Curt Campbell's Halcyon build thread

6sX7

Member
2018-04-30 5:08 am
Well, Zman pointed me to some data on the BiFrost and now I understand.

I will just say, I'm finally hearing what NP's F6s and the Alpair 10Ps are capable of. I kept thinking that because of the FR design and the input transformers on the F6s, I should be hearing a more zero-feedback triode tube amp old-school sound. Nope, was all in the BiFrost. Now I'm fussing again with the speaker positioning and might need to be a bit more off-axis. Zippy high end.

Still a bit of shoutiness and hardness here and there but may be recording & volume dependent. I do tend to keep cranking it because it sounds so good (until it doesn't). The other thoughts I have are possibly overdriving the F6 clone or that I have the polarity reversed on the Alpairs (relative to the SB woofers). I did get them mixed up and didn't see a clear indicator for + on the frames. Don't have enough experience to know if some sort of suckout is causing the problem but easy enough to pull the drivers and swap the leads.
 
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6sX7

Member
2018-04-30 5:08 am
Been turned on and playing music solidly since last night, so about 24 hrs. The case feels at a uniform temperature, whereas yesterday there were colder spots. The sound has mellowed a bit or my ears have adjusted. The shoutiness seems to occur less often. Still have to play about with positioning. These Alpair 10Ps are much more capable than the bifrost led me to believe. There is quite a bit of high end I wasn't hearing before.

So, yeah, Zman01, the idea of a new set of speakers is quite on hold. As much as I was ready to sally forth and tilt some audio windmills, where I've gotten to makes me quite happy. I now hear what all the fuss is about regarding the Halcyons.
 
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6sX7

Member
2018-04-30 5:08 am
aw cheez. There is nothing halcyon about the Halcyons. Not with this DAC and these F6 clone monoblocks. The immediacy, presence, detail, sparkle, etc. are all there. Just keep putting on album after album and keep being amazed. Listening to the opening of INXS's "Never Tear Us Apart" off of the Donnie Darko soundtrack just has me marveling at the vocals of Michael Hutchence.

I dare say, I'm going to try getting these F6s into balanced operation (I affectionately call monsterblocks) this week and I'm not too concerned about the doubling of the output impedance like I was when I had the Bifrost in the lineup.

extra stuffing is for turkeys.
 
So I planned to do final wiring and perhaps even mounting of drivers today on my cabinets. However, true to the Murphy's law curse that this speaker build project has suffered, I discovered another problem. (Also it is Friday, the 13th!)

Quite by mistake I am sure, I was shipped the wrong woofer's. They are the 4-ohm version, which of course will not work with the crossover design. I have contacted my supplier to see if we can exchange as the woofers have never been mounted or connected to an amp. Some have not been opened. But we will see. So I can make wiring progress today, and perhaps even put in the foam for the A10p sonotube, but that will be it for now.

I am very encouraged by 6sX7's success and cannot wait to hear what these will sound like.

Hopefully I can get the right parts soon!

-david BTW
 

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It'll all be worth the effort. Especially with them fancy caps and coils. Crossing my fingers you get the woofers swapped out easey-peasey.
Hello,

Well I put in the foam in the A10p sections today, and wired up all the speakon and faston connectors to all cables. So I guess it is on to teasing stuffing now while I wait for two things:

1- T-Nuts to attach the bottom crossover bases to the cabinets. They are due in on Tuesday
2- The correct SB Acoustic woofers. My supplier (Madisound) has been very good about exchanging them for the correct ones. They should also arrive next week.

6sX7: Did you settle on 12oz of for each TL and 6oz in the center?
 

6sX7

Member
2018-04-30 5:08 am
Dave BTW,

yes, 12 oz. for the lines and 6 oz. for the center. I'm considering taking the center fill out but haven't had a strong urge. This new DAC has tightened up the bass considerably while still deep. I'm more curious about how Curt hears it and easy enough experiment. Just haven't had a huge urge given how the system sounds now. Planning for tomorrow night.

Of course, I still want to try the F6s in balanced monsterblocks but, again, things sound about right and enjoying right now.

-tom
 

6sX7

Member
2018-04-30 5:08 am
Yup. I like the 6oz. in the main chamber. Seems to tighten up the bass to be about right. This is in a living room I affectionately call "the landing room" as the house is a tri-level and the living room opens up to the dining room/kitchen upstairs and to the den downstairs. So big space with a weird upward sloping ceiling.

