Question: What causes Bluetooth interference?

Answer: Bluetooth technology was originally designed in 1994 by Ericsson Denmark as a wireless alternative to transferring data short distances over RS-232 cables. The name “Bluetooth” comes from King Harald Gormsson, whose nickname was “Blåtand,” which is “Bluetooth” in Danish. The Bluetooth logo is a combination of the Runic characters H and B, the initials of Harald Bluetooth. The intention for this new wireless technology was to transfer short data packets from devices at short distances. The two devices would create a short term PAN (personal area network) and use the ISM (industrial, scientific, and medical) band, which is unlicensed between 2.400 and 2.485 GHz. Doing so would allow for the signal, once initiated, to frequency hop to avoid interferences. Bluetooth technology does a lot behind the scenes and often, seemingly, “just works,” but there are still a lot of ways Bluetooth signals may be interfered with, causing issues with the initial pairing as well as dropouts and signal skipping.

To better understand RF signals in the 2.4 GHz spectrum, take a look at the diagram above, which shows Bluetooth channels as well as Wi-Fi channels. The thinner Bluetooth channels take up less space and have different purposes. The advertising channels are the frequencies where Bluetooth receiving devices are consistently checking to see if there are any new devices to pair with. The pairing process consists of the receiving devices checking to see if there are any transmitting devices on these channels saying, “I’m here and I want to pair.” After the two devices have completed their pairing connection, they choose an open Bluetooth channel and begin their bidirectional transmission. If there is interference between the two devices, they may frequency hop at 1,600 hops per second to a determined pattern of channels.

The Wi-Fi channels in the diagram are much wider and take up more spectrum. If there is excessive Wi-Fi in the same area this will use up many potential Bluetooth channels. Also, if the Bluetooth devices are in close proximity to a Wi-Fi transmitting device (router), this can cause interference and other performance issues. As with any RF device, as you get closer, the signal strength intensifies. When your Bluetooth device is in close proximity to a Wi-Fi device, your Bluetooth device may have to hop to an open channel if the original Bluetooth channel occupies the same space as the Wi-Fi channel. Many Wi-Fi routers transmit on multiple channels simultaneously, and if there are excessive Wi-Fi signals in close proximity taking up most of the spectrum, your Bluetooth devices may not have any open spectrum to frequency hop to. This is a common cause of Bluetooth interference. Moving your Bluetooth devices away from Wi-Fi signals will help maximize the performance. Additionally, it is recommended to configure your Wi-Fi devices to allow for sharing the limited spectrum for all your wireless devices.

Another common cause of Bluetooth interference is having an object that impedes the signal between the two devices. Wireless devices perform best when there is a direct line of sight between them. When you add anything between them – from a thick piece of clothing to the giant water vessel known as the human body – the signal is impeded. Remember, Bluetooth was originally designed for short-distance transmission. If you have anything between the two devices, you have the potential for a loss in the signal. Many Bluetooth devices have an internal antenna (which is, thus, already blocked a bit by the device’s casing) so it is good practice to be conscious of the space between the two devices. Additionally, Bluetooth was designed to transfer data packets, similar to how the internet functions. In recent years, Bluetooth has come to be commonly used for transferring media, and the timing of these small data packets is important for maximum performance. When using the internet, your data packets may take a longer time, but you do not notice if there is a slight delay in the delivery. However, when it comes to delivering media, it is very important that data packets are sent and received every 625 microseconds. The delay in the delivery of data packets is often the reason for signal buffering and audio drops in the Bluetooth signal.

Other common issues of interference come from other devices that operate in the same spectrum. Smart home devices often incorporate Zigbee technology, which also operates in the same spectrum. This means if you have multiple smart home devices, excessive Wi-Fi transmitting devices and Bluetooth devices all in a close space, there is a high potential for the Bluetooth devices to underperform. Remember, Bluetooth was not designed to transfer media. The company that oversees the Bluetooth technology, SIG Bluetooth, is often making changes and advancements, but you may still encounter some performance issues. To get the most out of your Bluetooth devices.

