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Struggling to understand the power needs of 1983 Cornwall 1.5s


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Confirmed with Crites that these speakers should ~98db efficient. Replaced caps and tweeters from Crites. 

Paired them with a 20wpc Schiit Aegir and Freya +. 
 

with volume set to 3 o clock position, I’m getting peaks of about 98db using a decibel meter on my phone. 
 

 

Does this sound like the speakers are functioning properly?

 

maybe I’m missing something but I keep reading on here about people who power their vintage Klipsch with very low power thanks to the sensitivity. 
 

is it expected that I would have to crank a 20w amp?

 

(please take it easy on me, I’m still trying figure this all out) 
 

 

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Phone db meters are not anywhere close to accurate.

How far away is your phone from the speaker when you're measuring?

Also, you'll need to know the input voltage to the amp to understand how much power the amp is putting out.

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7 minutes ago, wuzzzer said:

Phone db meters are not anywhere close to accurate.

How far away is your phone from the speaker when you're measuring?

Also, you'll need to know the input voltage to the amp to understand how much power the amp is putting out.

I found a pretty reputable iPhone app for measuring decibels. I know it’s not perfect. 
 

do you know of any resources that would show me how to test that everything is performing as it should?

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Phone db meters can be useful and accurate, the app I use is much more useful than the Radio Shack db meter, and I found it was calibarated about the same.

 

Perhaps a volt meter across the speaker terminals at speaker or amp can be helpful, maybe about 2.83 volts is 1 Watt at 8 ohms.

 

98 db is very loud and uncomfortable, I find 80 db at about 10 feet away to be a fairly loud and lively listening level.

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6 minutes ago, the real Duke Spinner said:

Larger amplifiers ate necessarily about Loudits more about reserve power and bass control

I runn 200wpc for this reason

Never get about several wattsbutits the peaks. !!

 

 

 


Once more, and engrish this time plz……….

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On 6/18/2022 at 9:55 PM, jason.justice said:

Confirmed with Crites that these speakers should ~98db efficient. Replaced caps and tweeters from Crites. 

Paired them with a 20wpc Schiit Aegir and Freya +. 
 

with volume set to 3 o clock position, I’m getting peaks of about 98db using a decibel meter on my phone. 
 

 

Does this sound like the speakers are functioning properly?

 

maybe I’m missing something but I keep reading on here about people who power their vintage Klipsch with very low power thanks to the sensitivity. 
 

is it expected that I would have to crank a 20w amp?

 

(please take it easy on me, I’m still trying figure this all out) 
 

 

There is something wrong in the gain structure of your system, I think. Are you sing your Freya + in active mode? Even in active mode, it's not a high gain preamp, if your source is on the low side, it might feel like there is not enough "juice". It's not about the amp's power output, it's about how much voltage you give it at the input.

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On 6/18/2022 at 5:59 PM, the real Duke Spinner said:

Larger amplifiers ate necessarily about Loudits more about reserve power and bass control

I runn 200wpc for this reason

Never get about several wattsbutits the peaks. !!

 

 

 

Reminds me of a pair of push-pull 2A3 amps I built.The guy who designed them (Henry Kuck) demonstrated to me 150watt peaks on these amps.Hope you're well Henry! Yes, they still exist!

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When listening to efficient loudspeakers while using an amplifier with watt meters, it is impressive to get big sound at 1 watt. Then you turn it up a little bit louder and it is heading into the 10 watt range. Wow, this sounds awesome, let's go even louder when suddenly the meter is swinging towards 100 watts, but you haven't turned the volume knob very much.

 

It is good to have Klipsch speakers, even with big powerful amps.

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On 6/20/2022 at 10:45 PM, Rolox said:

There is something wrong in the gain structure of your system, I think. Are you sing your Freya + in active mode? Even in active mode, it's not a high gain preamp, if your source is on the low side, it might feel like there is not enough "juice". It's not about the amp's power output, it's about how much voltage you give it at the input.

Agree that if you are using the pre-amp in passive mode that your volume control gain setting will likely be in the high range even with high-sensitivity speakers. That does not sound out of line.

 

If you are using the tube active stage (+12dB) then yes, it seems a little strange to have the volume control that high up in range. But, as already mentioned, the system gain may just need to ride high on some tracks and not so much on others. 

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The rotation angle of your preamp's volume control has little bearing on actual power output, though that is unusually high. 

 

To figure the sound level in your room,

1 watt is 98 dB at 1 meter

Add an amp and another speaker  +6 dB, 104 @ 1m

Double the distance to 2m (6.5 feet) is -6 dB, 98 dB

Double again to 13 feet, -6 dB, or 92 dB, @ 1 watt, plenty loud for peaks and a 20 watt amp still has 13 dB of headroom for Flim and The BBs.  I sit almost 13 feet from my La Scalas. 

 

You won't lose quite 6 dB/doubling of distance in a reverberant field (room) so this exercise is conservative.  

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