Altec 414z enclosure guidance

Thanks so much for this info Bowtie. I went with the Solens reluctantly after I wasn't able to find the values I wanted for the HF portion of the circuit in other caps. 'Project fatigue' may have been an issue as well and I just wanted to get going on it.

I went with higher end Solen SB caps for the 4uf value on the HF portion of the original N-800f network, Clarity Cap ESA 10uf + .47uf Mundorf Supremes for the LF 10.5uf value.

Sadly, I cheaped out on the 6uf in series with the HF for additional compensation and got Solen PB series (the "fast caps" that everyone uses I think) + Mills resistors.

The 4uf Solens I'm using for the original network are actually pretty decent caps (and something like 1000% more expensive than the PB "fast cap" series I'm using for HF compensation).

I've replaced caps here and there in components before and have very basic electronics knowledge, but this project has been a crash course in crossover design for me.

All that to say: It didn't occur to me that the cap in the series position at the end of the HF network would have a disproportionate impact on the sound because of its position in the circuit, but now I realize now this fact should have been obvious to me.

Is there a particular cap or family you'd recommend specifically for the 806a/811b?

As far as I'm concerned, if the series position is critical for the horns, no expense (within reason) is too great.

I've come too far to screw it up by using cheap caps.

Thanks again for your insightful input!
 
I was wondering if you'd progressed any on your build. Also looking forward to pics.

I'm about to start on my own project based on the Altec 606 cabinet. It will have 416-8Z woofers, 802D drivers, and 511B horns. Like you, I researched crossover possibilities until I was sick of them. So, I decided, for now, to install a simple 12dB/octave Butterworth network at 800Hz with an L-pad for horn attenuation. I have all those components now ready to be assembled.

Here is the reason I'm telling you this, even at the risk of your having to do even more reading: I ran across this Zilch thread that I'd somehow missed: http://audiokarma.org/forums/index.php?threads/using-altec-30904-atteuator-with-511-416.155640/

In this thread, Zilch not only further discusses the 30904 attenuation/equalization network, but the simple conversion of the 30923 horn section to 16 ohms. In addition, he tells how to use an L-pad to make the eq effect adjustable. In effect, what one ends up with is the Model 19 network with greater adjustability on the mid frequencies.

So, I've decided to use the Butterworth network (with horn attenuation L-pad) followed by the 30923 eq with L-pad adjustability for the mids. I'll end up with a simple network with external L-pads with one marked "horn attenuation" and the other marked "mid-range."

I'll be posting my build under another thread. Hope to build the networks first so that I can confirm that they will work as planned.

geeDeeEmm
 
I was wondering if you'd progressed any on your build. Also looking forward to pics.

I'm about to start on my own project based on the Altec 606 cabinet. It will have 416-8Z woofers, 802D drivers, and 511B horns. Like you, I researched crossover possibilities until I was sick of them. So, I decided, for now, to install a simple 12dB/octave Butterworth network at 800Hz with an L-pad for horn attenuation. I have all those components now ready to be assembled.

Here is the reason I'm telling you this, even at the risk of your having to do even more reading: I ran across this Zilch thread that I'd somehow missed: http://audiokarma.org/forums/index.php?threads/using-altec-30904-atteuator-with-511-416.155640/

In this thread, Zilch not only further discusses the 30904 attenuation/equalization network, but the simple conversion of the 30923 horn section to 16 ohms. In addition, he tells how to use an L-pad to make the eq effect adjustable. In effect, what one ends up with is the Model 19 network with greater adjustability on the mid frequencies.

So, I've decided to use the Butterworth network (with horn attenuation L-pad) followed by the 30923 eq with L-pad adjustability for the mids. I'll end up with a simple network with external L-pads with one marked "horn attenuation" and the other marked "mid-range."

I'll be posting my build under another thread. Hope to build the networks first so that I can confirm that they will work as planned.

geeDeeEmm

IIRC, Zilch's project of adding the EQ/attenuator to the N800/N1200, that actually directly led to the Z19 crossover. Once he had done that, he saw the fundamental similarity to the Model 19 network- and decided to create sort of a hybrid of the two- the Model 19 crossover, but bi-ampable and with more usable adjustment range.

The only issue, is that the Z19 is 1200 Hz. Now, if you have 811 horns- that's a GOOD thing (NOT going all the way down to 800Hz). But, with the 511- the above addition of the EQ/attenuator to the 800 Hz network, may produce nice results.

Regards,
Gordon.
 
I was wondering if you'd progressed any on your build. Also looking forward to pics.

I'm about to start on my own project based on the Altec 606 cabinet. It will have 416-8Z woofers, 802D drivers, and 511B horns. Like you, I researched crossover possibilities until I was sick of them. So, I decided, for now, to install a simple 12dB/octave Butterworth network at 800Hz with an L-pad for horn attenuation. I have all those components now ready to be assembled.

