Distortion from speakers or receiver? (1 Viewer)

[Ten_Smith]

When I play CD's and set the volume on my Denon above 0, the low end music does not sound right. The detail seems to go out of the bass. I know I said distortion in the title, but I'm not sure if that is technically the right term for the problem I am hearing. Based on what I hear, I suspect it is the speakers 6.5" woofer having a hard time handling the low frequencies at high volume. But, I really don't know.

So, is it the speakers or the receiver that is messing the sound up?

Receiver: Denon 1802 (80wpc).

Speakers: Acoustic Research PS2062 (sensitivity 90db, recommended amp 20-125 watts, Freq Resp 45Hz-20kHz ±3dB).

Configuration: Speakers are set to Large (no SW yet).

I only occasionally have a desire to play it that loud. I'm hoping its the speakers, and that a sub-woofer will help cure the problem.

 

[Vince Maskeeper]

Well, even if it isn't the "speakers" per se- I think a subwoofer could cure the problem. Even if the distortion is coming from overdriving the receiver- having an out board sub with its own power will probably help things a bit, allowing you to back down the master a touch and reducing the load on the internal amps by sending bass material to the sub instead.

I assume your Denon is like mine, and like goes to +4 or +6 Max volume position- and if so I cannot imagine trying to play music from CD at 0 on my denon 3300. I think CD playback at -10 is extremely loud on my system (heck, on a dolby ref calibrated system 0 would offer about 100db+ of playback level RMS!!!!!) I would guess that the whole signal chain is being slaughtered by this much RMS level.

-Vince

 

[John Garcia]

It sounds like a little of both. What you are likely hearing is most likely the driver trying to reproduce frequencies below it's capability, and even moreso at louder volumes.

At the same time, as Vince said, it sounds like you are driving the amp quite hard, even with small speakers. My calibrated ref level is -8. If I turn it above 0, amazingly I don't really get distortion, but it is WELL beyond comfortable listening, as -8 is already loud. I normally listen between -20 and -12 for movies & music. (Marantz SR6200, 105wpc, Paradigm Mini Monitors set to small) If I set the Minis to large, I can easily bottom them and drive them to distortion at very loud levels.

I think you are already know what the answer is, and that is a sub. Again, as Vince said, that will allow you to run the mains small and will free up some headroom on the amp. To get a feel for this, set your speakers to small (just to try it out). You should not hear the same distortion because 1)No lower frequencies thanks to x-over, which means 2) more power is available for the mid and higher frequencies because you are not driving the amp as hard.

 

[Ten_Smith]

Vince, you're right about the volume. I rarely play it that high.

I can see how a SW would solve the problem either way. Part of the reason I was asking is that I am re-evaluating the speakers after having had them for a while. And this is the only noticeable-to-me flaw I've detected (i know there are better speakers out there, I'm talking noticeable flaws, initially I had felt the bass a little muffled, but that seems to have improved with further playing).

 

[Kevin Deacon]

Don't drive your amp that hard as the clipping will fry your speakers. Better to have more power than too little.

 

[Ten_Smith]

John, I didn't see ur reply before I started writing my last one.

I like the idea of setting the speakers to small, and I'll try that this weekend.

Another thing I'm trying to do is decide what the highest allowable setting for the receiver is. Then tell the wife. On my old Denon stereo receiver I would not allow it to be set above half-way. On the new 1802, I'm thinking somewhere around -4. Anyhow, thanx guys.

 

[Bob McElfresh]

Ten: what some people do is this:

- setup a SPL meter at your primary listening position

- Use the test-tone feature, or a AVIA/Video Essentials test tones and adjust the main volume control until the noise reaches the 75 db level. Then mark this spot on the dial or note the front-panel reading.

I think this will give you a volume close to "reference level" and takes into account all the room/speaker/alignment factors. (or at least a good gauge for when you push things too hard.)

Remember that if you turn/move your speakers, it can have a large effect on the sound level at the listening position so remember to do this again if you move the speakers.

Good Luck.

 

[Vince Maskeeper]

Remember that Bob's post about a ref level pertains to movie soundtracks. his volume position you will achieve with calibration tones is absolutely ideal for watching films- which are created with a median level at about -30...
However- since modern CDs have a median level of about -.1 (OK, a bit of sarcasm on my part, it 's closer to a -3/4db average level), CDs will appear about 30db louder on average than a film soundtrack. Unless your receiver offers a compensation for different inputs (which most only offer a 6db adjustment anyway), the dolby ref level setting on a receiver will probably cause damage to both the equipment and your hearing with a CD.
Dolby ref level setting and a CD would equal approx 105db of sustained output (technically more with coupling of the stereo speakers).
Dolby ref level setting and a DVD would equal approx 105db of PEAK output, but usually about 75-80db of average level.
To have a DVD soundtrack and CD soundtrack seem resonably even, the mast volume position while listening to the CD would need to be reduced by 20db or more!
-V