Good Speakers for Low Watts

I own and like my klipsch Heresys . However as a bass player you will find that they roll of entirely at 50cps and start their decent at around 100cps. In additiion you would be smart to buy the Original Heresy not the ll or lll.
The price for a pair of the ls is closer $400-$500 in good to excellent condition. There are ways to improve the sound by changing to a new crossover, which is a good idea anyway. That adds considerably to the cost.
Low level listening to low frequences is why vintage equipment had a "compensator" or the later "Loudness" switches. I have read that at low volume the low frequencies get lost thus the bass boost. These are things you might consider.
I can say that most small monitors in the price range you are talking about are very good . However they are generally incapeable of producing really low bass. To the average ear, it is barely noticed.

NHT SB-2 or SB-3. I used a pair of the 3s with a 50 watt Audio Refinement Complete. Very smooth sound and good at low volume.

I used to have a Musical Fidelity A-1. It gets very hot, enought to fry an egg on top. Be advised most units have volume control or selector switch failure due to the knobs breaking. My selector switch broke. I finally gave the amp away. I'd have to say it was a really nice unit for the money, purchased for something like $350 back in 1985. What about the Class A Belini amps?
Speakers: Believe it or not I used a pair of Spica TC-50's and it was loud enough for me. If you have the room, a pair of Altec 19's or JBL Jubals or L-300's if you want LOUD with 20 watts...

Intermezzo 2.6 active with RABOS.

Many on this forum will disagree, but if you are going to use a 20-35 watt amp, I would recommend that your speakers have a sensitivity rating of at least 95 dB. I you go lower you will lose the pleasure of dynamic range. (The range of sound intensity a system can reproduce without compressing or distorting the signal.) With speakers in the 90/dB range your amp will clip on the loud passages and your recordings will sound flat.

HG

If you're looking for a newer spk., I'd look for a Tannoy Fusion 2 or an older MX-2M. These have soft dome tweeter and offer decent bass. Very easy to drive w/lower powered amp. Good stands are mandatory. (Plateau RT-23 are exc. affordable stands. $80 New Inc. Delivery. Fill w/lead shot for even better sound.) Will look and sound very good. Good Luck Bill.

The Audio Concepts Sapphire III is rated at 90 dB and is a superb speaker. They can often be had in the $400 range.

The MF A-1 as I recall was a bit of a problem child as far as reliability according to my reading on the net. It runs very hot also. I had a chance to get one cheap but declined after researching it.

Probably klipsch will be your best bet, I know the RB7's which are the reference series klipsch are excellent at all you are talking about, and they are compact, will play loud, and very clear.. Best paired with the tubes like you are requesting as well.. you can find many reviews in the positive for this speaker all over online, and I think new they are around 700.00… used I bet you can get them for close to half that, or at least shipped for another 50 to 100 bucks.

Klipsch Heritage series.

I'm sure you'll get lots of suggestions. The tough part of your question is the assumption I'm making that, as a bass player, you want to be able to hear other basses pretty well. Hopefully others who make specific recommendations will have kept this in mind. Good Luck!

psb alpha, klipsch heresy, totem rain