Not really, large speakers are more efficient than small ones.
In the 1950s & '60s, most amplifiers had quite modest outputs, but were used with large speakers in full sized enclosures.
These were much more efficient than the relatively tiny speaker enclosures used today.
The reason modern power amplifiers use beefy transistors is because they need to produce high power to get reasonably high acoustic power out of small, inefficient, speakers.
Still with large speakers you want higher damping factor to get good quality as they have more mass. This doesn't mean greater power but does mean better designed and bigger transistors as they can archive lower output impedance.
Still, for the lab there's nothing wrong with moving a large speaker with small transistors, but you do want to have some considerations, no DC to the speaker is usually a good one. Knowing the polarization point of your transistor and choosing it correctly is another. You are using a single transistor, that's class A and you can't get away from it. Let's say an inverting NPN stage, so you can only source what the resistor in series with the speaker can take from half supply and you can sink what the speaker can take from the other half limited by the max colector current of the transistor. In general you want the transistor collector to be sitting between your rails taking the maximum current the speaker would take when the transistor is almost off. For the other side you would travel as far as getting the same signal so you get a symmetric signal. You could offset the output a little to get this just a bit better but won't change much the output power from there.
So with this, 8Ω 9V (4.5V per rail). The peak current should be around 0.5A, times the 4.5V the transistor should be able to dissipate 2.5W at idle, as well as the resistor. When signal is present the dissipation would be lower as some of that power will be absorbed by the speaker, getting up to about 1.5W best case.
This means that if you don't want it to be hot you need at least a small heat sink and a transistor able to handle that 0.5A without much trouble. You could go for 100mA instead, but you won't get the 9V swing any time soon, instead more like 1.6V peak to peak, at those 100mA, 80mW. This you can archive with a smallish transistor without getting too hot to touch but still warm.
JS