I've done a fair amount of music and movie listening with these. I'm very impressed. To begin, I anxiously wired everything up, hit play, and instantly fear overwhelmed me. These sound terrible! What did I do. I spent all that time and money and these sound really really bad. I measured. Ok, something was seriously wrong. Very little top end output. I had a look at my wiring and found I had the 15ohm shunt resister in series and the 1ohm series resistor in parallel. Ha, whew, close one. Fixed it up and was instantly blown away. But that instantaneous feeling is NOT how you judge a speaker. Of course I was blown away. My creation was finally alive. And I didn't seriously screw up. I'm thrilled. Ok, measure, measure, listen, measure, listen, x10, stop. Take a deep breath, swap some resistors around, look at the model, measure, compare. Ok, I got it.
I ended up padding the tweeter just a tad more, and changing the 10uF cap for a 12. Oh and the parallel coil on the tweeter was a 0.18mH all along (all I could get) without adding any resistance. The woofer was left untouched.
So, lets be subjective. Well, first off, I really was not expecting any bass from this thing. The more I worked on the project, the more I knew I would need a sub. My listening impressions tell me I have no need for a sub for music and I prefer without. For music, I have set my sub XO to 60hz because the 80hz just sounded unnatural compared to the bass from the Appreticeships. Don't misunderstand me though, these are NOT bass performers
Just... better than expected because I had such low expectations. I really pushed these a few times. See this video to see what I mean: http://youtu.be/kVRDF-lyVyw
If you have the space, you may want to use one of the other tunings above. Just keep the baffle 200mm wide. I don't think there was a need for me to tune as high as I did. I could hear all the bottom E notes on bass guitars, just not much power behind them. I haven't stuffed the cabs with poly fill yet, just a light dusting. I'll put a pretty big wad in there I think. I'll play with that yet.
They sounded very flat, in a good way. Very tonally balanced. More so than possibly any speaker I've heard, but that not saying much. I haven't heard too many hifi speakers. Totems come to mind. The Apprenticeships are very clean sounding. The last good speakers I heard was a pair of Planet 10's EL70, which I loved and want to build next. They are a full range. I'd say these technically performed better. Stronger bass, flatter response, etc. The EL70's were more... magical??? I dunno. They did different things. These rock, but the EL70's didn't. Jazz music doesn't have quite the transparency (what ever that is) compared to the EL70's though.
Where these lack is outright power. These don't go stupid loud, but plenty loud for me. The bass IS lacking, even though I'm content. With a sub, they have more than enough and you can crank these way up. Otherwise there isn't much to complain about. I've heard better speakers. Even way better sounding speakers. But, for the size and price, I haven't hear any commercial speaker this good.
I know a lot of member here will look at this build and think it's lousy. But they'd be missing the point of why I, or anyone else would build these. I wasn't interested in giant monkey coffin E-waves this time.Measurements
Well, I was resisting posting final measurements because of my room reflections and poor measurement equipment, but I decided it's the best thing to do, so here you go:
Note, blue is with a 1ohm tweeter series resistor, and red is with a 2ohm. Red looks and sounds better to me. Sorry they're not lined up at the same db. Green is reverse null.
If I get around to it, I'll post in room measurements and off-axis measurements. In room, the top end comes down nice and flat. Just what I was aiming for
Well, I got around to taking off axis measurements, and doing a better job of measurements altogether. Wife and kids are away, so I rearanged the living room. Here you go:
First is a combined nearfield of the woofer, the farfield, and the port nearfield. Note, the stich was made at 500hz, which shows a dip. This is a little sketching in that zone. Likely fills in that trough in the listening position. Remember the farfield measurement was taken where full 6db baffle step would occur. The design is about 2 or 3db of baffle step only.
Then we have horizontal measurements at 15 and 30 degrees. Room is to reflective for me to get 60. See how flat it gets just a little off axis. I won't toe them in, unless I want some extra sparkle and air.
And vertical above axis. About what was expected.
Last, vertical below axis. Better than expected.Costs
Below I've included ALL my costs other than a hole saw and maybe a couple other odds and ends I didn't feel were a cost to the speaker. Like the 2-1/2" hole saw is a tool I didn't have and can be used on other speakers, or other non-speaker related projects. The cost that are in italics are costs I felt are optional and shouldn't be reflected against the speaker costs. For instance, shipping was really high compared to if you live in the US or something. Or the cost of veneer, cause you could finish these with bare MDF if you really wanted to.
Drivers, ports, and binding posts including shipping - $99
. Excluding shipping - $80
MDF - $6Spray Paint - $2.50
XO parts - $30Veneer - $50
All in all, I got a good deal on XO parts, overpaid on shipping, scored some free wood. I'd say this is a $150 project. I kept my #1 objective, great, although I ended up veneering driving my cost to ~$200. I also met objectives 2 - 4 I think! My wife loves how they look in the living room compared to my last towers. It was simple to build and used a simple network that I learned a lot doing. This worked out well.Credits
AVSforum - for letting me host this design/build.www.zaphaudio.com
- for providing 3rd party driver measurements.
kbgl - for consistently offering suggestions and feedback on my enclosure and XO results.
Dave at Planet 10 hifi - for hooking me up with cheap XO component and letting me hear some great sounding EL70s.
And all the others I've missed stepping in here or there, or websites I've drawn information from.Disclaimers
This design is free to use for personal use if not for profit. I doubt anybody would try and profit from this design, but it would sure make me mad if someone did. This project is open to public viewing so people can learn, and/or build a pair of speakers for personal use. Use outside of that scope is absolutely prohibited. This design is copyrighted C. Ryan Bouma 2011 in all WTO countries. Although not required, I would appreciate anyone wanting to use this design, to PM me indicating so, and I would like to offer any assistance.
I am not responsible for use of this design that may lead to any losses of any kind. If you spend money building this speaker, and you don't like it, all you get is a "sorry".
Proper use of this design includes all the above posts (4) as a whole.
This design/build is not a form of any endorsement to the products and/or vendors used in this speaker build.