High freqeuncy hum in speakers

[sud98]

Hi,

I have been listening to my paradigm monitor 9's for two-three months and through with the burn-in period.

I do hear occasionally a high frequency sound which is very irritiating, but I am not sure if its due to the source or due to the speakers.

Coupled with the fact that I suffer from mild tinnitus (Tinnitus - Wikipedia, the free encyclopedia), so wanted to know of the ways to troubleshoot the source of the problem?

Any help appreciated?

 

[odyssey]

Yes, simple
disconnect each pc of equipment behind the amp and see when the hum goes away. Typically, hum isnt high frequency. So first disconnect the CDP/DVDP and if that doesnt take care of the problem, disconnect the pre, if none of these help, its in your amp. How loud is it? can you hear it from your seating position?

cheers

 

[venkatcr]

This could be because of improper wiring, or carrying the speaker cables and electrical cables in parallel for some distance. Isolate the issue and see what happens. It could also be because of lack of proper earthing of your equipment. I had a similar issue with a sub that was creating a hum when powered on. I realised the coaxial cable and the power cable were in parallel for about 5 feet. I separated the two and the hum vanished.

Cheers

 

[sud98]

May be hum is not the right word, but its something from the tweeters.

Its audible from my seating position (18 ft) but I do have sharp ears

I will try and isolate electrical wiring from the speaker cables and see what is the cause.

How would I check removing the cd/dvp, I will need a source to check right?

 

[odyssey]

The noise is audible without the source playing I assume? If thats the case, you just power on the pre and the power without a source connected, raise volume to your normal listening position and then check.

cheers

 

[kapvin]

If you have tinnitus, it could be your ears as well. I suffer from tinnitus too (as did van gogh.. so we are in august company..) are you asthmatic?

typically, if it's sound from the tweeters, which comes intermittently, (i'd assume you can hear it while there is no music playing) and you've tried the solutions listed above, it's almost definitely your source chain. if you can isolate which source component; you can trouble shoot around that, if it comes with mulitple source components, then i'd focus on the amp.

hope this helps.

edit : just noticed that you have the UMC-1 -- which firmware are using. update the firmware to the latest(feb 11) if you are using the october firmware- i've also had problems with unpredictable behaviour with october 10 firmware

 

[sud98]

If you have tinnitus, it could be your ears as well. I suffer from tinnitus too (as did van gogh.. so we are in august company..) are you asthmatic?


edit : just noticed that you have the UMC-1 -- which firmware are using. update the firmware to the latest(feb 11) if you are using the october firmware- i've also had problems with unpredictable behaviour with october 10 firmware

I use 7.x firmware. Let me sit tonight and do troubleshooting one by one.

I will be doing the following steps -

1. Play a music cd of good quality see, whether the high freq has some pattern; if not easily seen, check multiple cd's

2. disconnect the bdp and play radio (fm) and then see if this is audible

3. not play any source and check for the sound

4. disconnect the pre and see if the sound is apparent

5. try and re-arrange the power cables of each to check the problem

Let me know if there are better steps, will post results tonight

P.S. - I do suffer from allergic cold but the tinnitus could also be through a blow from a football I got recently

 

[sud98]

Did my first round of tests, the results are slightly strange.

1. I listened to a cd (Louis Armstrong) which has quite a bit of high frequency passages, but there was no add-on high frequency sounds even between sounds or extra shrillness
So I assumed that the source/pre/power are fine

2. I played a movie using my laptop and streaming via Tversity and a 100 mbps cable to the Oppo and the shrill sound was back.
I first suspected it was because of the audio settings of the UMC1, but modified it to Direct, still no difference.

Is it possible that this sound is from laptop/ethernet cable?

 

[venkatcr]

As Odyssey had mentioned do the following:

1. Disconnect you laptop completely. Remove all cables to the amp/system.
2. Keep the amp at noon position. Power on and power off your other sources one by one. If you are not getting any sound, you are halfway safe.
3. With the same sources, play some music using the same CD. If you do not hear a hum, you are 3/4th safe.

S a last step, connect your laptop and try again. If the hum reappears, then the hum is certainly coming from the laptop or the way you have connected it.

cheers

 

[dragonxwas]

if you are using it with laptop it is natural for you to have a hiss sound, thats due to the laptops soundcard being embellished and bombarded with emf all around..

also this can happen if the amp inside the monitors has a high gain factor and picking up Rf signals, probably white fm noise..

try keeping the volume to the lowest as possible on the monitors and use maximum volume from laptop..this should fix the problem..also with this if you are not able to hear this hiss again..then probably this was due to the amp inside picking up fm signal..

P.S.: The hiss noise will only seep in when there is no signal from the source..

 

[kapvin]

Did my first round of tests, the results are slightly strange.

1. I listened to a cd (Louis Armstrong) which has quite a bit of high frequency passages, but there was no add-on high frequency sounds even between sounds or extra shrillness
So I assumed that the source/pre/power are fine

2. I played a movie using my laptop and streaming via Tversity and a 100 mbps cable to the Oppo and the shrill sound was back.
I first suspected it was because of the audio settings of the UMC1, but modified it to Direct, still no difference.

Is it possible that this sound is from laptop/ethernet cable?

unlikely to be the cable or the laptop. do check the sampling freq of the movie audio stream, maybe the oppo / umc-1 has a problem with that. I assume this is a SDvideo + sd audio soundtrack (since with HD video + HD audio you are testing the boundaries of the 100mps bandwidth). also check with other streaming sources.

finally I guess the D/A conversion is happening on the UMC-1. what if it happens on the Oppo (anaolog out) do try that out too

 

[sud98]

Thanks Kapvin.

I did upgrade to the new firmware for UMC1. Now while playing the same material, there was almost no noise. I have a feeling that it may be due to some settings (as the firmware upgrade does a factory reset), but not sure how to troubleshoot the player versus processor settings.

Do note that the paradigm's are quite high in sensitivity so it may be I just need to lower the gain in the pre on high frequencies, but would wait for a professional opinion.

The oppo was sending the sound as bitstream, changing it to lpcm didnt make a diff (pre-upgrade).

My worry is when I set the auto callibration it may come back, and not very confident on the manual settings.