from Harbeth 30.1 to SHL5+, an upgrade or lateral move?

I know all the discussions here are centered around comparing the speaker models but if you really like the sound of your current speakers and just need more bass, you may want to try a different amplifier - or even a preamplifier, to see if they can plug that missing bottom end. I don't know the what the output impedance of the Quad amplifier looks over the frequency range but if they were designed to match/support the weird impedance curve of the Quad speakers, it may simply not be a good match for the Harbeth speakers. Just something to consider.

"Do you experience the same on your 30.1 pair? I am using Quad 99 and 909 for it. "

I mainly listen to classical and jazz. I find the soundstage perfectly fine, but then soundstage is not something that concerns me too much.

I also find the bass to be satisfactory. Obviously, the 30.1s do not go very deep, and a bigger speaker or subwoofer would go much lower. But I don't find the bass with the 30.1s "weak" or "thin".

As others have suggested, it could be an amplifier issue. I'm not familiar with your Quad amps, and I'm using Exposure (MCX preamp and 3010s2 power amp). It might be worth trying another ampllifier to see if this improves things.

I agree with all the comments here. I was trying to buy the 40.1 a few years ago but could not afford them so I bought the SHL5+ in the fall of 2015. They are driven by my Audio Research Reference 75 and the soundstage is really great. Bass will never be like the bigger Harbeth's but these are so musical that i'm sure that if I ever sell them, i will deeply miss them. I hope to upgrade now to the 40.2 soon. Will be great if I can keep both.

Hi all, this is a follow up after 1.5 year using 30.1 .

To recap, I had problem with bass of 30.1, it was 'thin' and 'weak', i was disappointed with it and wanted to move to other speaker (SHL5+)
However, last week, a friend suggested me to use power conditioner in my system. I never believed in the power conditioner of any kinds but I still bought one because this friend has long been sensible in choosing audiophile equipment.

After getting a power conditioner from eBay, I put it in the system. I played tracks that I usually played to see if there is difference brought by the power conditioner.

Here are the improvements that I notice:
- the bass is noticeably stronger, more defined- musical instruments are separate, also, their positions on the stage are more pin pointed.
- the background is darker- the mid bass is revealed, I never knew I missed this range of frequencies and did not  much understand when people talked about "mid bass" 
The music is now more musical, especially the guitar is more romantic.

Everything is just like I have upgraded to a better amp or better DAC. Or to put it simple, the difference is like when you view the same picture in 720p and in 1080p. Everything is sharper, more beautiful. Now I have no complain about the bass of 30.1 anymore. Together with the marvelous mids and highs, I know I am going to keep these speakers for a long time. :)

FYI, the power conditioner I bought is a used Richard Gray Pole Pig, I used it with a RGPC High Tension power cable. I paid about $600 for these.

I believe there are other power conditioners that can make the same improvements, if it's possible, please share your experience with your power conditioner so we have more options to choose regarding the power conditioners.

Thank you all.

Best,
Huy.