When watching a DVD movie, do any of you have a problem with dialogue vs sound effects and music? If I turn up my system volume so the dialogue is clear, then when music, explosions, or some other effect appears, it's VERY loud. I turn up my center channel to help bring up the dialogue, but it doesn't seem to help much (I turn my subwoofer down a bit with DVD as well, but that's fine). With VHS & satellite, the system doesn't pose the same problem. Is this common? Please help!

I think you are describing a similar problem I have with center channel dialogue. While I have a 950 it also occurred on my previous Denon AVR3300.

In a nutshell on DD5.1 and DTS the main (and perhaps, surround) channels are feeding a little too much ambient signal into the center channel. This makes dialog more difficult to comprehend. Whenever the problem is bothersome I hit a button on my remote and switch the sound to PLII-M using alternate analog cables. My HDTV, digital cable box, and DVD have all their outputs hooked up to my 950, digital and analog.

I believe that what you are experiencing is the incredible dynamic range of DD and DTS soundtracks. You might find the following thread at HTF about the topic informative.

Have you tried "Night" mode (only available with DD)? I have had some success in these situations by enabling the highest "Night" mode compression and turning the volume up (which then can be higher than usual).

-Steve

Garrett, Ellen, & sfw:

Thank you for the quick replies. The HTF thread offers a ton of info (which I'll read further), and the "night mode" idea has crossed my mind, but I haven't tried it yet (but I will now).

Thanks folks - I'll keep you posted.

MD

There is another issue, besides dynamic range, going on here. (If this is mentioned in the HTF thread I apologize as I didn't read it all the way through.)

Most center channel speakers that I've seen are in the MTM design, layed on its side. The problem there is that the critical voice ranges get cancelled out by the two midrange/woofers in certain listening positions due to the sound being out of phase. In the "sweet spot" you will be OK as the two drivers reinforce each other. But other places they can cancel, called the lobing effect. This is especially true off-axis. So while the dialogue gets cancelled out, you have the left/right speakers going full blast, thus drowning the sound.

Why this design became the standard for center channels is beyond me. My center is

----t----
w-------w
----m----

so the midrange for vocals is a single point source. You don't really depend on the center for the low frequencies so if the woofers cancel it is not as apparent. My center is a DIY from Audax available as a kit or scratchbuild. It is also BIG.

Better than the usual center, if not using something like mine, is just a two way standing upright. Unfortunately, this is not the most appealing visually.

[This message has been edited by zacster (edited July 29, 2003).]

Zacster,

Interesting.

I recently replaced my run-of-the-mill centre speaker with two Koss CM1020s (to match my front mains - which I'll get to in a minute.

The 1020s are threeways - with a tweeter / mid / woofer. Each one is 33" high and I place them on their sides, top to top, to give a 66" array. Since they weigh 60 lbs. each, I made a steel frame that hangs from the ceiling and places them directly above my rear projection widescreen HD monitor. This puts their accoustic centre smack dab at the horizontal centre of the screen.

I run them full range, equalized flat down to 30Hz and up to 15kHz, both driven with a 200 W/ch amp, with 3dB of dynamic headroom. (Actual amp power is probably a higher amount than that since the speakers have a nominal impedance of 6 Ohms - and I've had the amp bench tested to 251 Watts continuous.)

After running this set-up for three months now, I can tell you that I hear no lobing effects - no peak or null spots throughout any of my listening area. These speakers could be deemed fairly efficient (95 dB SPL) and they can easily hit peaks of 120 dB. With them I've never had better, more clear, or more dynamic centre channel sound. I'm also sold on having full-range capable speakers in the centre. It's very noticeable to me.

As to the front mains, they are Koss CM 1030s - big brother to the 1020s. Given my success at pairing up the 1020s, I just recently acquired another pair of 1030s and have stacked them, top to top as well, to make a 6.5' high column - which literally goes from floor to ceiling in my low-ceilinged main theatre (with 1/8" to spare - with the base removed from the top one!). This puts the acoustic centre at the vertical mid-point of the front wall - which happens to line up pretty well with the vertical centre of my monitor's screen. It also means that while the bottom speaker's woofer remains "coupled" to the floor, the top one gets coupled to the ceiling. In this mode I likewise cannot hear nor detect anny nulls or peaks in my listening area.

I guess my point is that while I don't disagree with you at all about the possibility of lobing effects (I've certainly read and heard about it before), in practice you can have situations where it's not a factor - and where (at least to my ears) you can have some absolutely terrific sound.

Regards.

Jeff Mackwood

Just to interject my experiences, I find the center to be a problem with a lot of sources. My system is calibrated so that I can do mixes here and deliver them to a dubbing stage with no level surprises, and this is always no problem. Playing mixes from a dubbing stage here sound like they did when mixed, including the center. With DVDs and satellite, the center is all over the place, with differences between the matrixed processes and discrete 5.1 etc. I don't know the source of the problem, but I know it ain't in my system. I just live with it.

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[This message has been edited by Wayne Charlton (edited July 30, 2003).]

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what do you all think of using the phantom mode and no center channel??

Thanks Wayne.

While I had heard of D'Appolito before, I must confess that I did not specifically connect him with what I am doing.

I must also confess that while the success with the 1020s is what pushed me to stack the 1030s, and while I had thought of trying something like it for at least a couple of years, it was a recent ad by RBH Sound showing their modular stackable T Series of speakers that was the final push I needed. But then again, maybe it was the brunette in the ad as well! (And is that a grill cloth dress she's wearing?)

Regards.

Jeff Mackwood

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Wayne:

I am afraid I have to disagree with a portion of your last post. While it may be true generally, I know that it was not true in my particular case.

I ran my home theater system for over a decade using phantom mode and no center channel speaker. I started on a Yamaha in the days of Dolby Prologic and a 1050 for DD 5.1. I attribute this to the superior imaging and sound stage that my old Dahlquist DQ-10's provided. I never had problems being able to isolate the dialog. Almost without regard to seating position, I was still able to point to the speaker. This included mono sound sources like newscasts. My sense is that others with excellent imaging speakers could also achieve the same result.

I would like to point out that when I switched to NHT speakers, I purchased a matching NHT center that pretty much conforms to your recommendations except that I have the center setup horizontally. What I have noticed is an increase in the dynamics and sound intensity by switching but this could easily be a function of the efficiency difference between the DQ-10's and the NHTs and the additional amplification the center is now getting. FWIW I have not noted the lobing but then I wasn't doing critical listening in an off center position. I will try to see if I notice it.

I had a session with Gladiator and Zorro in DD, and used the Night Mode as suggested by "sfw". It worked very well - particularly Gladiator! Surround was still excellent but the levels were not as extreme. I could hear ALL the dialogue, yet the effects were still "thunderous" but just not as loud. I have to say, this worked great for me. I don't think I lost any surround quality. I'll keep working with this. Try it.