rjon17469

For the hiss, examine the audio input wires to the control module, as well as the speaker wires themselves, and see if they run along any power wires. AC-carrying wires induce magnetic fields around them. If that magnetic field encounters another wire, such as your speaker wire, a current can be induced in it, at the frequency of the first wire (i.e. 60Hz) and at a volume depending on the level of interaction. To get rid of this, always run audio cables and power wires at 90 degree angles apart to each other, never parallel. I doubt you have a ground loop issue, as I would think it would be in both channels if that were the case. Failing that, I cannot say what might be the cause of your hiss. Double check the computer audio output with headphones to confirm it isn't the computer. In regard to the break-in period, every speaker needs to be broken in. Primarily, to the extent of my knowledge, the spider (folded suspension assembly behind the cone) comes out of the factory relatively stiff. As the speakers are used, the spider loosens up a bit and allows the speakers to play fully. My PM 2.1's definitely needed a break-in period to sound their best. Also, avoid blasting your speakers during this break-in period. A large number of speakers fail within the first month of ownership, in general, because they were not properly broken-in and pushed to and beyond their limits too soon. To break-in, I usually do ~20 hours of playing, starting at normal casual listening volume and moving up slowly, so by the end of the 20 hours they are loud, but not blasting.

I know this board is more commonly used for troubleshooting people's Klipsch speaker systems, but I felt compelled to share my experience to show the quality of the products Klipsch produces. I ordered my Klipsch ProMedia 2.1 system on June 17th, 2003, and received it on June 25th. That system is still sitting right in front of me, working just as well as the day I opened the box. However, there is more to the story. Over the past ~5 years, I have been anything but easy on these speakers. They have been used for countless parties and gatherings, on numerous occasions have been run to their limit for the sole purpose of annoying other people, and served as a test bed for my ever curious mind, including experimenting with making the satellites wireless as well as tests in heat generation. Besides blowing a few fuses, they never stopped playing. What is even more amazing is that I obtained a full 2.1 speaker system of high quality, which lasted through continual abuse, for under $200. Try finding a situation like that from another manufacturer. Just wanted to throw this story out there for people considering purchasing this system. It is well engineered, and very much worth the money.

You could do all that, although you'd be putting one of the RB-25's to rest! My recommendation: keep the RB-25's as mains, and get a RCX-4 for your center. It should match very well, give you better overall system performence, and save you some $$$, as I believe you can find RCX-4's for under $200. Reece

I have the PM 2.1, and I can say there was a noticeable improvement in sound quality during the first few months of using the system. As always, you results may vary :-) but I wouldn't be surprised if they do break in and sound better. Reece

How close is your subwoofer to your monitor? I don't believe the subwoofer is shielded at all, and has a high density magnetic field. Reece

And glue it.

One element of how much it sags is the mechanical damping factor, but the other part of it is the cone weight. The higher the cone weight, the lower the fs of the driver, and therefore the better sub driver it makes. To calculate the percent of sag, you can use this equation: 24,849 / (xmax * fs^2). Remember, there's no qms factor in there, which means the suspension stiffness is not directly related to the amount of sag (however it is related to the driver fs). If you do want to measure T/S parameters, here's a website I like which makes it pretty easy: http://www.bcae1.com/spboxad3.htm Reece

Also, multiple caps in parallel tend to have lower output resistance (and lower inductance if you're interested in that). Reece

---------------- On 7/15/2005 10:55:29 AM DrWho wrote: The original PM subs uses an EQ and I don't know the T/S parameters for these drivers so my design comes from modelling a similar driver ---------------- Not the best way to build a subwoofer and expect good results. If you want to get good results, you're going to need to take the T/S parameters of the drivers you're using. Taking the T/S parameters of the drivers you're using will answer one more critical question: is this driver suited for a down-firing application? When mounted in a down-firing position, all drivers sag a certain amount. You can determine the amount of sag from the T/S parameters. As a rule of thumb, if the sag exceeds 5% of the driver's one-way linear excursion, it's not suited for a down-firing application. Reece

Sounds good! I haven't seen it yet. :-( I'm waiting for it too though. The system looks absolutely sweet. Granted, no USB or firewire, but it still does have a mini-jack in for hooking up to a computer or something. The wait continues... Reece

No problem. Just to clarify: putting two sats in parallel on one channel would probably fry the channel, due to the fact that you would be cutting the impedance in half, and therefore drawing double the current. However, if you put the two sats in series, you would actually double the impedance, and therefore cut your current in half, actually making life a lot easier on your amp. The drawbacks: probably slightly worse sound and lower total output. Enjoy! Reece

---------------- On 6/27/2005 5:11:09 AM roofies wrote: You guy's think this would work alright? ---------------- Depends. First, what absolutely not to do: do NOT hook up two sats to the same speaker output on your sub. This is the quickest and most efficient way to turn your subwoofer into a 17.5 lbs paperweight. Second, what I recommend you don't do: don't use a y-cable to hook up both front and rear inputs to your laptop and then place the 4 speakers in the typical surround arrangement. This typically creates an echo/comb filter effect and ruins the stereo image; basically a lot more bad than good. Third, what I recommend you actually do: use a y-cable to hook up both front and rear inputs to your laptop and then place all the left speakers where a stereo left speaker would go, and all the right speakers where a stereo right would go. So you end up with no speakers behind you, but rather all of them still in front of you. Either that or just use the front L/R input of the PM 4.1 and just run two speakers. Either way. Hope this helps. Reece

If I were doing this, first I would make sure my reciever has at least 4.1, but probably 5.1 or 6.1 or whatever PRE outputs, meaning they are still line level signals, before going to the amplifier. Hook the front and surround pre-outs to the PM 4.1 inputs. The sub automatically pulls its signal from I believe the front L/R, and therefore needs no hookup. Just make sure all the speakers are set to full and not small, assuming your receiver has those features. As a reminder, do NOT hook up the speaker outputs of your receiver to the inputs of the PM 4.1!!!! Let me know if you need more help. Reece

The white dot is THX's recommended level that you put the subwoofer at to create a flat frequency response, with no other bass boost running.

I believe they are 4 ohms.