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Mono or stereo in ceiling?

12945 Views 40 Replies 10 Participants Last post by  Sound reno
Tired of searching and reading so much nonsense.

New house construction, ceiling speakers for WHA used almost exclusively for background music. The exception may be in bedrooms where I may want the option of piping sound from TV to an in ceiling speakers pair if it turns out to sound better lying in bed than the TV or a sound bar.

All common living spaces, outdoors, just background only. Well, around the pool may be louder than just background occasionally!

Mono speakers or stereo speakers? I don't mean single speaker stereo (which I'd use in small rooms if I maintained stereo signal path), I mean mixing down to mono prior to amplifier and using any number of truly mono speakers in a space.

I've seen this suggested as:
- it's background
- you aren't oriented in traditional stereo direction often
- separation may be odd in some rooms... Guitar over here, vocals over there etc.
- often differing room boundaries for L and R
- increases independent channels and perhaps zones?

I've seen arguments against:
- many common WHA systems seem to assume stereo, as volume per zone is on a pair of channels, not each independent channel.
- still maintain some stereo imaging
- less cancellation/combing than from widely spaced mono sources
- plan HTD sent as an example assumes stereo in every zone
- plan local AV integrator sent assumes stereo in every zone.

Personally, going mono seems logical but most entry to mid level WHA systems don't appear to be designed this way. Anything I'm missing here?
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Most commercial installs use mono, only because large installations with lots of speakers use 70 Volt for wiring and power vs 8 ohm. Mono doesn't matter in a mall or other large space.

Residential is different as most everything is 8 ohm and used in a stereo setting. Most rooms will sound great (depending on the speaker/room design).

8 ohm has better bass than 70 volt too, if we are talking the exact same speaker.

Some systems (like VSSL) can set certain zones as mono and can be good for certain room shapes where mono may be better, but these are rare.
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Awesome, thanks. Short concise answer. I could learn from that!
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I say - pick, choose, plan.

That is, pick products which allow you to mix and match stereo and mono zones.
Choose which zones will be stereo, and which will be mono.
Plan your speaker placement accordingly. Put stereo speakers in the best location for the best sound and results and run them in stereo. For mono zones, place your speakers for best even coverage of the space.

I use a product which let's me mix and match my zones, which I do. I have many rooms with televisions that run in stereo. I put the speakers near the TV on the wall, or use angled speakers in the ceiling near the TV location.

Other areas, like bathrooms and outside, I have the system set for mono and it automatically mixes the stereo feed down to mono.

Everything is 8 ohm for the better audio reproduction.

Yes, commercial uses 70v, but have no doubt that some rooms are designed with stereo setups and use 2-channels of amplification for sound reproduction. I've seen a ton of variety in commercial setups.
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For rooms where you want to go mono, just use one dual-voice coil speaker.
70 volt systems can be stereo as well.

Yes you can use a dual voice coil but it's easier to blend the signals at the low level. Uses one less amplifier.

When there is a central sitting area as main listening area, use stereo. Otherwise use mono. Outdoor landscaping it typically mono as you are moving around the yard. And, because of the wire lengths, might also be 70 volt.
For rooms where you want to go mono, just use one dual-voice coil speaker.

If you are going to use a WHA system with 2 channel stereo amplification to each zone.... I agree this is the best option for zones where you don't want to (or can't) install two speakers, just run a 4 wire cable, install 1 speaker and done! I did this for the bedroom and bathroom zones in my system and I am very happy with the results.
Seems there is a choice to be made between many common consumer WHA devices like the HTD and monoprice systems, maybe Russound?, that don't provide any downmix to mono options that I can see, and more upscale matrix equipment like crestron.

To be honest, I looked briefly at the used crestron gear market and it seemed like yet another time consuming diy project. My minutes are already double booked with doing a lot of the theater construction work, building a ton of speakers, building six more multichannel amps, programming a Lutron system, getting up to speed and programming an automation controller.

I sort of want something here that just works out of the box but doesn't require a dealer to install and program.
If you want to downmix an analog signal to mono you take 2 y cables and connect them together and you have mono, problem solved in about 10 seconds and $3
I was thinking before that doing that would create a stereo version and a mono version of each input before a WHA controller, which would make selecting a source problematic, but I suppose that can be done between WHA controller and amplifiers. Maybe it is that simple, since those zones would always be mono. Would definitely reduce total number of amplifier channels needed. Thanks for the suggestion, I had dismissed that earlier without thinking it through well enough.

Of course, I'd use a resistor in line with each output to isolate the sources. Using a Y meant for splitting signals can cause backfeed from one source channel to another and possibly damage them.
Of course, I'd use a resistor in line with each output to isolate the sources. Using a Y meant for splitting signals can cause backfeed from one source channel to another and possibly damage them.
A resister suppresses in both directions...not just a "backfeed" (of which there isn't any issue in this application).
Just put a Y cable and be done.
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Line level output devices expect to be connected to a high impedance input/sink, not the low impedance of another output device. Adding a few-k resistor in line for a few pennies is an easy way to ensure that is the case. There "probably" wouldn't be an issue with most devices, but that would be really hard to know until you had a problem.

