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1bigpig

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  1. @Schu This is a quick and dirty SMAHL tweeter sweep. I say quick cuz, my wife said "Turn that sh!t down!" So this is all I got. The tweeter was at 1m but the mic was not exactly the same height as the tweeter (thus "dirty"). Funny thing, it matches the DE120 "factory" curve almost exactly. B&C DE120 factory curve: Bruce
  2. @SchuI posted the individual drivers on my first post. But this is it again. I have not had a chance to run a sweep on the new SMAHL tweeter yet. Maybe sometime this week. All sweeps were full range 1v at 1m. UMIK mic height was adjusted for each driver. The blue line is a CTS K77 tweeter. Bruce
  3. @Wirrunna just wanted to post a quick update since I have been absent. I decided to try DaveA's SMAHL tweeters. I decided that I could not get past the tweeters being mounted behind the motor board. I was able to install them (with a slight amount of manual sanding of the opening) and then promptly went out of town. So I got back and have been listening to them. My sound memory is not what it use to be after being gone for a week, so I don't know for sure if it is a significant upgrade or not. Without any adjustment, it does seem to be brighter. I have not had a chance to EQ the tweeters yet. I believe it is either no EQ or EQed for the K77--which is why it might be too bright. What IS an upgrade is my decision to upgrade to a MiniDSP 4x10. Now I can control everything in one program AND I do notice less noise than the 2 2x4HDs. I guess if I knew I was going to do this project from the start, I would purchase the 4x10 instead of two 2x4HDs. It is about $100 more, but the unit is nicer and has less noise. I already had a 2x4HD from another project, so buying a second unit was a cheaper way to go active for the La Scalas. For kicks, I decided to plug in the ALK "Super" AA passive crossovers I built--I added banana plugs to make it a super fast swap the speaker between active and passive-- and I do think the analog crossover has very smooth presentation. It is not an apples to apples comparison, as I am using a tube amp with the passive compared to solid state amps for the active. I guess I need to wire in the tube amp into the mid-range and see if I get the best of both worlds... So more testing to do and I want to measure the new SMAHL tweeters to see what their curve looks like. Bruce
  4. @Wirrunnathese had AA crossovers as stock (if not stock, the crossovers are the age as the speakers). I saw a pair of '85 K-Horns that had AL crossovers. Unfortunately, the bottoms has a little water damage (probably had water damage from Hurricane Harvey in 2017 and while the speakers were only in a few inches of water, the veneer and bottom MDF material was all bubbled and warped. I passed, but I keep kicking my self thinking this would have been a "better" project since I would have re-veneered the front and build some corner baffles so they would not have to been placed in a real corner. Unfortunately, I have not had time to mess with my speakers this week. With what little time I have had, I have been reading up on phase alignment. While I have questions, I think they will be answered as soon as I run some sweeps and look at the results--or at least I will have a better formulated question to ask here. Speaking of tweeters, have you heard DaveA's SMAHL tweeter? I have a mental block with tweeter (and midrange horn) mounted to the back side of the motorboard. The cutout acts like a diffraction slit. The SMAHL tweeter is flush mounted to the outside face. The downside is that it is just a lens and not a true horn. Either way, they both use the same DE120 driver. Lastly, has anyone ever put a 45 degree chamfer on the outside of the mid range horn cutout? Would it make a difference with sound dispersion/refraction. Logic says it should be smoother but maybe someone has tried it and found it made no difference because of the long wavelengths of the midrange. First world problems, right?! Bruce
  5. @Wirrunna yes I am running a stock '79 LaScala and '80 with Atlas 55V drivers. One has a CTS K-77 and the other is an EV K-77. I have not opened the doghouse yet, as no need. I did purchase some Crites K77 (DE120) replacements tweeter, but have held off doing the swap so far. I did rebuilt the AA crossovers to ALK's "what wrong with the AA crossover" specs. It sounded way better than the stock AA--probably dues to the age of the old caps. The original AA had a lot of "brightness" and a fair bit of sibilance. The "new" AA is much smoother but still has some honk/harshness when turned up. Turned up is relative, as I am running a 300b SET to drive these. This is what drove me to look at the active crossovers. To learn something new and the ability to adjust the honky-ness of the mids via crossover. The MiniDSP