Q&A # 153 - December 23, 1999

Staff

Q I'm interested in purchasing a new Dolby Digital (Yamaha RX-V2095) A/V receiver. This product has DACs set at 20 bit sampling. As DVD audio will utilize 24 bit/96 kHz sampling, will the loss of 4 bits of information in the digital bitstream be detectable? Also would there be any difference in sound quality with or without using DSP effects?

A The first DVD Audio players will only have 5.1 analog outputs which will be connected to your receiver through the 5.1 analog inputs, so the 20 bit DACs in the receiver are irrelevant. Using 5.1 inputs on receivers bypasses all DSP mode capability. Only the volume control and perhaps the tone controls will be active.

Q I am considering purchasing the DVDO iScan plus and the Toshiba SD-5109 progressive scan DVD player. Question: 1) Does the Toshiba progressive scan work with S -Video or only with color stream? 2) Is there any benefit in having the Toshiba 5109 DVD player and the iScan plus working together to improve picture quality? I am displaying movies with my DLP 800 x 600 Kodak projector (it has a 15 pin RGB S-Video & connector).

A The 5109 only outputs a component progressive signal. The DVDO iScan Plus can output component or RGB de-interlaced signals. The Toshiba has a slight advantage because it's all done in the digital domain, and its internal de-interlacer can read the Inverse-Telecince flags (3:2 pulldown) The iScan uses complex algorithms to determine how to re-assemble the frames. With the iScan, you can de-interlace other sources like VHS, LD, DSS, and Video Game consoles. With your DLP, you will need a transcoder ($800) to convert the component to RGB on the 5109. You can directly connect the iScan. For an all around great product, you can't go wrong with the iScan. But for pure DVD, the 5109 does offer a superior picture over the iScan. Colors are more saturated and slightly cleaner. Even video-based DVDs look good on the 5109.

Q I'm moving into my new house next week and think that your advice is indespensable. I've decided to build my home-theater system very gradually over the next three years. First, I'm going to put together audio components that can eventually be integrated into a home-theater system good enough for quality two-channel audio listening. I'll probably purchase in the following order:  DVD Player, DIY Floor-standing speakers, Yamaha RX-V2095, 16:9 60" TV, DIY Surrounds, DIY Center channel speaker, DIY subwoofer, CD Player, 5-Channel Power Amp, Tube Preamp. The tube preamp is going to compromise either the theater or the two-channel application, depending on how you hook it up. Either the RX-V2095 will go through the preamp, or the preamp will go through the 2095. Both ways line up extra electronics where they're not needed, though I suppose you could run the CD player's analog inputs into the preamp and switch cables at the amplifier anytime you wanted a change in sonic character. So here is my question. Where speakers are concerned, I want to build from "scratch" --- no kits. I have access to high quality low-resonant hardwood and know a little bit about how to get a high-gloss finish to keep my significant other happy. I haven't seen any high-end DIY floor-standers in Secrets yet. Can you recommend where I can find such a project? 

A Even if you didn't buy all the parts at one time, that would be a kit, wouldn't it? The only thing that you'd be selecting yourself would be the building materials. While that's certainly a fine route to go, is that what you want? Check out www.madisound.com for speaker building ideas. They offer not only kits, but a vast variety of drivers, computer assisted crossover design, and a helpful staff to boot. Hot drivers to look at include the NHT 1259 woofers, as well as mids and tweets from Audax, Dynaudio, Morel, Vifa, Scan Speak, etc. If you'd like us to do a DIY floor-standing speaker, Ralph Calabria's your man to set things up.

Q I have a set of SAT6 Cerwin-Vega speakers (2 sats plus a sub), and when I bought my new JVC 884 amplifier, I had to verify the impedance of the speakers and sub, because the JVC allows me to choose between 8 or 4 ohms. But the manual says they are all 4 ohms, and on the back of the speakers and under the sub it says 8 ohms. Who is right ? I can't find any info on the web. Also, there is no sensible difference when I try them in 4 or 8 ohms.

A They are probably 8 Ohms if that is what it says on the back of the speakers. Selecting 4 Ohms on your receiver just limits the maximum voltage that is on the rails, so you won't hear any specific differences in tonality. You just can't turn it up too loud when it is set at 4 Ohms. The receiver keeps you from doing that.

