Official Classe SSP-800 thread. - Page 97

Originally Posted by Roger Dressler

The PEQ functions correctly, but when the filter is set to a higher Q, it causes an odd side effect. Whenever there is audio within the passband of that filter, it causes a wideband noise to be produced. The filter that did this in my case was addressing a room resonance, so it was much higher than one would use for general EQ shaping. Q=12 @ 80 Hz, gain -6 dB. So I deactivated that filter for the time being. I have various other filters running that cause no audible problems, like Q=2 or 3.

I suspect most folks never encounter the problem.

Originally Posted by Kal Rubinson

Do you have any idea of what the threshold for this is? All my Qs are less than 10dB (and are under 50Hz) and I have not heard any consequent noise.

Originally Posted by Roger Dressler

The PEQ functions correctly, but when the filter is set to a higher Q, it causes an odd side effect. Whenever there is audio within the passband of that filter, it causes a wideband noise to be produced. The filter that did this in my case was addressing a room resonance, so it was much higher than one would use for general EQ shaping. Q=12 @ 80 Hz, gain -6 dB. So I deactivated that filter for the time being. I have various other filters running that cause no audible problems, like Q=2 or 3.

I suspect most folks never encounter the problem.

Originally Posted by Roger Dressler

It's not a hard threshold. The easiest way to determine is to find a test disc (or a test generator) with a sine wave tone near the center frequency of the filter. I found that the noise is proportional to Q setting, and to gain. Highest at +3, lowest at -20, and none at 0. At lower Qs the noise is so low that it's covered by the music.

If your filters are in the subwoofer path, the noise will be less audible as it is restricted by the sub's response. Mine were in the main speakers.

It took me a while to even notice that the problem existed--as it required just the right stimulus, as it is not there all the time. When I reported it to Classe, they said only one other person had mentioned it. Either it is largely inaudible, or not many folks use the EQ. Turns out it has been there since day 1, even with the single DSP platform.

Originally Posted by Roger Dressler

When I reported it to Classe, they said only one other person had mentioned it. Either it is largely inaudible, or not many folks use the EQ. Turns out it has been there since day 1, even with the single DSP platform.

Originally Posted by Teejoo

I think that was me, or there's a third person. I can hear it very well, and it sounds like a tweeter is broken.

Originally Posted by Roger Dressler

That makes you the third. What are the settings of the filter that causes it?

Originally Posted by Roger Dressler

That makes you the third. What are the settings of the filter that causes it?

Originally Posted by SamothUK


I've not noticed this with the sub EQ, but then the sub can't reproduce the kind of high frequency noise I've experienced here.[/i]

Originally Posted by SamothUK

I've reported it in detail to Classe back in Feb - I see the same symptoms other people report. Here's and excerpt of what I sent to Classe :

Experimenting with manually sweeping sine waves, it became very obvious that when the frequency matched that of the filters I'd set, there was a quite loud hissing much higher up the frequency range (so with my 3 way floorstanding speakers, although the sinewave was at 65Hz and quite quiet, there was quite a distinctive hissing from the tweeter).

The volume of the hissing seemed to be affected by the Q setting more than anything - the narrower the Q (higher values) the louder and more prominent the high frequency hissing was. Amount of gain made little difference unless gain was set to 0dB. It happened with either of the bands in effect, I tried switching individual ones off.

I've not noticed this with the sub EQ, but then the sub can't reproduce the kind of high frequency noise I've experienced here.

Originally Posted by Teejoo

I think that was me, or there's a third person. I can hear it very well, and it sounds like a tweeter is broken.

Originally Posted by SwainDtV

I have a similar problem.

"...sounds like a tweeter is broken" is what I experience in bass frequencies. With every bass punch I hear a hiss; only with digital connections (coax and HDMI). In analog bypass there is no hiss. And after I reboot the SSP everything is back to normal for a while.

I didn't mentioned it before because I was unable to find the correct words to describe the problem and I'm still using the single DSP and first firmware release. I don't use PEQ; room EQ is disabled.

