I've found over the years that it's truly all a matter of choosing among compromises. For me, soundstaging is important to my enjoyment of a lot of the music I play. In the various rooms and setups I've had over the years, I've found that anything placed between the speakers will have some audible negative impact on soundstaging. So, I avoid having anything between my speakers to the greatest extent possible.
Nevertheless, in my current setup I do have a single 24' wide by 42" tall open shelf equipment rack between my speakers, but sitting about 36" behind the front plane of the drivers. This works and soundstaging is good, but the rack still compromises slightly the soundstaging that would be possible without it being there. (When we set up the room, my listening partner and I tried other locations for the rack, and we could hear the impact of the rack in each location.) Placing the rack well between the speakers but well behind the front plane of the drivers proved to be the best compromise in this room.
If my room were over 16' wide instead of 14.5', I'd be more inclined to go with a side wall. But with just 14.5', the rack on the side created soundstage balance problems that were more problematic than being placed between the speakers. At least there, the soundstaging impact was balanced and symmetrical. Getting it well behind the front plane of the speakers was a key factor in making this position work for us.
What I've found is that, generally, if the rack between is open shelving, is modest in size, and is behind the front plane of the speakers, I've not observed much compromise. If the rack is short, even better. The worst compromises I've heard have been in listening rooms with a large piece of furniture between the speakers and in the same plane with the front of the drivers (like the room I had for many years with a full soundboard 53" tall upright piano between the speakers!)
FWIW, I've listened in many rooms with racks to the sides or rear of the listening position where 20-25' single-ended interconnects were run to mono-block amplifiers at the speaker location. In those setups I've never been able to tell that the long interconnects were creating much of a problem.
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Nevertheless, in my current setup I do have a single 24' wide by 42" tall open shelf equipment rack between my speakers, but sitting about 36" behind the front plane of the drivers. This works and soundstaging is good, but the rack still compromises slightly the soundstaging that would be possible without it being there. (When we set up the room, my listening partner and I tried other locations for the rack, and we could hear the impact of the rack in each location.) Placing the rack well between the speakers but well behind the front plane of the drivers proved to be the best compromise in this room.
If my room were over 16' wide instead of 14.5', I'd be more inclined to go with a side wall. But with just 14.5', the rack on the side created soundstage balance problems that were more problematic than being placed between the speakers. At least there, the soundstaging impact was balanced and symmetrical. Getting it well behind the front plane of the speakers was a key factor in making this position work for us.
What I've found is that, generally, if the rack between is open shelving, is modest in size, and is behind the front plane of the speakers, I've not observed much compromise. If the rack is short, even better. The worst compromises I've heard have been in listening rooms with a large piece of furniture between the speakers and in the same plane with the front of the drivers (like the room I had for many years with a full soundboard 53" tall upright piano between the speakers!)
FWIW, I've listened in many rooms with racks to the sides or rear of the listening position where 20-25' single-ended interconnects were run to mono-block amplifiers at the speaker location. In those setups I've never been able to tell that the long interconnects were creating much of a problem.
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