Speaker progress 01

As mentioned recently, one of my projects is building a horn loaded speaker.
The design is a BillFitzMaurice DR250.
http://billfitzmaurice.info/forum/viewtopic.php?f=12&t=1099 (SPL charts)
I have one DR250 already, and once I finish this one my sound system will be much more complete.
Right now I'm running 2 Gemini 1204's (Cheap 12" mains) They put out sound, I won't say good sound, but adequate for most people's taste.
The DR250 sounds far better though, and if I didn't need to run in stereo I would use the one I have instead of the two others. It's also noticeably more efficient, which I care about more than most. For more on that, here's one of my favorite technical writers who can explain it much better:
http://sound.westhost.com/articles/pwr-vs-eff.htm
He has many other good articles too.

Anyway, I've been taking photos, and I've got a few here:
Sorry for the terrible photo quality, I left my good camera at work, 
and while I really like my cell phone, its camera is not a strong point.

Lots of tweeters! I'm not a big fan of pizeo tweeters. They usually sound awful, but I'm using them because 1, they actually sound pretty decent when arrayed and properly EQ'ed. And 2, the horizontal dispersion is worth it. I have at least a 160 degree field of coverage on my working DR250 with no noticeable high frequency loss. My other speakers beam like crazy, probably covering 40 degrees.
I'm not really that unhappy with my mains, considering what I paid for them, I knew what I was getting, and they've held up reasonably too.

Custom jig to cut the tweeters:

 Marking the speaker mount for a center point. Pretty symmetrical.

Speaker mount finished cutting. I had to make a router jig for this too, as you can see in the photo below.

All marked up and ready to cut!

Partly cut, just need to get the middle section.

Figured I'd go with the scroll saw, it's easy to drill a hole big enough for the blade, and I think it actually cuts straighter than our jigsaw.

One more piece finished! Hopefully there aren't any mistakes, I don't want to have to cut this piece again!

This post probably wasn't of as much interest to other readers, but I wanted to have it on here kind of like a journal entry that I can look back at.

Just Projects

I'm glad to have a break, but I have plenty to do over the break.
My breaks always seem to be doing something else instead of not doing... Not that that's necessarily bad.

A couple of my projects:
Build a shed, 3 wardrobes, a horn loaded speaker, and A guitar tube amp.
Besides working on the Redwall Project, cleaning up my lab, and work.

I actually have some photos, so here are two:

Can anybody familiar with a compound bow spot the problem?

Second unrelated photo just because. It's my blog, so I should probably put some more photos of myself on here every once in a while, and I happened to have that one on hand.

More posts soon. I'll probably do one on the speaker next.

My Backpack (contents)

So, after my first college semester, I thought maybe I should clean my backpack out, and while I'm at it, why not take a picture?

Just for fun, (I mean, now I actually have time to do this sort of thing...kind of..)
Here's a list

(Click for larger)

1. Graphing calculator (Ti Nspire non-CAS)
2. secret invention prototype demo in case
3. Ethernet cable
4. Velcro ties
5. Fishing line
6. VGA cable
7. 1/8" to RCA cable
8. Swimsuit
9. Goggles
10. Spare scantrons
11. Laptop
12. USB power plug
13. Broken combination lock (used on a project as a weight)
14.  Dual screwdriver
15. Outlet strip
16. Econ textbook
17. Headphones (Sennheiser HD280 Pro)
18. Cable tester
19. HD video camera
20. Non-graphing calculator
21. Whiteboard pen
22. Spare laptop battery
23. Automatic wire strippers
24. SPL meter
25. Scissiors
26. Slide rule (yes, I have used it in class on a test :)
27. Flashlight
28. Radio
29. Traffic cone (goes on flashlight for directing traffic)
30. spare AA batteries
31. Dynamic mic
32. Pencils
33. Compass case
34. Compass
35. Spare cell phone battery
36. Computer mouse
37. Alligator clips
38. Bible
39. Notebooks (you can't tell, but there are 4, and one has three sections)
40. Granola bars
41. An inch worth of old tests, notes, etc.
42. US Constitution, Declaration of Independance, and the Articles of Confederation
43. Antenna
44. SDR (Software Defined Radio)
45. USB power plug
46. USB current meter
47. 16GB USB 3.0 flash drive
48. Sharpie
49. Deodorant
50. Laptop charger
51. Another spare cell phone battery
52. Clear demo lock
53. Rugged, waterproof 64GB USB 3.0 USB drive
54. Pen I got at orientation that I use for all my notes
55. Earplugs
56. Charging cables and headphone splitter adapter
57. Calculus textbook