I still haven't figured it out what is causing the hiss to return. My feeling is that it returns after I used an input with a HDMI connection for the first time after the reboot.

After my upgrade to the dual DSP at the end of this week I hope this problem is solved.

Originally Posted by Roger Dressler

Got it. Nice to have the various mutings working when changing modes and sources.

Originally Posted by mt14942

I wish I could get it. I'm Having a problem I beleive because I have Windows 7 on my laptop. I am going to try one more time today. If it doesn't work I will call Classe next week to see if they have any suggestions.

Originally Posted by adidino

What kind of issues are you having with Windows 7?

Originally Posted by mt14942

Once I got to the step where I initiate the Downloader a window pops up that reads detecting but just stays that way. Maybe I wasn't patient enough which is why I am going to try again today.

Originally Posted by racerguy

If you are using USB, are you absolutely sure you have identified the correct IRQ line for the port per the instructions? If you have not, you will never get a connection.

Originally Posted by adidino

I'm assuming you are turning on the Classe from the back at that moment? It can't already be on.. you need to turn it on (from the back only).

Originally Posted by mt14942

Since downloading the latest firmware code I have played a handful more DVD-A disc's and cd's with the HDMI connection and did not notice any audio truncation this go around. For the most part the SSP-800 seems pretty stable to me. I have also been comparing HDMI with the balanced analog connection and one thing I noticed is that with HDMI the volume levels are about 4db higher than with the balanced analogs, is this the norm? Also when comparing a couple of cd's, the sound of the main vocals were more focused to the right and with the analogs the vocals were more towards the center. I wasn't expecting this because I have the same front speaker level configuration set in the A1 as I do with the SSP-800. It was like with the HDMI connection the right speakers volume level was 2 to 3 db higher than the than it is with the analog connection. I seem to prefer the sound of 2-channel music with the balance analog connection vs. HDMI it seems to have a wider soundstage and warmer sound, but I have only compared a couple of cd's so far. I always liked the way my A1 sounded with my Parasound Halo P7 pre-amp. The P7 is pretty good multi-channel pre-amp that has balanced analog outputs for 2 channel. I feel that the SSP-800 sounds as good if not better.

Originally Posted by mt14942

I have also been comparing HDMI with the balanced analog connection and one thing I noticed is that with HDMI the volume levels are about 4db higher than with the balanced analogs, is this the norm?

Originally Posted by mt14942

with HDMI the volume levels are about 4db higher than with the balanced analogs, is this the norm? Also when comparing a couple of cd's, the sound of the main vocals were more focused to the right and with the analogs the vocals were more towards the center.

Originally Posted by racerguy

This is a common manifestation. A significant boost in gain (4db is significant) can magnify gain differences between channels. What may have been a completely inaudible .5db gain difference between right and left channels at your prior nominal level can be magnified into an easily perceivable difference when the overall gain is increased.

Originally Posted by mt14942

This might be the case, however I did first adjust the gain levels, all be it by ear, before comparing. I am starting to prefer the HDMI for multi-channel DVD-A disc's. I even felt that multi-channel SACD sounded as good with HDMI as it does with the m/c analogs even with the players (A1UDCI) limitations when it comes to SACD. I may wind up going with the HDMI connection for all multi-channel (bluray, DVD-A and SACD) and the 2-channel balanced xlr's for all 2-channel music.

Originally Posted by Sharp1080

That's my preferred way of connecting my sources into the SSP-800.

Originally Posted by Sharp1080

That's my preferred way of connecting my sources into the SSP-800.

Originally Posted by mt14942

Recently I noticed that I was not getting the SSP-800 OSD menu on my display. I switched the SSP-800 off from the back and also disconnected the HDMI cable. After about one minute I switched it back on reconnected the HDMI and the OSD menu came back on to my display. Not sure why it disappeared in the first place? Has this happened to anybody else? The good news is it came back..