klinemj
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Post by klinemj on Feb 11, 2014 21:20:12 GMT -5
Oh...let's do rehash the Mac/PC debate...please!?!?!??!? Boom started it! Seriously, Keith's points on intuitive depends on what you are used to really applies. I see as many people here doing amazing work-arounds on apples to get them to do something as I see people trying to figure out what to do on a PC. Let's face it, they both have issues...
Mark
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Post by novisnick on Feb 11, 2014 21:36:29 GMT -5
Oh...let's do rehash the Mac/PC debate...please!?!?!??!? Boom started it! Seriously, Keith's points on intuitive depends on what you are used to really applies. I see as many people here doing amazing work-arounds on apples to get them to do something as I see people trying to figure out what to do on a PC. Let's face it, they both have issues... Mark There must be something to your post Mark! Im sitting here reading your post listening to Pandora >. DC-1. >. XSP-1 > XPR-1 > Klipsch and the PC running the whole show, decides its time for a reboot after 30 minutes of run time,,,,,,,,,how sweet of it!!!!!' im sure they all have there problems Now, back to the Olympics Nick! |
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Post by pop on Feb 11, 2014 23:05:07 GMT -5
New laptop = fresh install on an SSD. No problems. Very stable, very fast. Begone with all the bloatware. You will never look back. SSD for boot drive and programs is the ONLY way to go. Using a mechanical drive is how the cavemen do it. Since you don't download to a boot drive you almost never have to reformat.
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Post by RightinLA on Feb 12, 2014 1:03:07 GMT -5
Sigh... OK - I'll bust a move on one tomorrow. You can borrow my spare XSP-1 to see if you like it or not. |
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Post by Deleted on Feb 12, 2014 1:33:38 GMT -5
New laptop = fresh install on an SSD. No problems. Very stable, very fast. Begone with all the bloatware. You will never look back. SSD for boot drive and programs is the ONLY way to go. Using a mechanical drive is how the cavemen do it. Since you don't download to a boot drive you almost never have to reformat. Ug! - I wid you Pop...  |
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Post by Boomzilla on Feb 12, 2014 6:43:55 GMT -5
RightinLA kindly offered "You can borrow my spare XSP-1 to see if you like it or not."
Thank you kindly, but with Emotiva's return policy, I decided to check out a gen 2.
Also, I tried out the system last night with attenuators, Oppo bass boost, and subwoofer bass boost - Not a happy mix. Yes, the bass finally has enough amplitude to match the satellites (and sounds pretty good!), BUT -
The attenuators, despite both being labeled -12dB, are mismatched. One channel is significantly louder than the other.
The attenuators, despite working, mess up the dynamics and frequency balance of the satellites.
The extra gain (whether from the Oppo or the sub) messes up the frequency response of the sub, making it sound overly boomy.
For these reasons, I plan to use a preamp. The follow-up question then becomes:
Since the Oppo is no longer being used as a preamp/bass manager, should I continue to use it as a DAC? I have two other options on hand that might suffice...
In favor of the Oppo: It has a VERY GOOD SOUNDING DAC. By using the Oppo, I avoid extra equipment on the rack. I can stream to the Oppo via ethernet; the other DACs require optical or USB. The Oppo has balanced outputs, the other DACs don't.
In favor of the Jolida: In a word, tubes! It has a sound of its own (but slightly) that is simply ravishing.
In favor of the AudioQuest Dragonfly version two: It needs no separate power supply and is the most compact.
Of course, who am I kidding? I'll try them all & keep the one I like the best! I've done this comparison before, but with all the DACs feeding the power amp directly. Having the preamp in the system may change the sound.
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Post by Chuck Elliot on Feb 12, 2014 8:04:00 GMT -5
Sub matching can be a PITA.
I read your posts since getting the sub, and although I don't have any experience with the Oppo, I do have some observations.
Even with the XSP-1 bass management is no field of dreams. Being 12dB/12dB, if your selected crossover frequency is near the natural high-pass slope of the mains, the combined effect is no longer 12 dB.
I've stated before in other threads that I am not in the camp that believes in unlimited power for all occasions. In my view running a 98 dB speaker with a 800W amplifier can be problematic is several areas and I believe you may have hit one of them.
Think about what's going on. The Heresy is running in the mud. VERY little signal is needed to achieve a given signal level.
The sub on the other hand is busting balls to get the low end up to the same level.
You must have a lower power power amp on hand - give it a try.
I wish Emotiva had a gain control on all its amp. But, even that only clamps the input signal - the noise floor remains the same.
I also wish Emotiva would build a stand-alone analog bass management unit with selectable crossover/slope/gain, but there may not be the market.
PS As an example: I'm running my HT Heresy IIIs on a UPA-2. The 1259 subs at around 87 dB have a 300W Anthem behind them.