Here is the reason I'm telling you this, even at the risk of your having to do even more reading: I ran across this Zilch thread that I'd somehow missed: http://audiokarma.org/forums/index.php?threads/using-altec-30904-atteuator-with-511-416.155640/

In this thread, Zilch not only further discusses the 30904 attenuation/equalization network, but the simple conversion of the 30923 horn section to 16 ohms. In addition, he tells how to use an L-pad to make the eq effect adjustable. In effect, what one ends up with is the Model 19 network with greater adjustability on the mid frequencies.

So, I've decided to use the Butterworth network (with horn attenuation L-pad) followed by the 30923 eq with L-pad adjustability for the mids. I'll end up with a simple network with external L-pads with one marked "horn attenuation" and the other marked "mid-range."

I'll be posting my build under another thread. Hope to build the networks first so that I can confirm that they will work as planned.

geeDeeEmm

Pls show us some pics when you have those all together! Are you planning on putting the horns in the cabs or on top?

I really like the 606 cabs. I wish I could bribe my wife into letting me put a pair in the living room.
 
I'll start a new thread once I get started. Plans right now are to mount the horns on top of the cabinets. My horns and drivers are that beautiful Altec hammertone green and just too pretty to hide!

GeeDeeEmm
 
I was wondering if you'd progressed any on your build. Also looking forward to pics.

I'm about to start on my own project based on the Altec 606 cabinet. It will have 416-8Z woofers, 802D drivers, and 511B horns. Like you, I researched crossover possibilities until I was sick of them. So, I decided, for now, to install a simple 12dB/octave Butterworth network at 800Hz with an L-pad for horn attenuation. I have all those components now ready to be assembled.

Here is the reason I'm telling you this, even at the risk of your having to do even more reading: I ran across this Zilch thread that I'd somehow missed: http://audiokarma.org/forums/index.php?threads/using-altec-30904-atteuator-with-511-416.155640/

In this thread, Zilch not only further discusses the 30904 attenuation/equalization network, but the simple conversion of the 30923 horn section to 16 ohms. In addition, he tells how to use an L-pad to make the eq effect adjustable. In effect, what one ends up with is the Model 19 network with greater adjustability on the mid frequencies.

So, I've decided to use the Butterworth network (with horn attenuation L-pad) followed by the 30923 eq with L-pad adjustability for the mids. I'll end up with a simple network with external L-pads with one marked "horn attenuation" and the other marked "mid-range."

I'll be posting my build under another thread. Hope to build the networks first so that I can confirm that they will work as planned.

geeDeeEmm

This sounds great GDM - I actually had seen that thread - and came close to doing the full 30923 HF network, but costs were mounting and I decided to hold off.

Based on my reading of the Skywaverider 9844 thread (pp 3-6) and the one you linked to, my understanding is that the 6uf cap and 8 ohm paralleled resistor is the equivalent of the 30923 T-Filter being set to max attenuation into an 8ohm HF load, and into the 16ohm load of my 806a will give me a ~3db of additional compensation.

Assuming I'm understanding that correctly, I figured 3db of additional fixed compensation was a good middle ground to start with and I can make changes or do the full T-Filter later on. Does that make sense?

Any advice on specific caps to use for the 6uf value?

Definitely want to see pics of your project! I'll try to get some if mine posted up over the weekend.
 
Aaron, I'm not advanced enough to be recommending anything to anybody. My electronics understanding is very rudimental and I have to base my decisions on the superior understanding of other people. Zilch's work has been invaluable to me in making it this far. Even though I've been building speakers for about 40 years, it's only in the last three that I began to study actually designing my own crossovers. Previously, I would just build textbook designs and simply add in factory crossovers.

In essence, I'm in the learning/building/experimenting phase that others here went thru many, many years ago. Best of all, I'm having a blast doing it.

GeeDeeEmm
 
OK! I am impressed!

GeeDeeEmm
Thanks! In these pics, not too much has been done other than a lifetime of stripping off the old layers of paint, sanding, then a single coat of stain. I'll be sure to keep that thread (ahem) posted.

I dug the second pair of original inductors out of that g*#&$ f'&$! tar/wax today, conveniently at the veeeery bottom of the steel canister.

I'm 80% of the way done, but at that point in the project where I'm pushing through on sheer will.
 
I'm 80% of the way done, but at that point in the project where I'm pushing through on sheer will.

I hear 'ya, bub. I finally started cutting wood yesterday for my Altec 606-style cabinets. (I'll be starting a thread when I have a few more pics.) The first cut I made, a 45 degree angle with my skil saw, I neglected to check my blade depth. Naturally, the blade wondered off to the side of the mark. Waaaay off the mark. Spent the rest of the day correcting for the mistake. (You'll see why when I start the thread.)

Oh, well. At least I wasn't spending my time digging inductors out of tar!!!!!!

Keep us up to date. Love these projects.

GeeDeeEmm
 
...But, with the 511- the above addition of the EQ/attenuator to the 800 Hz network, may produce nice results.

Regards,
Gordon.

