Speaker connection precaution

[tympany]

Hello, I am new here and was wondering if anybody could help me decipher some information relating to an amplifier board that I have ordered. It seems to be badly translated from, I imagine, Chinese, but seems to be important. Below is the description from the site. The part that concerns me is Precaution 2, as I don't want to fry the chip!

Feature:

1. Original PAM8610 chip as amplifier chip, power can reach 10W + 10W.

2. As pure class D amplifier board power requirements is relatively high, the exclusive use of the power amplifier board enthusiast 2200UF capacitor filter, the elimination of exchange voice, without interference, GOOD sound quality.

3. Using automatic placement machine production, the board is more beautiful.

4. Strip 5.5X2.5 standard power outlet, power input is very convenient. (Positive outside and negative inside)

Overview:

When the power supply voltage of DC 8V-12V, PAM8610 be able to 4Ω load 10W + 10W output power, high-quality sound.

Technical Parameters:

Power: typically 10W

Voltage: DC8V-12V

Can drive speakers: 10W-15W, 4 -8 ohm

Built-in power-impact sound canceling circuit, no power on impact sound

Subjective sound experience:

PAM8610 (10W) power to the PAM8406 (6W) bigger, more powerful speaker can drive, found this amplifier board can drive two 25W speakers.
Listen really surprised, it is hard to believe that such a small piece of the chip can be issued so great volume, stereo effect is very good, indicating a high degree of chip channel separation. Case of playing music, the performance was better than expected, chip minimal heat, the sound was amazing, more transparent treble, bass, or a certain amount, quality count in a small amplifier board in the upper level, listen to music from a very comfortable .

Precautions:

1: Power supply voltage can not exceed 12V

2: 4 speaker wire connection is completely independent, does not allow total access! Just one of the cases appear immediately burn IC

Package included:

1 x Audio Amplifier Board

I'd be grateful if anybody is able to work out what it means.

 

[Nigel Goodwin]

Presumably it simply means don't connect multiple speakers to it - it's minimum load is 4 ohm, connecting two 4 ohm speakers per channel makes 2 ohms, which will over load it and kill the amp.

It's output claims are probably fairly imaginary as well - on a good 12V it might just about manage 10W.

 

[alec_t]

It might mean that the speaker is connected in bridge mode, so neither wire should connect to ground. On the other hand .......

 

[JimB]

Welcome to ETO.

What the cryptic message #2 means is that to connect the speakers, use two wires to each speaker.
Each pair of wires must connect to only one speaker.
The speakers must not connect to each other in any way.
The wires must not connect to a common ground.

Does this help?

JimB

On edit:
I agree with alec_t, the amplifier outputs are "bridge mode", a connection to ground will result in destruction of the amplifier chip.

 

[tympany]

Wow, I didn't expect so many replies, and so quickly! I want to make a sound bar for a Toshiba tv in my kitchen, with awful sound, and was hoping to use 4 speakers (!) I have 2x 10w and 2x 3w. I am a tinkerer and don't know much, as you might have guessed.

Since this thing has cost me the grand sum of £3.24 - including postage - I may well risk connecting all 4 speakers (sorry Nigel), and if it blows I can just order another one, or similar, and wait another few weeks for it to arrive.

At any rate, I will let you know what happens, when it arrives.

Once again, many thanks to you all.

 

[Nigel Goodwin]

Wow, I didn't expect so many replies, and so quickly! I want to make a sound bar for a Toshiba tv in my kitchen, with awful sound, and was hoping to use 4 speakers (!) I have 2x 10w and 2x 3w. I am a tinkerer and don't know much, as you might have guessed.

Since this thing has cost me the grand sum of £3.24 - including postage - I may well risk connecting all 4 speakers (sorry Nigel), and if it blows I can just order another one, or similar, and wait another few weeks for it to arrive.

What impedance are the speakers?, if they are 8 ohms then connecting them in parallel would be fine.

However, just randomly wiring speakers together isn't likely to work well, nor is sticking them in random boxes.

The biggest issue with sound on a TV is lack of bass, as there's no room inside for decent size speakers. The same also applies to sound bars, which is why they almost always come with a sub-woofer.

Sony had a great idea, a bluetooth sub-woofer output on some of their TV's - so you could buy a special Sony sub-woofer to give you decent bass, and the internal speakers for mid and highs. Unfortunately they priced the sub-woofer stupidly high, and you could buy a pretty decent sound bar (including sub-woofer) for far less money.

If your TV has a headphone socket?, then all you need is a decent pair of computer speakers, preferably ones with a sub-woofer - simply plug those in and it will utterly transform the TV's sound.

Another option, which I did for a number of customer where I used to work, is to disconnect the internal speakers and feed the amplifier out to a pair of sockets (I used line mounted two pin DIN sockets), and connect a pair of bookshelf speakers - I generally used Sony ones (which we had to hand), which aren't terribly great speakers - but they made the TV sound absolutely incredible.

