Jump to content

lowerFE

Members
  • Content count

    135
  • Joined

  • Last visited

  • Days Won

    9

lowerFE last won the day on October 17

lowerFE had the most liked content!

Community Reputation

35 Excellent

About lowerFE

  • Rank
    Super Power Member

Recent Profile Visitors

155 profile views
  1. So after reading this thread over the past year and amazed and the technical depth and extreme attention to detail paid to the tuning of this system and going "man I really want to hear this!", I flew and went to check out this system. And boy what an amazing system to listen to! My mind was blown as I was amazed by one thing after the other. All the work put into getting the tonal balance of this speaker correct really paid off big time. The whole system just sounds really "correct", and the more I listen to it the more I'm amazed by it. I brought my Reference Mini's with me as a comparison, and there was a very obvious difference in sound quality. I thought my speakers sounded really great, but it sound noticeably "off" when compared to this system. The speakers had a fantastic amount of detail, and the transients are awesome! It felt like I'm listening to a pair of really good headphones (and few people realize how hard and impressive it is to achieve this), but I also get the enveloping sound that makes speaker listening so pleasurable. It's the best of both worlds. What's even more impressive is the bass. I don't think I've heard bass so tight and full sounding in a room, which is clearly due to the complex integration efforts of multiple subs and individual EQ's to get such flat bass over a large number of seats. The clarity and tightness is seriously impressive. Again, just like a headphone, and that is actually something I've never heard before from a subwoofer. It is straight up the best sounding bass I've heard in a room. Now when you also get the whole body physical sensation from bass, addictive is an understatement. One thing that is unforgettable and blew my mind is how great the speakers sound in the kitchen! I don't think SME has ever mentioned this, but it was indeed one of his goals. It was remarkable hearing a correct tonal balance with almost no treble roll off in a different room! I still can't believe this is achievable. It must be the combination of controlled directivity speakers and properly placed diffusers pulled this amazing magic trick of a feat. I've heard a lot of amazing home theaters, but this is the first time I heard imaging from surrounds. It was trippy to be able to pinpoint the location of the sound going across the rear stage. I really wish we watched an action movie and be able to so accurately track the position of the sound effects. This is even more impressive as I seem to clearly have less ability to hear imaging compared to other people. Speaking about imaging, the speakers reproduced phase manipulated music tracks far more accurately than anything I've heard so far. It must be the room treatments that are preserving the phase accuracy of the speakers. It was like "oh this is where it is supposed to sound!" I was also exposed to the dark secrets of the time domain in room correction. That was a revelation to me to be exposed to so much more information and tools to analyze room acoustics. Now it makes sense why and how the room is mucking up the sound. It's all in the time domain! Now I am able to correlate measurements and subjective judgment of how good (or bad) the room sounds. I have so much to dig and play around with now. Measurements really can tell you about how good something sounds if you look at the right things and how to interpret it properly. Thank you SME and his wife for being such amazingly gracious hosts. That was one hell of a weekend! Oh, and did I make it clear enough that your system sounds good?
  2. JTR Speakers Captivator 212Pro Discussion

