jocko_nc

and...

Here is some progress... The maple ought to look sweet. I hate vinyl. I oversized the corner braces with the 1 5/8 stock, I will probably skip the cross barce I had originally planned. Careful, well-thought use of the table saw made for a good fit on the 45 degree corners. It glued up well without a proper jig for such things.

Well, it has been a couple of weeks and I am back in the garage making a mess... I posted a DIY Heresy center channel project a while back. In the end, I had (2) Heresys, (2) subs, and a DIY center. Problem, the subs were built to match another set of speakers from a different house. They are all-black cubes for which I was never able to devise a grille. Time for n extreme makeover. I want a pair of subs that go with the whole vintage thing. I want the construction to be more old-school, to be similar to the Heresys. Thus, I am using veneered wood cut on a 45-degree corner and fitted with corner braces. The front baffle will be recessed to allow for a simple tweed grille. Also, I am going to ditch the internal amplifiers this time and go with a separate 2-channel amp, an H/K Citation -22 I have had laying around. The subwoofer controls onboard my AVR may work, or I may need to go with an EQ, a la a Feedback Destroyer or something. I found some sweet 1/8" white maple plywood locally for $5.00 a 4 x 8 sheet. (It helps to be where the furniture in made) I made panels from this plywood and 3/4 MDF. The resulting material is excellent, the best of both. Note: I got real furniture wood this time. Corner braces are cut from 1 5/8" thick poplar stock. Front baffle will be double-thick, MDF over birch plywood. I will edge-veneer like Klipsch did. The drivers are the same, 10.00 Dayton Reference / Hi Fidelty subs in a Precision Port enclosure tuned to 22 Hz. The Daytons are excellent drivers. Here is the concept. Stay tuned... jocko

Grilles for all are in the works: I have them for the Heresys. The center channel will be easy. I need to rebuild the sub cabinets, from black cubes to oiled plywood in a design similar to the Heresys. All will be the wood / tweed look.

Final pic. Here is the installation. Side-by-side from the same amp, the voicing was really, really close. My ears could not consistently find a difference. The biggest difference I could hear comes from the walls, one of which is more lively than the other. Bass? Similar. Neither the DIY center nor the Heresy have very much of it. No problem, I am using plenty of subwoofer L and R, essentially a satellite setup. As a center in 5.1, I had to boost the level a bit in the setup. I assume that is because the center is running off the Yamaha AVR, not the power amp. The voicing among the three sounds great, a whole lot better than I was able to achieve without the DIY. You'll see what I mean about a tight fit... I'd call it a great success. jocko

If I even mention mounting one of those "big boxes" in the ceiling, I am a dead man... I'm very lucky to be able to get away with what I am currently up to. jocko

I have a bit of listening to do. I am taking it upstairs today to hook up with the other Heresys. Then we'll know. I think I am pretty close, close enough to warrant going upstairs. The only question I have is the mid-bass from the woofer and/or the current being sent to the mid. I have to side-by-side with a proper Heresy for that. As far as the next project, as long as the garage is a mess, I am cutting wood. jocko

Now on to the next project: I need ceiling-mounted rears. They have to go in the ceiling. I came across an idea when I was demo-ing this thing. The Polk Monitor 5's I was using as speaker stands are really pretty efficient, probably 91-ish. ($10.00 at the Goodwill last week.) They are 6.5 inch 2-ways with an 8.00 passive radiator. Take all the guts out and mount to a ceiling baffle, perhaps one from PE. I'd have to lose the radiator. What the heck, I'd never build a full enclosure for them anyway. They have all the parts I'd need... Hmmmm... Think that would be worthwhile for rears? jocko

o.k. I agree the number of screws in that rear panel is insane.

Insert picture narrative here...

As long as the consensus is that I am crazy with this... Final assembly.

Hickory, NC, western part of the state. I would say observations confirm your predictions: The low-end did fill out once the rear panel was fully sealed. Open sounded odd. However, partially installed was the worst. Now it sounds like, well, a Heresy. The side ports only worked once the rear was in place. I agree on low-end being less important for a center channel, I was really concerned with the mid and tweeter. I think this will work fine, at least for now. I did glue foam sheet to the rear panel. That is something I have always done with DIY projects, I liked the way it deadened the high-frequency echo when I was building my subs. There is hardly room in there for any more. jocko

Crossover is stock right now, except that I swapped the caps for some new Daytons. From my first impressions, the side-facing woofers and the port angles will probably have more to do with bass response that anything done in the crossover. I may just leave it go. So far, I have only compared to some Polk monitors, the ones in the picture holding up the project. I would guess the highs and mids are working just about right for Heresys. The comparable sound is right where I would expect. The bass, however, will be another matter. It sounds weak, but, of course the Heresys are bass-weak as well. I have yet to fully mount the rear panel due to the fact that I expected to play with the crossovers some. The rear panel is very important, much mid-bass comes out the back. I may try to take advantage of that fact. ???. Also, I am playing on a less-than-optimal amplifier right now. Next, these go upstairs and get swapped out for a Heresy. I have just the spot for this, it will fit precisely in my cabinet. jocko

First sound... She gets a workout tomorrow a.m., its way too late for that now.

Minimum size from the initial drawing...

My only regret was the quality of the plywood...

Ready for some music... Final finish will wait.

and again...

also...

Here is a look at partial assembly with a coat of stain to find the glue spots... Some more sanding to do. Unfortunately, I have to go to work so this thing will sit for the rest of the week. I capped the port covers with angled hardwood pieces to cover the end cuts of the plywood. Otherwise I used edge veneer. Not too bad.

Here is the schematic... Type E.

Crap, I did that wrong. I should have dug the old books out first. All else equal, it is related to the square of the turns. I was hoping not to have to wait on UPS. jocko

Of course, my meter cannot even accurately measure that low.... Number of turns? I recall from physics that inductance is directly related to number of turns. This coil has six layers of windings, three would have 50% less turns. Hmmm. jocko

I'm messing with a Heresy crossover now. See prior post regarding center channel DIY with dual 8.00... Question: I was going to cut the woofer inductor by half. My sheet says Type E uses a 2.5 mH coil. It is iron-core and does not use terribly large gague wire. DC resistance is about .85 Ohm, which seems high for an audio inductor. ???. From what I see, a 20 gague air core at 120 mH has a similar DC resistance. Is that what I should go with? While I sit here, I have half a mind to unwrap 50% of the windings on the old coil... ???. All else equal, when I get to 50% of the DC resistance I will have half of the windings gone. Am I an idiot to try this? jocko

More... The port end covers have to go on last. They will just be plywood with edge veneer, fastened with screws and finish washers. Probably a thin gasket bewteen the two. You have to be able to get at the woofers somehow. The front baffle will be fixed, just like the Heresys. Likewise, the rear will be accessable. I went ahead and screwed the top and bottom from the outside. They are countersunk, I will fill with a dowel rod abnd finish off. I've done that technique a lot in the past. It looks allright.