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Post by Boomzilla on Feb 12, 2014 8:15:58 GMT -5
Sub matching can be a PITA. Words of true wisdom there, Chuck - I agree! ...if your selected crossover frequency is near the natural high-pass slope of the mains, the combined effect is no longer 12 dB. Correct - This is why I selected a crossover point nearly an octave from the speakers' natural roll-off ...In my view running a 98 dB speaker with a 800W amplifier can be problematic is several areas and I believe you may have hit one of them...The Heresy is running in the mud. VERY little signal is needed to achieve a given signal level. The sub on the other hand is busting balls to get the low end up to the same level. This is no longer an issue IF I use a preamp (such as the XSP-1) with bass management. Why? Because if I'm using the full-range outputs of the source, then the bass level is already matched to the rest of the spectrum. The only thing that the preamp must do is separate frequencies & send each range to the proper output. This completely steps around the issues of the "point-one" channel at the source. |
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Post by garbulky on Feb 12, 2014 8:24:22 GMT -5
I remember Keith mentioned to put the attenuators at the end where the RCA jacks connect to the amp (and not at the beginning where it starts at the DAC). Apparently this helps prevent problems with what you described with the dynamics etc. I've not tried it. When I used attenuators I heard the same issues you did (namely the dynamics and the frequency balance) and people told me such a thing was impossible as it's simply a resistor. But that has been my experience. I haven't tried connecting them at the input of the amp though...
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Post by Boomzilla on Feb 12, 2014 10:11:05 GMT -5
I don't want them hanging off the inputs of the amp. If one gets bumped, the jacks could break off the amp. I'm not risking $1.5K of amplifier to $25 of attenuators.
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Post by Chuck Elliot on Feb 12, 2014 10:39:55 GMT -5
A cross over around or slightly above 100Hz works well with the Heresy, but you can take advantage of the resultant 24 dB slope by setting it around 60 Hz. The XSP-1 is fixed with a 12 dB slope and I then dialed in the sub with a 24 dB slope. I level match with the gain control of the F15HP as they have a 600W plate amp.
I don't concur with the attenuator issue. I use them in a number of spots with my HT system to match levels instead of using DSP digital division to attenuate.
As usual YMMV and I only offer my experiences.
Chuck
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KeithL
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Post by KeithL on Feb 12, 2014 11:29:10 GMT -5
Since you mention it; I'll explain why that can matter.... If, for example, you were to connect the output of an XSP-1 (preamp) to the input of an XPA (power amp) directly (let's solder the boards right together), the output impedance of the XSP is much lower than the input impedance of the XPA, and so the signal would go from one to the other without significant alteration. Now, if we add an interconnect cable between them, while the inductance and resistance of the cable should be insignificant, the capacitance of the interconnect cable will to some degree interact with the output impedance of the source device to act as a low-pass (high-cut) filter. With a "normal" interconnect cable, this effect will occur far above the audible frequency range, and so will not be audible at all. This is the way things normally work. (This is also why some weird audiophile interconnects can affect the sound; because they have resistance, inductance, or capacitance values so far from the norm that they do affect the frequency response. The technical term for these is "badly designed junk".  ) Now, when we add an attenuator, we are adding resistance to the connection..... If we put the attenuator on the output of the preamp, while the preamp sees a slightly heavier load due to the attenuator, the output impedance of the preamp (as seen by the cable, after the attenuator) will be RAISED. Since we then have a higher source impedance "feeding" the same cable capacitance, the "filter effect" occurs at a lower frequency - possibly low enough that it does become audible. (Whether this happens to a significant degree will depend on the capacitance of the cable and the exact internal design of the attenuator; it will be worse with longer interconnects.) Since we have raised the source impedance as experienced at the cable, the cable will also be more susceptible to hum pickup. HOWEVER, if we put the attenuator at the input of the power amp instead, the cable is still directly connected to the output of the preamp, so we now have the same low source impedance of the preamp feeding the same interconnect capacitance, so our filter effect stays happily in the inaudible range, and our resistance to noise also remains the same. (The impedance of the attenuator now "counts" as part of the load impedance instead of as part of the source impedance.) Whether any of this will make any audible difference will depend on the particular interconnects and attenuators you choose (different attenuators use different circuit topologies and different resistor values; different cables have different inductances and capacitances), but it certainly makes sense to connect them in the way that will minimize the possible bad interaction - just in case. I remember Keith mentioned to put the attenuators at the end where the RCA jacks connect to the amp (and not at the beginning where it starts at the DAC). Apparently this helps prevent problems with what you described with the dynamics etc. I've not tried it. When I used attenuators I heard the same issues you did (namely the dynamics and the frequency balance) and people told me such a thing was impossible as it's simply a resistor. But that has been my experience. I haven't tried connecting them at the input of the amp though... |
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Post by KeithL on Feb 12, 2014 11:34:55 GMT -5
The best compromise would be to put the attenuators NEAR the amplifier; put a very short interconnect between the attenuator and the amp (say six inches) so it can hang safely down. OF COURSE, you could simply try them at both ends; if you don't hear any difference with your particular attenuators and cables, then put them anywhere you like  (Whether it makes any difference will depend on your cables and the specific attenuators you have. Odds are, if we're talking about two foot interconnects, it isn't going to matter much, but the likelihood that it will make a difference increases as your interconnects get longer.) I don't want them hanging off the inputs of the amp. If one gets bumped, the jacks could break off the amp. I'm not risking $1.5K of amplifier to $25 of attenuators. |
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Post by Boomzilla on Feb 12, 2014 11:42:42 GMT -5
Thanks, Keith - Your "it matters where the resistance lies" makes sense. Even so, I'm NOT hanging long, rigid attenuators off the RCA inputs of my power amp. I did it with my XPA-2, and when a cable got pulled accidentally, the leverage was sufficient to break the circuit board that the RCA jack was attached to. Electrically, it may make sense to put attenuators at the input of the power amp, from a "S**t-Happens" standpoint, it doesn't. So no more attenuators for me, thanks.
