Jump to content

etc6849

Regulars
  • Posts

    676
  • Joined

  • Last visited

Everything posted by etc6849

  1. Hi Chris, Is it better to do the REW sweep at say 90dBC and then attenuate all the dips out completely or to have an individual max boost at a high number with a target mid curve (15dB like you do above)? Another PEQ filter tutorial I was reading said to set the max boost to 0dB (sounds overly cautious)?!? I guess this is in fear of over driving a driver or causing phase distortion? I'm thinking I used a target of 8dB when I tried this on my XMC-1 (has 12 band PEQ for each channel), but then when I rerun my measurement at 90dBC SPL, I noticed THD at some frequencies had gone up (while most THD remained the same). Am I correct in thinking that if I use an individual target set of 0dB THD my driver's distortion would not have increased? Also, what are there any drawbacks to just hacking the curve away and setting the target just above a dip (instead of in the middle)? Forgot to mention: shelving shows up in the latest version of REW as it lets you set crossover slopes for roll offs (but uses up some of the PEQs). Any advantage to doing this on the Yamaha instead of using a normal shelf filter? PS: you were right about the Ashley XR1001's. When I used 12 watt resistors to make the impedance of the MF and HF close to 10 ohms each (took a 4.5 and 6 ohm resistors; amp really was seeing a 3.2 ohm impedance on one of the drivers forgot which now), but I noticed there was only a slight decrease. This didn't make sense as 10 ohms is a nice load the amp should like, and the hiss was still there even with my processor (XMC-1) turned off! Then I unhooked the Ashley and the hiss was at a very low level as before: very hard to hear at the MLP. Will the Yamaha SP2060 I ordered give me any trouble? I'm hoping there are adjustable level controls that will fix any issue like this on the Yamaha?
  2. etc6849