I usually also keep a rechargeable bluetooth speaker in my backpack, but on an average day this is about what I would have.
On the list, items 33 and 34 should probably be combined, as should 35 and 51.
And the little dot above the compass I forgot to label is a 1/4" to 1/8" stereo adapter

Overkill? Yeah, maybe, but it's nice if I need something, I usually just have it right there...4 layers down ;)
Oh, what does it weigh? Not sure exactly, but around 30lbs, so maybe half what a standard military pack would weigh. I must say though, when I take it off, I go a little quicker, especially up stairs ;)

Happy Holidays everyone!

Right now

This is about my life right now...

Except the balloons I'm (trying to) hang onto are college and CRU

Air Force Flash Orchestra

I like to post at least one Christmas related video, and a little early doesn't hurt...
Beautiful video!

Happy Thanksgiving!

Sorry I haven't posted anything in so long. I've just been too busy with college.
Hopefully I'll be able to post here more soon.
Anyway, happy Thanksgiving everyone!

Live Sound Part 2

Well, the movie night came and went, and was a success. Attendance was estimated between 150-200, which is at least double the attendance from last year! Here are a few photos, and then I'll list the setup.

Here's how I set everything up.

Blu-ray player -> mixer -> GEQ -> crossover -> amps -> speakers.

Blu-Ray player: generic consumer model. RCA and HDMI out.
Mixer: Zoom HD16CD (Used for volume control)
Graphic EQ: ART HQ 231 (Very nice tool)
Crossover: BBE DS24 (Not my top pick, but it does what I need, and for $100...)
Sub amp: GTD Audio TN-350 (Nice cheap 1RU amp for subs. A little noisy for tops.)
Mains amp: QSC RMX 1450 (Love this amp, class AB! But it weighs almost 50 lbs...)
Subs: 2 BFM Titan 48's. Great speakers, hitting 105 + dB peaks @ 30 feet, and they were just cruising.
Mains: Gemini 1204's They were mostly adequate. With EQ they sounded pretty good in one spot.
Looking forward to upgrading the Gemini's to DR250's. (I have one, building a second)
The sound quality, efficiency, and horizontal dispersion of the DR250's is astonishing when built with the melded array.

Subwoofer setup. (Makeshift v-plate)

In case you haven't noticed, I like hyperlinks!

Sorry, no photos of it in full action. No video either. I would have liked to get some, but it wasn't really practical for me, and I wasn't really in a position to leave and ask someone either. It was pretty dark anyway, I'm not sure the camera would have gotten much.

Future improvements:

I'm pretty happy with most of how it's set up.

I have a lot of very nice equipment, accumulated bit by bit.

Future upgrade possibilities include:

Second 4U SKB rack case for the EQ and other future gear.

Real screen. A 10' X 20' white tarp is great for the price, but is highly prone to wrinkles. I'd probably look at one of these:

http://www.amazon.com/Carls-Blackout-Cloth-16-Projector/dp/B007KA7BAA/ref=sr_1_3?m=A1TUL287LCIBXW&s=merchant-items&ie=UTF8&qid=1404937731&sr=1-3

http://www.ebay.com/itm/Carl-s-Blackout-Cloth-16-9-9x16-Projector-Screen-w-Edge-White-Gain-1-0-/330996889594?pt=US_Projection_Screens_Material&hash=item4d10f3b7fa

Second DR 250 (currently building)

So, if you know anyone who wants to do an outdoor movie showing, let me know... My rates are usually much cheaper than competing rental companies, and you get someone to run it and do all the setup...

Live sound

This post is a description of my system., and most of the rationale behind it.
It's slightly out of date, but I'll do an update soon.