 

[alec_t]

Is the amp one of these?

 

[tympany]

Hi Nigel. They are all 4 ohm. I was planning to wire them parallel, but will initially try it with one speaker on each channel, before I do this, just so that I know it works, before I blow the IC!

It's not so much the lack of bass, but the mid-tones just sound distorted, and I find it jarring. I'm not after hi-fi quality, I just want a comfortable clear sound.

I must say, I like your alternatives, and will probably give one of them a go if I fail with this. I have some old computer speakers somewhere.

Let's face it, practically anything's going to sound better than it does at the moment.

 

[tympany]

Hi Alec, no it's this.

Ah. I've just realised that you're right, having looked at the IC!

 

[Nigel Goodwin]

Hi Nigel. They are all 4 ohm. I was planning to wire them parallel, but will initially try it with one speaker on each channel, before I do this, just so that I know it works, before I blow the IC!

It's not so much the lack of bass, but the mid-tones just sound distorted, and I find it jarring. I'm not after hi-fi quality, I just want a comfortable clear sound.

I must say, I like your alternatives, and will probably give one of them a go if I fail with this. I have some old computer speakers somewhere.

Let's face it, practically anything's going to sound better than it does at the moment.

Yes, most TV's have crap sound - the absolute worst were Samsung a few years back - they not only had tiny downward facing speakers, but also almost all of the cone was blocked off by part of the plastic cabinet, leaving just a tiny fraction of space for sound to escape. They were really completely unusable.

 

[Diver300]

Hi Nigel. They are all 4 ohm. I was planning to wire them parallel, but will initially try it with one speaker on each channel, before I do this, just so that I know it works, before I blow the IC!

You can put the two speakers on each channel in series. That will give you 8 Ohms and it won't damage the amplifier.

 

[audioguru]

Instead of looking at the Chinglish instructions the amplifier came with, why not read in Google the good English in the American datasheet of the PAM8610 amplifier IC?
With a 7V supply its output into 8 ohms is 2.2W at low distortion and is 4W into 4 ohms.
With a 12V to 15V supply its output is 7W to 10W into 8 ohms. If 4 ohms is used then the output power is the same but the heating is doubled, they say a heatsink is needed.
Of course the outputs are bridged, a speaker wire is not grounded.

 

[tympany]

You can put the two speakers on each channel in series. That will give you 8 Ohms and it won't damage the amplifier.

This looks like a happy solution for me, as I can use all my speakers, still get the power, and not destroy the IC. Thank you.

 

[tympany]

Instead of looking at the Chinglish instructions the amplifier came with, why not read in Google the good English in the American datasheet of the PAM8610 amplifier IC?
With a 7V supply its output into 8 ohms is 2.2W at low distortion and is 4W into 4 ohms.
With a 12V to 15V supply its output is 7W to 10W into 8 ohms. If 4 ohms is used then the output power is the same but the heating is doubled, they say a heatsink is needed.
Of course the outputs are bridged, a speaker wire is not grounded.

Thanks, I will check it out.

 

[audioguru]

Speakers in series produce an odd frequency response. Your little 3W speakers probably resonate at 150Hz to 250Hz and will have a resonant impedance of 70 ohms which will reduce the output of the larger 10W speaker at that frequency.

 

[tympany]

Speakers in series produce an odd frequency response. Your little 3W speakers probably resonate at 150Hz to 250Hz and will have a resonant impedance of 70 ohms which will reduce the output of the larger 10W speaker at that frequency.

Wow, I'm getting plenty to grapple with here! Does that matter, though, as the 10w speakers would be producing mid-range, and the little ones would be tweeting. ?

 

[audioguru]

the little speakers mess up the upper bass (150Hz to 250Hz) from the larger speakers. Aren't the larger speakers also producing bass sounds?
The bass feeding into the little speakers might make them sound strained.

 

[tympany]

the little speakers mess up the upper bass (150Hz to 250Hz) from the larger speakers. Aren't the larger speakers also producing bass sounds?
The bass feeding into the little speakers might make them sound strained.

Phew, I feel 'blinded with science'. Must go to bed.

 

[crutschow]

If 4 ohms is used then the output power is the same

Why is that?
Typically a 4 ohm speaker will output more power since the max peak output voltage of a solid-state amp usually doesn't vary that much with load.

 

[Nigel Goodwin]

This looks like a happy solution for me, as I can use all my speakers, still get the power, and not destroy the IC. Thank you.

No, you won't get the power, you'll only get a quarter of it, and you don't have much to start with - which was why I didn't suggest series connection.

Don't worry about Audioguru's paranoia, series connection really makes VERY little difference in practice, although it's best with identical speakers.

But as I said, no power that way.