What do you do when your Bluetooth devices are not pairing?

• Make certain your devices are properly set up and in the pairing mode.

  • This will allow the receiving device to survey the advertising channels and the transmitting device to transmit a pair request.

• Make certain your Bluetooth devices are close to each other.
• Make certain your Bluetooth devices are away from interfering devices that may be in the same spectrum. This may include:

  • Microwave ovens
  • Cabling and connectors for cable and satellite service
  • Poorly shielded power lines in the wall
  • 4 GHz cordless telephones
  • Wireless RF security video camera
  • Wireless Wi-Fi speakers
  • Neighboring Bluetooth device (device in a close apartment/home may connect through walls)

What do you do when your Bluetooth devices are paired but dropping out or have an audio issue such as skipping?

• Make certain your Bluetooth devices have a good line of sight operation and have limited impeding material between them.
• Make certain your Bluetooth devices are away from other interfering devices in the same spectrum

If you have further questions on Bluetooth interference, please contact the Audio Solutions Department.

Why does Bluetooth suck so bad?

• Thread starter

  DaveC426913

• Start date

  Nov 6, 2023

• Tags

  Bluetooth Headphones pairing

• Nov 6, 2023

• #1

DaveC426913

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TL;DR Summary

Maybe someone could let me in on the secret of how to operate it pain-free.

1. Turn on the headset. It says hello and then makes a sad noise, telling me it isn't paired.
2. Press the little PAIR button (which is integrated into the On/Off button) (see pic 1).
3. Wait.
4. It does not pair.
5. Press the OTHER pair button. (between the + and - volume) (see pic 1).
6. Wait.
7. It does not pair.
8. Go up to the TV, see that the little box has no Bluetooth lights on. Press them. (see pic 2)
9. Wait.
10. Remember I have to hold the button.
11. Press and hold the button until it flashes.
12. Turn headset off and back on.
13. Press the PAIR button.
14. Sigh and press the OTHER PAIR button.
15. By now, three minutes has gone by and my blood pressue is in triple digits, but ...
16. My TV show is blasting away .... on the other TV in the room upstairs.
17. Tear the whole thing out and throw away in disgust.

(Serious question here. I really do want to understand if - and possibly how - it's supposed to operate painlessly.)In the 20th century it was printers. In the 21st century it's Bluetooth devices. Every experience with Bluetooth is fraught with repeated failure that just pours gasoline onto a fire of building rage. It is all I can to do not bite these devices in half in my frustration.This is related to the headphones I bought, mentioned elsewhere in this forum:But that was about wiring it up to my TV. This is about Bluetooth in general.So, my nightly ritual when wanting to watch TV is as follows (Note that this process must be repeated for EACH set):OK, one thing at a time. Nevermind for the moment why it broadcasts elsewhere, at full blast, waking up the whole house. Am I really doomed to go through this stupid try and try again ritual every single night?

Last edited: Nov 6, 2023

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• Nov 6, 2023

• #2

phinds

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I empathize. I have a dinosaur-friendly dumb phone that has no WiFi but is able to take a grand total of 12 low resolution images and it keeps my contact list of phone numbers. I've tried several times to connect it to my computer via Bluetooth, which is the only way, to get a pic or more importantly to back up my contact list.

I have succeeded a grand total of one time. Bluetooth seems to have been designed to help people remember how to swear.

• Nov 6, 2023

• #3

DaveC426913

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phinds said:

Bluetooth seems to have been designed to help people remember how to swear.

Yoinking this.

• Nov 6, 2023

• #4

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Bluetooth is still a (very slowly) developing technology and many older devices do not make it simple. I have some devices (fairly new Bluetooth speakers) that seem to connect effortlessly to my PC once they have been paired the first time. The first pairing always requires some selection of devices. After that, just turning on those devices causes the PC to connect. I have another device (relatively old Bluetooth headphones) that always requires me to select it on the PC to be connected. So it is not a question of Bluetooth communication as much as a question of how different devices implement the connection logic.

