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[ Desparate, need help or I'm giving up on audio ]

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Old 05-05-2003, 10:04 PM   #1 of 13
RogerD
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Desparate, need help or I'm giving up on audio


Hello, I have an unusual problem with my system that I have tried desparately to figure out to no avail. If I can't get it resolved soon, I think I am going to just sell my equipment to save myself any more aggravation. Let me explain: I currently have Paradigm Reference studio 40 speakers and a Denon PMA-2000IVR integrated amp biwired with Synergistic Research Alpha speaker cable. I can never get consistent sound out of my system. In fact, most of the time it sounds like crap. On the rare occasions it sounds good, I get excellent imaging, great dynamics, bass, detailed midrange, etc, but most of the time my system sounds flat, no midrange, nonexistent imaging(in fact, it just sounds like two speakers outputting sound, almost like its in mono), no dynamics, and a big drop in power. The Denon is a powerful amp, when it sounds good, It only needs a quarter turn to get loud but most of the time, I can turn it to the 1 o'clock position and it isn't very loud. Now, before this amp, I had (and still have) a Carver stereo receiver, and an Integra 5.3 home theater receiver which both exhibit the same symptoms as my Denon. I have ruled out the amps since they all do the same thing. It's not the speakers, since my previous Klipsch RF-3's did the same thing my Paradigms do now. I have tried different cables, line conditioners, etc with no luck. I thought maybe it is a voltage problem but I have a Panamax 1000+ which always reads 120 volts and a Monster 3600 line conditioner which also reads 120 volts consistently. When things sound good, everything sounds good (CD, DSS, VCR, DVD, etc.) so it isn't any one source. The thing that is so frustrating is getting a glimpse of how good things can sound, only to have it all go away the next day. I thought It was just my imagination, until a friend was over and my system just happened to go from sounding bad to good and he immediately noticed the difference without me saying anything. It can go for a month or so sounding flat and lifeless and then suddenly for a couple of days sound good and then go back to sounding bad. I am pretty desparate at this point and would greatly appreciate any advice anyone can give. If I can't figure it out, I'm going to sell everything and get the hell out of this frustrating hobby! Let me tell you, nothing is more frustrating than spending a good sized amount of money for a stereo that does't sound much better than a boombox most of the time!
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Old 05-05-2003, 11:27 PM   #2 of 13
imported_Dave Dahl
 
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How are the speakers positioned in the room?

-Dave
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Old 05-05-2003, 11:48 PM   #3 of 13
Jaime B
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Roger:

This happens to more audiophiles and more often than you may think. Usually it's due to severe voltage swings or very dirty electric power.

Since you have already mentioned that your voltage is very stable at 120V, your problem doesn't originate with a voltage fluctuation.

Do you live in a heavily industrialized area, is there a power generating plant nearby emitting lots of EMI? Anyway, I'll give you my two cents worth - you need to regenerate your power (PS Audio, Exact Power EP-15, etc.) or at least get a balanced power conditioner (60V one leg, 60 volts the other). There are plenty of these, Equi-Tech, Balanced Power tech., Furman reference, even Monster has a balanced unit in their extensive line.


Before you throw in the towel on this hobby, try (on loan)
either type of line filter AND throw away that Panamax! My experience is that it degrades everything in its path! Good for lightnning spikes only...


My bet is your electric sockets are outputting 120v "sinus tachycardia" - go for a regenerator and get rid of both filters currently in use in your system.

Let me know if this solves your not-so- uncommon problem1

jaimeB
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Old 05-06-2003, 12:02 AM   #4 of 13
Jaime B
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Roger:

Forgot to mention, in case you were wondwering, regular line conditioners do not fix deformed electrical sine waves.

Just in case you haven't tried a power regenerator, give it a shot!

If that doesn't work, there is always that Bose radio
(now with CD player!) with Acoustmass bass loading and many other low-tech goodies for your enjoyment...

