collapsed soundstage

[Bigmoney]

After my last posted I sat down to enjoy some grateful dead. Much to my surprise there was no imaging but rather concentrated sound coming from the center between my speakers. It sounded as if the musicians all fell down in the middle of the stage. I have always unitl now been happy with my imaging. Nothing on my system has changed other than the recent addition of blue jeans cable interconnects and I switched from single wire to bi wire using monster z2 reference cable. Has anyone experience such an imploded soundstage. I wonder if my new cables need to be burnt in although I have always been skeptical of the burn in claim. I took out a test cd which has imaging tracks on it. The cd begins by a woman speaking from the left speakers only, than images her voice to the left of center, than center, then right of center, than only the right speaker. On ever section from left to right the voice was concentrated in the middle. My system has always imaged perfectly. I truly am in need of help, this issue is beyond my knowledge.

[E-Stat]

Nothing on my system has changed other than the recent addition of blue jeans cable interconnects and I switched from single wire to bi wire using monster z2 reference cable. Has anyone experience such an imploded soundstage. I wonder if my new cables need to be burnt in although I have always been skeptical of the burn in claim.
Easy way to find out. Revert to using the old cables. You may find (as I do) that new cables take a little while to settle down. I was cautioned that would be the case with my JPS Labs interconnects. No big deal.

rw

[blackraven]

Try switching back to single wire and see if it makes a difference. Did you change the speaker position in your room? Did you accidnetally change a setting on your receiver?

I doubt that cables needing burn in would cause an imaging problem but I could be wrong.

[bfalls]

It almost sounds like you've changed to mono mode. Where both front channels have the same signal resulting in everything imaged to the middle. I used to notice this on TV where the station wasn't stereo.

Since you've changes cables, you may also have channels reversed where left is right and right left. I'm guessing the latter, since you'd probably have an indicator on your front panel if you were in mono. I don't think bi-wire has anything to do with your problem.

[Bigmoney]

I don't have a receiver. I use a rotel rc 1070 preamp with a rotel 1080 amp. No receiver. It does sound very much like mono. How could this happen?

[bfalls]

I'm not familiar with the Rotel 1070 Preamp, but unless there's a mono/stereo option my best guess is you've either switched interconnects, or speaker cables.

If the interconnects are switched, instead of the soudstage from the left speaker being from left speaker to center, it would start at the left speaker and go further left, the same with the right speaker leaving a more difuse image with a hole in the middle.

If the speakers cables are switched you'd have the same results. It's also possible you have the speakers out-of-phase (the + and - switched on one speaker). If that's the case you'll notice an absence of bass and no defined image. I would recheck all the cabling. If all your L and Rs and + and - are correct. I would start substituting your previous cables back into the system one at a time. It's possible one of your interconnects have been wired incorrectly.

Another method would be to do what Estat recommended and revert back to original. Once you're back to a known correct state, then start putting the new cables in one at a time and listen between each change. Basic troubleshooting procedures. Question changes, revert to known simplest form, implement changes one at a time and test the change.

[Bigmoney]

I fixed my problem. It simply was trial and error. I noticed I was using both preouts of my preamp, one for my amp and the other for my subwoofer with a y adapter. I disconnected the subwoofer and my soundstage reappeared. Is there a reason my system plays mono when both preouts are plugged in. Does this have something to do with that the 2 pre's are for biamping?

[E-Stat]

...and the other for my subwoofer with a y adapter.
Sounds like you summed the outputs and forced mono. For a single subwoofer, just pick a side.


Does this have something to do with that the 2 pre's are for biamping?
Yes. Or dual subs.

rw

[Bigmoney]

Okay that makes more sense....funny thing is that my dealer convinced me I needed the y adapter to use my sub....I was skeptical and didnt think I needed it but he just threw it in at no cost. Otherwise, if his ignorance and my suggestibility hadn't prevailed I would have never had this issue.

[E-Stat]

Okay that makes more sense....funny thing is that my dealer convinced me I needed the y adapter to use my sub....
For preamps with single outputs, that would make perfect sense. In this case, the "Y" would split the signal output into two directions with one going to the power amp and the other going to the sub. I presume you funneled two outputs down to one with the secondary jacks.

rw

[Feanor]

I fixed my problem. It simply was trial and error. I noticed I was using both preouts of my preamp, one for my amp and the other for my subwoofer with a y adapter. I disconnected the subwoofer and my soundstage reappeared. Is there a reason my system plays mono when both preouts are plugged in. Does this have something to do with that the 2 pre's are for biamping?

Where was the 'Y' adaptor located? Did you use the Y connector to combine Right and Left preamp outputs to feed a single cable to the sub? If that's the case, you have shorted the R & L preamp outputs which forced the preamp in to mono mode -- you lucky it didn't cause any damage.

The majority of subs have Left & Right RCA inputs. In that case run two cables from the preamps L&R outputs to the sub. If your sub has only a single "LFE" RCA input, then as E-Stat suggests you can connect just one preamp output to the sub. However results might not be satisfactory if the bass in for a particular recording isn't about equal for both channels.

[E-Stat]

However results might not be satisfactory if the bass in for a particular recording isn't about equal for both channels.
In which case, a single sub would not be ideal either. Bass loses stereo content around the same frequency it becomes non-directional. I use dual subs in my HT system.

rw