is no actual need for them to just getting a Sonos Amp which makes the most practical sense but not the best SQ sense.

Still not in a hurry. the Bryston still sounds wonderful, it has not sold yet and my wife hasn't made any threats.
@atmasphere "There's a recording of the Saint Saens Organ Symphony on EMI that has 16Hz pedal tones."

I've got the Telarc recording. I have no idea how low does it go or how low my system limbos, but when that organ blasts through my Aerial 7Bs, the house rumbles and you feel it in your chest even at moderate volume.


I might have to see if I can get a copy of the EMI CD.