Very best,
jaimeB
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Old 05-06-2003, 01:01 PM   #5 of 13
AaronBatiuk
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RogerD,

From my point of view (Electrical Engineer), this sounds like a floating ground. In other words, one (or more) of your components has a bad ground (i.e. zero voltage reference) connection somewhere within it's circuitry.

A bad ground could absolutley create exactly the problems that you are describing. Lack of bass, poor imaging, vastly decreased volume, etc. The problem is that the signal (normally referenced to ground, or zero volts) just floats around with no real reference. It can still induce a signal in the device it connects to (which could be anywhere in the signal chain), but this signal is weak, and rolls off at lower frequencies. If the temperature, humidity, etc. are just right, the bad connection may connect well enough temporarily, which can explain the good performance that you occassionally see.

My advice to find the problem is to selectively exchange each major component in the signal chain, one at a time, until you find consistent performance. One variable at a time.

Start with the interconnects between CD transport (or whatever source) and your integrated amp. Some interconnects have a very tight centre conductor and a very loosely fitting shield/ground. I had a very similar problem to what you described and found it out just by wiggling the interconnects. If different interconnects don't help, put the originals back in and move on.

Then move to the transport itself. Use your DVD player or some other device as a source.

If that doesn't help, then the next likely suspect can only be the integrated amp (unless you have something else in the chain, like an EQ). Swap it out with a borrowed receiver or integrated amp. If you don't have a friend to lend you one, pick one up from a local audio shop with a good return policy. Heck, you may end up keeping it.

If you find that the amp is the problem, the take it to a good repair shop and tell them that you suspect a bad ground or a bad solder joint in the signal path. With hundreds or thousands of solder joints, the likelyhood of having one bad one isn't so remote.
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Old 05-06-2003, 09:01 PM   #6 of 13
RogerD
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Thank you for your replies guys. Jaime B, I have thought about a current regenerator type of product but they are expensive! For example, the PS audio 300(their least expensive model) goes for $1,000 and can't handle power amps-mainly just digital and analog sources. The ones designed for amps are out of my price range. You mentioned some other brands that I haven't heard before. Any specific recommendations? I would be open to trying one in my system if I could find a dealer with a return policy if it doesn't help. It is hard to believe that my power could be so "dirty" that it would cause the problems I have but I supose it is possible. I don't know if it would acccount for the lack of power from my amp though. That seems like a current issue from my wall. Do you know if it's possible that my AC could be reading 120 volts but still be low on amperage?

AaronBatiuk,

You mentioned a floating ground in one of my components as a possibility. I'm not sure if it would be in my amps because all three exhibit the same problem. In the past I have actually just hooked one component up at a time (MD, CD, DVD, DSS, etc) and I still have the same problem. Is it possible that the ground in my electical wiring could be faulty behind the wall? I do know that when I plug into a certain outlet in the room the 'ground OK' light on my Panamax and the Monster power center fail to light, but on a different outlet the light comes on. (The problem, however, occurs on both outlets). I am under the impression that a bad ground would not cause a decrease in power, but rather an increased possibility of component damage due to electrical storms, surges, etc. since the excess energy cannot travel to a solid ground. (I could but completely off, since I know relatively little about home AC).
Any further insight would be greatly appreciated as I would love to find out the cause of this extremely irritating probem and for once be able to just sit back and enjoy rather that always focusing on the sound!
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Old 05-06-2003, 10:34 PM   #7 of 13
Jaime B
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Roger:

Your best bet is the ExactPower. Their site is www.exactpower.com and their telephone number is 866-392-2822. (Chatsworth, California). I have no idea if they'd be willing to lend you a unit. It reconstructs the sine wave and is rated at 1800 watts, so it will handle your whole system. Not cheap at $1,799...

However, before you do that, have a licensed electrician rewire your music room to the breaker box with 14 gauge wire (he'll know better than me ), and install a new breaker while he's at it. Maybe this will correct your dilemma!!!

