How much does the Arc Ultra benefit from adding Era 100s or even a Sub-Mini?

I find my Era 100s add a lot to my TV listening when the source material has sound in the rear channels. Some content, even if showing as 5.1 doesn't have much/any sound there.

If you don't object to sounds that should be coming from the back of the room coming from the front you can place the surrounds up front. That really sounded odd to me when I've tried it.

I have a larger room so I added a Sub 4 and it makes a big difference. I'd hate to have to choose between surrounds and a sub, both add to the experience. 

If you’d want to use a Sub, I’d go for the Sub, not the Sub Mini. The Arc Ultra already has a bass speaker of it’s own, so in my opinion needs the bigger Sub.

Thanks everyone for the input.  I may go pick up a pair of Era 100s to “try them out” and see how much they add to the sound experience with the Arc Ultra.  If I add the 100s at the rear corners of the room, they’ll have to be placed on the floor, which I suppose is not ideal placement but perhaps TruePlay will help with some adjustments to address the poor position.

There are a number of commercial stands to consider but you can also make adequate stands yourself.

Two 4 foot pieces of 1x6 or 1x8 inch wood, and a small piece for the top and bottom.

Using pine is fine if painting it and cheap, oak if you want to stain it is prettier and not much more expensive.

A good quality wood glue is all that is needed to hold things together. Some rubber bands will hold it together while the glue drys..

That will give you nice, sturdy corner stands, no bigger in floor space than the 100s.

Another question, and hopefully I word this right:  When you add surrounds like the Era 100s, does the Arc Ultra continue to output exactly what it did before the surrounds are added and the addition of the surrounds add to/build upon the Arc Ultra output, OR with surrounds, does the Arc Ultra reduce certain aspects of what speakers it uses to output sound and the surrounds pick that up so that it’s ultimately the same “total” output after surrounds as before surrounds?

As far as I’m aware, it modifies the data put out by the Arc/Arc Ultra, and moves the surround channels to the appropriate speakers. 

When surround films/music are produced, there are multiple channels — L/R, Center, Bass, Surround. If ARC ULTRA is used alone it will handle everything. As SUB’s and surrounds are added, those elements are offloaded to the specialist speakers. It’s difficult for a speaker that is physically in front of you to convince you that a sound is emanating from behind.

This all makes sense.  Thanks. 

I picked up two Era 100s this afternoon and I’m working with them now on placement.  So far, they definitely add to the sound experience of the Arc Ultra.  I have a Sub Mini arriving tomorrow (cost limitation given the Sub 4 is out of budget at this point) and will see how incorporating that impacts the sound experience.  Is there a preferred location to place the Sub Mini?

Placement is very room dependent. The best method is to put it on a long extension cord and try multiple spots in the room. Prioritize sounding good at your primary listening location. 

Thanks.  Good idea.  I assume the area right next to the sitting area should be avoided as a general rule?

Ideally a subwoofer is placed near the plane of the soundbar. Sound travel is pokey at about one foot per millisecond. If a subwoofer is too far from the screen, bass will not seem well synchronized with front audio and visual action.

As Stanley_4 noted, best subwoofer placement is strongly tied to the room physics. Moving the listener and/or subwoofer a few inches can have a major effect.

Thank you, @buzz   I have a place on either side that is near/in-line with the plane of the soundbar and TV screen.  Will try those locations first.  

Folks have placed the earlier Subs and Sub 4 flat on the floor under the viewing couch or between it and the rear wall.

The placement in relationship to the soundbar is an individual thing, some folks notice the delay, others don't. At 1130 feet per second, or 344 meters per second, the delay isn't long in most rooms. Other folks have more directional hearing perception for low frequencies than others and front/center is all that doesn't bother them.

Bottom line, your ears, your room, your Sub. Make it work for you.

I have my Subs in varying locations, not all dictated by getting the best sound but by what space is avaliable. My Arc's sub is a couple feet behind it and both are in a corner in a diamond shaped room we sit in the opposite corner of the diamond. My Beam and Sub placement is similar but the room arrangement is square with me sitting at a 45 degree angle to it. Both were a happy alignment of space and sound. My 300 Atmos pair have the sub centered on a wall below them. Not optimal Sub sound for the room but good enough at my normal setting position, 3 feet in front of it with the 300s a bit above my head. Atmos sound there is amazing. My Play 3s sit on a shelf beside a corner of the garage with the Sub on another shelf below them.

OK, the Play 3 and Sub combo there is a bit silly but the Play 3s were displaced by 300s and the Sub was returned by a kid when it failed to obtain spousal approval, she likes the Arc and Play 1s I passed on to them though. After failing the spousal approval in a couple other rooms here the garage was the only option.