The Red Horizons (desktop speaker)

[jeff_free69]

This is a build I recently finished, based on mzisserson's "New Horizons"
http://techtalk.parts-express.com/bl...gcategoryid=12

I first heard the original version of these when Mike brought them to the recent NY-DIY event . They were first up, and in a rather large room, I was afraid they might get swallowed up. But heads were turning from the massive opening gong of "Fanfare for the Common Man". These little guys were impressive!

I wanted something good for my desktop and the small footprint (5.5 x 7) on these fit the bill. They are taller than most computer speakers, but that is an advantage since the drivers are right at ear level.

The bottom line is that the sound for this application is sweeter than sweet.
I've got some more detailed build photos that I'll be posting shortly...

[the kid]

very nice!

[KLR]

Those look awesome. I like how you positioned the woofer.

Can't wait to see the build pics.

[jeff_free69]

Those look awesome. I like how you positioned the woofer.

Thanks, I wanted to get away from an all-black finish. My original thought was to use some solid oak I had for the baffle. That would allow me to blend it with the same light white tint I used on the desktop and shelves I built a couple of years ago. But I couldn't come up with a decent way to match the rest of the MDF box (I was thinking about using the teak vinyl laminate) but was unsure if it would work aesthetically).

So I decided go from subtle to bold. I think Mike's "Red Heads" won the middleweight division at the NY DIY, and thus the "Red" theme came to be. The pincushion woofer calls so much attention to itself i figured to emphasize rather than try to ignore it, by rotating 90 deg (as we say in the software biz, "Its not a bug , its a feature" )

Nothing fancy here - just some plain old but* joints. But hey, anytime the project can stand up on its own for a test fit without any help, its a beautiful thing!

[jeff_free69]

WARNING:

Beware of cheap table saws (ie Firestorm)!

it has a nice long, extended table. But the fence is never precisely 90 degrees and wobbles like a drunken sailor.
Hence the need to clamp down a square and keep it in check.

I only shot myself in the stomach once with those narrow cuts too small to grab.
Lesson learned: its only funny when it happens to someone else.
You may laugh now.
.
..
...
OK, thats enough

[jeff_free69]

The port for this design is 6.5" long and actually goes on the bottom (I always save my sloppiest work for here). Otherwise you'd have to make the cabinet deeper or put it on top. (I thought about sticking it on top like a unicorn, for increased dramatic effect; but only for a short while

The usual way to route a hole using a jig requires the attachment of some kind of supporting scrap piece fom underneath to prevent runaway when you complete the circle. But for this little hole (less than 2") in a cabinet already glued up, I tried a new technique : back off the last pass and leave a sliver just strong enough to not give way. Then take a sharp chisel to finish the job and the munchkin pops right out. This has been working fine for me, just need to get a feel for how much to leave. but of course you have to careful not to ruin your work.

[jeff_free69]

I painted only the baffle. To finish the bulk of the cabinet I went for the Dayton Black Ash Vinyl Laminate. This is pretty decent looking with a nice grainy texture and very forgiving to work with. So it doesn't call a lot of attention to itself and is fine for non-showcase projects (BTW I don't feel the same about the silver vinyl).

Check out the PE how-to on the right way to do this.

Working by myself, with a small cabinet, it was easier for me to apply the cabinet to the vinyl, rather than vice versa. This is probably as clear as mud , but basically:

-layout the vinyl,
- hold the cabinet and let just 1 corner touch,
- visually lineup the long edge and lower the side, but let just the edge touch.
- If its perfectly aligned, let the whole side down. Once you do this the whole alignment is locked in all the way around. So you have to be sure what "perfect enough" means

[jeff_free69]

A couple of coats of primer on the MDF baffles.

A beautiful day and no tropical storms in sight, so I improvised an outdoor spray booth. The red satin paint had to be done indoors.



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NEXT UP the crossovers....

[johnnyrichards]

I like the bold use of color on the baffle - I do the same thing quite a bit.

