xsp-1 preamp and stealth 8s - input sensitivity question

[oolalajp]

greetings,

these questions may have been asked before, so apologies in advance.

i am curious about "correctly" matching the input sensitivity of my stealth 8s with the xsp-1 pre-amp.

i have been listening to my stealth 8s and xsp-1 for about 2 years now and have been completely happy with the sound. i've adjusted the bass roll off, bass tilt, and treble tilt to my liking, and after recently purchasing a turntable, i've been fiddling with the stealth 8s input sensitivity settings, but i don't really understand what i'm doing.

i recently changed the input sensitivity setting on the stealth 8s and have it set at -6db. that (to me, in my setting, with my system) sounds best, but why does -6db sound better than +6db?

 - what are the factory settings when the stealth 8s are shipped (i didn't note them before i changed them)?

 - why are they set like that?

 - is there an optimum setting/match between the stealth 8s and the xsp-1?

 - why does the sound change when i change the input sensitivity settings? for example, when adjusted to +6db, the sound is muffled and the soundstage all but disappears, especially if left at the same volume.

i know i may have left out crucial information for some of these questions to be answered, so please fire away.

and thank you in advance for taking the time and making the effort to consider my little audio enigmas!

[socketman]

What you are doing when you turn up the volume on the XSP is you are increasing the voltage that it sends to the amp inside your speakers. What you are doing is finding a balance between the output voltage of the XSP and the input sensitivity/gain of the amp. The amp takes the signal from the XSP and increases it proportionately to produce sound from the speakers. If you turn the gain on the amp too low you will overdrive the XSP and introduce distortion thus the need to find a happy medium.

I find this explanation quite informative since i am not a lpropeller head like keith or lonny LOL

www.audioholics.com/audio-amplifier/amplifier-voltage-gain

[oolalajp]

dear socketman,

thank you for your reply. i have read (twice) the article you linked and am pretty sure i understand very little, though it's clear that i am not making optimum use of my equipment if i don't get this setting "correct".

here's what the XSP-1 manual says:

Gain Structure:


Nominal Output Level: 0 dB = 1 V.

Nominal Gain (Volume set to “0”): 1.

Maximum Gain (main outputs): +12 dB.



and here's what the stealth 8 manual says:

The Stealth 8 will nominally reach full output with an input level of 1 VRMS. (Of course this will vary depending on other settings and program content.) The Input Sensitivity control offers the ability to adjust the gain of the Stealth 8 by approximately +/- 6 dB for matching purposes.


where do i go from here? and thank you and/or anyone else who might be able to answer my (simple?) questions. muchos gracias!

[socketman]

When the front panel of the XSP is displaying 0db it will be outputting 1v from its line out theoretically. I say theoretically because your source often doesnt comply to any specific output level. If your bluray player has a different output than your Xbox or a DAC it will result in a different output level from the XSP-1 which may over drive or under drive your speakers amplifier. There are videos on youtube on how to measure the the voltage ouput of your pre amp or whatever you would like to measure but it is done at a specific frequency so different frequencies will result in different outputs. I would stick to the center point on the amp gain unless you feel the XSP-1 is not driving the speaker amp to full output. Unless you are severly over driving the the amp you should not hear any differences , i suspect you are hearing differences becasue the ear is so sensitive to even small increases or differences in volume. Try to listen to the music and not the equipment.

[oolalajp]

again, socketman, thank you for your reply. i am indeed using my ears and listening to the music and not the equipment, but the analytical part of me brain is also interested in knowing how it all works together.

[socketman]

The advantage of buying all your separates from one vendor is that all their equipment is designed to work together in harmony, though like i said some sources can alter what the pre is putting out. Most amps do not incorporate any gain controls and i suspect Emotiva put them there for compatibility with other brands of receivers and pre's that have different gain structures. As always set it to what sounds best to you rather than what might be technically correct.