MiniByzy (Mini Byzantium) Build Thread

[Pete Schumacher]

Re: MiniByzy (Mini Byzantium) Build Thread

Well, we're on the third iteration of the crossover, and the "magic" is starting to happen.

Ryan ran a sweep yesterday with the new XO in place. With power input over 1W, how's no more than 0.3% THD from 150Hz to 20KHz? And 0.1% from 1000Hz on up? Not too shabby!!!

Response plots will be coming once the final voicing is accomplished.

[Pete Schumacher]

Re: MiniByzy (Mini Byzantium) Build Thread

Hell yeah. I might have to stop by on my 5k mile roadtrip from AK to FL next year and have a listen!

We're certainly on the way. We'd be happy to show it off!!!

Hi Pete,

Which version of the NE225w are you using, 4 ohm or 8 ohm? Thanks.

4 Ohm. But the parameters of both woofers will allow either to work in the enclosure, with a 3dB loss of sensitivity for the 8 Ohm.

[raiderone]

Re: MiniByzy (Mini Byzantium) Build Thread

Hi Pete,

Which version of the NE225w are you using, 4 ohm or 8 ohm? Thanks.

[greywarden]

Re: MiniByzy (Mini Byzantium) Build Thread

Hell yeah. I might have to stop by on my 5k mile roadtrip from AK to FL next year and have a listen!

[Pete Schumacher]

Re: MiniByzy (Mini Byzantium) Build Thread

Did some extended listening with the pair yesterday. While there's still a little tweaking yet on the woofer, it seems to me that the tweeter is dialed in. And does it sound fantastic in that WG! There was plenty of crisp attack, and effortless reproduction. That WG and RS28F were made for each other!!!!

Those two little woofers had the room pressurized nicely on many occasions. And even when they were pumping it out, the midrange stayed flawless. There was a nice tall, wide and deep soundstage to go along with the impressive dynamic capabilities. One track I played had a cello as the featured instrument . . . mmmmmm. It was like he was in the room. :p

Anyway, a little more eval time is in order, to make sure that the NE225W is dialed in. Should have that finished by the weekend.

Seriously considering painting the whole cabinet in Cadillac Black Diamond . . .

[DoubleTap]

Re: MiniByzy (Mini Byzantium) Build Thread

Yea, battery died and I didn't save measurements ... no worries though, I'm sure I'll take about 10,000 more measurements in the process.

The first stab passive network had a bit of a bump centered around 700hz, which is normally a very bad area to have a bump. Any metal cone woofer with a bump there can melt ears, but the Vifa sounds damn smooth even with the bump. I think we're going to be very glad we chose that woofer!

And I couldn't believe as Pete said, how smooth the RS28 is in that waveguide. It makes a 1st order network simple, and with the network in place it had less than .1% THD all the way down to below the xover at 1000hz.

We'll probably have the stereo pair running tomorrow or Tuesday, will post pics and measurements soon. I've been swamped trying to finish up a couple orders and get them shipped.

[brkitup]

Re: MiniByzy (Mini Byzantium) Build Thread

I didn't know you could powder coat wood...learned something new.

If you heat the wood to a really high temperature the powder will stick to it and start to melt. My company doesn't have the capabilities to do this, however. We only do metal parts, and use the normal electrostatic charge to attract the powder coat. It's an interesting idea though.

[winslow]

Re: MiniByzy (Mini Byzantium) Build Thread

I didn't know you could powder coat wood...learned something new.

[brkitup]

Re: MiniByzy (Mini Byzantium) Build Thread

My camera is [email protected], and wouldn't improve on the picture above, believe me. That's exactly how they look right now, but you can't get an idea from a picture of how smooth they actually are when you put your hand on them.

The next pics of these will be of the baffle and enclosure finishes in their various stages of completion.

Debating whether to paint, powder coat, or vinyl wrap the baffles. I love the idea of powder coat, as they have some that cure at 350 in 10 minutes. We'll be doing a trial with a sealed MDF baffle before I submit the baffle Ed made for these enclosures.

I powder coat for a living, but I've never tried to paint speakers with it. It does leave a very nice hard finish.

[Pete Schumacher]

Re: MiniByzy (Mini Byzantium) Build Thread

It was a very productive day on Friday.

We actually got some measurements on the woofer and tweeter in the enclosure, and listened to some music with a crossover installed.

First, that waveguide performs incredibly well with the RS28F, using a pretty darn simple network. We took a distortion sweep, and with the network in place, we were looking at amplifier distortion levels from 1000Hz on up, 0.1% and better, mostly 2nd order. And the response plot was flat from 1200 to just above 15KHz. Over that range, maybe +- .5dB. The "glitch" above 15Khz is a very narrow 2dB dip, returning to reference level at 20KHz. One thing's for sure . . . I don't see any baffle diffraction ripple. There's no way the RS28F, flush mounted on this baffle, would have the super smooth response this does, without using massive roundovers.

The woofer was a real surprise. This Vifa "Subwoofer" has a fairly smooth response out to 10KHz. That was the surprise. We were getting some really nice bass output from that single 8" unit.

Overall, the first crack at a crossover shows real promise. We listened to a few tracks, and I sure was liking what I heard. A little tweaking might still be in order, but we'll know better when there's a stereo pair playing.

I'll post those plots later. It was late, and Ryan's laptop ran out of juice before we could complete another set of measurements.

[Face]

Re: MiniByzy (Mini Byzantium) Build Thread

Can you get a smooth, glassy finish with powdercoat, though?

Yes, I had a shift knob and some other car accessories powdercoated and they all came out with a nice gloss black finish. Imo, it would be an easier and cheaper to get a nice finish from powdercoating than having a bodyshop spray them.

[greywarden]

Re: MiniByzy (Mini Byzantium) Build Thread

Can you get a smooth, glassy finish with powdercoat, though? Idk I've only ever seen some cheapo powdercoated wheel job that wouldn't cut it on a speaker.

[Eric.DeYoung]

Re: MiniByzy (Mini Byzantium) Build Thread

There is a place where I live in Grand Rapids that professionally powder coats MDF - they brought in a couple samples to work that instantly made me think "speakers!" Such a durable finish too. That's my vote!

Edit: The stuff that the guys brought in was similar to a traditional matte black textured powder coat on steel, but that website introduces a whole bunch of different options! Similar to this: http://www.powderbuythepound.com/BLA...E_TEXTURE.html

[Pete Schumacher]

Re: MiniByzy (Mini Byzantium) Build Thread

Is your camera broken? :D

My camera is [email protected], and wouldn't improve on the picture above, believe me. That's exactly how they look right now, but you can't get an idea from a picture of how smooth they actually are when you put your hand on them.

The next pics of these will be of the baffle and enclosure finishes in their various stages of completion.

Debating whether to paint, powder coat, or vinyl wrap the baffles. I love the idea of powder coat, as they have some that cure at 350 in 10 minutes. We'll be doing a trial with a sealed MDF baffle before I submit the baffle Ed made for these enclosures.

[D, Rose]

Re: MiniByzy (Mini Byzantium) Build Thread

Um,... they look just like they did before I sent them, unless St. Louis makes cabs appear differently than they do in Detroit.;) I think Pete likes them!!!