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Old 05-10-2013, 17:32
blueisthecolour
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Years ago I bought a hi-fi system from Richer Sounds which consisted of a Cambridge Audio A5 amp and a pair of Mordaunt-Short speakers. I absolutely loved it, the sound I got out was amazing and it used it as my home sound system for everything. However last year the A5 packed up so I borrowed a amp of my uncle (which by coincidence was was an older version of the same model (CA A500)) and surprising the sound quality wasn't much different.

Nevertheless, I decided it was about time I bought a new amp so I went back down Richer Sounds last week and ended up getting the Cambridge Audio Topaz A10. I wanted to get the A5 again but the sales assistant convinced me that if I had the money I was better off with the A10. So I set it all up and i've got to say that i'm pretty disappointed with the sound. Everything just sounds flat - I mean there's obviously decent bass but I'm not getting anywhere near as full a sound as before.

I was wondering if it has anything to do with the fact that the A10 doesn't have bi-wire output like my others did? I read online before buying that bi-wiring is basically a '100 scart lead' scam and the assistant said the same, so I wasn't bothered about it. I've still go bi-wire coming out of the outputs into the speakers though in case they needed it.

I'm not sure what advice i'm after here, just hoped people could give me some tips or reassurance.
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Old 05-10-2013, 17:41
chrisjr
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I take it you have connected both pairs of wires from the speakers to the amp. or have replaced the shorting links that the speakers may have had before you connected up the A5.

If you don't have both sets of speaker terminals connected to the amp then you will only be driving either the bass or treble speaker depending on which speaker terminals you were using.

That would certainly be the first thing to check.
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Old 05-10-2013, 17:51
blueisthecolour
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I take it you have connected both pairs of wires from the speakers to the amp. or have replaced the shorting links that the speakers may have had before you connected up the A5.

If you don't have both sets of speaker terminals connected to the amp then you will only be driving either the bass or treble speaker depending on which speaker terminals you were using.

That would certainly be the first thing to check.
Yes, I bought some more bi-wire cable and wired up both sets of points on each speaker to the output on the amp.
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Old 05-10-2013, 20:58
briancbb
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Are the speakers wired 'in phase'? If not the sound will be dull.
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Old 05-10-2013, 22:48
Menoetius
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Assuming all wiring is correct and your speakers aren't faulty, I'd consider this - it could just be a poor amp.

It's a pity that the sales advisor didn't recommend something like the Denon PMA-720AE over the AM10, there's only 20 difference.

Par for the course though, as Richer Sounds are the only retailer that sell Cambridge Audio. I'm not knocking Cambridge Audio as a brand, they make some good kit.

But as they sell the Denon for almost half retail price at 189, it has bugger all margin in it for them. The AM10 makes them a few quid - lots more margin.

If you're sure everything is working as it should and you're not happy and you've not had it for 7 working days (returns policy) then change it for something else.
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Old 06-10-2013, 18:58
blueisthecolour
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Are the speakers wired 'in phase'? If not the sound will be dull.
Hi. What does that mean?

Basically, I twisted together the two ends on each bi-wire and then connected them to the amp. I then bi-wired the speakers as normal.
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Old 06-10-2013, 20:01
chrisjr
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Hi. What does that mean?

Basically, I twisted together the two ends on each bi-wire and then connected them to the amp. I then bi-wired the speakers as normal.
This is where you get the +ve and -ve wired the wrong way round on one speaker.

In crude terms the noise is made by the speaker cone moving in and out. If the speakers are in phase the cones move in and out together in synch. if they are out of phase one moves out while the other moves in.

What this does is cause sounds to partially cancel each other out and leads to a poorly defined stereo image.

So it is important that the +ve terminals on the amp are wired to the +ve terminals on the speakers and -ve to -ve. Having speaker cables with different wire colours helps but I have used cables where the only way to tell which wire is which is a ridge in the insulation down one of the pair. In that instance it is all too easy to get them wrong.

So worth double checking you've got the wiring all correct.
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Old 06-10-2013, 21:05
blueisthecolour
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This is where you get the +ve and -ve wired the wrong way round on one speaker.

In crude terms the noise is made by the speaker cone moving in and out. If the speakers are in phase the cones move in and out together in synch. if they are out of phase one moves out while the other moves in.

What this does is cause sounds to partially cancel each other out and leads to a poorly defined stereo image.

So it is important that the +ve terminals on the amp are wired to the +ve terminals on the speakers and -ve to -ve. Having speaker cables with different wire colours helps but I have used cables where the only way to tell which wire is which is a ridge in the insulation down one of the pair. In that instance it is all too easy to get them wrong.

So worth double checking you've got the wiring all correct.

Ah, no that was the first thing I checked.

One thing I did notice was that when I took the wiring out of the 'HF' points on my speakers it appeared to make no difference (whilst removing the 'LF' ones completely removed all bass').
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Old 06-10-2013, 22:14
chrisjr
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Ah, no that was the first thing I checked.

One thing I did notice was that when I took the wiring out of the 'HF' points on my speakers it appeared to make no difference (whilst removing the 'LF' ones completely removed all bass').
If there was still some noise coming out of the speakers with only the HF section connected then that proves the tweeter is working. If however there was no noise at all with only the HF section connected then the tweeters could be blown.

That is not at all unusual. The tweeters are the most likely units to go, had to replace more than a few over the years.
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Old 07-10-2013, 10:18
blueisthecolour
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If there was still some noise coming out of the speakers with only the HF section connected then that proves the tweeter is working. If however there was no noise at all with only the HF section connected then the tweeters could be blown.

That is not at all unusual. The tweeters are the most likely units to go, had to replace more than a few over the years.
Thanks for the tip,

There was some noise coming out with only the HF section connected but it was distorted and extremely 'tinny'. Do you think it's possible that I could have damaged the tweeters when I connected the new unit? I did accidentally set my cd player up to the 'Phono' output when i first tested it.
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Old 07-10-2013, 10:29
chrisjr
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If you blasted loads of volume into the speakers then that could cause some damage. It all depends on the power output of the amp vs the power handling of the speakers. Although you can also damage speakers with an underpowered amp driven into gross distortion.

Being extremely tinny is normal for tweeters. They tend to only put out the very highest frequencies. So that isn't necessarily a fault. But distortion is potentially a fault, assuming it isn't present in the feed from the amp.
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