Speaker output when there shouldn't be? (1 Viewer)

[Jose G]

Here's the deal: I gave a friend the S&V home tune up disk to set up his system. He says there was bass coming from the left main speaker during the sub level set up. I said, "Yes, when the system compares the level to that speaker." He says, "No, even when the sub level is playing there is bass coming from the left front." What gives? Is this a speaker issue or a receiver issue? I told him to switch speakers (mains) and see if the problem continues- assuming that if it does it's a receiver issue and if it doesn't it's a speaker issue. Any other ideas while I wait for his reply?

 

[JeremyFr]

I would say its a reciever issue because a speaker will not just spontaneously make noise it has to get some type of electrical signal from the reciever. This is a very odd problem, it could be some part of output stage I.E. transistors or something that may be failing in the reciever I would take it into a shop and have it checked to see if there is an internal problem on the amplifier of the reciever or possibly the decoding section.

 

[Jose G]

That's what I think too. I'm waiting for him to call back and let me know what he finds with the speaker change. Thanks for the input.

 

[Justin Ward]

Is the subwoofer powered? Or is the sub simply between the receiver and main speakers with a built in crossover? If the latter, maybe there is an error in the subs crossover/wiring area. Just a guess though.

 

[Jeff-Watson]

Justin took the words out of my mouth. If the speakers are in the same run as the sub as opposed to the sub being fed the lfe signal via the sub out on the receiver that very well may be a crossover problem.

 

[Jose G]

That also crossed my mind, but I know the sub is powered and fed the lfe from the receiver, so I think it's his unit. Thanks though.

 

[Geoff L]

Is he positive that he has it, the receiver, in DD and NOT in a DSP or DPL.

Also is the DVD player outputing Bitstream and not PCM?

Check all speaker wiring just to be safe and eliminate another possible problem, though this shouldn't effect this particular test.....

Make sure to cover all the basics first!

Regards
Geoff

 

[Burke Strickland]

Although I am not familiar with the S&V disc, on the Avia disc, when they are identifying each channel, when they get to LFE, the voice announcing the LFE channel is coming from the front left speaker in addition to the low level "rumble" coming from the subwoofer. That is the way it is supposed to work (on the Avia disc), since not every system actually has a sub and they want you to know the test is occurring in any case. This is also different from the "level comparison" or "phase test" output to both the front left and sub at the same time.

You know the S&V disc and its tests -- if the S&V disc has a test like I described for the Avia disc, and if what your friend is hearing is something like the Avia channel ID sequence test, of course there is no need to redo his entire wiring scheme. :>) But if it is truly a case of sound being generated when and where it shouldn't be, then hopefully checking out the possible configuration issues others have suggested will isolate and correct the cause.

Good luck --

 

[Jose G]

It's not the speakers. They do the same thing when switched. The dvd player is set to dolby, not pcm. All connections are right. The left main and the sub go back and forth during the sub balance test. It's just that the left main will also broduce some sound when the sub is playing, which doesn't make sense to me. Sounds like his receiver, but he's never had a problem with the receiver before he says. I'm wondering if the S&V disk just does this during this test. Can't imagine it does, though. Oh well, thanks for all your thoughts.

 

[Mitch Stevens]

I've been away for a couple of weeks now, and I'm so sorry, I could not check on this sooner. I hope I'm not too late in reply.

I have a Philips receiver, and I get the exact same thing when I am calibrating my speakers with Video Essentials. It's absolutely nothing to be worried about. I have my main speakers set to "large" because they are, (and also, because my receiver doesn't have an option to change them to small) and when Video Essentials gets to the sub, the mains will also play extremely loud deep bass (I have two 15" woofers in my mains).

Anyway, what I do, is I calibrate all my speakers, and then disconnect the mains as soon as the sub test comes on. Then I plug the mains back in. I would tell you to tell him to do the same, OR he may try setting his speakers to "small" first (if he can).

Anyway, I have heard from about 10 people that they also have to do the same thing (switch to small) or else their mains will play the bass test.

 

[Jose G]

Mmmm. I asked him and he says the mains are set to small and it still happens. This is good to know though, Mitch. So it could be the test disk after all. I guess they didn't isolate the individual speaker tracks well enough when mixing the sound on this dvd. It does seem odd though that both S&V and V/E, in the business of audio testing, have this happening on their disks. Makes me think it's supposed to happen. Mmmm. Something doesn't make sense here. I'm still thinking it's the receiver in his case. I'm going to get the disk back from him and see what it does on my unit. Maybe I didn't notice it before, but I doubt it.

 

[Mitch Stevens]

Jose, you probably wouldn't notice it, unless you have your mains speakers set to "large". Hmm...it seems strange that it's still happening to him, even though his are set to small. I've heard from the people that I know, that setting them to small seems to correct the problem.

Like I said, my receiver does not let me set my mains to small unless I set my center to large, and I wouldn't want to do that, being as though my center is indeed a very small speaker.

 

[ChrisWiggles]

I am pretty sure that a receiver HAS to have the small setting option to be licensed from Dolby, so that comment confuses me. Anyway, this makes complete sense if VE is outputting the Bass via a main channel, instead of the LFE. I am not familiar with VE, but I know Avia runs the sub tests via a main channel, so if you set your speakers to big the bass should come through the speakers. If the bass is coming from both, most likely there is bass in both parts. You probably should have your speakers set to small anyway. If there is a track that comes from only the LFE, than no, there should not be any bass coming from the mains. If the mains are set to large, and sub on, any bass that is from a main channel, ALL that bass should come from the speaker and not the subwoofer.