Hauxon's SRS 1.2TL restoration

I did a test today and noticed something interesting. If I play a low frequency note, low enough so I can easily see the woofer cone excursion I noticed the dimensional array (outer row) seem to receive much more powerful signal. While the SDA (outer) speaker array thumps in and out the inner array barely moves. This is the same on both speakers. I also found that the of the inner array the lower 2 speakers move the least.

Video:
https://www.youtube.com/watch?v=Ko6VRK1Mb88&feature=youtu.be

Normal?

I would appreciate it if someone would do a little test to see if their 1.2TL behaves the same. Tidal test track here: https://tidal.com/browse/track/3740847

There we might have a hint at why I've felt the bass has been weaker than expected. I did swap the lowest of the 6503 for a 6503 woofer from my SDA 2B. No change and the woofer I pulled from the SRS worked flawlessly in my 2B. There's definitely something not right with the wiring or in the crossover.

During troubleshooting yesterday I was wondering if this had anything to do with me using one of the original 0.4mH coils. Not likely though since it's in the tweeter crossover part. I did however realize I had not noticed the jumper at E-H!!! There we might have the reason for the "dark" sound.

I will need to trace my self through everything after work tonight. I won't quit until I'm 100% confident with the speakers and the modification...

I'm going to pull out the crossovers for inspection after work. If I read the schematics correctly the C1 (13.5uF) and L1 (2.0mH) function as low pass filter for the stereo array. I did position the L1 inductor flat on the crossover board. Although this orientation in relation to the L2 should be all right I have a hunch that I might be having problems because of that so I will fit it like it is on the original crossover and (and drawn on the Gimpod). I will also try measure the capacitance of the two 6.8uF caps to see if they will give me the expected 13.6uF.

One thing to add regarding the crossover build. It's a while since I finished the crossover so I've just been listening and watching TV. While listening I started to feel the sound was too much on the right, especially with spoken male dialog or singing, the image was always tad right. Other than that generally the sound was good and image where it should be. I ran through the internal wiring detaching each woofer (all 16) to seen if something had become lose and found nothing wrong. So I decided to swap the crossovers and voila! the image was now left oriented. I pulled the crossover for inspection, nothing everything where it should be and soldering looked good. I to resolder everything in the mid/bass section of the crossover. No success! Being a bit tired I decided to rest it for a while and not bother you guys with it.

New few weeks later I decided it was time to take another look into it. The problem was always on the back of my head. The only way to solve this was what I apply to problems at work, divide and conquer, simplify until I could isolate the failure. I still have the old crossovers so I plugged it in and no problem there. Wiring ruled out. I downloaded VituixCAD crossover design software tool and drew up the bass part of the crossover. Since the problem occurred within the range of the human voice I knew it was in the 100 Hz to 250 Hz range. With testing different values I could rule out the capacitors so the problem must be with the 2mH inductor. I disconnected the interconnection cable and biwire cords to make it easier to hear the difference. That way I could put my ear against the (inner) woofers and easily hear that the upper bass / low midrange was cut off. I pulled the crossover to inspect again. Long inspection with a magnifying glass ...and, nothing I could see.

I've been doing a little research regarding the coating Jantzen puts on the big 16 mH inductor. Seem the connection leads need to be scraped or the coating burt off for proper connection. I had used sandpaper on the 16 mH inductor so I was not too worried the problem was there. The 16mH is connected to the dimensional array on the other side and should not affect the stereo array. The problem did remain after disconnecting the interconnect cable. I knew the inductor was the problem. However the inductor is just a bunch of rolled up wire ..so what could be wrong with the inductor who looked perfect and was positioned on the crossover board as is should. I inspected the under side of the crossover again examining the 2mH connections soldering. One of the wires was a bit longer than the other so the solder didn't cover the end where I cut the wire like on the other side. ..could it be the coating/enamel wasn't burnt off?? My soldering iron is an old 25W Weller, maybe it just does not get hot enough to burn the coating off?? So I desoldered the inductor and cut the wire off short enough to to the solder would cover the end of the wires. And voila! I almost got a tear in my eye when I connected it back and problem solved.

And wow balanced the speaker sound all of a sudden! I just sat down for 2 hours and listened to many of my favorite tracks. So finally my SRS 1.2TL sound like the high-end loudspeakers they are, so smooth, so powerful.

I guess we can finally graduate the crossover. I will buy a hotter soldering station (probably Hakko 88) in the near future an resolder all the inductors for ease of the mind. ..well I also have a single inductor from the each of old crossover in my new one I forgot to order. But sound wise it's close to as good as it will get.

I will just listen and enjoy for now. The next improvements will be dampening. I'm delaying the tweeters until next year since I have to spend some on dental repairs, implants and crowns in the next few months. Will dig up this thread and post when something is new.

Best,
Hrannar

The funny thing is that there is no warning or instruction with the inductors or on the Jantzen or HiFiCollective websites. So noobs like me don't have the slightest idea. I've done a few hours of googling looking for what you're supposed to do or how the manufacturer (Jantzen) likes you to do it but can't find anything. Some things I guess must be learned the hard way.

Hahaha! I just might some day in 2020!