Curt Campbell's Halcyon build thread

Given the accuracy (lack of), how much of a shelf?

I'm wondering if that was some of the shoutiness I experienced. But then, it seems to have resolved itself going to balanced mode in the 1stWatt Clone F6s I built. So the chain of reasoning isn't quite there. Guessing it was more of a distortion product.

Have you pulled the main chamber stuffing to see how it affects the sound?

Now that I've found I have plenty of gain with the Benchmark DAC3, I'm considering building a set of balanced F4s. It'd cut the output impedance by a little over half compared to the F6s and many diyers that have built them say the circuit is as neutral as they've heard (cathode follower).

Not sure when but next steps for the Halcyons are to pull the x-overs, upgrade them and mount externally. After that, can try some active x-over stuff.
 
So after a few weeks of daily listening and a few rough measurements, I have decided to explore padding down the A10P at least 2 dB to compensate for the difference in lower efficiency of the SB SB17NRX2C35-8 woofers. I am asking the experts here what the bestway would be to accomplish this with the existing crossover.

Curt Campbell suggests changing the resistor R2021 to a lower value to make the balance change the other direction. Will adjusting the resistor higher in value, or a parallel resistor across the drivers be the better approach, or is there a much better way. I have read suggestions on the forum and other places for both ways. I would appreciate your thoughts.
 
I was surprised that there were not more replies to my question. I am an BSEE with many years of design experience in audio processing hardware. But my speaker building is limited. I was hoping for a few more clues as to how some of the experts out there would approach this. I can certainily simulate and calculate the crossover components accurately.

What has worked best when confronted with a change in efficiency in a driver such as this?

6sX7, I gave up trying to find the original woofers. I think that Madisound ran out of then just before I ordered my set. I haven't had time to work on this the past few days, but will soon. I will post what I learn.

-david BTW
 
I was surprised that there were not more replies to my question. I am an BSEE with many years of design experience in audio processing hardware. But my speaker building is limited. I was hoping for a few more clues as to how some of the experts out there would approach this. I can certainily simulate and calculate the crossover components accurately.

What has worked best when confronted with a change in efficiency in a driver such as this?

6sX7, I gave up trying to find the original woofers. I think that Madisound ran out of then just before I ordered my set. I haven't had time to work on this the past few days, but will soon. I will post what I learn.

-david BTW
I've noticed this thread is not the most trafficked. I've appreciated those that have stopped in to offer any help/advice.

Given the original woofers aren't available, I've thought about revisiting the design all together just need to start working the test equipment and experience. Hence the previous post about going to an active x-over. I very much like the MA Alpairs as they fit the bill for a "point source" with performance going up a notch when unloading the bass off of them. Definitely the direction I want to stick with, just need to find some in-production woofers to match them with.

I will keep an eye on this thread as I'm interested in what you learn. Will post on whatever my experiments get off to as I finally have the resources to build up a testing capability and try some real x-over design. Just need to get these F4 clones built so I have my reference system to work with.
 
Here is an updated report now that I actually have my Halcyon in place in my audio lab as intended. Finally they sound a lot more like I had hoped. I will post a photo after a bit of office cleanup. In comparison to my North Creek Kitty Kats, they are not quite as smooth or flat, but they do sound pretty good. The sound of the Alpair 10p is still the biggest issue for me. The bass is fairly well integrated with the full range and a lot more extended than my other bookshelf for sure.

I do think I can hear what 6xS7 has commented as shoutiness, just a touch. I also find that the top octave is just a bit too soft but expected I guess. My streaming source has a small DSP and if I add just a touch of top end it sounds better. A simple +3 dB shelf. (This is a streaming device and amp I designed for my former full-time employer. I am now retired and consulting only) When running at 96K sample rate, the Halcyons definitely have good resolution. If I push them hard the top end seems to get a bit congested, but for most of the type of music I listen to it is not a problem. Part of this may well be my class D amp. I hope to upgrade soon.

I also used my Audio Tools app from Studio Six Digital polarity test and found that one bass driver in one Halcyon was upside down (in phase) from the rest of the drivers. I also found that my streaming source was upside down in polarity from what it should have been. The low end is definitely better with all of the bass drivers in phase. I have made them all correct now including the Alpair 10p.

The Halcyons definitely sound very pleasant to listen to all by themselves but are a bit different from my bookshelf speakers. When doing A/B swaping the differences are very noticeable. However my best Hi-Res files are very pleasant to listen to when not compared. I guess that my present conclusions are that they sound very good and although are large physically, they are a great addition to my audio lab. I think I can listen to them and enjoy the music as required.

I have no need at this point to play with the stuffing as the bass sounds very good just the way it is. The Alpair 10p were purchased from Dave at Planet 10 and fully enABLe2 and broken in by him. The bass driver probably need a bit more breaking in as do the polypropylene caps in the crossover. So now that I can do a lot of listening I will post more eventually. Stand by for photos
 
  • Like
Reactions: 1 users
I mentioned above that during actual listening to various types of music, they seem to be very pleasant although quite different from my 2-way scan-speak based bookshelfs. They do seem a bit more cohesive as full range drivers usually do. I played them all day long today while working in my lab, and there was no fatigue at all. Not ready to jump to any conclusion just yet, but just exploring options.