Q I plan on buying a Paradigm Monitor 9, CC-350, ADP-350, and was concerned about burn-in time. I own a Sony 9000es, Rotel 985THX amp, SD-3109 DVD player, and was wanting to know a good procedure for proper burn time.

A What I do is put on a CD that has lots of dynamics, like a good symphonic piece, and turn it up to mid-volume. I set it on continuous play, so the CD will repeat over and over, and then I go about my other work. I leave it on all day long. Depending on the speaker, the burn-in may take a week or so.

Q I have a Pioneer Elite VSX-05 receiver, and I am using Jamo Classic 8s in the front and Jamo 28s as my surround speakers. The volume of the surround speakers was set to peak (10) in the receiver. However, I still not feel the sound coming out of the surround speakers is not loud enough in both music and movies (DD). I am using Monster Cables, so it shouldn't be a cable problem. If I put the Jamo 28s in the front, they fire up  loudly. What is the problem? Do I need a pair of real surround speakers instead of the Jamo 28?

A Your problem is the rear channel amplifiers in your receiver. They are not powerful enough to drive your speakers. Assuming you have rear channel pre-out jacks, you can get a two-channel power amplifier to drive the rear channels.

Q I have a Pioneer PDM-730 CD Player that is approximately 12 years old. It has an optical output and 2-channel analog output, but no digital coax output. I just bought a Yamaha RX-V595 which permits me to connect the CD player using the optical input of the DVD/LD. I was told by a dealer selling Onkyo equipment that the Yamaha dealer steered me wrong (which is why I should take the Yamaha back and buy the Onkyo from him) in recommending I use the optical input. He said they use coax for all audio because the DACs in CD players are always better than those in receivers, especially low-end receivers like the RX-V595. So he identifies the issue as at what point the DAC takes place. He told me if I could switch back and forth between the two, I could hear a significant difference. I have some Monster Cables between the CD and analog inputs for the DVD/LD of the receiver, and these are required to record to tape. The RX-V595 allows me to switch between analog and digital electronically instantly, a nice feature. I've switched between them numerous times and can't hear a difference. I listen to everything from Jimi Hendrix to Bach, and could care less about home theater. I have Phase Tech PC-100 towers and a Klipch KSW-12 turned down very low, 50 Hz and volume 4 (from a recommendation on a Q&A I found on your site, thank you.) I have some questions regarding this. Is the DAC in my 12 year old CD player really better than that of a new receiver? Should I be able to hear a difference? Is one necessarily better than the other? Thanks a lot for this site. It is really great to get opinions of substance from you guys instead of the practically useless opinions of most of the sites I've searched.

A The DAC in your old player might be better than the one in your new receiver, but it is not necessarily so. Specs are one thing. What is more important is what you can actually hear, not what you are supposed to hear. The optical digital connection is fine. Your other store just wants to sell you an Onkyo. Onkyo is good stuff too, but I see no need to take the Yamaha back and get something else. You have done the right test, switching back and forth between inputs. You heard no difference, so it is a done deal. Keep the Yamaha.

Q I have a speaker for the rear that is stated to have a frequency response of 50 Hz - 26 kHz, and an overall frequency response of 40 Hz - 26 kHz. The speaker's manual says that when playing DD, to set the speaker to SMALL. Based on the speaker's frequency response, when playing DD or DTS (as it has a overall frequency of 40 Hz - 26 kHz), is it OK to set it to LARGE?

A In my opinion, setting the speaker to "Small" with a receiver's bass management, is only appropriate when you have very small speakers that only respond down to about 80 Hz. The reason is that the bass management feature on receivers usually has a crossover at 80 Hz, and sometimes higher. To me, this is too high because low frequencies are directional above about 50 Hz, and you end up with too much of the bass coming from the wrong place in your listening room (wherever the subwoofer is sitting). So, I would suggest, in your case, setting the speakers to "Large". When receiver manufacturers give us bass management that allows adjusting the crossover frequency to between 40 Hz and 100 Hz, with lots of choices in that range, the "Small" vs. "Large" settings will be much more useful.

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