0 Members and 1 Guest are viewing this topic. Read 15673 times.
Loud enough to drown out my drunken neighbors terrible stereo system, then them calling the cops complaining of MY excessive noise, then when the cops show up at my next door neighbors place since the loud music was coming from their place because I have since turned off my music, they decided to mouth off to the officer and they get hauled off to jail for drunk and disorderly. I believe that is "Checkmate."
neekomax's Apple TV is using its S/PDIF TOSLINK optical output into the Decco DAC section, so impedance would not apply to the optical transmission. If you were using an S/PDIF coaxial output (which the ATV doesn't have), coaxial S/PDIF ouput impedances and coaxial S/PDIF input impedances of DAC inputs are standarized at 75 ohm, so it isn't much of a concern. You just need to use an appropriate 75 ohm coaxial cable. Steve
Public Service Announcement: Extended exposure to more than 85 dB will cause permanent hearing loss and possible lifetime pain.
For the sake of dynamics the source should actually be an order of magnitude lower,around 100 ohms or less.
This ten to one ratio minimizes the possibility of high frequency roll-off due to interconnect cable capacitance in combining with the preamp and power amps impedances to create a filter pole inside the audio bandwidth. A filter pole is always created when two components are connected together by a cable with capacitance,the trick is to have the 3dB down point well outside the audio band .......Scotty
Steve, I think the reason the frequency extension beyond 20kHz sounds better is that you have moved the filter pole created by the roll-off of the high frequencies further away from the audio band. When the filter pole is close to the audio band you hear the effects of the phase shift that comes along for the ride and these effects may extend clear down into the mid-range. Scotty
Ha. Right. Acurus DIA-100 amp = 10k input impedance. Peachtree Audio Decco preamp output impedance = no idea How critical is all this anyway?
Well, from a low frequency response standpoint, 10K input Z requires a large coupling capacitor to avoid bass loss. High frequency response is not too bad, maybe even enhanced. Cheers.
We already confused and baffled neeko, and everything you have said is true. I admit to dumbing down the explanations. I didn't want to get into specific examples. If we start telling him to avoid specific capacitance values for 1 meter cables,for example,then we have to specify the rest of the variables in the equation. Where do we quit? In as much as your products are tube based the 1.9k value isn't too bad.I was again generalizing and referring to SS gear. We frequently see output stages in consumer gear with 400 or 1000 ohm resistors in them to protect against shorts when values this large are unnecessary and hurt dynamics. Scotty
No way. If you measure the distance from from your loudspeaker drivers to the floor you will probably find that the distance from the floor of one or more of your drivers is 1/2 the wave length at 200 to 250Hz. This about 2.2 ft. to 2.75 ft.. If this is the case you have floor bounce cancellation which is a very common design fault in most consumer loudspeakers. You can try raising the speakers off the floor and see if that helps. If you have an iPhone you can down load an RTA app from studio six. It doesn't have the highest resolution but it will show you where problems are. Scotty
There's your ~ 100Hz to 200Hz bass dip. Steve
Could be you are measuring in a standing wave zone. That peak might disappear if you move back a foot. The hole may also be standing wave induced.You may also have the sub cranked to far as well. Have you tried swapping the speakers location yet. Scotty