Now, on to the the shoutiness. What is + and what is - on these Alpairs? Since I was experiencing the shoutiness again I decided to revisit the polarity of the Alpairs relative to the woofers since I got confused in the assembly, never getting a confident feeling I got it right. A battery test on the x-over end is useless because, well, big blocking cap. So I swapped the polarity since I was already messing with the stuffing. Voices now seem more natural, the odd shoutiness, hardness has diminished. I'm not sure if I'm deluding myself, given psychoacoustics but something seems to have changed for the better. Would a suck out at 400Hz due to the Alpairs and the woofers being 180 degrees out of phase be the cause?

Image is dead center and very strong so I know the phasing between the Alpairs is correct. Yay me! (one thing right)

And I got plenty of bass so phasing between the woofers is correct. (two things right)

Thoughts on the Alpair polarity?
 
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As as I soldered up my internal wires I tested the drivers with a 1.5 volt battery just to make sure. On my Alpair 10p, applying a positive battery terminal to the Red Terminal caused the speaker cone to move outward.

The same test on the SB woofers found that the larger of the two terminals on the woofers to be the positive one also.

There is also a test that can be done using the AudioTools app on an iPhone. It is called Signal Polarity and puts out an asymmetric waveform which it then reads using the iPhone microphone. It has worked well for me while testing already built speakers for polarity.
 
It also works well for testing system absolute polarity (a hotly debated topic). On a really good system I can hear the absolute polarity difference on a well recorded trumpet (which also has a asymmetrical waveform) so I always check for that. All my electronic designs guarantee absolute polarity. A positive going signal on the input results in a positive going signal on the output.
 
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It's been referred to as inverse distortion cancellation. When the amp and speaker (or in some cases amp stages) each produce sufficient asymmetrical distortion then their relative polarity matters.
Yes that is one mechanism for sure. However if you listen to a live trumpet the positive peaks of the waveform coming out of the bell of the instrument are much higher in amplitude than the negative peaks. When the polarity is inverted, the opposite is true, and on some systems and ears it can be discerned.

When I am editing vocal recordings, which I do a lot, I can also see this same asymmetry in human voice. It really does sound more natural when absolute polarity is preserved through the entire signal chain.
 

6sX7

Member
2018-04-30 5:08 am
As as I soldered up my internal wires I tested the drivers with a 1.5 volt battery just to make sure. On my Alpair 10p, applying a positive battery terminal to the Red Terminal caused the speaker cone to move outward.

The same test on the SB woofers found that the larger of the two terminals on the woofers to be the positive one also.

There is also a test that can be done using the AudioTools app on an iPhone. It is called Signal Polarity and puts out an asymmetric waveform which it then reads using the iPhone microphone. It has worked well for me while testing already built speakers for polarity.
Thanks Dave BTW. Now that I've got a second on red being + it comes down to having the correct lead wired up to the drive from the x-over. That's where I got confused because I didn't make sure to tag the positive lead. The Madisound supplied wire doesn't make it obvious unless you pay close attention to the barely visible printing on the sheath. Good times.
 

6sX7

Member
2018-04-30 5:08 am
Checking on any progress, Dave BTW.

I haven't had a chance to test the polarity. I've been too busy turning up the volume and tapping my toe. Maybe this weekend.

In the meantime, I ordered the DIY Biamp 6-24 x-over board. Once I have 4 channels of amplification going, it'll be time to experiment.
 
This weekend my plan is for a lot of work on the Halcyons. I thought I would be just mounting the drivers. However, I have made a couple of decision that will cost some more time. I did some research and found what is called a round-under bit was available for a router. This bit will allow me to put in a nice rounded edge on the inside of the baffles behind the speakers. Round-under bits are fairly rare, and I only found a few who make it. That is slated for work tomorrow morning (on PTO). I especially want to treat the baffle behind the A10p.

I have also decided that the side panels have a bit more flexibility than I had hoped and want to tread them internally to reduce panel vibration. This is a tricky business as they form the transmission lines so a thick foam like No-Rez is out. I am studying the idea and may or may not do anything. That is the big decision and task of this weekend.

After that, it is driver mounting time. I finished all the wiring, external cables (For a split feed to the FR and Bass) during the evenings. Almost there.

I will be very interested in your experiments 6sX7 with a digital crossover and bi-amping. I prepared for it, but may or may not ever get to it. I have many other projects lined up.

-david BTW
 
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