Sub Pairing With Harbeth 40.3 XDs

You don't need a subwoofer(s), but a parametric EQ.  For most pop/rock music the punch in the kick drum is in the mid-bass frequencies, say 100 to 160Hz.

I just replaced a Velodyne with a RELS812.  Just one 

unreal.  Don’t know why I waited so long

medium sized room. Everything got clearer

just killer

good luck

Willy-T

i would agree with the sentiment that harbeths (specifically including the mon 40s) should be driven with a high grade powerful solid state amp, if the best bass response from the speaker is to be had

while not a particularly hard load to drive, the speakers are not very efficient @ 85 db/w/m and at mostly 6 ohms impedance (down to about 5 ohms in narrow band of midbass), most tube amps won’t control the bass driver too well, if asked to play at good volumes

...and others replying about subs with other (smaller) harbeths, well those are a totally different can o’ worms, so to speak - the op query is about using the 40’s - c7, super 5 and p3 owners are in a completely different universe of bass response...

How big is your room? SVS ported subs are pretty amazing for the price. If you want the concert feel, ported subs are for you.

All the best.

JD

I must agree - my 40.2's have all the bass (and more) than I'll ever want.  And... they simply must be driven and controlled by a high power SS amp, with a high damping factor (4000 for the H590).

My 30.1's also sound superb with the H590.  

They almost have too much bass - but, that's probably the room / placement.