I've been into live sound for quite a while now. A few years ago I did the audio for the Strawberry and Harvest festivals in the Northern Neck. Last year I showed a movie outdoors to our swim team, and that was a lot of fun for everyone. I also did some sound for the local Bible Bee.

Last year my sound system consisted of a Zoom HD16CD 8 ch recording mixer, two of the cheapest 12" PA mains I could find, a Bose home theater subwoofer, a QSC RMX 1450, and various cables and mics.

I really like the mixer for recording. I got it used for $300, and I haven't seen anything before or after, new or used that rivals it for anywhere near that price. This comes close, but doesn't have an option to use it as a control surface, which is almost a necessity when doing serious recording.

The PA mains were Gemini 1204's. I wasn't expecting hi-fi, which was a good thing. I used a lot of EQ and processing, and eventually managed to get them sounding O.K. with a subwoofer. The subwoofer had trouble keeping up at high volumes, but actually did surprisingly well for what it was (two 6" drivers outside) I'm not really a fan of Bose, they're not usually the best option, but that was what I had available at the time. It was something like this

The amp is a good solid class AB amp, built very strongly. It weighs about 40 lbs. I talked to a number of people, and all the feedback was very positive about these amps. I also found a service manual for it, which I really like.
http://www.loudandclearproductions.com/library/QSC.pdf

Anyway, when I did the outdoor movie, I had to turn the amp up all the way, the clip lights were blinking, and I still wished I had a little more volume. (I showed Cars) So, I figured if I wanted to do it again next year (I did!) I should upgrade my sound system. The amp I was using was 280 watts/channel, and the speakers I have are only rated for 100W RMS. I don't like running things like that, especially with the way things are compressed nowdays.
I started looking around, and all the options looked expensive. About the cheapest step up I could find was some Yamaha speakers, and I'd still need a subwoofer to keep up with them. Subwoofers are expensive too, when I was looking, anything that looked plausible was north of $500...
I decided that wasn't happening. Maybe I could build some speakers... I searched around some, and came across this website: http://billfitzmaurice.com/
I looked through all the designs, and specs, and decided that these were much more attractive options.
When going through the used section, I found an ad for 2 T48's and a DR250 'make me an offer'.
So I did. Suffice it to say he just wanted to free up some space, and I was happy to help him out with a total cash flow of a bit under what one of the commercial subs I was looking at would have cost. Win-win!

The subs work great so far, and the DR is very efficient. I have been somewhat disappointed in the bass and mid response of the DR though, it has tended to sound rather shrill on its own. It is a significant improvement over what I had though, especially properly crossed over to the subs. On its own it doesn't sound bad with a little EQ, but it does need the EQ. (I'm still quite happy though, considering the price I paid)

Currently the way I'm thinking I'll get things set up is:
QSC amp for the subs,
GTD audio TN-350 for the tops
DBX Driverack PX, or PA+

The reason I'm looking at the GTD audio amp is that it's the only sub $1000 1RU amplifier that I could find that has enough power to drive my speakers to full capacity.
I'm going for 1RU because I have a 4 space SKB rack case, and I want the system processing and amps to all fit in that.
If I really wanted to have a compact electronics system, this would be very attractive:
http://www.carvinguitars.com/products/DCM2004LX
It won't bridge into 4 ohms though, and it doesn't quite have enough power to drive my subwoofers to their max. Not that I plan on running them up to the max, but I'd want to be able to, if nothing else, so the amplifier doesn't have to work as hard. (Of course, if I really needed compact, there's also Powersoft, but I'd rather pay for a semester of college for that much money)

Part of the reason I'm working on all this (other than that it's fun) is that I'm hoping to have a rig that I can rent out this summer. Still needs a little work...

Happy Father's Day!

Happy Father's Day!

Flat Surfaces

Everything in life has a purpose. Flat spaces are for storing things.

No, I'm not posting photos.

Vangelis

There is only one person in the world who can make movie soundtracks like this:

V.A.T.J.T.I. (excerpt) from Red Baron on Vimeo.

RedShark article

Amazing!