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HI thanks for your help. Sorry for not seeing this sooner. New driver plots are coming next week once I move the speakers to their final resting place (TBD). Klipsch did do a tapered top woofer, but the parts list from Canada I found only seemed to list one part number for the P-39f woofers, so I figured it was ok to tri-amp? Under this folder there are several REW files (.mdat) if you want to see the driver measurements used in the previous post (view details and pick the one prior to that date). There are also plots (jpeg images) that show the 240Hz dip has been there before I went active (thnk these were dated March 2016). https://drive.google.com/drive/folders/0B1J0a4OV_WGLS2lYYl85N1BRNkE I found last night that if I switch my speakers and subs around (plus move the speakers out more) it becomes a 200 Hz dip though. You speak of a path difference of 28"; could this be related floor and/or ceiling bounce? The direct path difference for the top and bottom woofer to the mic was 3-4" at most. I will attempt to debunk the floor bounce theory as I made some 8" x 2' x 4' bass traps I can lay on the floor and see. The mic was as pictured in my last post, so the only thing within 14" of it was the chair back which is well padded. PS: Also got rid of any hiss whatsoever in the right MR and TW by purchasing a member's used Benchmark AHB2 amp as even adding some H-pads I made previously (~ -12dB) wasn't eliminating it. Have it hooked to the right for now just for testing purposes, but found another one that is coming next week for the other speaker. EDIT: I think this is caused by room shape. Laying 8" OC 703 on the floor in front of the speaker helped a tiny bit, but dip was still there. You can hear the drop out when playing a 201 Hz sine wave and moving around. Judging by ear and test tone, if I move my chair forward 2 feet, it would fix it, but this would compromise imaging. I'm thinking of trying the speakers corner loaded up front as close to the front wall as I can get them?

Unfortunately, I think only a few people will ever hear what a calibrated and tri-amped system in a well treated room can do. Thanks so much for your help Chris! I had sunk a lot of free time and money into my system since I was at your place to capture the clarity of your system in my small room. I really want to tri-amp my rear speakers and my center later, but I think the money I've spent recently on the tri-amping project is enough for a few years! Even the shelves were several hundred in raw materials to build, another $80-100 for XLR cables and some DIY speaker cables, extra amps, Xilica processor, etc... Not a cheap solution, but well worth it in performance gains. I will setup alerts for one or two more Xilica XDxxxx's. Hopefully if I wait a few years I will find a surplus deal. For better or worse, this may be the end of tweaking things as I have reached the point where I don't believe there is a way to improve things audibly for stereo content in my particular room. It definitely sounds world class and life-like on every track I've played.

Thanks for taking such a detailed look! It is definitely true EGD is not flat, and this raises a question I had: Would you sacrifice a flat response for a better matching/flatter excess group delay (EGD)? Or do you think the way I matched phase is ok? I unwrap phase about the crossover and zoom in (using a band limited sweep around the crossover), then I'll change delay on the impulse plot incrementally until the angle matches (keeping track of how much delay I apply). I know I can get EGD to be ~-2ms which is a lot closer to the rest of the frequencies, but this comes at a price of phase alignment (if sub polarity is not swapped). However, I think previously I swapped polarity on the subs and obtained an even better EGD match, but then delay was very unrealistic (like 28ms+). I remember this option not affecting phase as much though. Maybe I should go with that one? EDIT: this Dirac calibration combined with accurate phase alignment sounds incredible. Still open to trying to improve EGD depending on your advice, but bass strings, drums, etc sound perfect and 100% life-like. One thing I did different on the Dirac calibration is I left the mic at the center of the mlp and didn't move it for the 9 measurements. I think this works since my room is well treated, and gives to a ruler flat response. Please see prior post above for new Dirac REW file.

@Chris A Here is the Dirac REW file: https://drive.google.com/open?id=0B1J0a4OV_WGLY2hMSV9YNDNwRmc Some really pretty plots in there for you to examine! Dirac did a fantastic job for me this time and did fix the 80Hz ringing. I also bypassed all PEQ on the XD4080 since I know Dirac can EQ things so well and also improve phase response. I am not worried about the slight hiss (may not hear it in a normally treated room, but I have a lot of absorption in mine). Well worth the upgrade in clarity versus passive crossovers, although the Palladium crossovers sound pretty decent stock, I can still hear details I had missed before on almost every track; especially strings and symbol decays. I definitely don't regret purchasing the XD4080 and would buy another if it was reasonable. The FIR filters are super nice!

@Chris A It's done? Please feel free to critique. REW file is found here: https://drive.google.com/open?id=0B1J0a4OV_WGLeTZGTGZyTEdKaGM I'm now using the 4x8 Xilica XD4080, tri-amping P-39f's (passive xo's removed), and also integrating two JL Audio F212 subs using the Xilica. I did this so I can use other pre-amps (such as the Oppo HA-1 via AES from my server in the next room) and not be "stuck" with the Emotiva XMC-1 when I want to use my subs. All drivers are time aligned to the best possible/nearest Xilica time delay setting. I used band limited measurements to fine tune the phase at each crossover region after first relying on a band limited impulse response measurement. Impulse, waterfall and phase is the best response I've ever achieved without using Dirac, and I'm only using a total of 6 PEQ filters for all front channels (2 subs and 2 for each of the front left and right LF drivers). After/if I calibrate using Dirac, I will post a new file. The 200 Hz issue is not a crossover, but a room issue and I can't move my main speakers to fix it. LF to MF is FIR XO at 500Hz (per Klipsch spec sheet). MF to HF is FIR XO at 3.8kHz (to avoid some >1% THD spikes in the HF driver). THD is very very low too at 90dB, measured with a Steinberg UR22 mk ii USB audio device and an Earthworks M30 mic at the main listening position, pointed upwards at the ceiling. However, I did not use the all-pass filters to correct for the phase shift for the Sub and LF 48dB/octave butterworth crossover at 80 Hz, and would like to explore this if it will give even better results. If there is a beginner tutorial on generating all-pass filter settings, I'm open to trying it. Rephase only does auto FIR filters which I can't use (these are only for crossovers and only 1500 taps are available on the XD4080). Also, there is still a slight amount of hiss from the XD4080, but no more than the Ashly XR1001's, probably less. If you have any ideas, please advise. Unfortunately the only amps I have to tri-amp with are the Emotiva XPR-1's (two for LF), and XPR-2's (two for MF+HF). The preamps I've tried are the Oppo HA-1 and Emotiva XMC-1. If I take the XD4080 out the slight hiss goes away for the most part. The MF horns are 106dB efficient, but I already added series resistance (so the amp sees ~10 ohms for HF and for MF drivers); this eliminated the amp's hiss for the most part. Thanks for all your help on this project! Pictures of the XD4080 settings are attached.

For the $160/each I paid for them (literally brand new used from ebay), the Ashly's are very nice. But yes, I obsess over graphs too much and want more accurate control with time delay, crossover slopes, etc.

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?

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.

Those fifteens look interesting for non-techies and techies alike. I bet they'll be very popular.

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.

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.

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.

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:

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.

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.

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.

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.

@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.

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:

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).

MF and HF passive XO board:

LOW FREQ PASSIVE XO: Outer connectors where speaker wires go:

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.

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.

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?