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Posted By: mrihar QS8 Roll-off Frequency - 11/13/15 09:02 PM
Hi, My Denon x4000 AudysseyXT32 consistently sets my rear surround QS8 speakers at a cross-over of 200Hz. At the same time, Audyssey sets my R/L surround QS8s at 150Hz.

Audyssey should be identifying the speakers' roll-off frequency according to what Audyssey is telling me. This concerns me for 3 reasons.

1) The two settings are different for the surrounds/back sets of QS8s suggesting the two sets of QS8s v3 are performing differently.

2)Both sets appear to be performing significantly above (worse than) the advertised frequency response. They should start rolling-off around 100Hz or so.

3) I can detect a higher pitch in the right back surround compared to the others during the AudysseyXT32 test which could support a defect argument along with 1)

Has anyone had a similar experience? For those using AudysseyXT32 with the QS8s, what are your cross-overs automatically set at.

I've always felt that my QS8 speakers sounded very tinny to the point where its difficult to listen when playing 2 channel audio through Multi Channel Stereo.

Should I be considering getting the one speaker exchanged? Is it possible all 4 of my QS8s are defective? I bought them as factory seconds.

Cheers,


2)
Posted By: pmbuko Re: QS8 Roll-off Frequency - 11/13/15 09:19 PM
No, your speakers are most likely not defective. A speaker's placement in the room has a huge effect on what it will sound like from any given listening position. The Audyssey MutiEQ process does take audio samples from multiple positions in the listening area, so it should get a more accurate picture of a speakers performance, but the effects of the room cannot be downplayed.

That being said, I'd experiment with manually overriding the cutoff frequency on your sides are rears by setting them to 100Hz. If you think they sound tinny, this probably won't help because it will simply move some of the bass from the sub channel back to the side/rear surrounds.
Posted By: Gr8_White_North Re: QS8 Roll-off Frequency - 11/13/15 11:53 PM
I would agree with the above post by pmbuko , this is definitely a room reflection/placement problem. Audyssey would set my QS4's at 60hz and I would raise it up to 80hz. I now use Dirac which does not control the crossover frequency , instead it measures the speaker full range and with my QS8's they extend down past 40hz though I still set my crossover to 80hz since I use 2 subs so no need to stress my surrounds. The room has a significant impact on how a speaker sound and reacts. Audyssey can also be guilt of exaggeration of the upper frequencies which is widely discussed in many forums. Share the layout of your room with a picture or diagram so others can help with placement and possible room treatment options.

Richard
Posted By: brwsaw Re: QS8 Roll-off Frequency - 11/14/15 01:39 AM
Swap the two pairs to confirm....
Posted By: Adrian Re: QS8 Roll-off Frequency - 11/14/15 03:18 AM
Make sure the drivers are working. I had a bad driver on one of my QS8s a few yrs ago which threw the Audyssey readings out of whack thereby setting the crossover very high.
Posted By: mrihar Re: QS8 Roll-off Frequency - 11/16/15 04:46 PM
Thanks for the replies. I checked the QS8 drivers and they all appear to be vibrating under load. I also swapped the R/L surrounds with the R/L rear surrounds. Wiring, stands and outputs from the receiver are all still locked to the same original position. I then ran the AudysseyXT32 setup again using the same 8 reference points and the same heights on the tripod.

Turns out I get the same cross-over calibration at the same speaker locations. In short, the QS8s where were calibrated with a 150Hz cross-over were now set at 200Hz and vice versa. Thus, I have to conclude with the rest of you that the speakers are not defective.

I suppose I can try a manual cross-over setting of 80Hz. The 200Hz makes no sense at all considering the EP500 I have starts to roll-off at 150Hz thus leaving a big gap between 150Hz & 200Hz for the R/L Rear Surrounds.

Here's what my room looks like and what my current layout looks like. Actually I can't figure out how to attach a jpeg. I'll try to figure that out.
Posted By: fredk Re: QS8 Roll-off Frequency - 11/19/15 12:39 AM
I'm pretty sure I had the same issue when I set my system up. I set the crossover manually for the surrounds.
Posted By: AdrianD Re: QS8 Roll-off Frequency - 01/22/16 01:45 PM
I had a similar issue with a set of outdoor speakers; it came down to the distance between the amp and speakers and the gauge size of the cables I was using.
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