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12VDC versus 240VAC HiFi


Mohsen

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14 hours ago, dmr said:

Only possible issue is that speakers like this are most likely 8 ohm whilst almost all ordinary car stereos are happier with 4 ohm speakers so you want get the full power out of them. If they are loud enough this is not an issue.

You can always connect 2 x 8ohm speakers in parallel to give you 4ohms

6 hours ago, Mohsen said:

 

Thats useful info cheers. So if you were placing that amp say 5m from the power source and trying to work out voltage drop to size cable, would you use that figure of 640watts? e.g. if I ran 10mm2, I calculate around 10% voltage drop between battery and amp.

 

If you are worried about volt drop you could always fit a 100volt line system but that would be overkill and somewhat rediculous in a boat

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1 hour ago, dmr said:

Hiss crackle pop    hiss crackle pop   hiss crackle pop   hiss crackle pop   hiss crackle-pop + end of side distortion.  :D

and it wears out a bit more everytime you listen to it.

...........Dave

Very true. I used to have a Linn Sondek LP12 record deck in the mid 80's. Great sound but it was interspersed with loud cracks from static discharge and the "static cling" meant a fight to get the record off the turntable.

So I bought a device called a Zerostat, which was a gun like device that reputedly shot a stream of negative ions to counteract the static. 

All it did for me was lighten my wallet, so I sold the LP12 and bought my first CD player. Slight loss of "warmth in the sound but a complete lack of static induced interruptions to the music.

Some people prefer listening to the equipment rather than the music.

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3 minutes ago, cuthound said:

Very true. I used to have a Linn Sondek LP12 record deck in the mid 80's. Great sound but it was interspersed with loud cracks from static discharge and the "static cling" meant a fight to get the record off the turntable.

I had a pair of trousers like that once. Particularly loud after a curry too. 

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6 minutes ago, cuthound said:

Very true. I used to have a Linn Sondek LP12 record deck in the mid 80's. Great sound but it was interspersed with loud cracks from static discharge and the "static cling" meant a fight to get the record off the turntable.

So I bought a device called a Zerostat, which was a gun like device that reputedly shot a stream of negative ions to counteract the static. 

All it did for me was lighten my wallet, so I sold the LP12 and bought my first CD player. Slight loss of "warmth in the sound but a complete lack of static induced interruptions to the music.

Some people prefer listening to the equipment rather than the music.

The Zerostat was utterly and profoundly useless but there was an anti-static turntable mat which you could get for the Sondek, which was better. Can't recall the name, too much malt under the bridge since then!

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39 minutes ago, Jess-- said:

have a look at the tpa3116 amps on ebay (search for tpa3116 2.1 bluetooth), they have all the inputs / outputs on the back + bluetooth, are small, dc powered (ok on 12v or 24v) and have plenty of punch, 2 x 50w + 1 x 100w (all RMS)

downsides are that it is not car stereo sized (it's a hell of a lot smaller) and the crossover freq is not easily adjustable

I have 3 of them in use (1 with bluetooth and 2 without) and have had no issues despite them driving fairly meaty subs

I am really looking for a car radio because sadly I like to listen to radio 4 (even though its got very depressing of late, nothing but death and cancer and lifes traumas and the comedy programs are not funny, and radio 2 is full of brainless DJ chatter like how radio 1 used to be) and also something to fit into the car radio sized hole in the boat.

Those amps do look like very interesting though I think that huge power figure is quoted for a 2 ohm load.  I've mostly stopped doing hobby electronics (and work electronics) since moving on to the boat, I now mostly do software side of things, but I do get tempted, there are some very good buildings now available at very good prices.

...........Dave

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40 minutes ago, WotEver said:

Yes, but we all bought one, didn’t we? :D

Yes. ! I also read about a scheme were you wash your records and play them whilst still wet, never tried it though.

In my second job as a very young man I had almost exclusive use of a mini computer (128kbyte of RAM and a pair of 8 inch floppy disks). I remember thinking that with a lot more storage it could house all my LP's in digital format. I did a few sums and decided that it would happen but probably not in my lifetime.

............Dave

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7 minutes ago, dmr said:

I also read about a scheme were you wash your records and play them whilst still wet, never tried it though.

Ahh, I used to do a variant of this. I’d mist the record with deionised water while it played. You’d get a right slurry behind the stylus before it got half way through so you’d have to carefully clean both the stylus and surface (turning the amp down first) and then start again half way through. It was quite effective. 

I sold Hi-Fi in Tottenham Court Road for a couple of years in the 70’s for my sins :)

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5 minutes ago, WotEver said:

Ahh, I used to do a variant of this. I’d mist the record with deionised water while it played. You’d get a right slurry behind the stylus before it got half way through so you’d have to carefully clean both the stylus and surface (turning the amp down first) and then start again half way through. It was quite effective. 