Last edited: Nov 8, 2023

• Nov 7, 2023

• #5

Rive

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DaveC426913 said:

...my nightly ritual...

Erm... Isn't pairing supposed to be done only once? With the devices recognizing each other as a pair 'ever after' once switched on?The BT mouse I have for my tablet: was simple to set up and works like that.My camera was a nightmare to hook up to my phone (and then turned out that the whole BT thing is practically useless there) but still: works like that...

• Nov 7, 2023

• #6

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Being from Denmark I can't help but point out that they actually named it after the Danish "King" Harald Bluetooth. But I guess you knew that already. Also, I'm guessing that he probably had a bad habit sucking on his bad tooth. Maybe this explain the sucking? :P

• Nov 7, 2023

• #7

pbuk

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DaveC426913 said:

TL;DR Summary: Maybe someone could let me in on the secret of how to operate it pain-free.

DaveC426913 said:

So, my nightly ritual when wanting to watch TV is as follows (Note that this process must be repeated for EACH set):

Understand the difference between PAIRING and CONNECTING.So here is how that ritual looks from the POV of the headset and the transmitter plugged in to the TV:And here's how itgo.

• Nov 7, 2023

• #8

phinds

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Rive said:

Erm... Isn't pairing supposed to be done only once? With the devices recognizing each other as a pair 'ever after' once switched on?

Uh ... there is a difference between "supposed to do" and "actually does"

• Nov 8, 2023

• #9

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pbuk said:

So here is how that ritual looks from the POV of the headset and the transmitter plugged in to the TV:

.

.

Lol, that is absolutely. . . golden !

• Nov 8, 2023

• #10

DaveC426913

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pbuk said:

Understand the difference between PAIRING and CONNECTING.

pbuk said:

And here's how it should go.

That would be a good start, yes.Your two scenarios, above don't quite make this distinction for me.If I were to guess, pairing needs to happen first and,, need only happen once, whereas connecting needs to happen each time?I will try that, thanks.A friend has told me that there is a gap between Bluetoothand Bluetoothby. Apparently, much of the tears and heart ache I am experiencing might be attributable to the poor implementation of proper Bluetooth specs.Not that really helps me here, but any tidbit that narrows the culprit has the side effect of removing the evil mystery of the whole kit-n-kaboodle. At the very least, it means that maybe I don't need to unilaterally condemnBluetooth-enabled devices to behave so abysmally.

• Nov 8, 2023

• #11

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DaveC426913 said:

If I were to guess, pairing needs to happen first and, in theory/ideally, need only happen once, whereas connecting needs to happen each time?

DaveC426913 said:

A friend has told me that there is a gap between Bluetooth design and Bluetooth implementation by manufacturers and software developers. Apparently, much of the tears and heart ache I am experiencing might be attributable to the poor implementation of proper Bluetooth specs.

Yes.That is unlikely unless you are using very old devices. I have used Bluetooth for a long time and have not seen a problem like that. I did mention in a prior post that my Windows 10 PC treated an old device differently and needed to have it selected to connect (it was already paired). I don't know why that is happening or how your new transmitter knows what to pair with. In your case, it sounds like your Bluetooth transmitter is paired with some other TVs. That surprises me unless those TVs have separate soundbars that have paired with your new Bluetooth transmitter.

• Nov 8, 2023

• #12

DaveC426913

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FactChecker said:

That is unlikely unless you are using very old devices.

FactChecker said:

In your case, it sounds like your Bluetooth transmitter is paired with some other TVs. That surprises me unless those TVs have separate soundbars that have paired with your new Bluetooth transmitter.

Well, or verydevices.But you're right, it may not be the device so much as an unclear mental model of what it means to pair/connect and, more practically, what the steps are to do each.what's been happening is this: once I get impatient about my headphones not connecting, my M.O. is to go up to the transceiver and press andthe button for long enough until it starts. I'm sure this resets and restarts the pairing process, which is how it manages to connect to the upstairs sound system (at full blast, of course).If the world isn't a totally horrible place, the next time I want to use the headsets, I need onlythe transceiver buttonand this will simply wake it up and it will then allow the headphones to connect with no pairing shenanigans.

