Hi,
even if it is discussed here sometimes I am not sure how to setup the audio hardware und power supply for the HifiBerry Amp+.
First of all: My setup works on a Raspi 2 B under Rasbian 3.18.7v7. As music player I use softsqueeze/Java under x with a Watterott 7"-Touchdisplay and a TSOP4838 remote receiver attached to GPIO. Everything is fine. In the moment I use only two small 2 W speakers from my spear part box.
To optimize my setup I´m searching now for some hifi speakers but I´m not sure which one to take.
What specification must the speakers have?
The HifiBerry description says the maximum output is 25 W. Is this for both channels?
When I look to the specifications of speakers there is always written a nominal power and a music power. Must the nominal power of the speaker less than 25 W or can it be higher? I don´t want to burn the HifiberryAmp+...
Last but not least: What is the best choice for the power supply? If it is possible to attach speaker boxes of 60 W, what kind of power supply do I need then? 60 W either?
Sorry for these many questions but I´m not really an expert in these audio things.
Regards
Stefan
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9 comments
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HiFiBerry team Hi Stefan,
the power rating of the speakers is practically useless. It only tells you, what maximum power the speaker can accept without being destroyed. However you will notice this just by listening.
Basically you can use ANY 4-8 Ohm rated speaker with the Amp+. This won't damage the Amp.
You should select the speakers not by power rating, but listen to different speakers and choose the pair that sounds best for you.
The power output is about 45W peak power into 4 Ohm at 18V. At lower voltages and higher loudspeaker impedances it is less.
At 18V, we recommend a power supply of at least 3A (or about 60W).
Best regards
Daniel -
Stefan Kneip Thanks a lot Daniel!
This helps me to find the right ones.
Regards
Stefan -
Stefan Kneip Hi!
After a few days of thinking about the above mentioned there were some more questions coming up:
If I look to my 30 years old hifi amplifiers which has a power consumption of about 400 W I see a lot of heatsinks in the case which are neccessary to cool down the amplifier circuitry. The Hifiberry amp+ which is rated to 25 W has no heatsinks. My loudspeakers have a nominal music effect power of 120 W each and they sound good with my 400 W amplifier.
As Daniel wrote
You should select the speakers not by power rating, but listen to different speakers and choose the pair that sounds best for you.
the only criterion should be the sound.
But is this really true?
What would happen if I connect these 120 W speakers (which sound good) to the hifiberry amp+? Would the electronic circuit burn or will I hear nothing or only a very gentle sound?
So is it neccessary that the speakers music effect power fits to the 25 W output of the amp+?
What is the ideal power consumption or maximum power rating of the speakers to hear a good sound? Should they have more or less power in comparison to the amplifier?
I ask that because I don´t think that it is possible to bring the raspi/hifiberry amp+ in a speaker shop to test the equipment there. You have to use the amplifiers they have there and most of them have a lot more power than 25 W.
Could someone help me in my decision?
Regards
Stefan -
HiFiBerry team Hi Stefan,
the speakers can't burn the Amp. The power rating of a speaker only tells, what the maximum power is that the speaker can accept without getting damaged. Just connect your speakers to the Amp and test if you like the sound.
Best regards
Daniel -
Samuel Darby @Stefan
The heatsinks you saw in the shop will be bolted to the transistors used in class A or class B hi-fi amps. The design of these classes waste electricity as heat even when there is no sound playing. The amp+ uses what people call class D which is much more efficient so heatsinks are not required, do not be concerned about the heatskinks.
I am using rpi2/Amp+ with Kef Q3 floorstanders. The AMP+ will drive these speakers louder than normal listening volume without distortion. I have also tested with Q Audio 2020i. I was very happy with the sound with this 2nd combination but the added bonus here is the relatively compact size of both the speaker and amp/source. I believe that some recent bookshelf loudspeaker designs are using deeper cabinets to boost the bass frequencies using resonance, for example B&W 686. I like the sound but I'm probably in the minority. This is why it's important, as Daniel says, to test for yourself.
If you decided to take the Amp+ to a hifi shop to test, don't be surprised if the salespersons are sceptical. I took a different Class D amp to my local shop and they told me it wouldn't work well with Monitor audio BX 6 because "they need a powerful amp to move the larger speaker area". We plugged it in and it sounded great. Ignore what they say about everything, just do the test and pick the speakers based on:
1. Sound
2. Price
3. Size/Shape/Colour (usually someone in the household has veto over this point regardless of #1 and #2 so it's an important factor to get correct).
I would have no problem with replacing my Class A/B amps with the AMP+ for the airplay/squeezebox/multiroom scenario based on how they sound. I have a few niggles to figure out, like a suitable case, screen, IR remote, battery backup before I can replace the squeezebox that I use as my alarm clock. I also plan to combine a squeezlite/DAC+ with Openelec so I can remove the squeezelite from my living room (Openelec will use the HDMI and squeezelite the DAC+ and will look like separate inputs to my AV amp but from a single source - one less PSU taking up space too).
Regards
Sam. -
Stefan Kneip Hi Samual,
thanks a lot for your detailed answer. I was brave and tried out what you and Daniel suggested.
And... It really works fine!
It is amazing what power at high quality such a small amplifier can produce.
Regarding the case I bought the one from watterott which is transparent and gives a real technical look (even someone in the household accepted that).
Because I want to emulate the squeezebox with a display and remote control included, I decided to use a 7" Touchscreen display (from watterott either) and the java version of softsqueeze. Works perfectly fine!
Thanks again and best regards
Stefan -
Jesper Bay Lührssen This thread is worthless without pics! Stefan, mind showing (off) your finished Pi-Amp? -
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