I sold Hi-Fi in Tottenham Court Road for a couple of years in the 70’s for my sins :)

The centre of the HiFi universe at one time, I visited a couple of times. It all went wrong for me when the magazines stopped doing technical specifications and started using nebulous adjectives, and all that stuff about sticking safety pins in the curtains to change the room acoustics.

.............Dave.

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45 minutes ago, dmr said:

I am really looking for a car radio because sadly I like to listen to radio 4 (even though its got very depressing of late, nothing but death and cancer and lifes traumas and the comedy programs are not funny, and radio 2 is full of brainless DJ chatter like how radio 1 used to be) and also something to fit into the car radio sized hole in the boat.

Those amps do look like very interesting though I think that huge power figure is quoted for a 2 ohm load.  I've mostly stopped doing hobby electronics (and work electronics) since moving on to the boat, I now mostly do software side of things, but I do get tempted, there are some very good buildings now available at very good prices.

...........Dave

from memory the power figure is into a 2 ohm and supplied with 24v

for home use I have them running from laptop 19v supplies (ex toshiba if memory serves) and have them driving 2 x satellite speaker rated @70w rms  (3.5" driver + tweeter) and a dual 10" crunch audio sub (designed for car use but quite at home under a desk drivers wired in parallel to give an impedance of 3 ohms) although the sub is rated for 750w rms I think it could be destroyed at about 400w.

the tpa based amps do keep the speakers under very tight control even on very bass heavy music (I've not heard dub sound so good on such a small system running without any EQ). if you're into dub etc have you come across the baroquedub mixtapes (not really on tape), there's a lot of good selections on them.

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Some interesting responses and clearly a lot of experience in this area. 

I had actually tried to insight a debate on which was more viable on a boat, especially regards DC vs AC. Dmr, the reason I have avoided a car stereo head unit in my hypothetical setup is because I have to get a Raspberry Pi to handle other aspects of my system, so I figured the HiFi Berry add on will provide adequate signal to the speakers via an amp. As you said, most car stereo's have aux input on the front, which isnt ideal.

As for MP3's, it's obviously about storage space. I have around 300GB of music in MP3 format. If simply couldn't store that in CD format and in vinyl, no chance.

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The AC vs DC thing is really not clear cut, there are lots of debates on here on the same topic but regarding fridges. In the case of HiFi AC does has the advantage that the power amp supply rail is less likely to be limited to 12 volts, but as I have said, system to system differences are likely to be as significant as the AC-DC factor. There are also lots of ways to make AC so that is a factor too. The concept used by Jess is a good one...step the 12volts up to 19v DC, so that's another option.

As for 300Gbyte of MP3, I will work it out a bit later but suspect you will need than a lifetime to listen to it all :D, you will have to get your mates round to help! This does remind me of a non PC joke concerning an Irish gentleman who bought a video recorder to record the TV programs that he didn't like so that he could miss them while he was out.

We use Spotify extensively and MP3 is great for that, but anything that I really like and will listen to often should be WAV.

..............Dave

48 minutes ago, Jess-- said:

from memory the power figure is into a 2 ohm and supplied with 24v

for home use I have them running from laptop 19v supplies (ex toshiba if memory serves) and have them driving 2 x satellite speaker rated @70w rms  (3.5" driver + tweeter) and a dual 10" crunch audio sub (designed for car use but quite at home under a desk drivers wired in parallel to give an impedance of 3 ohms) although the sub is rated for 750w rms I think it could be destroyed at about 400w.

the tpa based amps do keep the speakers under very tight control even on very bass heavy music (I've not heard dub sound so good on such a small system running without any EQ). if you're into dub etc have you come across the baroquedub mixtapes (not really on tape), there's a lot of good selections on them.

Thanks, will investigate. Have also just found that this sort of thing is very big in Australia just now.

............Dave

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Another vote for wav here. Taking 5-10 times as much storage space as mp3 (in mb/gb) but hard drives just keep on getting bigger and cheaper so why not.

I've got the Bose acoustimass things - tiny little dual wall speakers and a big "sub" (it's not really a sub proper)... a system hated by many if not all hi fi buffs yet surprisingly enjoyable to listen to, especially for its size.

Raspberry pi seems to be becoming the boaters choice :)

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I'd be surprised if the average person of the average age on here having lived the average contemporary lifestyle really still has hearing undamaged enough to really appreciate the nuances that separate their version of true 'hi-fi' from a reasonable bit-rate mp3. Perhaps each post should be accompanied by a recent audiogram to establish the credentials of the postee?  Please note that I'm not claiming high ground here, because the effects of my naval career have effectively ensured that I'd be just as well ringing dial-a-disc!   (If you remember that service, chances are you're out too!) :unsure:

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Well, I’m in my 60’s and I recently replaced a temp MP3 with a wave and was as if someone had removed a curtain from the speakers. The wav absolutely sparkled by comparison. You’d probably not notice the difference on yer average TV but that’s not the point I’m making. Not everyone can appreciate ‘good’ audio, in which case there’s no point forcing something onto them that they can’t hear, and that has little to do with age (although hearing loss with age is of course undisputed). 