    Very impressive results for such a small cabinet, driver size, and low cost. Of particularly noteworthy aspect of the performance, which Jeff kinda pointed out already, is how little difference there is between the long term output and burst output. I've never seen a passive system driven by a K10/K20 report such small differences. I wonder what's going on. In one way it can be seen as excellent design that maximizes long term output, in another one could wonder what's going on with the drivers that they can barely handle 100V during burst testing. Anyone wanna chime in?
  3. Little update. I just moved last week for a new job, so I didn't get a chance to really work on the speakers much to deal with moving. But for something fun, I improved the limiter design a bit to get a bit more maximum clean bass output from the speaker before the limiter clamps the output. I've wrote a lot about my speakers so far, but this time here's a video of the Reference Mini's doing ~107dB of bass and 109dB peaks. The listening position is about 8 feet from the speakers. For reference the TV is 40". I promised there will be bass!
  4. Oh I've been enjoying this, but not as much as I would like to because I've had way too many things to do in the past couple of months. At certain times it feels like working on the speaker is a chore that needs to be done. Granted it was a lot of technicalities like measurements and stuff, but now the real fun begins with all the DSP, features, especially since soon I will have a lot more free time to play and enjoy. I'm going to get Dirac soon for this speaker and it should be fun as that should be a big step forward in sound quality in a room. There's going to be endless amounts of tweaking and optimization that I will be able to do with this. I think that's the best part, being able to incrementally and continuously improve the speaker and have features or combination of features that exist on no other commercial speakers. When I get a breather I got to catch up on what you have done!
  5. Yes I did. That'll likely go into the next speaker whenever that happens.
  6. Oh it'll be done more than right. There will be lots of tweaking, but it won't be the kind of minute tweaking that a lot of companies do. I will be focusing a lot more on the stuff that makes a bigger difference in creating a better subjective listening experience. This means LOTS of various DSP features that has seldomly or never been used with speakers before, but done right. It'll take a lot more than 9 months!
  7. Another update. After learning about measurements for some time, I think I'm getting a hang of how to really properly measure speakers. I don't have anything to show yet, because I ran into problems doing accurate polar measurements. I will show measurements when I have a full set of measurements ready. A few things I noticed. Turns out bipoles are tricky little things. Maybe this is why there are hardly any bipole speakers. I have to use these vertically. The midrange response is rippled and has a dip around 200Hz in horizontal orientation because the baffle is much wider, and the woofer is off center. This causes various interferences due to the path length causing the rear woofer to not integrate with the front woofer properly. The issue is mitigated in vertical orientation since the baffle is much narrower and the woofers are centered. One unintended bonus from the 200Hz dip in horizontal orientation is that when placed vertically, the 200Hz dip appears in the vertical plane, and it is actually pretty close to the typical ceiling bounce cancellation frequency in a normal height room. So the problem of ceiling bounce is unexpectedly reduced. I cleaned up the phase of the speaker and used FIR filters to do the bass boost, baffle step, high pass, and clean up the phase from the 3-band compressor. The bass is significantly tighter now, which isn't surprising because I had 6 major sources of phase shift (8th order HPF, 26dB bass boost, 2 LR4 band splitting for 3 band compressor) and it really screwed with the time domain of the bass. I did a comparison between doing the DSP processing at 44.1KHz and 176.4KHz. The comparison isn't ideal because it isn't blind, and it wasn't instantaneous because JRiver has to be restarted to change sampling rate. I *think* the 176.4KHz had a little more clarity, but the difference is very small. I went back to 44.1KHz because the delay for 176.4KHz is really long at nearly 2 seconds. I need to find a way to process the bass at a lower sampling rate so I can have 176.4KHz for mid and treble without the long delay.
  8. Not yet! Far from it actually. There's a lot of DSP optimizations and tricks I need to add on this. But at least right now I can have some fun listening to music as I continue to work on this. I'll be a little less busy for the next month or so, so it is actually great timing to be enjoying the heck out of these things I can't even imagine for you. I've had problems where it only happens at a high enough volume. I'm sure that happens for you too, but for the stuff you work on the volume would be This came in heavier than I expected. It weighs 14.7 pounds each. It's a heavy little sucker, and it always surprises people when they try to lift it. Now I have a silly little idea in the back of my mind to make the next speaker I build as heavy as possible That ATC monitor is indeed amazing. That doesn't substitute measurements though. I have done some measurements, but I don't think they are totally accurate. Soon I will be doing extensive polar measurements on this speaker. Gonna do it really right this time around, but it'll take some time.
  9. Long overdue update. Been incredibly busy lately, so here's a look at the progress I've done with this speaker.I added a preamp board into the speaker. The amplifier needed 2.7V of input sensitivity to reach full output, but my output stage on my Xonar U7 only outputs 1V. This is made from the OPA1642 op amp. The second PCB is for filtering the noisy auxiliary power from the ICEpower amp. The preamp steps up the voltage by 4x. Even though I only need 2.7x, I used 4x to allow spare headroom for the DAC. Now I can finally get full power from the amps and really crank out the SPL.There were many problems along the way. I had a lot of buzzing problems! I had a ground loop buzz problem that took a lot of effort to find the cause, and it was because the RCA connectors were directly mounted to the baffle without an isolator. Even though wood is a terrible conductor, it was enough to cause a very slight hum that was audible since the amp is running full tilt. I had another buzz problem that was extremely peculiar as well, and turns out it was a few screws that were not tightened inside. I had another buzzing problem that was because the rear end of the passive radiator isn't completely flat, so the washers were rubbing each other at high excursions. Another buzz was due to wires slapping the baskets at high volumes. 4 different sources of buzzing, and this has to be the hardest game of whack a mole I've ever played!I did some more tuning of the speaker. I need a really high quality speaker to be used as a reference for this speaker. So I went to a friend's house to use his ATC SCM150ASL's as a benchmark and reference. Before the tuning, while the Reference Mini held its own quite well, the ATC sounded noticeably better in every single metric. The speaker sounds much better after the tuning, and sounds much more similar to the ATC except in the bass. The ATC is a bit bass shy, and I like mine with more bass.
  10. I decided to reread some of the old responses to see if I can have a better understanding of everyone's responses now. I suspect there were things that went over my head when I first read this almost a year ago. I understand what everyone's saying perfectly now. I even got new understanding reading it again now. I was even able to follow SME's math! Thank you everyone who shared their knowledge.
  11. JTR Speakers Captivator 118HT

