Dan F

The 4.2 is only available in the US from the website. You can buy two sets of 2.1's, if you would like from Kebecson's; however this would be much more expensive. I'd stay with the 4.1 if I were you. -djf

You could try making a mock corner for the sub by putting two 4 x 4 sheets of plywood (or as big as you can make it).

quote: Originally posted by zmatrix: ...During the setup, I played test signals for all the speaker and they all sound out fine. But when I actually play the movie, either no sound or very little sound comes from the rear channels. I have my DVD player set up for Dolby 5.1 play. Any help you guys can give is much appreciated! It sounds like you've got it hooked up right. I take it these are modern movies with 5.1 sound tracks (some older movies would have only stereo or mono tracks). Some DVD's confirm 5.1 digital when in fact only a stereo signal is being delivered. Still others have virtually no surround information despite delivering a 5.1 signal. What DVD player are we talking about? Maybe someone here has experience with the particular player...

1. Double-backed foam tape 2. Velcro -djf

Some kind of grounding problem, sounds like. Are speakers and computer plugged into the same outlet? Does the buzz occur when the speakers are unplugged from the soundcard? -djf

It's true that it can be on any of the four sats, whichever is more convenient. Also, it's possible to remove the control preamp from the speaker, and mount it to your monitor or under the desktop.

You could hook them up to the tape out jacks using the cables suggested by Paragon; however you would not be able to control volume with the Onkyo remote. Looks like it's not a particularly good match. -djf

You would hook the green plug into the "main/front" output on the back of the XP; and the purple into the "surround" output. You will want to set the software for four speaker (4.0) application. -djf

Cabbage, are you back on yet? If not, one thing to try is to unplug the system, and plug it back in. ("Re-booting") (Sheesh, I'm starting to sound like an IT guy, now!)

Try moving the control sat a few inches, and see if it changes the sound of the buzz.

Does the receiver have either a preamp out or a line out?

Chances are your v.2-400 is one of the first 12,000 or so which had a higher gain than the later ones. The gain was reduced on later units of this model, because a small percentage of people found the high frequency noise to be objectionable. Both systems have the same power abvailable and the same maximum output. It does take a higher drive signal to get there, which should not be a problem unless you have a particularly low output sound card. As for the differences at "same" listening levels, it's true that the v.2-400 would have lower midrange output, which has the effect of enhancing treble and bass. If you are looking for the same relative tone balance as the v.2-400, then a 2-3 click boost in software treble and bass controls might do that. Hope this is helpful. -djf

You'll need to move the sub to a more favorable spot in the room. If you can get it against a wall, that's next best to a corner. Then, you will likely need to move it left or right a couple of feet to find the best spot. If all that fails, perhaps your whole rig can be moved to another wall? -djf

Cabbage; Glad we got it sorted out....Enjoy!

quote: Originally posted by SomeGuy15: I know little about Class D amplifier designs but even if power is created in proportional to the signal, your test impedences are extremely low. Can the Promedia's power supply handle 25 amps to amplifier? But my main question is can the Promedia power-supply and amplifier sustain 400 watts to the Promedia sats and sub for 30-60 seconds? What are the long-term continuous power ratings into 8 ohms? Again, the amplifier is rated separately from the speakers, (mostly because it is derived from the home theater side of the business). Thus, the resistance we use to test the amplifier is not necessarily the same as the speaker impedence. Since there is no standard "power test speaker"; it is necessary to specify a test resistor. We use the lowest specified resistance because, quite simply, that's what the amp is capable of driving. Only for the case of the speakers matching these impedences at some frequency or set of frequencies will you be able to "see" 400 Watts delivered simultaneously to the speakers (for 30-60 seconds). 25 amps? I've never done the math, but if that's what it works out to, then yes. I don't know what the rating at 8 ohms would be. Since it is a voltage limited system, you could estimate about 200 Watts; and this would be long term continuous. Hope this helps. -djf

quote: Originally posted by DwK: ...Will it hurt to have other speakers hooked up? Like I have 2 Fishers hooked up to my front channel They are Impedance of 8 ohms Imput power of MAX 100 watts. On the rear I have 2 fisher surround 8 ohms Imput max of 60 watts. ... There's no risk in using higher impedence speakers on these amplifiers. But because the amplifiers are limited in bandwidth, you may not get much low frequency output out of your Fishers. This itself is not a problem, because the subwoofer takes over. If the Fishers and the sub match up pretty well at the crossover frequency, it will work out okay. Chances are if it sounds good to you, then the match is reasonably good.

