Dan F
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Posts posted by Dan F
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Thanks, Mark.
>>Exactly what does the 400 Watts RMS rating mean. I.e. is it one channel driven, two channels driven, all channels driven? <<
First, a point of clarification. The term "RMS Watts" has no engineering meaning; however it is usually interpreted to mean Average Watts based on RMS voltage measurements into a reference impedence. As a practical matter, the measurements are usually done into a standard resistor.
Klipsch's rating is based on this method with the following conditions:
- The system is hooked up to 120 V.
- All channels are driven simultaneously; the satellites into 3.6 ohm loads; and the sub into 1.8 ohms.
- the satellite channels get 1 kHz input signal, the sub channel gets 100 Hz.
- the output voltage on each channel is recorded at the onset of clipping.
- The resulting calculation for each channel is added together to give the final result.
If each channel is driven separately, you are likely to see voltages that allow up to 75 Watts at each satellite.
Note that these are RMS values,and for sine waves, RMS is about 1/2 of peak power ratings. If the amplifier were rated for peak values, it would be about 800 Watts.
The "onset of clipping" is around 1% THD. Not a lot more power is observed at higher distortion levels.
A few additional clarifications:
There are some speaker protection circuits in the system, which would make independent measurements a little tricky; however sine-pulse testing would confirm these levels.
Some audio gear is rated at long-term continuous as opposed to short term continuous. This component is rated for short term, which relates more directly to how audio gear is actually used (i.e., unless your program IS in fact 8 hours of sine waves, the difference between the two methods is not significant, audio-wise). The difference in hardware, between a system that would be long-term continuous (and this one) is about $50 worth of aluminum.
Since this is a switching power supply, the size of the power supply has no relation to the power output, as it might in conventional audio gear. We're just going to have to get used to our audio equipment getting lighter weight, and higher performance...
The combination of efficient power supply and optimum power design is what allows a 400 Watt amplifier in such a small space in the first place.
>>What's the recommended placement in a 12 x 12 room to get performance that is as neutral possible<<
Corner placement almost always reveals the nominal character of the subwoofer. This is where the room effects are minimal, and the gain of the three reflecting surfaces is as uniform as possible. That said, if I were trying to knock down a 70 Hz bump in a square room, I would try to find a point along the diagonal that coincided with a null, to get the smoothest possible response. Could be two feet from the corner, could be five. It can be calculated, but I'm late for work <g>.
Mark, thanks for facilitating the dialog. I'll be happy to answer any followup questions you may have.
-djf
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quote:Originally posted by Hell:...definitely getting some bass out of it though on both tracks it's not tight, feels the sub drivers are "fluttering" on the low notes, perhaps that's normal considering the bass lines....
Well, it's a rare possibility (though it fits the symptoms) that one of the two subwoofer drivers is reversed polarity. This could be a woofer magnetized or wired in the wrong direction, or, more likely, a wire harness error.
This would cause the woofers to flap around a lot, and not produce much useful sound.
In any case, it's not something you should have to screw with any more. Send an e-mail to Amy referencing this thread, and she'll likely arrange a replacement system or sub.
-djf
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The new 4.1 has an internal speaker difference (crossover) that many believe is an improvement.
The CP-1 adds the headphone and MP3/Aux jacks. If the sound difference is the most important aspect to you, then get the 4.1's.
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quote:Originally posted by Hell:...I'm wondering if there's something wrong with the sub. ...
There must be something wrong with either the soundcard/setup, or possibly the speakers. What sound card do you have, and can you tell me the software version?
-djf
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quote:Originally posted by EADG:...All was fine for a few hours then I noticed the subwoofer was firing randomly. Boom boom..... boom..boom. It thumps away quit happilly regaurdless if I'm playing music or not.
Hmmm. Is there anything else used on the same circuit, like a sewing machine, refrigerator, or anything with a motor?
Does the system thump when it's hooked up to anything else, like a walkman?
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The problem I see with hooking them up directly is that the ProMedia sats were designed to work undistorted only with the ProMedia amp. If you want to experiment with it, and want to be sure you don't run the risk of damaging the speakers I would suggest you put a electrolytic capacitor (non-polar, 100 uF) in series with the speaker. This of course voids the warranty, but would work in a pinch.
Impedence-wise you shouldn't run into any problems with this approach.
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You summed it up pretty well yourself.
Yes, either system will put out room filling sound volume. Sometimes dorm furniture layout makes it tough to place rear speakers, but if you think you might use the system for 3D gaming or DVD playback, it's worth the extra effort to try and place the rearspeakers.
You might consider getting the 4.1 and either using or stowing away the rear channels for future use.
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How old are your speakers? If they are more than about 18 months old, you may be among the 1% or so of folks who experienced a noise problem with the release version.
If that's the case, you can order a CP-1 preamp which will add new features and improve the noise performance of your speakers.
If the speakers are relatively new, then something else is going on, and I suggest you contact Klipsch tech support.
-djf
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Klipsch ProMedia Customer Service # is
1-888-554-5665
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I would first try hooking it up to a walkman or something like that to listen and rule out the possibility that it is the soundcard.
-djf
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Lots of folks use the ProMedia speakers with their PS2's.
Check to make sure the adaptor you bought is a stereo RCA plug to stereo minijack adaptor. Note; this is not a splitter. Also, be sure any related hook up cables or extension cables are stereo format.