    Very impressive results from such a high efficiency, pro style driver. I wonder what is the Cms on the woofer to get such great deep bass and upper bass efficiency. Amazing output from just a 700W amplifier. Looks like the driver had just enough excursion and linearity to produce the 25-30Hz region of highest excursion levels with the given power. Kudos for JTR for coming up with such a high performance subwoofer for such low price. The engineering is obvious to get the most performance possible with modest parts, and that's real engineering skills.
  12. Yes, I just need to add mass to it to drop the tuning. Tang Band has 2 versions of the passive radiator I use, one with 25g Mms and one with 55g Mms. Based on what I'm seeing it looks like I have the 25g version when I thought I got the 55g. I'll just add enough mass until it hits the desired tuning.
  13. I got the speakers yesterday, and I'm grinning uncontrollably as I listen to my speaker. I implemented the crossover and did some rough tuning. Even with no bass (passive radiators tuned too high), the sound quality already greatly exceeded my expectations. The beryllium version of the Scanspeak Illuminator tweeter is 100% worth the 2.5x higher price. I expected minor improvements over the non beryllium version in my previous speaker, but the difference is drastic and immediately noticeable. The tweeter sounds sweeter and more detailed. The Wavecor woofers are a significant upgrade over the Tang Band W4-1720 woofer. I'm hearing a ton of lower midrange detail I've never heard before. The speaker also has much greater dynamics capabilities. Listening to music, especially classical music at high volumes is thrilling. I can't wait to put this speaker through an extensive measurement and tuning session.
  14. I might do that, but that'll be the last resort. The issue is that the noise floor is too high, especially when measuring the rear response for cardioid experimentations. The parking lot I'm using has a few cars driving by every minute, so I'm always crossing my fingers hoping no cars come driving by when I'm doing a sweep Now that's extreme! This will work for speaker measurements, but I have found that when I measure in my front yard my house actually acts as a wall and I can see a dip in the bass region caused by the reflection of the house. Good to hear you're going to do speakers! I think you'll find them to be just a little more complicated than sealed subs .
  15. Thank you! And yes, lots of DSP tinkering and measurements next. I'm trying to find good spaces to do measurements, and that's proven to be difficult. There is an outdoor parking lot which is great for ground plane measurement, but the asphalt surfaces ruins the measurement accuracy above 500Hz or so. Measuring at an indoor basketball court is fantastic, but they are really reluctant to let me use it, and when they do, it is at most for 1.5 hours, which isn't much time at all. I only have 3 hours worth of booking time lined up, and I need a lot more than that, especially for cardioid experimentations.
×