    Yamaha SP2060

    Sweet deal on this. Ordered a Yamaha SP2060, but it wasn't cheap even at $400 under MAP. If anyone wants to sell one for my rear speakers feel free to PM me.
  3. Those fifteens look interesting for non-techies and techies alike. I bet they'll be very popular.
  4. Got my right speaker all back together and I'm just wowed. Despite the medium to low amount of hiss you can only hear when nothing is playing, things sound out of this world. Real tri-amping combined with 1-2 years worth of acoustic improvements make a great combination. I have never heard anything with this level of clarity and smoothness (some tracks before were a little harsh, but sound incredible tri-amped). On some of the most dynamic tracks I have, strings and plucks are indistinguishable from real instruments where they only sounded kind of real before. The same holds true for voices which are absolutely jaw dropping. Although they probably have some of the better passive crossovers, I have no idea why Klipsch would spend years developing these speakers with such excellent drivers, then cripple them like they did. Why can't manufacturers at the $20k price point provide an outboard box with an active crossover in it (bought my pairs used for $8000 and $6400 which is still a huge amount of money)? I am on a slippery slope now as my center (which I don't have room for now) and rear speakers pale in comparison with their passive crossovers installed. Spending another $2-3k to build more matching shelves, buy three more XR1001's and add more amps is worth it given the improvement that is apparently possible. Just not sure about the space constraints.
  5. Thanks again Chris for all your help. I owe you and your wife dinner next time I'm in Arlington! Make sense. Could be that with the mic 13" from the midrange, the midrange was dominating and so the excess delay issue did not show up. I think my system is going to sound fabulous when I'm done (well already sounded great before). I'm half way finished removing the XO's from the right speaker.
  6. Not surprising I guess since the drivers are not physically aligned in the speaker? I was going to let Dirac handle the alignment as my active XO is analog.
  7. It's definitely the amp (e.g. with only the amp hooked up mid and high has hiss). Ordered a selection of the Vishay/Mills 12W non-inductive wire wound resistors (expensive at over $4 a peice, but I didn't want to use a regular wire wound resistor like what radioshack has). Vishay resistors: http://www.vishay.com/docs/31801/mra.pdf The Palladium brochure says this about the midrange: "The inverted dome midrange driver operates from 500 Hz to 3.5 kHz and is a unique design, not found on any previous Klipsch product. The driver sensitivity of 106 dB allows minimal excursion at normal playback volume. As cone excursion reduces, so does distortion. The 4.5-inch aluminum dome is driven by 3 high temperature N35H neodymium magnets, ensuring linearity under a range of listening volumes..." And the spec sheet says mids are crossed at 3.2kHz?!? However, I get less THD and less dip when using 4kHz. I am seeing an anomaly on the excess group delay plot at 4.76kHz. Must be the room? Otherwise, I think group delay looks decent at the MLP (about 2 meters)? 13 inches from high and mid drivers: AT MLP:
  8. Any time you change shift by 180 degrees you have a shift in polarity, but the wrapping was confusing me apparently. The attached is a much better way to view phase (I clicked controls in REW then unwrap). I assume ideally, you'd want as flat sloping (very linear) curve as possible? Mine has a drop at the tweeter and changes slope through the mid-range. Not sure what to do to make mine more ideal as the Ashley XR1001 is an analog active crossover, but Dirac will clean up the phase plots. Can't wait to do the other channel. Measurements below are at MLP, no subs, no Dirac and both use the Ashley XR1001.
  9. Measurements below are at MLP, no subs, no Dirac and both use the Ashley XR1001. IMD is also lower with no passives. No passive XO's uses XMC-1 processor via HDMI. Passive XO's uses the very nice stereo Oppo HA-1. Even with the noise advantages the Oppo has, IMD has lowered considerably for some of the side-bands with the passive XO's removed.
  10. Here are some THD curves. Parts are lower than before and some are slightly higher. Measurements below are at MLP, no subs, no Dirac and both use the Ashley XR1001. Note for the distortion readings top one uses XMC-1 (HDMI) and bottom uses Oppo HA-1 preamp (USB DAC). This could explain why parts of the curve have lower THD. Got too tired to hook the Oppo back up, but it is probably the nicer preamp between the two wrt to noise (asynchronous USB DAC, fully balanced, no video circuits, no FM/AM, etc...). IMD is also lower with no passives. Someday I will hook up the Oppo HA-1, but I have it listed for sale on craigslist so hopefully no one buys it first! Ok, They will in next post. Hit the 2Mb limit again.
  11. Here are some pics of the MLP and how I measured the above measurements. Also showing the new settings on the Ashley XR1001 for no passive XO's installed.
