• New Patreon Tier and Early Access Content available. If you would like to support AVForums, we now have a new Patreon Tier which gives you access to selected news, reviews and articles before they are available to the public. Read more.

Wiring Multiple Speakers

cooper55

Standard Member
Hi, I'm new to this forum and looking for advice. I have a small therapy office in a smallbuilding that I share with 4 other therapists. The noise carries so easily through the building…you can literaly hearpeople talking at normal levels in the other offices with all of the doorsclosed! My goal is to play white noise in each office and hallway tohelp reduce the ability to hear other conversations and to improve privacy. I went to Amazon and purchased a Pyle Home PCAU44 Mini 2x120 watt RMS at4ohm Stereo Power Amplifier. I will be running(6) Pyle Home PDIC51RD 5.25-Inch Two-Way In-Ceiling Speakers with 4-8 ohmimpedance. I will be connecting an Ipodto the amp to play the white noise loop.

My question is how to wire the speakers? I've heard that it is easy to burn up an ampif special wiring considerations are not met. Parallel wiring vs Series wiring? I know nothing about this stuff. Can anyone point me to ‘easy to understand' instruction on how to wireup these speakers. Thank you so much.
 
Last edited by a moderator:

BlueWizard

Distinguished Member
Did you by chance explore White Noise Noise canceling machines. There are mechanical devices that create a sound like wind blowing. Because they are mechanical, they break up airwaves and diffuse them.

Also, rather than pure continuous White Noise you might try audio tracks like Rain or Ocean or similar. These are relatively easy to find.

As to wiring speakers, there are certain combinations what work best. First can we assume the PYLE speakers you bought are 8 ohms. The impedance matters.

The best combinations are FOUR 8 ohms or NINE 8 ohm per channel. THREE speakers on each channel, for a total of SIX is an odd combination that doesn't fit well together.

In a sense, the goal is to come up with a combination of speakers, that fall in the range of 4 ohms to 16 ohms per amp channel.

Here is one example of 4 speakers wired in a way that the total is the same as a single speaker -

4x8tot8ohm.jpg


Speakers in Parallel Divide, so Rt = O/n = Impedance in Ohms of one speaker / number of speakers = 8/2 = 4 ohms

Speaker in Series Add, so Rt = R1 + R2 + R3 + ... = 8 + 8 = 16 ohms.


In the Diagram we have we have two banks of two in parallel, then those to banks connected in series.

Two 8 ohms speakers in Parallel is 4 ohms (Rt = 8.2 = 4). To 4 ohms banks in Series is 8 ohms, assuming you are using 8 ohm speakers (Rt = 4 + 4 = 8).

In the second example, you have two banks of two series speakers. Then those two banks are wired in parallel. So, two 8 ohm speakers in Series is 16 ohms (Rt = 8 + 8 = 16). Two 16 ohm banks in parallel is 8 ohms, exactly the impedance of a single speaker (Rt = 16/2 = 8)

This can also be done with 9 speakers. THREE 8 ohms speakers in parallel is (8/3) is 2.66667 ohms. Take THREE Banks of THREE and wire in series and you have 2.66667 + 2.66667 + 2.6667 = 8 ohms. That is more speakers than you need, but it is a further illustration of the point.

So, if all the speakers are the same, in Parallel -

Rt = O/n = 1 speaker in Ohms / number of speakers

In Series, any speaker of any size simply added -

Rt = R1 + R2 + R3 + ....

If the speaker are unequal and in series, each gets a signal in proportion to its individual impedance. This is not something you will have to worry about, but it is there for reference.

Now the actual wiring is not as complex are you might think. Wires can be run from each speaker back to the amp, and the Series/Parallel can be worked out at the amp. Here is an illustration of two speakers in series, wired together back near the amp -

351317d1352539596-8-speaker-setup-check-advice-twospkrseries.jpg


Depending on where the speakers are, the can be wired in the wall as well. Here is an example of that -

351316d1352539576-8-speaker-setup-check-advice-twospkseries.jpg


For four speakers you simply double up on this configuration. The speaker are wired in Series, and each represents a gang. Then just wire the Gangs as you would a single speaker back at the amp. When the second Gang is wire to the amp, that is in parallel, and you have the Series/Parallel configuration as seen in on the Right side of the first diagram above.

I don't have a diagram for it, but a Parallel/Series set up can be wired with equal ease.

Please note, I am only showing and discussing ONE Amp Channel. The same configuration would be mirrored on the other Amp Channel.

One assume since you have a Stereo amp, you will somehow have to have Stereo Sound, so two speakers in each location, one for the left channel and one for the right channel. This will especially work best if you can find some of the Environmental CD's (rain, wind, ocean, etc...) and Rip them to your iPod.

Here is a link to one of my old posts that explains how various impedance can be combined in various ways. It is a bit mathy but not beyond comprehension.

http://www.avforums.com/forums/av-amplifiers-receivers/543347-nature-impedance.html

That should get you started.

Steve/bluewizard
 
Last edited:

cooper55

Standard Member
BlueWizard - that was an incfedible reply. Thank you so much for taking the time to share your knowledge.

I did look into sound machines, but I would need to purchase many of them and cost is a factor. I figured I could run speakers and play whatever I need via the ipod.

Last question - because I have 6 speakers, do you recommend that I split the series/parralel to run all 6 on one channel. Or would you run four in series and then run the other two on another channel?