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30 minutes ago, WotEver said:

Well, I’m in my 60’s and I recently replaced a temp MP3 with a wave and was as if someone had removed a curtain from the speakers. The wav absolutely sparkled by comparison. You’d probably not notice the difference on yer average TV but that’s not the point I’m making. Not everyone can appreciate ‘good’ audio, in which case there’s no point forcing something onto them that they can’t hear, and that has little to do with age (although hearing loss with age is of course undisputed). 

to my ear I get the following (in order of worst - best quality)

Horrible...
96kb mp3

Rough...
128kb mp3
96kb AAC+

Acceptable...
192kb mp3
128kb AAC+

Good...
320kb mp3

Excellent...
192kb AAC+
CD / Wav (assuming wav is 44,100 khz / 16 bit)
24 bit flac (supposedly higher quality than cd but beyond my hearing)

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3 hours ago, Johny London said:

Another vote for wav here. Taking 5-10 times as much storage space as mp3 (in mb/gb) but hard drives just keep on getting bigger and cheaper so why not.

I've got the Bose acoustimass things - tiny little dual wall speakers and a big "sub" (it's not really a sub proper)... a system hated by many if not all hi fi buffs yet surprisingly enjoyable to listen to, especially for its size.

Raspberry pi seems to be becoming the boaters choice :)

Wow this thread really has side tracked; serves me right for using the term Hi-Fi. If someone wanted to start converting physical media to digital media today, I would recommend flac/lossless format, without a doubt. Unfortunately when I started, MP3 was the only really viable solution, with 32GB hard drives considered big!

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17 hours ago, WhiteSuit said:

Interesting topic, I love my music and listen at home with NAD equipment driving B&W speakers preferably from a vinyl source. This provides what I consider to be a realistic hi fi sound. My wife has no musical taste so I also have a set of B&W headphones which shields me from mind numbing tv!  When you have a good setup you don't need to be unsociable with volume to appreciate the sound. 

I was advised by my local car audio shop not to use domestic speakers with car CD player as the ohm difference requirements would destroy the speakers. Their advice was Alpine CD player linked to Focal speakers and a sub. I was impressed and upgraded basic component speakers initially and they are reasonably impressive for their small size. I don't think I can justify the £250 price tag of the matching sub and find a place to fit it for the improvement it would give. 

My question is how to wire in a socket to plug in my decent headphones as this would give me the best sound for pound as I am the only person on board who requires this. Car sets don't have a headphone output. Could I simply wire in the second speaker output from the set to a headphone socket? The only details I can find are that they have a resistance of 26 ohms. Any answers please?

Two reasons not to. 26 ohms is the AC inductance and they will have a lower DC resistance so if you turn the volume up too far you will fry them.

Speaker output has more distortion and hiss then a headphone jack.

If the car stereo has RCA out for a booster use that, you may need a preamp. If it got optical use that with a preamp.

Something like this:

http://www.ebay.co.uk/itm/Car-Audio-Stereo-Radio-Pre-Amp-RCA-Input-Output-Line-Driver-Signal-Amplifier/280637557198?hash=item41574d49ce:g:7YIAAMXQ855RwDJC

 

As for the ohm diffrence car/home speakers I'm not really with your local audio shop there unless your home speakers have lower ohms in which case i would be more concerned with

blowing the carstereo.

Strangely my wife does consider headphones unsociable so my Jamo speakers live in the garage where I can pretend to do something useful.

 

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18 hours ago, WhiteSuit said:

My question is how to wire in a socket to plug in my decent headphones

Simply connect your headphones to the speaker outputs with a couple of 50 ohm 1/2 watt resistors in parallel. You don’t need to do anything complicated. 

58 minutes ago, forsberg said:

Speaker output has more distortion and hiss then a headphone jack.

I guess you’ve not looked inside a lot of consumer audio products. The headphone output is rarely anything more than a 75 ohm resistor across the output. 

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2 hours ago, WotEver said:

Simply connect your headphones to the speaker outputs with a couple of 50 ohm 1/2 watt resistors in parallel. You don’t need to do anything complicated. 

I guess you’ve not looked inside a lot of consumer audio products. The headphone output is rarely anything more than a 75 ohm resistor across the output. 

Does hundred's count as a lot? I've rarely seen that in anything for the mid-range market with decent output.

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12 hours ago, WotEver said:

Simply connect your headphones to the speaker outputs with a couple of 50 ohm 1/2 watt resistors in parallel. You don’t need to do anything complicated. 

13 hours ago, forsberg said:

Thanks for that , do you mean one in the positive for each channel?

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