• Nov 8, 2023

• #13

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DaveC426913 said:

If the world isn't a totally horrible place, the next time I want to use the headsets, I need only tap the transceiver button once and this will simply wake it up and it will then allow the headphones to connect with no pairing shenanigans.

That sounds right. You probably need to make sure that the headphones are on and ready to connect. For the correct initial pairing, you might also need to make sure that the transmitter is not still paired with the upstairs sound system and is paired with the headphones. Once that is done, you should not need to do it again.

• Nov 8, 2023

• #14

pbuk

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DaveC426913 said:

If I were to guess, pairing needs to happen first and, in theory/ideally, need only happen once, whereas connecting needs to happen each time?

DaveC426913 said:

A friend has told me that there is a gap between Bluetooth design and Bluetooth implementation by manufacturers and software developers.

DaveC426913 said:

Apparently, much of the tears and heart ache I am experiencing might be attributable to the poor implementation of proper Bluetooth specs.

That's about right.Bear in mind that in order to stop e.g. your neighbours from evesdropping on your telephone conversations, Bluetooth connections are always encrypted. Pairing is (mainly) the process of setting up the encryption between two devices before connecting them securely for the first time.Not really, but the word "Bluetooth" covers many different protocols including both the way devices communicate in the radio spectrum and the way different types of data (e.g. audio, video, binary data) are encoded.Not all protocols are implemented by any one device (there is no point in your headphones being able to decode the movements of a wireless mouse for instance), and so there is scope for confusion. Also Bluetooth has been around for 30 years and there have been some changes in the technology along the way breaking compatibility between older and some newer devices.But in 2023 the technology is pretty mature, and any problems you are getting now are likely user error. I am particularly impressed by the way I can be listening to music on a streaming service on my noise cancelling headphones on a flight to a country I have never visited before, hire a car when I land and hook up my phone to the car which picks up the playlist where I left off, and then interrupts the music when I get a call from home to take it handsfree in the car.As you are trying to connect headphones with the transmitter they were supplied with, this is unlikely.

• Nov 8, 2023

• #15

DaveC426913

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pbuk said:

I am particularly impressed by the way I can be listening to music on a streaming service on my noise cancelling headphones on a flight to a country I have never visited before, hire a car when I land and hook up my phone to the car which picks up the playlist where I left off, and then interrupts the music when I get a call from home to take it handsfree in the car.

Actually, the Bluetooth in my car works astonishingly well too - how I would expect a mature technology to behave.

1. Why does Bluetooth have poor sound quality?

The main reason for poor sound quality in Bluetooth devices is due to the compression of audio data during transmission. Bluetooth uses a lossy compression algorithm to reduce the file size and transfer data quickly, which results in a decrease in sound quality compared to wired connections.

2. Why do Bluetooth connections frequently drop or disconnect?

Bluetooth connections can drop or disconnect due to various factors such as low battery levels, interference from other electronic devices, or physical obstructions between the devices. Additionally, older Bluetooth versions may have weaker connections, leading to frequent drops.

3. Why does Bluetooth have a limited range?

The range of Bluetooth devices is limited because it uses low-powered radio waves to transmit data. These radio waves have a shorter range compared to other wireless technologies such as Wi-Fi, which uses higher frequencies. Moreover, physical obstructions and interference can further decrease the range of Bluetooth devices.

4. Why is Bluetooth pairing and connecting so complicated?

The process of pairing and connecting Bluetooth devices can be complicated due to the different Bluetooth versions and device compatibility issues. Additionally, some devices may have different ways of initiating and completing the pairing process, making it confusing for users.

5. Why is Bluetooth draining my device's battery?

Bluetooth consumes a significant amount of battery power, even when not in use, because it constantly searches for nearby devices and maintains the connection. This is especially true for older Bluetooth versions, which have higher power consumption. To conserve battery, it is recommended to turn off Bluetooth when not in use.