Thanks again!

Coop
 

PSM1

Distinguished Member
Could you not buy another 2 so that you have 8 speakers. This means you could run 4 off each side (2 in series with 2 sets in parallel) which would keep the impedance as 8ohms.
 

cooper55

Standard Member
I dont have anywhere else to put more speakers. We have one in each office and common area...no more rooms to put them. Is it possible to run all 6 together, on the same line? Would another option be to run a staight speaker wire from the amp to each speaker individually or would that fry the amp?
 

PSM1

Distinguished Member
Could you not put 2 speakers in a couple of the rooms? You want the amp to see a 8 ohm impedance and also a balanced load on both left and right outputs. The easiest way to achieve this is with 8 speakers.
 

cooper55

Standard Member
I really don't have any other place to put more speakers. I'm pretty much maxed out with space and accesibility to get to more locations.

The speakers are rated with a 4-8 range of impedance. I really don't understand the calculations involved, but there is no way to use 6 speakers for this? Would it be better to purchase another amp so that I could have a set on one amp and 4 speakers on the other?
 

PSM1

Distinguished Member
Impedance works like resistance.
So if you have speakers in series then you add the impedances together so 2 8 ohm speakers in series would give you 16 ohms.
If you have receivers in parallel then you add 1/impedance so 2 8 ohm speakers in parallel would give you 4 ohms but 3 speakers in parallel would be under 3 ohms.
So 2 speakers in series and another in parallel would give just over 5 ohms if they are 8ohms. However, since the speakers appear to be down to 4 ohms then this lowers the impedance to under 3 ohms, this is very low and can cause damage to the amp.
You would maybe better getting a multizone stereo amp like the Teac 980 so you can power the speakers separately.
 

BlueWizard

Distinguished Member
The goal is to make the final combined impedance of the speakers on each Amp Channel be in the range of 4 ohms to 16 ohms.

Using 6 speakers, you can not get balanced sound, though you can conceivably get the final impedance in the correct range. Here is on example -

222517d1296247901-audio-novice-looking-amplifier-threespkrserpara.jpg


However, because Speaker 1 and Speaker 2 are in series they each only get HALF the applied signal and are therefore each quieter than Speaker 3 which is connected directly. So, the output from the speakers are not uniform loudness.

Assuming these are 8 ohms speakers, the final impedance is 5.33 ohms, which is in the working range of 4 ohms to 16 ohms.

I created this graphic for someone who wanted the speakers in different rooms, and because of the nature of the room, unequal loudness was OK. Perhaps you are in a similar position. Perhaps you can live with the Main Waiting Room being louder, and the patient/client rooms being a bit quieter, or vice-versa.

Keep in mind, you are probably working with Stereo Content and therefore it would be best to put Stereo sound (meaning two speakers) in each room or location.


There are In-Ceiling speakers, that while a single speaker, they allow the connection of two stereo channels. Each single speaker has a transformer on it with two inputs, one for the Left and one for the Right Stereo channel. The Transformer merges the sound into a single Mono sound track which is then played through the single speakers. These are commonly used in Bathrooms that are too small to accommodate more than one speaker.

Here are some examples of In-Ceiling Single Speaker Stereo speakers with an explanation at the top of how a Single Spekaer Stereo speaker works -

Celing-Speakers.co.uk - Single Speaker Stereo - In-Ceiling

So, again, this allow for two Stereo Channels to be played through a single speaker.


As to Environmental Sound, I did a quick search that these are the first few links that came up -

Environment and nature | British Library - Sounds

Soundscapes - Environment and nature | British Library - Sounds

EARTH | EAR

I have no doubt a more exhaustive search would come up with better sources of more appropriate sounds. Keep in mind that steady white noise gets a bit monotonous. Sea, Wind, Rain, etc... will ebb and flow with some variation.

For what it is worth.

Steve/bluewizard
 
Last edited:

BlueWizard

Distinguished Member
Here is another variation of the Single Speaker Stereo speakers. This one, rather than a transformer, uses Dual Voice Coils on the woofer, and has two separate tweeters, and is priced at a very low price -

16.5cm (6.5") DUAL VOICE COIL CEILING SPEAKER WITH DUAL TWEETERS

Here are the specifications -

Woofer - 165mmØ (6.5")
Tweeter - 2 x 20mmØ (0.75")
Frequency response - 45Hz - 20kHz
Power rms - 75W
Cutout - 193mmØ
Impedance - 8 ohms
Mounting depth - 76mm
Sensitivity - 89dB @ 1W/1m
Dimensions - 86 x 227mmØ
Weight - 1.4kg

Here is another source of a very similar speaker -

CEILING MOUNT 6.5'' STEREO INPUT SPEAKER : CMS65S

And another -

Ceiling Speaker B404A Stereo - CommsAndSound.com

Just to show you that speakers like this are both easy to find, and reasonably priced.

Steve/bluewizard
 

cooper55

Standard Member
Blue Wizard & PSM1, I really appreciate your quick response, suggestions and knowledge of the topic. I'm going to get this done this week and will let you know the outcome.

Thanks again.

Coop
 

The latest video from AVForums

Guardians of the Galaxy Xmas Special, Strange World, Bones and All, and Cabinet of Dr Caligari in 4K
Subscribe to our YouTube channel

Full fat HDMI teeshirts

Support AVForums with Patreon

Top Bottom