Simple, reasonable, soundbar advice

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iH8usrnames

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Joined 2018
#1
I've never concerned myself with home theater sound, and still don't, but I do like better quality than internal speakers.
Currently, I use a pair of Elac UB5's with an old Harmon Kardon amp for better sound.
I am in the process of remodeling the family room. When complete the UB5 speakers will not work in the space ergonomically; one would be on a book shelf, the other would be on a 36" tall stand in front of a floor to ceiling window.

My only real option is a sound bar that is connected to the full motion arm supporting the television, so the speaker and TV move together.

Goals:
  • 65" wide sound bar
  • Frequency response of 80hz-20khz
  • Use subwoofer to cover 30-100hz range
  • Stereo is a minimum. LCR if its reasonable for possible future surround.

I know this is pretty vague. I'm hoping some good folks here can guide me to some good 2"-4" drivers that can cover this range with reasonable fidelity.
It did occur to me that using a pair of good car audio speakers from the likes of Infinity or Focal might be a good idea?

If I am completely off my rocker, let me know.
 
#3
No children.
No loud sports parties.
Most used for movies.
I will use a sub to handle 30-100hz.
This is where I am lost - how large a driver(s) would I need to get reasonable output from 80-100hz and above.

I'd imagine something in the 4" range would do the job but I do not know.
When I started thinking of automotive speaker something like 4x10 or 4x6 speakers came to mind.

https://www.crutchfield.com/S-S3LQBaifdo9/p_108R6432CM/Infinity-Reference-REF-6432cfx.html

My wall mount can handle 125lbs and the television is 60lbs; so I can add some weight without too much concern.

I also stand corrected, the width is 57", not 65".
 
#6
Avsforum and YouTube has a lot of examples which may help in filtering ideas. While I get by with 5.1 / 2.1 surround sound I did have a listen to a sound bar at the Bose store years ago which was impressive but surely a satisfactory diy version could be made for much less.
 
#8
rayma said:
Think it still needs a 4" driver to get down to around 100Hz.
Maybe someone has built something similar, and can give you suggestions.
Click to expand...
I am not arguing that. As I said, I have no idea. I really am leaning toward the car speaker idea - somebody with more engineers me took the time to design a product, presumably include a crossover, manufacture, and sell it. I'd hope they did a decent job.

I'd imagine Focal, Infinity, JL, or JBL, produce a decent product in a 4x6, 4x10, or 5-1/4 two way configuration. It would cost a premium over buying individual component parts.
 
#10
If your couch is fixed, put the woofer under it.

Many 2.1 plate amps are sold, that is then a fairly simple job of assembly and a little bit of cabinet making.
You could also put speakers on each side of the seat, left and right, no need to use the screen arm in that case.

How is the room treatment?
How big? (Height also)
How is your hearing?
How loud do you need to go?

Practically, for most work, a TDA 2030 based plate amp is good enough. 12-0-12 / 3A transformer

Some people use a FM module with it, adds memory card / stick and Bluetooth functions also.

Or simply buy a used one, there are always people who want to dispose off their stuff, for many reasons.
 
#12
I’ve been working on this solution for a while now and have been prototyping my design over the past couple of weeks for just a center channel with good off axis response.

Small drivers behave much like extended range tweeters and produce the needed off axis response. Problem is still their range is limited and they don’t handle much power. The solution is multiple drivers but in a typical array arrangement, their off axis response is terrible. The answer to that is Bessel Array wiring where 5 identical drivers are used and wired in such a way that their combined response is the same as a single driver…….and it works.

Three groups of 5 of these wired in a Bessel series array will do exactly what you need in a compact, thin LCR

https://www.parts-express.com/Dayton-Audio-PC83-4-3-Full-Range-Poly-Cone-Driver-295-154?quantity=1

Port tune each group to 100hz as your spec calls for. Each array with 5 drivers will now handle the low end load without issue. Keep the baffle close to the screen and use the screen surface as boundary gain/extended baffle……you won’t need to add a baffle step compensation network.

For $165 US dollars, you’ll create a sleek, great sounding LCR with excellent coverage and off axis response.

Here’s a link to Bessel function and wiring recreated from Floyd Toole’s work
https://www.angelfire.com/sd/paulkemble/soundf.html

Good luck! I’m extremely encouraged with my center channel prototype that I’m working on. My design is intended for high output use and differs in that it’s a two way and uses 2 shallow mount 6” sub drivers to handle to low end and crosses over to the array at 400hz. It can easily hit 105db with no power compression or distortion to 55hz.
 
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#13
I’ve been working on this solution for a while now and have been prototyping my design over the past couple of weeks for just a center channel with good off axis response.