As for your question regarding voltage vs. amperes, I graduated from Georgia Tech 23 years ago and only took one course in electricity and nearly flunked! the formula is as follows: watts = volts x amperes x power factor. Draw your own conclusions! (Volts is a constant, so if an amp is to produce more watts, it needs MORE amperes, and the wiring to permit that).

Lets have an expert answer this one!

very best,
jaimeB
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Old 05-07-2003, 09:46 AM   #8 of 13
Bob McElfresh
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For about $5 you can go to the hardware store and buy a small "Outlet Tester". This will tell you if your outlets are reversed polarity, missing a ground, etc.

I recently read a thread where a member was able to measure some funny voltage swings. He called the power company and they came out, did their own tests and re-attached his power service. This seemed to solve his problem.

Someone mentioned "Speaker Placement" which can cause many problems. If the AC power tests dont show anything, try this:

- Pull out as much furniture from your room as possible (as an experiment).

- Put your L/R speakers according to the "Rule of Thirds": Pull them 1/3 of the way into the room, and position them 1/3 of the way in from the 2 side walls.

- Use a laser pen held along the speaker cabinent to see where the L/R speakers are pointing. You want them to focus 1-2 feet in front of your primary listening position.

- Now sit down and listen to some favorite MUSIC (not a DVD movie). Music is a lot harder to reproduce, but has a lot more information.

My HT system is quite good for being in a 'challenged' room. But a few years ago I had to pull everything out for wallpaper to be stripped and new paint. I managed to put back in the TV and HT/Speakers as the only items for a few days. The change in sound using all the 'proper' placement rules was shocking. During U.S. Marshals there is a phone call that bounces from a closed/stuffy office to an outdoor swamp. The ambient sound on this movie reflects this. My ears almost popped from a pressure-difference as the walls acoustically moved out/in/out/in during these phone calls.

This will at least tell you if your placement needs work.
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Old 05-07-2003, 09:56 AM   #9 of 13
AaronBatiuk
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Quote:
You mentioned a floating ground in one of my components as a possibility. I'm not sure if it would be in my amps because all three exhibit the same problem. In the past I have actually just hooked one component up at a time (MD, CD, DVD, DSS, etc) and I still have the same problem.
Well, it sounds like you get the problem with different amps and different sources. Have you tried swapping out the interconnects? I would still try borrowing a friend's receiver and if possible, their CD player as well.
Quote:
Is it possible that the ground in my electical wiring could be faulty behind the wall?
No, I don't think so. Most audio components arent' grounded anyway. Their power supplies use a transformer, which effectively isolates them from any real voltage reference. That is why having a common ground is important. Usually, the only way for components to establish this common ground is through the ground (shield) of the interconnects.

As I said before, I had experienced the very same symptoms that you have -- very low volume, tinny sound lacking bass, and a lot of cross-talk (poor separation). I found that of all six interconnects between my SACD and receiver, none of them had established an actual ground connection. A little bit of sideways pressure on both ends of one of the cables forced the RCA's shield to make contact, and voila! all was well. I then used a pliers to squeeze all the RCA's outer shield connections together just a little so that they made good electrical contact.
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Old 05-07-2003, 09:59 AM   #10 of 13
Bob McElfresh
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PS: Are all your outlets on the same 'leg' of your power service? Consult an electrician.

Your house really gets 240 volt service. This gets split into 2 120 volt 'legs'. Half your circuit breakers run from 1 leg, half from the other. Your lights/motors dont care, but if your electronics are plugged into the 2 different legs - they will see a ... 45 degree phase shift.

Now every electronic device has a power supply that tries to rectify this into DC power making the phase shift issue moot. But this is fairly sensitive electronics mixed with power amps. The results could be different from the theory.

Note: If you try my experiement above, ONLY hook up your CD player and amp to start. If the sound is good, slowly add ea