Hi,

I apologise in advance because I'm not too familiar with the technical aspects of hi-fi, but here goes...

Until recently my separates system consisted of a Technics SA-X30L receiver, a pair of Sony SS-CSP55 speakers and a Technics SL-PG390 CD player (among other things) and an issue I observed was that, even with the volume control set very low (about 0.5 on a scale of 0-10), it was still unbearably loud. I confirmed that the amp and speakers have the same impedance (8Ω) (the label on the amp actually says 8-16Ω, but the speakers are rated at 8Ω), but I've also read that apparently the line-out voltage of newer equipment is higher than that of older equipment (although I'm having a hard time finding any definitive specifications, I'm guessing that my receiver is 80's gear, judging by its squareness and the amount of discrete components it contains, and the CD player looks newer than that).

I recently swapped the receiver for a standalone amp and tuner (a NAD 3020E and Technics ST-X999L respectively, but I also experience the same issue with this setup, although the NAD does have a 'low level' switch which alleviates the problem. Another system I can compare it with consists of a Marantz PM4000 amp and Eltax Symphony 4.2 speakers and, with the low level switch on, my setup sounds roughly as loud as the Marantz/Eltax one with the volume control set to a similar position (about a quarter of the way round) and the loudness switch off (both the Marantz and Technics ones have loudness switches, but they just compound the problem further).

Could anyone please shed any light on what might be the cause of this?

1337atron

One person's 'too loud' is another's 'lost in the background noise'. What many people consider unpleasant loud from a hifi system is markedly below live music levels. Few home systems can approach live music levels, regardless of the type of music played. Even though I often like music louder than most people who have listened to my system, the volume control is never near maximum, usually less than 50% up. There isn't anything defective or unusual in this.

Speaker efficiency, the ability of the speaker to convert electrical energy into sound energy, is a major factor in how loud the output will be for any given input. There are major differences in speakers.

Different sources provide different signal levels: with three CD players and a DVD/CD player to choose from, I get a different loudness from each for any given CD, for any given volume control setting. Tape decks and tuners are each different from each other in this respect.

@ 1337atron: From the tests you've described with the other Amps, the problem seems to be line out level of the player.

I am guessing that the CD plays at professional line level (+4) and the amp is expecting it at consumer level (-20). the "low level" switch changes between these levels.

You could fix that with a preamp.

Have you ever run across a CD player that outputs at the +4dBu level?

I was wondering this as well, since it also seems to affect the tuners (both the separate one connected to the NAD amp and the integrated one in the receiver, which seems strange). Despite the fact that the CD player has an optical output, I'm pretty sure that it would be classed as consumer rather than professional grade, likewise with the tuner.

The size and acoustics of the room also obviously contribute to the perceived volume, but the NAD/Technics setup (with the low level switch off) seems much louder even when using headphones.

1337atron

If your receiver/amp has a tape-monitor loop, you can insert an inline attenuator into the loop (between tape-out and tape-in) and turn the tape monitor switch on. That will route the signal through the attenuator. (You would have to experiment with different levels of attenuation, and you might need to string a couple together in series.)

This is a "loudness compensation" switch. It boosts the bass at low-volume settings to compensate for the fact that our hearing is less bass-sensitive at low levels. At higher volume settings, the loudness switch should have little or no effect.

Thanks for the information and the link, although I'm in the UK and am having a hard time finding anywhere which sells them so I'm looking for a DIY solution (given that my soldering skills aren't *too* bad!).

I came across <a href="http://amps.zugster.net/articles/attenuation">this</a>,and would I be correct in assuming that the attenuator you linked to is basically similar to the L-Pad schematic shown there?

Ideally I'd prefer not to route it through the tape monitor, as I've got that hooked up to a tape deck for recording, but after further testing it seems that it might actually just be to do with room acoustics (given that to room in which the NAD/Technics setup is situated is much smaller than the one with the Marantz one) - either that or it's all in my head.