Small drivers behave much like extended range tweeters and produce the needed off axis response. Problem is still their range is limited and they don’t handle much power. The solution is multiple drivers but in a typical array arrangement, their off axis response is terrible. The answer to that is Bessel Array wiring where 5 identical drivers are used and wired in such a way that their combined response is the same as a single driver…….and it works.

Three groups of 5 of these wired in a Bessel series array will do exactly what you need in a compact, thin LCR

https://www.parts-express.com/Dayton-Audio-PC83-4-3-Full-Range-Poly-Cone-Driver-295-154?quantity=1

Port tune each group to 100hz as your spec calls for. Each array with 5 drivers will now handle the low end load without issue. Keep the baffle close to the screen and use the screen surface as boundary gain/extended baffle……you won’t need to add a baffle step compensation network.

For $165 US dollars, you’ll create a sleek, great sounding LCR with excellent coverage and off axis response.
 
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#14
mayhem13 said:
I’ve been working on this solution for a while now and have been prototyping my design over the past couple of weeks for just a center channel with good off axis response.

Small drivers behave much like extended range tweeters and produce the needed off axis response. Problem is still their range is limited and they don’t handle much power. The solution is multiple drivers but in a typical array arrangement, their off axis response is terrible. The answer to that is Bessel Array wiring where 5 identical drivers are used and wired in such a way that their combined response is the same as a single driver…….and it works.

Three groups of 5 of these wired in a Bessel series array will do exactly what you need in a compact, thin LCR
Click to expand...
While I truly appreciate your suggestion I think this is way more effort that I am willing to put into watching television. Maybe its not as complex as it sounds? I also though comb filtering was an issue with arrays? <-- likely I am ill-informed or just dumb.
 
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#15
A Bessel array doesn't behave like a line array......it uses either 5, 7 or 9 drivers only but it is preferred to only use the 5 driver array for audio. The drivers are wired in an arrangement where 2 are out of phase which creates the point source polar pattern of a single driver. The advantage is power handling with 3.5x the power handling of a single driver.

A brief explanation and wiring can be found here https://www.angelfire.com/sd/paulkemble/soundf.html

A detailed use explanation and measurements can be found here https://pearl-hifi.com/06_Lit_Archi...ns/Effective_Performance_of_Bessel_Arrays.pdf

It's not complicated at all and requires no crossover components. The driver i suggested has the needed response pass nband for your application and because it's so small, has a polar pattern much like a 1.25 inch dome tweeter. 3 groups of 5 would fit your application for 65" with three sealed chambers of .2 cuft each which should give you an F3 around 110hz so a perfect match for a subwoofer crossover at 100hz.
 
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#16
I really do not want to poo poo the Bessel Array but I just do not understand how it does not result in comb filtering, etc.

1703179793494.png


If I have five speakers lined up horizontally, driver D is out of phase, all others in phase.
For a left right combination I assume one would reverse the order of drivers for the other channel?
I just noticed the issue of ohm load; If using 4ohm drivers the load would be 14ohm or 1.6ohm - correct me if I am wrong but could that not be an issue?
I did some google foo and found bits of info here and there on Bessel Arrays but the few links I followed did not dumb things down enough for my Neanderthal brain.
I searched youtube and found several lectures on bessel function. The ones I sampled did not seem audio related. Maybe the search algorithms are against me?

Maybe I just need to see the details of construction and some measured results?
 
#17
mayhem13 said:
A brief explanation and wiring can be found here https://www.angelfire.com/sd/paulkemble/soundf.html
Click to expand...

Also I'm trying to understand the schematic for the stereo wiring, (A stereo layout does not require two banks.) It says ganged pots rotate in opposition? Can this be omitted? Where is the other speaker lead connected to the amps?

Maybe it would be better using 10 drivers with one set of 5 for each channel?
 
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#18
What you could do is build it with 5 drivers, each with external speaker connections. Then just use two drivers for stereo for now, and if you need to convert it to a mono center channel bessel array in the future you can just rewire it up that way. The drivers would each have to have their own chamber, might be hard to keep them close together.

edit: actually no, only the drivers intended for stereo need their own chambers, much simpler!
 
Last edited:
#19
tansand said:
Also I'm trying to understand the schematic for the stereo wiring, (A stereo layout does not require two banks.) It says ganged pots rotate in opposition? Can this be omitted? Where is the other speaker lead connected to the amps?

Maybe it would be better using 10 drivers with one set of 5 for each channel?
Click to expand...
That stereo wiring diagram makes me motion sick.
Honestly, I just assumed two banks of 5 would be required for stereo and 3 banks of 5 for LCR setup.
 
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