Which speaker to replace Dunlavy SC-V?

This reference type speaker is often used for monitoring/mastering; IMHO, stick with the Dunlavy V's (provided you like their straight forward accurate qualities).

IMHO, some reasons to change might be;
1) if you were to move and the V's were simply too big in their new location. (a pity but you really have no choice)
2) if you wanted to create a combined stereo/HT system with timbre matched speakers all around and/or needed speakers with a larger sweetspot (Dunlavy V has narrow dispersion and correspondingly small sweetspot).
3) if you wanted a speaker with similar qualities that can play louder

Absent any specific requirements for a change, another high quality large reference speaker will certainly give you a slightly different sound...but is this worth the trouble/expense and risk of making a change? (slightly different does not equate to better; some material will sound slightly worse and some material will sound slightly better, all depending on the mix/mastering of the source material).

On the other hand, large speakers that sound markedly different are most probably not as good (for you), which is again a reason to stick with your Dunlavys (recall, you have already stated that you like them).

This review (see below) suggests you already have a real gem of a speaker, which I expect you well know.

http://mixguides.com/studiomonitors/Reviews/studio-monitor-audio-899/index.html

Chris,
Long reverb time can be mitigated with plenty of acoustic treatment...if you can accept to hang many panels around the room (especially the rear wall behind your listening position)....

one of the things i,ve noticed when i had my Dunlavy,s is that as stated by John Dunlavy in the owners manual you should place them across your long wall in your room with more distance in between them than distance between the speaker and the sweet spot (somewhere between a 60 to 90 degree angle, a lot of toe in). This way they sound absolutly fantastic

This is necessary for speakers that have narrow dispersion like the DAL V's...ideal for a precise image with a minimum of reflected energy. Some call this the "equilateral triangle" setup. However, it will only give you a small sweetspot for critical listening and therefore it is not well suited to HT or situations with two or three listeners.

Sean,

The DAL V's might NOT be a narrow dispersion "design" but they do throw out a narrow dispersion pattern, this is well known being quite senstive to adjustments of toe in. As I stated, this is not ideal for HT where a broader dispersion pattern and a larger sweetspot is more desirable. They are still undeniably a fantastic speaker and I have never heard anyone call their bass response inconsistent.

Sean,
I agree that a single listener will benefit from narrow dispersion speakers in HT when in the sweetspot, but my thinking is that most HT should be designed so that several people can enjoy a movie together.

IMHO, the use of narrow dispersion speakers for HT will yield a less balanced surround sound experience than wide dispersion speakers, particularly for those seated furthest from the sweetspot.