Q&A # 213 - January 16, 2001

Staff

Q I have a Denon AVR-2801 receiver. My front and rear speakers are rated at 8 ohms. My center is rated at 6 ohms.  I'm not sure what setting to put the receiver on - 4 or 8 ohms.

A In this case, use the 8 Ohm setting. Even if your center was 4 Ohms, I would suggest using the 8 Ohm position, and then just using the volume control to turn the center down a bit since it would draw more power at the default setting. However, if you had two or more speakers that were 4 Ohms, then you should use the 4 Ohm setting. If they were all 6 Ohms, you could try both settings and see which worked better.

Q I am thinking of selling my mission 770 speakers for some Mission 753s. I find that the 770s are fantastic speakers but not as good as the 753s.  However I feel the 753s lack some bass. Should I change my cables /  interconnects or should I possibly buy the Mission 753F?

A The 770 appears to be replaced by the 771. The 753 no longer exists, at least on Mission's website (http://www.mission.co.uk/main.htm) . So, you must be talking about some used products or closeouts. Anyway, if you like the overall sound of the 753s, but are missing the deep bass, simply get a nice subwoofer to handle the lowest octave. The Missions tend to be tall and thin, so something like a Sunfire 10" sub or Velodyne HGS-10 would be perfect.

Q Greetings. I just bought a pair of Heybrook HB1 2nd-hand speakers. But to my disgust, when I opened up the speakers for cleaning, the wool inside the speakers was really dirty - there were some roach eggs, dust, and some sort of white patch stuff. I was thinking of replacing them, but as a beginner, I'm not sure what types of material would be suitable. Can I use cotton wool too?

A Wool, being from an animal, is subject to insect infestation. Rather than using wool or cotton as replacement, use the polyester pillow stuffing that you can find at bedding stores and also at craft shops. Use about the same amount, by volume, that was in the speakers to begin with. By the way, the white patches are bundles of spider eggs.

Q I have a Denon AV Amplifier (AVC-A1) that really upsets me. Whenever I play a movie or music, the sound from the speakers appears and disappears. It happens on different channels once in awhile. Sound appears again when I raise the volume suddenly, but then disappears again. What's wrong with my amp?

A This sounds like a problem in the volume control circuitry. Time to take it to the repair station, and hopefully, it is still in warranty.

Q I have a regular stereo Hi-Fi setup (Marantz PM-17 with B&W CDM7SE). I just purchased an AV receiver (Pioneer VSX-908RDS). How should  I connect it without affecting my existing setup? Is the following plan OK: Connect rear and center to the Pioneer directly and then connect the Left and Right pre-out of the Pioneer to the Aux input  of the Marantz. The Marantz manual says to connect a surround processor to the Tape 1 IN jacks. Or should I use the pre-out of the Marantz and go to the Pioneer (which INPUT)?

A For minimum change, use your first plan, i.e., front pre-outs of the Pioneer to the Aux input on the Marantz. If you ran the pre-outs of the Marantz to the Pioneer, this would alter the signal path of your CD audio listening considerably.

Q What are proper settings for my center channel, to get more volume from dialogue while watching movies in surround sound. (center channel bass/treble/+/-)?

A One thing you would not want to do is boost the bass in the center channel. The reason for this is that when the speaker is sitting on top of a TV, there is some emphasis of the bass in the 120 Hz region, and this can make voices sound a bit chesty. Turning the bass down would affect much more than the 120 Hz area, so that is not a good idea either. Many receivers have an option in the setup menu for altering the center channel voicing to reflect things that are done to the sound track in anticipation of the movie being shown in a commercial theater. So, experiment with those, along with just a simple increase in the volume control for the center channel.

Q I recently purchased a Parasound 1500a to go along with my Denon 4800. I  now use this Parasound to drive my front left and right speakers. Is there now more power going to my center and two surround speakers, or was I  mistaken in thinking that having an amp for two channels would make a  difference? Also, do I need to get a separate amp for my center channel because it might be too weak compared to my front two speakers?

A Although you won't have more power to the center and rear, the power that does go there will be cleaner when playing loud passages, because the power supply in your receiver is just supplying those three channels now. So, it will be less likely to sound harsh. Because sound to the rear is not used all that often, and is usually not very intense, it is likely you will be just fine with the existing receiver amplifier driving the center.

Q I'm happy with the audio performance of my home theater for movies (its primary use), but I'm having a problem with music reproduction. In addition to some classic and modern rock, I listen to a lot of orchestral music (movie scores, mostly). In the opening and end titles to the Star Wars score (1997 2 CD re-release), the horns spit. Now, I know that in real life horns do spit a bit, but this is really harsh, and masks some of the strings in the background. Is this just the way things are? A recording thing? A problem with my choice of equipment? Or a possible problem with my equipment itself (broken tweeters)?  My speakers are Carver 5.2s, my processor/amp is a Yamaha DSP-A1, cables are Monster OMC, and a Panasonic A310 DVD player is spinning the CD.

A Horns are typically very efficient, and the DSP-A1 has lots of power, so I don't think that is the problem. My guess is that your DVD player is not doing a very good job of playing CDs. This is a common difficulty. However, if the Star Wars CD comes from the original movie sound track, remember, that was mastered in the late 1970s, so it could just be a problem with old analog tapes. I would suggest borrowing a dedicated CD player and see if it still occurs. You could also take your DVD player into a store and ask to connect it to a system there, and play your CDs on it to see if the problem happens with other amps and speakers.

� Copyright 2001 Secrets of Home Theater & High Fidelity
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