I like the idea of using straight XLR connections throughout. Oppo to XSP-1, XSP-1 to XPR-2, all neat & clean. Since the signal from the Oppo will already be full-range, 2-channel analog, the XSP will need do nothing but volume control and bass management. Despite the "by-guess, by-God" labeling of the XSP's crossovers, I can put something together that works by ear.
If I had a pair of subs, I'd use them as speaker stands and use Chuck's recommended 100 Hz. crossover. Since I currently have but a single sub, I think I'll cross over lower or maybe even run the satellite speakers full range & cut in the sub below the normal roll-off. This will work swimmingly with any acoustic suspension speaker, but not so with ported or passive-radiator speakers. To avoid cone flap, I'd like to cross those over using a high-pass filter.
The level mismatch goes away if I use either lower gain amplifiers or less-sensitive speakers. I could plug up my "pro" Crown amps for lower sensitivity, or I could use my DefTech SM65 speakers for the same reason. For the moment, though, I'm enjoying the dynamics of the Klipsch speakers and until I get tired of them, they'll stay in the system.
ON THE PSA HV15: It HUMS! I hooked it up to the RCA full-range outputs of the Oppo. With NO music playing, the sub SHOULD be asleep. Instead, it turns itself on from the "auto" position and hums slightly. I'm assuming that this is a ground loop between the Oppo & the sub? Any suggestions for killing it? Maybe a groundless "cheater cord" for the sub?
Boomerater
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Post by Boomzilla on Feb 13, 2014 7:53:39 GMT -5
I'm currently running the subwoofer from full-range right & left channel outputs of the Oppo BDP-105. It hums. I've tried the following to tame the subwoofer hum:
1. Unplugged all signal cables & turned the sub on = no hum (the sub is NOT defective)
2. Plugged the sub into the same socket as the Oppo = still hums
3. Used an ungrounded power cord to power the sub = still hums
This leads me to believe that one of the ground shields of the two interconnects has different resistance than the other. I'll test this theory today with the VOM. If a bad interconnect is to blame, then I can discard it & substitute another.
The fact that the ungrounded power cord failed to solve the hum leads me to believe that the problem is NOT in the power supply but rather in the signal wires. If necessary, I could fabricate a stereo pair of signal wires that used but a single ground wire for both channels? As an aside, I've fed the power amp from the same pair of RCA jacks that currently feed the subwoofer with no hum at all, so I don't think that the imbalance is sourced from the Oppo. Another factoid - the main speakers are dead silent (power amp fed from Oppo's XLRs) while the subwoofer hums.
Are there any tricks I've missed?
UPDATE: I checked the signal and ground impedances of all the connectors - All were a uniform fraction of an ohm. Grounding problems of the signal wires are NOT the cause of the hum. Now I'm COMPLETELY out of ideas. WHY IS MY SUBWOOFER HUMMING?
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Post by Boomzilla on Feb 13, 2014 16:47:42 GMT -5
Try as I might, I've been unable to prevent the subwoofer from humming when attached to the full-range RCA outputs of the Oppo BDP-105. I've looked all over Google to see what is recommended, and so far, I already knew everything I read.
The sub didn't hum when attached to the single "subwoofer out" of the Oppo, but it was so low in amplitude that it wouldn't match the satellites. I'm now trying to run the satellites full range & run right and left channel full range signals to the subwoofer. By setting the subwoofer's internal low-pass filter to the natural roll-off frequency of the satellites (50 Hz.), they sub and satellites should match. However, I can't get that far because every time I turn the subwoofer on with both channels attached, it hums (fairly loudly).
See the post above for things I've tried so far.
I throw myself on the mercy of the Lounge here - why is my subwoofer humming and how do I stop it?
Thanks - Boomzilla
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Post by melm on Feb 13, 2014 17:00:22 GMT -5
I would think a call to PSA would be in order. I've never heard any hum from the sub at all.. of course I'm running it in a more standard configuration.
Mel
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hemster
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Post by hemster on Feb 13, 2014 17:03:06 GMT -5
Have you tried changing the sub's crossover frequency to see if the hum is better/worse at either end of the spectrum?
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Post by Deleted on Feb 13, 2014 17:10:11 GMT -5
Cheater plug?
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hemster
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Post by hemster on Feb 13, 2014 17:41:33 GMT -5
Per his earlier post, he tried that already: |
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(Whether it makes any difference will depend on your cables and the specific attenuators you have. Odds are, if we're talking about two foot interconnects, it isn't going to matter much, but the likelihood that it will make a difference increases as your interconnects get longer.)
