Pimoroni Speaker pHAT sounds very raspy


#1

Hi
I hooked up the Pimoroni Speaker pHAT to a Raspberry Zero W. The speaker and LEDs work but the sound is very raspy. I checked the soldering 3 times in the speaker and on the Pi zero. It seems ok to me. I connected it to a pi 3 as well. I think it is a bit less raspy but very hard to tell.
Any idea what I can try next?
I could provide a video or audio if it helps.
Let me know if you like to get some pictures as well.
Thanks


#2

What version of Raspbian are you running? I do believe Stretch is recommended / preferred.


#3

I have Raspbian GNU/Linux 9 (stretch).


#4

Ok, just wanted to confirm that you were running the latest. I have the pHat Beat and it had some sound quality issues during the transition from Jessie to Stretch. They were quickly solved though by Pimoroni.
Good beefy power supply with lots of current capacity?
Do you have another speaker you could try?


#5

A video might help- it’s not the best sounding speaker in the world, so it’s hard to tell normal “raspy audio because tiny speaker” from “raspy audio because something is broken.”


#6

Hi
Is there any option to upload a video? I don’t have my own domain that I could use.


#7

If you have OneDrive / Windows PC, upload it there and post a link to it. I link to my public Onedrive folders all the time. You just right click the file or folder and select “Share a OneDrive Link”. Then right click and past in your post. Like this, https://1drv.ms/f/s!AjOYwiwlwDtpgUMsp2qnevKpGEHb


#8

Thanks!
Here is the video:
https://1drv.ms/v/s!AgpY6WAoKIKFhVuyZTYyXgam0Y09


#9

That does, indeed, sound completely awful, but I noticed your soldering could use a little improvement from the video, many of the joints are balled toward the top of the pin and might not be making a sound electrical connection. This can definitely cause this sort of distortion.

You should aim for a volcano-shaped joint which covers the copper ring around each pin, if you reheat each joint by touching the tip between the pin and copper ring, without adding any additional solder, then it should flow into place once it’s hot enough.

To avoid doing them all at once, you can look at the necessary pins here and try tweaking those first to see if it helps: https://pinout.xyz/pinout/speaker_phat

Start with BCM 18, 19 and 21. And make sure the ground pins are good too.

Look at the solder joints detailed here:

Source: https://blog.adafruit.com/2016/12/26/new-reference-card-soldering-101/


#10

Thanks I’ll give it a try.


#11

I tried to solder it again. Might look worse than before. The speaker sounds the same. Not sure if I should try to solder it again.


#12


#13


#14

The Raspberry Pi looks a lot better. The speaker pHat looks a little rough though. Some isopropyl alcohol and an old tooth brush will clean it up some, and get rid of the leftover flux. Ideally the brush should be antistatic, not sure if a tooth brush is or isn’t but I’ve used one in a pinch and didn’t do any damage.


#15

Thanks everyone. I tried to clean it up and solder it again. No change in sound.
I’ll call it a day and move on.


#16

I couldn’t resist and ordered some new speakers. They seem to work much, much better. I still hear a slight crackling noise but this might be the connection.
Seems like the problem was the speaker not the soldered connections.
Here is a video:
https://1drv.ms/v/s!AgpY6WAoKIKFhV8BJQ0xYGx7truX


#17

Those the Adafruit speakers? If yes I have a pair of those on my bread board rig. To be hones I haven’t used them much other than to just make sure they worked. I had ambitions of playing tunes on it but basically only listen to the odd You Tube video. They sounded Ok near as I can remember. Mine are fed by an analog audio amp plugged into the Pi’s analog audio jack.


#18

Yeah, I herd “something” in the video. A bit of distortion or something? Not sure what caused it though? It’s all didgital between the Pi and speaker pHat so I would expect it to work or not work at all? I’m no expert on this stuff though. Was that a live stream or a download and play the file from the Pi?


#19

I played an MP3 from the Pi Zero. It came with the speaker software installation.
Yes these are the Adafruit speakers.
I found speakers for around $1 on eBay. I probably just order one and hook it up to the board.


#20

Ok, if had been a live stream that might explain it. I’ve had skips and drop outs on my Pirate Radio when using the Bluetooth while playing a live stream.