I had seen a suggestion to mix down to mono before WHA to expand available zones but many don't work that way as channels are linked in pairs. Mixing between WHA and amp seems an easy solution that for some reason hadn't come to mind. Glad I asked!
In my last house, I had it in the ceilings of three rooms-kitchen, bedroom and great room. It was in stereo and used exclusively as background music. I never noticed and problems with sound as background. Of course, it would not be appropriate for traditional listening. Most receivers have a mono button or option. You can always engage that to try.
Half of my house is mono - bathroom, kitchen, guest, garage, outside etc. Other rooms are stereo. Less outputs are used, less amp channels needed. For just background music I would prefer it. You can get more creative with speaker layout/zoning, like dropping a single speaker above the bar, or a hallway, or 3 in a long dining room without using DVC and eating up amp channels.

You don't need to do Crestron DSPs for that. You can get QSC/biamp/Symetrix etc DSP used and cheap and the software is not dealer locked. None of the consumer level stuff can touch the capability of those devices.
Any specific qsc, symetrix or biamp models you recommend I take a look at? DIY Crestron wasn't something that I thought I wanted to get into, but not against taking a look at less traditional routes for consumer installs so long as software is available and open.
You can always stack up to 4 of the older Biamp Nexia units. These are very old units (I used these over 10 years ago) but still more capable than anything consumer oriented. You can find the Nexia CS for under $100 easily on eBay. Each has 10 inputs and 6 outputs (mono of course) so if you stack 4 that's 40 in/24 out for $400. Half of that if everything is stereo.

There's Biamp Audia - these are chassis which can have an array of I/O. These can also have cobranet for audio over ethernet. Unless you know exactly what you are looking for I would avoid these. Their newer line is the Tesira, you can find good prices on the standalone (probably not enough I/O) or AVB ones. The Dante Tesiras popup every once in a while. Last one I saw was around 1K.

Newer Symetrix units have Dante and can be had cheap if you keep an eye out, I think they are hitting the sweetspot for price/utility. I grabbed a Radius AEC for $350 a while ago. That's a 12 in/8 out. I found a 12 output expansion unit (x12) for $150 (these retail around 2K.) I've grabbed some misc Dante I/O pieces when they pop up. Shure 4 output unit ($200) Symetrix 4 output ($100) etc. Dante audio isn't going anywhere and the prices can be reasonable if you buy used.

For example something like this:


I would not buy that one - it's mislabeled as it's not an AEC unit and it's the V1 unit without the expansion port. At $500 no...if it hits around $250-300 it's a decent price.

QSC has the Core 110. These are relatively new so they don't popup all that often. Every once in a while I'll see one pop up for not much more than dealer price (new)

How many zones are you wanting to do?
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18 zones would work pretty well for now, 24 would be a little more flexible and give room for any future expansion, 12 would be possible combining some adjacent living spaces and to be honest the decreased complexity on control might offset the decreased flexibility.

How are those units you mentioned controlled as far as in a residential setting selecting a source, changing zone volume etc.
That's a lot of zones. How many of those zones would you want to do mono? Analog I/O gets expensive on commercial DSP stuff. For a large house with 20+ zones going the commercial route might be worth looking into as far as audio ducking, paging, EQ and whatever else pops up.

For example, I'm going to add an in-ceiling sub to my kitchen. I don't have to worry if my WHA supports it, or re-wiring the speakers in that zone. I put it in, run the wire to it and set a xover on the output and I'm good to go. I have a VOIP card in my processor which is used for different things.

As far as control all these guys usually publish their control protocol on their site. Every one I've used has been easy to program control for. These companies make keypads, but they're usually somewhat expensive and I don't see them pop up on ebay often.

Zektor also makes audio processors that have rather high I/O count.

What solution was the A/V integrator proposing for this?
AV suggested Russound. I got a quote from HTD that would probably meet our needs just fine. We use Amazon echo devices now for background music and to be honest I think music from Amazon, paging/announce function etc of the echo devices would be what we used 90% of the time. I'm tempted to just put echo dots in ceilings everywhere, the HTD amps with priority sensing input, and wire everything back to equipment closet to add WHA matrix later. Would be nice to have local speakers play sound from TV in a zone. That's probably the biggest use I could see. Might occasionally play local music if someone brought a CD or something.

As for stereo/mono, I could see anywhere from 3 to 9 of the zones being mono depending. Some mono or a single dual channel speaker would both be fine.
See, I think you absolutely need to check the specifications on any product which you get which is a source selector audio matrix to ensure it does stereo to mono mixing per output.

Not sure why someone is talking about DSPs. Those are PRICEY!!!

In all seriousness, we could figure something out for you using 3 Crestron BIPAD8 units. Each one is a 16x8 unit with buffered outputs, so you can stack 3 of them. They will do room by room mono/stereo selection. A little work and they could be pretty well integrated with a phone for control of your source/destination/volume. Not much to it really. Like, $400 materials, maybe the same in labor or so and you could have a 16x24 setup. (amplification NOT included)
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