allows you to EQ the system, but so far, my experiences with room EQ (REW and Audissy) has left my systems sounding dull and uninteresting. I do understand a lot of music is just that--dull and flat, but I find that if I remove most of the sibilance and harshness but run the speakers with just basic correction (drivers, not whole system), it sounds a lot more dynamic and exciting. Maybe that will get fatiguing after long listening sessions, but right now, I don't have enough time to sit down and listen to more than a single album at a time--if that much. A lot more learning is what I have to do. My understanding of digital crossover order and phase was incorrect. I also need to learn how to better use REW--offset with the desire to listen to actual music instead of sweep tones. Just for the record, the ALK "Whats wrong with the AA crossover" crossover points are: ALK AA Woofer 1.3mH 975 hz Low pass 6dB per octave Squawker 47mF 420 hz High Pass 6dB per octave .3mH & 2.2mF 6000 hz upper band pass 12dB per octave tweeter high pass ~5000 to 5500 hz high Pass 18dB per octave Once I look at the schematics of some other Klipsch crossovers, I will see if I can reverse the crossover points and slopes. Then I will make a MiniDSP .xml file for these different crossovers so other MiniDSP users can load them to "simulate" the crossovers of yore. Back to the grindstone...
  6. @Chris A Thanks! I am gonna look at the "Using REW to Determine Time Delay". I am also reading Scott Hinson's "Determines crossover points via driver distortion". I am trying to learning all this stuff. There is a LOT of features and stuff to learn in REW. I have not explored the "group delay" or "minimum phase" features of REW. That is something that I am gonna investigate. When I took my measurements, I did not put anything on the floor between the speaker and the mic. I will definitely do that and take another set of measurements. Do you recommend anything in particular? Cargo blanket, rubber mat, bedding/comforter or something else between the doghouse and the mic? FYI, I am using a UMIK-1 for my measurements mounted on a camera tripod with a meter yard stick to measure distance. Lastly, I understand that 1st, 2nd, 3rd and 4th order in passives changes the phase by 90' for each order. I was under the assumption that in the digital domain, the crossover order did not change the phase. Am I wrong with that assumption? I got some homework to do tonight. Bruce PS the MiniDSP has 4 settings. I am thinking of copying the cross over points and slopes of different Klipsch crossovers to see how "different" they each sound with a press of a button--but that is for another day.
  7. I am new to active crossovers, new to using REW to test speakers and Klipsch speakers. So I am hoping someone with more knowledge can "look over my homework" to make sure I am on the right path. @Chris A or anybody else with active speakers or familiar with active crossovers, I would be happy for y'all to look at driver graph and then see if crossover points are correct. This is a tri-amp setup via 2 MiniDPS 2x4HDs (one doing left channel and the other doing the right) with 3 AIYIMA A07 amps. While I am not overly familiar with REW, I have watched a few videos on how to use it to measure your speakers. Scott Hinson has video on how to measure each driver and I tried to follow his steps to get my response graph for each driver (1v @ 1m because I have neighbors). While it may not be perfect since I could not take my speakers outside to measure each driver, I think they are close. Then again, I maybe fooling myself, which is why I am hoping someone can look this stuff over and tell me I am all wrong or on the right track. Lastly, I attached 4 MiniDPS settings "screens". The low pass, for the woofer, the band pass for the squawker, and the high pass for the tweeter. The 4th is the time delay that I derived using the tech paper that MiniDPS posted on measuring impulse response to time align your drivers. There is no delay for the woofer, a 2.8ms delay for the squawker and a 4.45ms delay for the tweeter. I have tried to verify these settings and there is still a few uSeconds of variance between all the drivers. If I change the delay on the tweeter, the impulse either fall just in front or just behind the squawker--I can't seem to get them to align perfectly. This could be because: I am not familiar enough to using REW to measure the impulse correctly OR I think I am hitting the delay resolution of the MiniDSP OR I could just have totally messed up the original impulse response measurement and these number of nowhere remotely correct. So fi these delay settings seem incorrect, I would be happy to revisit them. With all this said, they still sound a LOT better than it did with the original AA crossover. So I think I am on the right track. Thanks!
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