  12. @DrWho @Chris A Have the left hooked up with no passive xo. But mid and tweeter have a hiss that is audible at the MLP with nothing on but just the amp. I hate to add a wire wound resistor back, but was thinking to put a 4.5ohm in series with each HF and MF driver. Probably do it at the back of the amp and solder it on the speaker cable. Was looking at these: http://www.parts-express.com/mills-45-ohm-12w-non-inductive-resistor--005-4.5 So would you live with a hiss or add a resistor? Measurements below are at MLP, no subs, no Dirac and both use the Ashley XR1001.
  13. Thanks for taking a look. What you say makes a lot of sense as I can hear bass differences in certain areas of my room (even though my bass performance is very very good). The only plots where things are very close to the same are at the bottom of the last page where I compare lazy tri-amping using the Oppo HA-1 with the Ashley versus using a wye XLR adapter to feed the MF and HF signal directly from the Oppo HA-1 preout. However, even those have a little less than 1-2dB loudness difference since I removed the Ashley from the circuit! Both have no crossover to subs, use the Oppo HA-1 lefts channel via USB DAC input and I didn't move mic from MLP. I have already took out the passive XO's for the left channel (no turning back now). Hopefully I can get some measurements very close to the levels found below for the same speaker with/without sub. Fool's tri-amping low volume (using XLR Wye adapter to feed MF and HF amps): Versus the lazy tri-amping low volume (using Ashley XR1001): Fool's tri-amping loud volume:
  14. Yes. I do a frequency sweep using an Earthworks M30 mic and a Stienberg UR22 mkii USB audio interface as input to REW. REW's output can be over HDMI to my processor, or out the UR22 mkii or even an Oppo HA-1 using it's USB input. REW can do THD and individual harmonic distortion curves (thinking mine is set to show up through 10th harmonic) that are displayed after doing the above sweep measurement. The Earthworks M30 mic I have should be +/-1dB or less, but I'm lazy so haven't sent it to them to calibrate it. I plan to point the mic one meter at the center of the associated driver for the level matching using the Ashley dials (unless you have other advice). I plan to tie the woofers together, although the P39f might be a 3.5 way design (LF passive XO has separate connections for each woofer). Dirac will fine tune/EQ things at the MLP using the same mic, but I normally point it at the ceiling for the 9 Dirac measurements that are averaged at the main seating position (one seat calibration).
  15. LOW FREQ PASSIVE XO: Outer connectors where speaker wires go:
  16. I only removed the bars that would normally allow only one speaker wire to connect to LF, MF and HF at the same time. Internal passive XO's are still in circuit though, they just aren't tied together with the external bars that would normally go under the binding posts. LF passive XO (board #1 in speaker) has hookups for individual woofers (top, mid and bottom) and an input. MF/HF passive XO (board #2 in speaker) has separate hookups for midrange and high frequency drivers. Can't attach anymore pics right now due to 2MB limit. Will post pics on next post. May have to wait for someone else to post here though.
  17. Lazy approach: Ashley Settings: Used in Mono 3-way mode; on XR1001 serves the left, another serves the right. All levels set to U on Ashely (XMC-1 sets overall channel level and Dirac on the PC is able to fine tune level is very small increments). Response affects damping at the crossover region only and is not slope, all Response settings set to 6. LF XO set to 500Hz, MF XO set to a little below 4kHz. Dirac on my PC acts as a virtual soundcard that uses filters I measure via 9 measurements at the MLP. It is setup to use a slightly downward tilted/sloping house curve. I play all my media through a server in another room using a long Redmere HDMI cable from Monoprice.
  18. I found Rod Elliott's site again as the previous host site went down. http://sound.whsites.net/bi-amp2.htm#dc-protection He discusses the need for a capacitor to protect the tweeter due to near DC transients that occur for example when you turn on an amp. Do most add a large capacitor when tri-amping?
  19. The manual for the Ashley has this interesting feature to fine tune the crossover bands if there are dips. So should I just go off the speaker specs at first and adjust for crossover frequency for peaks only (probably also going to look at THD also) and use the response/damping factor control for dips? "Response - adjusts the damping of the filter affecting the response shape at the crossover point. The dial calibrations refer to the amount of attenuation effected by the filter at the crossover frequency, i.e., a setting of 3dB means that the filter’s high-pass and low-pass outputs are each “rolled off 3dB at the crossover point”. This describes Butterworth filter response, or a gentle 3dB peak at the crossover point where the two filter output signals overlap. To obtain a flat signal, or “Linkwitz-Riley” response, set the Response control to “6”. To obtain a notch at the crossover point, turn down the response control past “6” to best suit your needs. The purpose of this control is to help offset the inaccuracies inherent in typical loudspeakers, helping you to achieve a flat system response. NOTE: The Response control is not a “slope” control. The Response control only affects filter response shape in the immediate vicinity of the crossover frequency; the ultimate crossover slope is a fixed parameter." Also, forgot to ask this, but should I check polarity of the midrange and tweeter and what's the best way to do this without removing them (will only have access to the bottom of the speaker)? Is it true that sometimes drivers are installed with polarity swapped (when compared to that of the woofer) to get the best possible passive crossover region?