I've seen one example where the subwoofer caused rattling of a PC card enough that a capacitor value changed with the program material; leading to the feedback. This is called circuit "microphonics". This would likely only occur if the sub and the PC were right next to each other on a wood floor. Another possibility is there is something like this going on in the sub itself. This would require Klipsch Customer Service to take a look and resolve. -djf

You're absolutely right about potential instability caused by severely reactive loads. Some speaker designers attempt to cure speaker phase problems by diving the capacitive reactance; and I think this is where most of the problems occur. Also some electrostatics have a hard reactance to them. The amplifier is in fact tested at full output for a minimum of 30 seconds. I don't know the actual value of the filter caps, but since this is a Class D supply, it wouldn't compare to conventional power supplies (where it is important). The filter caps are not depleted because the power is created in proportion to the signal, and on demand; as opposed to a storage type supply. -djf

quote: Originally posted by SomeGuy15: ...Finally regarding the term "short term continuous". What does this actually mean? Yamaha regards the short term power rating as the PMPO rating. Using simple electronics, if the sub amp was driven at maximum specs (160 watts into 2 ohms), it'll draw almost 9 amps. Can it actually be sustained for more than a couple of milliseconds? Wouldn't the amplifier IC overheat? ... This doesn't even include power to the satellites? How much power can the amplifier supply to the Promedia sub and sats continously for say 30 minutes without extra cooling or a power supply upgrade? Peak Music Power Output does refer to milliseconds of signal duration and doesn't really present a useable figure for audio signal reproduction. Short term continuous refers to 30 to 60 seconds worth of full power, after which some heating will take place. Most program material, as you probably know averages 10 dB below peak values, so the amplifier is running relatively cool. Then, a relatively long duration crescendo would test the upper limits for this short but meaningful time. This is the pattern that music and other program materials follow, and so the amplifier was tailored for optimum performance under those conditions. A 30 minute rating would be somewhat less, but probably in the 250-300 Watt range. -djf

quote: Originally posted by SomeGuy15: ...was a purely resistive load used to test the amplifier or complex impedences (ie. speakers). As you know a purely resistive load is much easier to drive than a speaker's complex impedence... We use a power resistor which can dissipate the high power indefinitely, which is a much more stable load than a loudspeaker. A speaker voice coil can rise in temperature (and therefore in impedence) over time. Speakers do have a complex impedence, but a resistor equal to a minimum impedence value is a tougher load.

quote: Originally posted by Dr Sevrin: So how does this relate to the real world? Wouldn't loads of 8 ohm (for the sub) and 4*6 ohm (for the sats) give a more realistic measurement, or am I missing something? Also, is there any truth to the rumor that the 4.1 sub is different from the v.2-400 sub? (edited 04-30-2001).] We rated this amplifier so that it relates more to separate/ hi-fi amplifiers. As you may know, home hi-fi amps are often rated with different standard loads. The impedence of a loudspeaker is a variable with frequency, so you have to pick a resistive value to go with. We picked these values because they were reasonable test cases for the amp. The 4.1 amp is electrically identical tio the v.2-400; but has a different layout to facilitate manufacturing. -djf

When adding the rear speaker input, it does double the amount of bass. The speaker control takes the rear channel information and mixes it into the sub just as it does the front signal. When there is program material in the rear, the low frequency portion of it is reproduced by the sub. -djf

Good questions, Mark. In the case of the subwoofer rating, the 1.8 ohm reference impedence is derived from the minimum impedence specification (2 ohms -10%)for two four-ohm subwoofer drivers hooked in parallel. The reference impedence of the amplifier is in fact different from the impedence typically measured on the speakers. The speaker impedence is typically dialed in by the system designer based on a number of factors including several independent of the amplifier (such as optimum level and headroom matching of subs and sats). In the case of the ProMedia systems, the satellite speakers themselves would probably get an independent impedence rating of around 6 ohms. -djf

Some program material contains passages with substantial extreme low frequency output (below about 30 Hz) which, being below the useable limit of the system will result in some distortion and port "chuffing". If this is what you are hearing, then it's fairly typical, and one of the tradeoffs in making the system as strong as it is for most program material. This extreme limit of program material, on average, is not very common (except in ultimate bass test signals!), so hopefully you wouldn't run into it every day. -djf

This sounds like feedback. Do you have a microphone hooked up? If so, does the problem exist when the mic. level is set to "min"? It could also be something vibrating in or near the sound card leading to an electrical feedback. Does this still happen when all your controls are set to flat?