4 driver per speaker full range - design help

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All,

Might be my 1st post here..

Currently my AV seup consists of a 55Inch TV (49 inches wide) on a 60 inch wide TV stand. There are columns of shelves next to the stand.

Which leave 5.5 inches per side to mount speakers over the wall, And there is 2.5 inch space left below the TV.

I'm in the process of setting up a surround system for the setup (17 x 22 feet room).
Which makes me to plan a 4 driver array of 2"full range drivers crossed at 120Hz and 2 small active subs mounted on the shelves for a 5.2 surround.

FYI, I have a marantz 1508 thus dont want to load it too much.

My question is. What should I do to design the 4 driver line array so i can avoid comb filtering, i.e. CTC distance etc...
Does this count as an array? if not what this setup might be called as?
Does it make sense to add a tweeter at center, or on all of them, to make it sound better.

My goal is size to performance ratio.

Help for a newbie please?
 
I've not really done much more than build speakers from plans where other people have already plugged the speaker parameters into bits of online software and done the brain work to come up with required volumes for cabinets.

So I have a question relating to the post above. If you find a design you like and scale it down in size (driver and cabinet) what's the likely overall effect? Can you take a design for a 4 inch driver halve all the dimensions and get something that works with a 2 inch driver but perhaps with less bass?
 
I've been fascinated by line arrays and reading up on them. Probably the best single compilation of information I have found is called "Design Guidelines for Practical Near Field Line Arrays" by James Griffin, PhD

It's available online in various places and one place that it currently seems to be available is
https://audioroundtable.com/misc/nflawp.pdf

Long story mostly short, to get true line array behavior:
To get line array behavior characteristics that extend up into the higher ranges, you want minimal center-to-center space between the drivers (if you have separate high and low frequency drivers you can gain flexibility)

To get line array characteristics that extend down into the lower ranges, you also want the total overall length (height) of the line of drivers to be substantial in relation to the wavelength of some fairly low frequencies.
These considerations are somewhat in tension with one another, especially if your goal is to use a single driver type- and pretty much mutually-exclusive if your goal is to use a limited quantity of small drivers.
A nice condensation of data on frequency and wavelength is here:
https://www.jdbsound.com/art/frequency wave length chart 2013.pdf
A nice bit of overview of different combinations of numbers of drivers, driver impedance, wiring schemes, and overall resulting impedance is here (this is by no means the last word on every option but it is the single nicest 'cheat sheet' I have found for some fairly pragmatic variations)
arrayimpedance-revised

If you are not budget-constrained, a row of 8 or 18 of these would be a nice arrangement, and they have the benefit of having a built in grille:
FR59EXE
some of the info indicates that they reach down to about 325 hz in a sealed enclosure and about 180 hz in a ported enclosure. Some people say that the effect of the many drivers in a line leads to extended lower frequency performance compared to single drivers, but I don't know if that's proven or universally accepted.
Comb effect seems widely debated and, in actual listening experience with music, apparently less of a big deal in practice than it is in theory.
Good luck and have fun and please do share what you arrive at for a design, and results after you construct and deploy it!
 
4 drivers do not make an array.

You will get all the inconvenient X of an array with none of its benefits.

Try using a single 4" driver. If you find one with a low Vas and a small enough bezel, it could work.

Or, can you put the "in" the walls? There are a number of in-wall speakers out there that might do the trick.

If nothing can be done about moving some shelves away, then maybe a commercial sound bar could be looked into.

And next time you rebuild the movie watching room, consider a design that will allow you to add some speakers.
 
Gonna agree with Perceval on this - a single pair of any of the usual suspects of 3 - 4” drivers per side (Fostex, Mark Audio, TangBand, Peerless/Vifa, Dayton, Faital Pro, etc) and unless you can finagle a bit more space, maybe forget about a centre altogether. Presumably you’ll be able to include some type of powered sub, without which a HT using drivers this small would be quite underwhelming.

My son has one of those Bluetooth sound bars with subwoofer (can’t remember the brand) for his bedroom TV, and I’ll keep it polite by saying that it’s definitely better than the shite built into the TV, and certainly convenient.
 
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