VDS
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Posts posted by VDS
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I assume the cable is XLR at one end and RCA at the other (IOW, no additional connectors added to an otherwise three wire cable). This probably is not the problem, but have you measured whether the pin 1 and pin 3 on the XLR side side of the cable are electrically tied together ?
yes, no additional adapters attached to cables.
checking pin 1 and 3, with a ohm meter?
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No isolator, would certainly be willing to try one.
RTA is a little confusing, many options i dont understand in control pop up window, did set to 1/48th smoothing though
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2 minutes ago, VDS said:
AHHA, Finally found something. When i unplug interconnects from Pass Amp noise stops! Pass is single ended only, no XLR
But that make sense right, your literally creating a gap in signal chain, or am i off base?
Wondering if the connection to the high frequency amp causes problem, or just doesnt allow problem to get to the speakers?
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12 minutes ago, mikebse2a3 said:
Is this noise always audible without music..?
Is the noise audible in both channels..?
Is the noise in the HF only or do you also have noise in the LF also..?
Do you have all the equipment plugged into a common power strip..?
Make sure all light dimmers are turned off when testing for the noise..?
How long are your interconnect cables for the pre-amp to xilica and xilica to amplifiers…?
What models are your pre-amp and amplifiers for HF and LF..?
AHHA, Finally found something. When i unplug interconnects from Pass Amp noise stops! Pass is single ended only, no XLR
Always audible, except when i turn Xilica off and leave everything else on.
Both compression drivers, (2 way speakers)
All equipment plugged into power strip. Tripp Lite. isobar ultra
No dimmers in the house
All interconnects 3' - 6'
All power cables are standard 3 prong audio, except bluesound Node 2i, ungrounded 2 prong
Pass xa25 highs, Crown K1 woofers, Aric Audio Motherload pre 6SN7
Separated all power cables from signal cables
Nothing else electical in room turned on, lamps, tv,
Tried to match pitch with tone generator on phone, probably 6000-10,000hz
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5 hours ago, Chris A said:
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The sound is similar to how your ears ring after being around very load noise for too long.
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Separated all power cables from signal cables, no change.
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1 minute ago, PrestonTom said:
Come on guys ... this is just a guessing game at this point.
The OP needs to be more articulate by what he means by "whistling". Please be more specific, otherwise we are only guessing and any advice you get will be very suspect.
Trying to describe sound is always difficult. Its a very high pitched, over 15,000hz?, piercing sound. not loud, but audible between songs. The high pitch is really is unpleasant on the ears. it does not change volume when raising volume, or preamp gain. if i turn off xilica it stops,
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4 minutes ago, Chris A said:
Also, using RCA (unbalanced) connections are much more susceptible to electrical noise from supplied power--dimmers, other equipment in-room, etc. can produce significant amounts of "common mode" noise, and that can even extend into upper frequencies.
Chris
I do have xlr to rca for preamp our to Xilica in, and xlr to rca from Xilica to high frequency amp. These are inexpensive cables, I could look for higher quality xlr to rca cables?
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Chris, I did measure and made some adjustments, I’ve got all 100-15,000hz levels to within 6dB from peaks to valleys , after 15,000hz it rolls off. “Hum” Is very high frequency.
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Hi,
set up new speakers, everything good. Moved them to new location in house, (started in studio in separate building on property), same equipment and now I’ve got a persistent very high pitched whistle, whine, ear piecing frequency.
Not very loud, but clearly audible, sure I would have heard it in previous location, heard as soon as I got system up and running in new location.
Seems to be coming from the Xilica 4080xp, stops when I turn Xilica off.Anybody with Xilica or other DSP experience this?
Could it be grounding at this high pitch? Subtly different electrical supply in home vs studio?
many ideas on how to troubleshoot this?thanks for any perspective, Ted
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Back to capacitors. I recently bought and 10 yr old diy class A amp. I noticed it ran REALLY hot, not class A hot, but HOT. I drilled about a dozen 1” holes in top which had helped a lot. Any way to know if the power supply caps where prematurely degraded by the high heat environment? The skins seem to have shrunk and a very slight bulging might be seen? It sounds pretty good, but, as always, can I change something and make it better?