It's usually one of these things. Let us know if that doesn't sort it out.
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It depends on the question. The boostaroo may be helpful if someone wanted to use multiple headphones directly off a wimpy source. I'm interested in it myself because my laptop computer audio output is too low. This product might be just the thing for all sources that are designed to run off a battery. However, most powered products, like desktop computers, televisions, stereos, etc., have an adequate headphone out and wouldn't need the help.
The input of the ProMedia doesn't take much current, so it's not likely to load down any device to the point where it needs the boosting. The only applicability I can think of is if the user is using multiple headphones directly off a player, and also wants to feed the ProMedia. Then I can see a booster making a difference (but that's a pretty special case).
At the other end, the ProMedia headphone amp itself is pretty robust, and I'd be surprised if it didn't drive multiple headphones by itself; therefore not requiring supplemental boosting.
In summary, splitting a TV output is not likely to require additional boosting. And the Boostaroo seems on the surface like a neat product with a good applicability in portable audio.
-djf
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quote:
Originally posted by ForMatPrO1:I'm gonna buy my Klipsch Promedia 4.1 tomorrow!!! 230Volts version, I've been waiting 2months for this system to get here!!
Congrats. You're going to like them.
-djf
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quote:Originally posted by holmesjd:Can I run only two of the satellite spkrs with the sub just like the 2.1? TIA for any suggestions...jeff
Yes, you can either run just two of the four sats, or split the signal (using what they call a headphone splitter).
-djf
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quote:Originally posted by fatathaland:actually, it's the soundcard that came with my HP pavilion xt846it says this :Compatibility3-D Stereo, PCI, 16-bit SoundControllerAMC97 codec (on motherboard)LocationCrystal Sound ChipNoise CancellationYesLine OutYes3-D SpatializerYesWavetableYesTone ControlNo---------thats all i could find. come to think of it, i tried these on another PC that had a S Live card in it, and there was no hissing...at least not that i noticed. What would be a good, economical, entry level sound card that would eliminate this hiss? about how much would it cost me?
Creative makes a nice card for about 30 bucks. It's called the PCI 128. It's going to be better than the on-board card. You may have a little hassle with defeating the on-board card, though. Do you have the HP manual?
You could also look for stuff from Turtle Beach or pick up a closeout Aureal card in the spare parts bin.
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It's for headphones, which means it is probably 24 gauge. You need something a little more substantial. I would splice regular Radio Shack speaker cable onto the bare ends of the existing cable. That can be anything 18 gauge or heavier.
-djf
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Is there any other kind?
(sorry, couldn't resist
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The loose part could be a minor thing, or a major thing. It's best to determine what it is before going on.
You can unplug and carefully open the amplifier and locate the loose part. Then, give Amy a call, who can help determine whether the part is a necessary component of the amplifier, or something extraneous.
-djf
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If the speakers sound okay, they very likely survived intact. (and...let's be careful out there).
The rear channels are louder than the fronts with the knobs centered. In most installations, the front speakers are closer than the rears, and so this was the balance chosen. Obviously, you want to adjust the controls to the balance you prefer.
You can get a CP-1 preamp from the web site. Do a search on CP-1, and it should take you there.
-djf
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1. You'll get 6 meters of rear speaker wire. You can splice onto that if you need more.
2. You can drill through the steel stands that come with the speakers and mount the speakers upside down on the ceiling. This actually works pretty well. Remember to use good anchor type bolts, or screw one side into a joist.
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Actually, from what you are telling us, I would suspect the sound card. What kind of sound card is it?
These speakers often reveal problems with sound cards; problems that would have been masked with other multimedia speakers.
-djf
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quote:Originally posted by totalkaos:Since they are both the same speakers, one is being driven by almost less than half the power of the other. Doesn't under driving tend to cause harm to speakers?thanks
There is some truth to this rumor in the general case. With some marginally designed speakers, it is possible to blow a tweeter using an underpowered amplifier. This happens when the underpowered amp is overdriven. That sends high harmonic energy into the tweeter. If the tweeter has insufficient protection, or the amp is just very nasty, a tweeter can be overloaded.
Fortunately, the amps in the ProMedia line are well-matched to the speakers, so neither of these things happen.
Normally, an underpowered amp is not itself a problem. It only becomes a problem when overdriven (with extremely high distortion) into an underdesigned loudspeaker.
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rol1; We're restricted by a licensing agreement from disclosing the details of the amp. A long time ago we posted the basic preamp schematic, and that's probably all we can do for now. Maybe in a year or two we can do that for older speaker models.
Sorry, I know that's not all that helpful.
-djf
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No, it's just something getting locked up in the subwoofer circuit. It's the evil digital curse...Never thought you'd have to reboot your loudspeakers, didja?
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It is the same sat; different amp.
The CP-1 will not work in any way with the 4.2 system. The preamps are not interchangebale between the 2.1 and 4.1/CP-1; but are interchangeable among the v.2-400/4.1/CP-1.
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ProMedia 4.1 RMS Rating and Subwoofer Setup
in Personal Music Systems
Posted
No problem, Swerv. Thanks for highlighting the discussion. The more people know about audio, the better they enjoy their Klipsch speakers and the audio hobby in general. Glad to help.
-djf