[mzisserson]

Great Build Jeff! I am very happy you are enjoying them Thanks for choosing one of my designs They look far better than my own

[jeff_free69]

The crossover is Mike's recently revised version. Its a little simpler the the original. I splurged a bit and didn't choose the NPE caps for the woofer. Only problem is this is a tight fit to begin with. So I split it into separate boards. (always have to allow for easy extraction since the baffle is peramanently attached)

Also provided was a suggested range of R values for the tweeter levels. This is always a very welcome consideration all published designs should have. Especially with budget drivers, where a couple of dB of driver to driver variation would not be completely unexpected. Plus I was going to put these on a desktop and they are originally designed to a more standard placement (at the NYDIY they were on stands and at least 6 feet from any wall.

To accomodate my compulsive tweaking, I improvised a switching network mounted on the terminal cup to provide a range of brightness: 5.6, 6.6, 7.1, 8.1 ohms






The tweeter XO ended up on the bottom, forcing the port placement a bit towards the front. The woofer XO is on the upper back. There's a single brace around the waist, but just no room to make a true window style (it would block the port)

[ahaik]

Jeff,
They look great!
I was very impressed with Mike's designs as well and loved the 'New Horizon'. I have purchased all parts a few weeks ago but did not have the chance to start building yet. Mine will be neon pink, they are a surprize (late) birthday gift for my daughter.
Asi.

[xavier]

Jeff, those are lookin' great. Regarding the adjustable tweeter: I do something similar on some of my builds. Before I run the wire from the crossover to the tweeter I run it out and then back in the backside of the speaker. I the just fiddle with the tweeter padding until I get it right for whatever set up I'm running the speaker in. Not as elegant as using a switch, but less stuff in the signal path.

[erikb]

Very nice!

[jeff_free69]

I had hoped to do some objective measurements by now, but I haven't gotten my act together with that yet. (My other hobby is recording original music, and that prject has taken over). It'll be nice to have empirical data to correlate to my subjective observations, but here they are for now.

The ND105s are relatively low efficiency and I am using the T-amp which has just enough oomph for a small office.

In the revised XO, Mike designed in a bit of "BBC dip" giving it a more relaxed presentation. This is really nice considering the very close listening position. Will that be appropriate for everyone ? - maybe not. I think you should always try to pay close attention to what the designer uses to voice their design (this is the part of the process where graphs and measurements start taking a back seat to personal preference).

I don't always listen to Cello solos or Norwegian Fish-Slapping Dance Folk Music. So its nice to have something that can also do justice to some of the current pop, rock and world beat music I also enjoy.

These can handle aggressively mastered CDs like White Stripes and REM nicely. Though for the Norwegian Fish-slapping Dance, you may not be able tell exactly how fresh the herring was

The soundstage has nice depth, ambience and detail; its always believable, but politely not in-your-face. On more conservatively recorded types of acoustic music, I sometimes feel I can visual the music coming from behind the monitor. Overall the nearfield experience is very intimate, engaging and enjoyable. In some ways its even better, since the room is out of the way.

One issue I have from the desktop environment is a slight exaggeration of the bass response around 120hz. Since I wasn't planning on bass trapping my desk, I resorted to a more radical solution I haven't done for decades : EQ! Win Media player has a graphic EQ and a cut at that frequency puts it back in its place. A boost at 31Hz helps fill out the very bottom at low volumes. This makes them very satisifying, though at typical 75 db levels its not chest thumping. If I wanted to override the BBC dip I could also fiddle with 1k 2k 4k, to get it the more forward detail that many DIY designs have, but i haven't had that pushed up lately.

SPIKES vs FEET - The feet turned out to be an extra couple hours of unanticipated work. I didn't think spikes would be appropriate for my desk. But the bottom port requires some clearance. So I had to improvise something and ended up with the somewhat retro-looking feet. I took the opportunity to build in a slight tiltback matching the monitor.

While i was in sawdust-making mode last month, I had enough scrap laying around for a second set with a slightly larger cabinet. So the pieces are all cut and ready for a potential cold weather project. It would be a little taller and deeper. The height is the same overall, but without the feet; And it would be deep enough for a front or rear port. I'll be curious to see if this extends and smooths out the bass.