| Author |
Thread: Impedance compatibility - amp & speakers (Cambridge vs Rogers) |
    
New member Username: Fredhammersmith
Post Number: 1
Registered: Jul-04
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| Posted on Sunday, July 04, 2004 - 12:08 pm: |
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Hi...
I am not really a technical guy. Just love my sound to be as pure and clean as possible.
I have a couple of Rogers LS3/5a speakers.
I just received a gift: a Cambridge Audio Azur 540 integretad amplifier.
My question is:
the amp is designed for 4 to 8 omhs speakers.
My Rogers are 11 ohms.
What will happen? Does that degrade the sound? Is it worst than that? |
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Silver Member Username: Soccer
Post Number: 222
Registered: Apr-04
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| Posted on Sunday, July 04, 2004 - 08:52 pm: |
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Nope, your amp will see a higher impedance, therefore work less stress, but it won't give you the full power announced. What's the Rogers's sensitivity? |
Silver Member Username: Kegger
MICHIGAN
Post Number: 662
Registered: Dec-03
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| Posted on Monday, July 05, 2004 - 10:12 am: |
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yes fred the higher impedance should not be a problem.
going the other way is where you run into issues.
and with that setup you should have a nice little system.
those speakers are about 85db sensitivity so it
would get real real loud.
also they drop off at low end quite steep so they
are a natural fit for a good sub. |
Silver Member Username: Soccer
Post Number: 223
Registered: Apr-04
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| Posted on Monday, July 05, 2004 - 08:36 pm: |
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Correction: 85dBm is a very low sensitivity, they would play much louder if they were about 90-92 dBm |
Silver Member Username: Soccer
Post Number: 224
Registered: Apr-04
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| Posted on Monday, July 05, 2004 - 08:39 pm: |
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High sensitivity speakers are a problem only to tybe amps, due to its outputs transformers |
Silver Member Username: Soccer
Post Number: 225
Registered: Apr-04
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| Posted on Monday, July 05, 2004 - 08:40 pm: |
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tube amps... |
Silver Member Username: Kegger
MICHIGAN
Post Number: 687
Registered: Dec-03
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| Posted on Monday, July 05, 2004 - 09:04 pm: |
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woops the statement:
"those speakers are about 85db sensitivity so it
would get real real loud."
should have read:
those speakers are about 85db sensitivity so it
would "not" get real real loud.
good catch joao ferreira
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Silver Member Username: Kegger
MICHIGAN
Post Number: 688
Registered: Dec-03
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| Posted on Monday, July 05, 2004 - 09:08 pm: |
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joao ferreira your statement
"High sensitivity speakers are a problem only to tybe amps, due to its outputs transformers"
should have read:
High "impeadence" speakers are a problem only to tube amps, due to its outputs transformers.
man if we both only proofread! lol |
J. Vigne Unregistered guest |
| Posted on Monday, July 05, 2004 - 11:00 pm: |
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High sensitivity and high impedance speakers have no, repeat NO, negative effects on tube amps. Almost all tube amps have transformer taps at 16 Ohms making certain they produce their rated power into any load from 4,8 or 16 Ohm taps. Try that with a transistor amp. I can personally attest to the quality of the LS3/5a's with tubes. |
Silver Member Username: Kegger
MICHIGAN
Post Number: 698
Registered: Dec-03
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| Posted on Monday, July 05, 2004 - 11:29 pm: |
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good to know jan.
i was just fixing the previous posts! |
Silver Member Username: Soccer
Post Number: 226
Registered: Apr-04
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| Posted on Tuesday, July 06, 2004 - 09:02 pm: |
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Ok, let's speak with "property of word".
KEGGER: nice catch also to you, I should have said impedance instead of sensitivity.
Now, when I say this amp works better with this impedance, I'm talking extreme cases.
Transistor amps don't get along with very low impedance, the same way tube amps don't get along with very high impedances, MEANING:
If you short -"zero" ohms- the amps outputs, it will blow the power devices if it's a transistor amp, but not if it's a tube amp;
If you open -infinite ohms- the amp's outputs (terminals "on air") you will blow the amp's outputs if it's a tube amp, but not if it's a transistor amp;
This is a general rule, which aplies to the great majority of tube and transistor amps.
In both amp types, the higher the sensitivity, the higher the volume will be, per watt. Generally, low sensitivity speakers tend to play better than high sensitivity ones, due to reactance issues that I'm not quite expertised to explain. The same way, high sensitivity speakers need amps with greater "damping factor" figures to achieve better performance.
NOTE: I always mean QUALITY WISE when I say "performance".
This time I hope I expressed my self correctly.
ENJOY |
