Axiom Home Page Forums General Discussion Advice from Axiom Owners Bookshelf or FloorStanding 5.1 System vs. Room Siz

I want to build a 5.1 surround sound system. The main speakers would be a 3-way rather than two-way design for the performance reasons cited in the video here. https://www.axiomaudio.com/m5-bookshelf-speakers

The 5-channel Class AB power amp https://www.crutchfield.com/S-4qWPQyxK7XD/p_313A52PB/Parasound-Halo-A-52.html https://www.stereophile.com/content/music-round-91-parasound-halo-52-page-2 driving those five speakers will feed the unbalanced inputs of a multichannel DAC like this one. https://www.exasound.com/Products/e688-channelDAC.aspx

And the DAC’s balanced inputs would be fed by two pairs of these powered subs https://jamesromeyn.com/speakers/subwoofers/ak-tall-subs/ or two pairs of these powered subs. https://www.rythmikaudio.com/F12SE.html

A standalone or software assisted DSP solution for bass management and room correction will be added later.

Presumably, the problem of classifying the “acoustically relevant” size of my listening room is that its basic dimensions spill over and extend into other rooms. And because it does so-and because there’s probably little that I can do to acoustically correct for this-how much will negatively impact sound quality?

My Listening Room

Width: 11 feet. But it then extends across a ~3.5 ft wide hallway, and which is ~ 14 feet long where the three doors can be closed there.

Then one foot past that hallway my listening room then empties into the kitchen that extends the total width by another 8 ft. And the kitchen length is ~ 10 ft. Then immediately past the kitchen wall the room’s width crosses past a 4 ft. wide L-shaped downstairs staircase, which extends my room’s 11-foot room width by another 11 feet, before turning to go further downstairs.

Windows. My room has three bay windows all on one wall which I usually keep closed and draped.

Length: Just under 20 ft.

Height: Triangular ceiling. Apex 11 ft that declines to 8 ft.

Therefore, given my room’s “effective size” and acoustical environment should I choose five 3-way bookshelf speakers, each placed on a ~20” high platform on the floor?

Or some combination of 3-way bookshelf and 3-way floor standing speakers?

Look at how "challenging" my friend's space is. Cathedral ceiling like yours. She thanks me every day for her walnut natural satin M5s, driven by my 20 year-old Denon and $99 Sony sub. The M5s are poised on $5, 10" high stands from IKEA.

There are no M5s to be heard. Just tall, deep, wide soundstage behind and beside them with solid images performing on that stage. With the right recordings, like Madonna's Vogue, the entire room is ablaze with prancing images.

She has no trouble rocking throughout her 4-story home!

You do not need floor-standing and on-wall would work great to de-clutter your space.

These are M2OW flanking my 10' bow window. I've also used M5OW in that location but found the bass over-powered my 22' x 12' living room which is open to the rest of the house. Wide, tall, and deep soundstage from both the M2 and M5. When I say deep, it's out the front window. And wide means 22'.

This is all very encouraging. Thanks! Except for acoustical materials, I dislike mounting speakers or any hardware on walls. But one big worry I always had with stand speakers as opposed to floor standing ones is knocking them over. I live alone. Your friend obviously has no such anxieties. But how about this for a fix: A solid wooden box under each speaker that overshoots their footprints by ~ 6". Then folding over a few ~ 20" lengths of 2" wide gaffers tape to form doubles-sided adhesive strips to affix the bottom of each speaker to its wooden box stand. Yes?

The solid box idea might be OK on carpet. A wood floor may resonate particularly since the box would form an acoustically resonant cavity. At my friend's, I mounted little rubbers under the M5 and the stand's legs in an attempt to de-couple from the floor. Works well!

The M60 may be a better bet but I can't say whether it would acoustically disappear as well as the M5.

BTW, I can tell you are the type who would NEVER knock over his speakers. So don't worry about it.

Well, except for the fact that I'm the king of bad luck, so I always err on the side of caution.

My flooring is carpeted. But it would certainly help knowing how speakers like the M5HP would sound crossed with two pairs of subs. And would I'd still be better off with M60 or M80? Any thoughts on this?

The M80s will play louder than the M5s. But you may find positioning them in the room is a challenge and you may not be able to get them to acoustically disappear.

With that amp and subs, I can't see a benefit with M60s. M60s may be a detriment actually for the same reasons as M80s.

The M5s would sound terrific with as many subs as you want. I've used them with up to 7 subs. Fantastic!

The M5s are far less prone to position error than the larger Axioms. They are as refined as the M100 and active LFR and far easier to succeed with quickly.

Open floor plans should be treated as a single volume, but since you're sitting closer to the loudspeakers within that volume, you don't necessarily have to upsize all the audio components. But if you like it loud, err on the side of more power and bigger speakers.

And Mojo, I'm detecting blank spots on the wall awaiting the next candidate weapon. May I suggest:

https://www.amazon.ca/GURPS-Ultra-Tech-David-L-Pulver/dp/1556349718

(I somehow have the first edition written 30 years ago, sitting with some of my Mike Pondsmith RPG's).

As my hearing is almost as good as it ever was, I would approximate that at ~ 6 feet no more, if not less than 45db SPL @1kHz, 53db @ ~ 8kHz, 65db @ 100Hz, and so on, below which my subs would take over.
https://en.wikipedia.org/wiki/Equal-loudness_contour

That speakers can achieve absence of their audible presence is certainly a good thing, especially if this happens along with a spacious soundstage and other characteristics that create and transport the listener to realistic sonic realm. That's why I've always found Enjoy the Music's performance check list extremely useful for evaluating hardware. See the bottom of this page. https://www.enjoythemusic.com/magazine/equipment/0214/axiom_audio_m100.htm