Your post shows that you know a good deal about this - but this line isn’t exactly true, or were you merely oversimplifying for clarity? For example, if we want to compare detonation and deflagration, we can look at this example:
Try to visualize a one-dimensional stationary combustion wave of a flammable gas and air mixture in a tube. We will assume this is a premixed flame, which is defined as one where the reactants are mixed perfectly before the chemical reaction. (as opposed to a diffusion flame, where the reactants diffuse into each other during the chemical reaction). Wood burning generates a diffusion flame, as opposed to a torch or gas burner which generates a premixed flame.
(Unburned gas) |F (Burned Gas Products)
U1-------> |a U2--------->
p1, T1, P1 | p2, T2, P2
Where U is the velocity of the gas, p is the density, T is the temperature, and P is the pressure, and C is the local sonic velocity. By looking at these variables, we can express relations between the two sides of the flame front to say whether what we have is either:
deflagration - where the combustion wave propagates at subsonic speed (controlled burning, in other words). These are found in Region III of the Hugonoit curve (and yes, technically, Region IV, except it is very hard to get anything into region IV since it is very hard to get combustion products to depart from the combustion wave at supersonic speeds), or
detonation - where the combustion wave propagates at supersonic speed (an uncontrolled burning). These are found in Regions I and Regions II of the Hugonoit curve, with said regions being seperated by the Upper Chapman-Jouget point, which divide them into Strong and Weak detonation points.
Deflagration and detonation are divided by Region V of the Hugonoit curve, which is an imaginary region since the Rayleigh-line expression implies that U1 (see below) is imaginary, and thus it is a physically impossible region.
But I digress.
For these cases, we have the following relationships:
Property Detonation Deflagration
U1/C 5-10 (supersonic) 0.0001 - 0.03 (subsonic)
U2/U1 0.4-0.7 (deceleration) 4-6 (acceleration)
P2/P2 13-55 (compression) 0.98 (explansion)
T2/T1 8-21 (heating) 4-16 (heating)
p2/p1 1.7-2.6 0.06-0.25
Which just tells us in a stable flame, we have a subsonic flame front, acceleration of hot exhaust gases away from the flame, a slight expansion of the exhaust gases due to lower pressure, a large heat addition (duh!), and a decrease in density. As opposed to detonation, where the supersonic flame front causes a large spike in pressure and density, casuing the “knock” one hears in car engines.