  20. How closely do I need to match the EQ the passives are adding if I were to fully tri-amp? Is this an OK process since my active crossover is analog (can only adjust gain, freq and damping near -3dB point, slope is fixed at 24dB/octave): http://ashly.com/wp-content/uploads/2015/08/xr-1001-2001-4001-crossovers-r01.pdf 1. Measure driver + passive network one at a time in REW (e.g. measure LF while muting MF and HF) with the mic pointed at the center of each driver (versus at the MLP like I've been doing) 2. Note slope and -3dB point of the filter from the REW plot (although I can't change slope in the Ashley XR1001) 3. Take my speakers apart and remove the crossovers, then make some jumpers to reach each of the connectors 4. Put settings into the Ashley crossover with gain very low, then raise gain while taking REW measurements until I reach a level close to what it was in 1. 5. Repeat for the other two drivers. I was going to ignore any other EQ the passive XO's are doing as Dirac can easily handle +/-10dB dips and peaks and fix automatically. My 600W per channel amp will be very large for the MF and HF drivers, but I don't think this should hurt anything? However, since the horns are much more efficient than the LF drivers, I will have to adjust the MF and HF gain dials on the Ashley to lowest setting. Also how should I be adjusting gain? Using the overall freq response plot or by using the signal generator and sending a single sine wave? You note that my gain is off when looking at the dual test tone plots. I ask this because clearly I mucked up level before as the room modes were causing some peaks for LF, I set LF to be lower than what it should be. I also typically don't use any smoothing in REW. Maybe I should use 1/48 smoothing when setting gains this time around?
  21. Same test as above (Oppo HA-1 feeding tri-amped P-39f and no subs), but replaced the Ashley active crossover with a XLR Wye adapter. Now this would be fool's tri-amping Appears to be a lot more side bands (and at higher amplitude) versus having the Ashley XR1001 limit frequencies to the passive crossovers.
  22. So I swapped in an Oppo HA-1 headphone amplifier/USB DAC. No subwoofer outputs now so I am only quasi tri-amping, but there are still the side bands (used a digital SPL meter to re-calibrate SPL in REW). I notice that decreasing the volume just 12dB, almost gets rid of the side bands (results in about a 26dB decrease in side bands). Note 87dB peak overlayed onto the same dual band signal, but with a lower preamp volume. This makes me think something is going on with the speaker itself (as you are saying) at greater than 75dB acoustic output at about 7 feet (e.g. MLP).
  23. Hopefully @DrWho responds, but I'm guessing to see if it's back EMF causing this, I'd need to do true fool's bi-amping where each amp gets the entire signal, while keeping the three passive crossovers isolated. If this plot shows the same side band improvement, I would have a decent verification that it was indeed from back-EMF from the drivers? I have to believe the large amps I am using have an adequate damping factor for the each driver + passive network, but maybe not it seems?
  24. I prefer the term lazy tri-amping but this is really quad-amping as I'm still crossing to my dual subs using my processor. If you click on the link at the bottom of my post, the REW file is there. The diagrams are in order with tri-amping on top, immediately following the normal single amp measurement. All measurements were crossed to my subs at 80Hz, so maybe I should call this lazy quad-amping? I took all measurements from the main listening position, and just measured my rear speakers (which are also P-39f's I bought from ebay). I am using REW to generate two test tones, then using REW to capture a single spectrogram of the acoustic output at the MLP. For the first two, we see side bands have decreased by about 15dB when using lazy tri-amping + sub for a dual band 60Hz + 200Hz signal. For the next two measurements at 240Hz and 800Hz, only one side band is decreased about 12dB. Lastly for the last two 2400Hz and 8000Hz dual band measurements, side bands near 5kHz decrease significantly when tri-amping. In fact, one side band drops 20dB and the other about 18dB. Not sure if this is fools tri-amping as I'm not sending the full signal to any amp, but I agree it is not full tri-amping either. I'm using two Ashley XR1001 active crossovers, plus the crossover in my XMC-1 processor for the subs to limit frequencies to the respective amps. I let Dirac fine tune everything on my PC as the software is doing 32 bit math and also has filters to match all sampling frequencies my HDMI output can do (time aligns everything too as shown a few posts up). I am game for trying to remove my crossovers next, but in your professional opinion, would I see a benefit besides improving the damping factor by wiring amps directly to the drivers? Have to be honest it is scary to rip open speakers I paid thousands of dollars for and risk over powering the drivers if I'm not going to see a medium amount of difference, but if it's going to make it sound better...
×
×
  • Create New...