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Topic: Which RCA input to use, 700mv or 900mv? (Read 673 times) previous topic - next topic
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Which RCA input to use, 700mv or 900mv?

Hello.

I recently got a new pair of active speakers (S1000DB), and I'm using both analog (PC) as well as optical (TV). The speakers have two analog inputs, however. One RCA pair is "700mv" and is labeled "AUX", the other is "900mv" and is labeled "PC." My analog source is a PC with a Xonar D1 sound card. I'm not sure which RCA pair to use to connect the 3.5mm line out from the Xonar to the speakers. I would assume I should connect it to the "PC" RCA pair, since the source is a PC, but this produces a quieter signal than the "AUX" and optical inputs.

The specs of the Xonar say:

Output/Input Full-Scale Voltage, 2 Vrms (5.65 Vp-p)

But I don't know what that means...  :-\

What I can say for sure, however, is that when I connect the optical out of the Xonar to the speakers at the same time as the analog out and switch between the sources, the 900mv PC connector is much quieter compared to the 700mv AUX connector. The 700mv AUX connector is in fact exactly as loud as the optical connector, which (perhaps naively?) makes me believe that's what should be used here, even though the source is a PC sound card.

Does someone know which is the correct RCA pair to use here?


Edit:
The full specs of the sound card are listed here: https://www.asus.com/us/Sound-Cards/Xonar_D1/specifications

 

Re: Which RCA input to use, 700mv or 900mv?

Reply #1
Hello.

I recently got a new pair of active speakers (S1000DB), and I'm using both analog (PC) as well as optical (TV). The speakers have two analog inputs, however. One RCA pair is "700mv" and is labeled "AUX", the other is "900mv" and is labeled "PC." My analog source is a PC with a Xonar D1 sound card. I'm not sure which RCA pair to use to connect the 3.5mm line out from the Xonar to the speakers. I would assume I should connect it to the "PC" RCA pair, since the source is a PC, but this produces a quieter signal than the "AUX" and optical inputs.

The specs of the Xonar say:

Output/Input Full-Scale Voltage, 2 Vrms (5.65 Vp-p)

But I don't know what that means...  :-\

What I can say for sure, however, is that when I connect the optical out of the Xonar to the speakers at the same time as the analog out and switch between the sources, the 900mv PC connector is much quieter compared to the 700mv AUX connector. The 700mv AUX connector is in fact exactly as loud as the optical connector, which (perhaps naively?) makes me believe that's what should be used here, even though the source is a PC sound card.

Does someone know which is the correct RCA pair to use here?


Edit:
The full specs of the sound card are listed here: https://www.asus.com/us/Sound-Cards/Xonar_D1/specifications


The difference between 700 mv sensitivity and 900 mv sensitivity is about 2 dB which is rarely enough to make a significant difference. The one with the higher voltage is going to be little louder all things considered, but you may not be able to reliably hear the difference with rapidly varying audio signals like music. You should be able to use them interchangeably
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Re: Which RCA input to use, 700mv or 900mv?

Reply #2
The difference between 700 mv sensitivity and 900 mv sensitivity is about 2 dB which is rarely enough to make a significant difference. The one with the higher voltage is going to be little louder all things considered, but you may not be able to reliably hear the difference with rapidly varying audio signals like music. You should be able to use them interchangeably.
The one with the lower voltage (700mv) is actually the one that's quite a bit louder (I don't have any measurement gear, but it sounds louder than just +2db, but obviously I can't be sure.) It is exactly as loud as the optical S/PDIF connection, in fact.

However, other than that, I assume I don't have to worry about any issues caused by using a line-out that has a wrong voltage? (Whenever something has "voltage" in the name, I immediately get paranoid about equipment damage.)

Re: Which RCA input to use, 700mv or 900mv?

Reply #3
"Sensitivity" in general means the input terminal expects something with at least 700 or 900mV max output. For example -10dBV (0.316Vrms) is the standard for consumer equipment, it doesn't mean 0.316Vrms is the maximum allowed voltage.

2Vrms max output is pretty common in consumer AV products, if it is as loud as the optical input, it is a good sign of ideal voltage. Don't worry and just use it.

Re: Which RCA input to use, 700mv or 900mv?

Reply #4
Thanks, everyone!

 
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