@Deang or others have perspective on this?thanks! Ted
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On 7/2/2021 at 5:50 AM, Chris A said:
Here is the spectrogram view for the SPL response measurement that I posted above, with the display settings menu shown so you can duplicate them:
Some things to notice:
1) Note the bottom axis here is time (the independent variable), in milliseconds, and the vertical axis is frequency (Hz), with the SPL or loudness represented by the scale on the right (dB) in color. The top of the SPL scale is automatically scaled to the maximum SPL measured during the sweep.
2) Note the tweeter's output in the top left of the plot as a vertical bar with a fair amount of decay trail within the first 1.5 ms. Note that the midrange K-55/K-600 driver/horn lags the tweeter's output by about 0.75 ms. This is the time misalignment of the tweeter and midrange, and it amounts to about 3.7 full wavelengths of sound at the crossover frequency of ~5000 Hz (i.e., 0.00075 seconds * 5000 Hz). That's a lot of time misalignment that is audible. The tweeter needs to either be moved toward the rear of the cabinet by about 10 inches (13584 inches/second speed of sound * 0.00075 seconds), or the tweeter needs to be separately amplified with its own amplifier channel and its output delayed by 0.75 milliseconds. This will result in a greatly increased sense of soundstage of the higher treble frequencies.
Basic question. In spectagram is the blue/green “fluff or clouds” on the right side reflected sound that the room is adding? Do we have want to see the colors taper quickly as they move to the right?
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the above is 1/6th smoothing
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Here's what I got. No idea how to read spectogram, I am researching to understand the data the spectogram gives.
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I should have said, using Dayton audio Umik 6 mic, I think I applied the correct calibration file (that was confusing, I’ll have to double check). Mic was 1 meter from front of speaker, level, (horizontal) pointing at point between woofer and mid horn. Like I said I was applied Var smoothing which showed a 10 dB range over the entire frequency range, of course fell of cliff at 38 hz.
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I should say I applied the Var smoothing, as that was a recommendation for novice users.
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Hi, learning to use REW now that my MEH 402’ are built. Testing my modified Cornwall 1’s and got 35-20,000hz all peaks and valleys within a 10 dB range. Is this “generally” all you can hope for with passive crossovers?
I don’t really know where to go from here. Any advice on other things to check next?
waterfall plot to check room reflections?
I’m just trying to learn the basics so I can start to “see” what I’m hearing.thanks, Ted
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On 6/23/2021 at 8:05 PM, Deang said:
DCM50 or BMS 4592-mid. There are a lot of BMS users out there.
I used the BSM 4592 mid with Dave Harris Horn, love it. I had a pair of DCM 50’s which are great, but to me the 4592’s are a little smoother and less “edgy”
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https://www.facebook.com/groups/528704021054561/permalink/847807369144223/
very vintage KHorns. Not mine.
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4 minutes ago, PrestonTom said:
VDS, Congratulations on you new arrivals.
If I may ask, and I am just snooping, where did you buy these from? If you would rather not say, that is fine.
Congratulations again ! It seems a shame to take power tools to them, but I understand your goal.
Good luck,
-Tom
Cory and Steven at Paducah Klipsch. They were back ordered from Klipsch, but I only waited 2 weeks. I also found a cinema supply place that also sells them retail, (can’t remember the name).
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3 minutes ago, Coytee said:
Hmmm.....so, that would be similar to ordering a perfectly cooked piece of steak..... and cutting it up into pieces?
Somehow, they both make sense!!
I’m putting faith in the same people that said 402’s sound great. Let’s hope the MEH reports are accurate ....I have faith they are
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My fiancé thought the Cornwalls were big, lucking she’s pretty accepting. I made dinner for her just to help smooth the transition. Knowing the dimensions doesn’t really prepare you for how big these are inside your home!
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I hope it doesn’t seem like I’m showing off. I feel kind of vain with this post. I just want to give a little more info to people contemplating the purchase of 402’s.
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High pinched whistling
in Technical/Restorations
Posted
Noise continues when preamp to Xilica cable is disconnected.