It does. Nice work Aaron, there seems to be a lot a great activity using Altec appointments lately.
 
I hear 'ya, bub. I finally started cutting wood yesterday for my Altec 606-style cabinets. (I'll be starting a thread when I have a few more pics.) The first cut I made, a 45 degree angle with my skil saw, I neglected to check my blade depth. Naturally, the blade wondered off to the side of the mark. Waaaay off the mark. Spent the rest of the day correcting for the mistake. (You'll see why when I start the thread.)

Oh, well. At least I wasn't spending my time digging inductors out of tar!!!!!!

Keep us up to date. Love these projects.

Will do GDM... And thanks again. Please be sure to post here when you start your build thread too...looking forward to seeing how yours progresses!
 
It does. Nice work Aaron, there seems to be a lot a great activity using Altec appointments lately.

Thank you sir! Here are a couple of pics with the cabinets roughed in and the 811b tested with 3M rubberized undercoating. They were painted multiple shades of white over the original Altec green, so black seemed the best option anyway.

Once I have the speakers up and running, I'm going to draw up some compact, triangular enclosures, with nice rounded corners for the horns. I'll have them CNC routed out of stackable layers of Baltic Birch...thought that would be the best counter to my wife's contention that my new speakers "look like air raid sirens."
 

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The first cut I made, a 45 degree angle with my skil saw, I neglected to check my blade depth. Naturally, the blade wondered off to the side of the mark. Waaaay off the mark. Spent the rest of the day correcting for the mistake. (You'll see why when I start the thread.)
It takes more time, but i like to use the skilsaw against a straight edge clamped to the sheet i'm cutting. Saws that use a cast aluminum foot are ideal as the foot is thick and nicely machined where it will guide along the straight edge.

jaaronb, looking real good! Congrats on your progress so far.
 
Thanks Bowtie.

I've used 5/8" threaded inserts from McMaster Carr to rear mount the drivers and keep the baffle fronts clean. Drilling 3/4 of the way through those baffles from the rear was a nerve racking experience.

I can see the light at the end of the tunnel now. The only major work left is bracing the cabinets thoroughly, reinstalling the fiberglass, soldering up the crossovers and final assembly.

As I close in on being able to fire these things up, I have three questions:

1) would someone here who is not a rank amatuer like myself be willing to take a look at a couple pics of one of my crossovers and let me know if I've done something "wrong"?

I'm using the N-800F schematic with an added cap/resistor stacked at the end of the HF circuit for added compensation. I've never wired a crossover before...

The circuit is rather simple, but I want to be sure I've wired it correctly - particularly since I'm using 16 ohm L-pads instead of the pot from the original design, and it isn't 100% clear to me if wiring the L-Pad to its published spec will yield the result of the original design, in which turning the pot "up" increased attenuation.

Also, at this point I have the original 20ohm resistor coming off the negative of the L-Pad, per the original N-800F schematic... I'm also not sure if this is correct, or if the addition of the L-Pad eliminates the need for that resistor.

Crossover is laid out, but not yet soldered. I can post pics that have all wires cleanly routed and clearly visible. I'd take REALLY appreciate some help on this one.

2) I've cleaned the throat of the 806a compression drivers using the masking tape technique - the bug screens at the bottom looked pretty nasty (one had a big staple sitting on it), but intact and not damaged. Should I consider removing the screens, or leave them as is? How hard an operation is it? I should probably send them into GPA for a regauss, but don't love the thought of throwing any more $$ at this project right now.

3) I've read the few threads out there on bracing the 9844 cabs, but some of the more knowledgeable guidance in them isn't 100% clear to me, and there doesn't seem to be consensus on the best method.

Any thoughts as to how best to brace them? My rough plan is to reinforce the joints with glue/screwed 2x2s on those sections where there are currently no cleats or blocks, then glue/screw 2x2 diagonals along the sides and back, and 2x2s front to back in the middle of the top and bottom panels. I'd then connect the top and bottom braces to each adjacent side wall brace at about 45°angles, forming a diamond shape as one looks into the box. Since my "design" removes the horn from the enclosures and pushes the front baffle out by .75", I have some internal volume to play with.

Thanks so much to everyone here for their wisdom and encouragement! No way I'd have been able take on a project like this without input from people here!
 
It takes more time, but i like to use the skilsaw against a straight edge clamped to the sheet i'm cutting.

My absent-mindedness was running WFO on the day I did this. (I'm waiting on pulling out my table saw until one of my sons are around to help me.) I had just purchased a new skilsaw with integral laser guide, so my (over) confidence supply was running high. Odd that on the same day that I purchased the new skilsaw, I also bought a decent clamping 4ft. straight edge! So, there it was, hanging on the wall - and I forgot that I even had it!!!! Age is killing my memory.:dunno:

Aaron, I would not even hazard a guess on your crossover questions, as I'm too much of an amatuer myself. But, I'll bet that if you posted pics of what you intend to do, Bowtie could answer your query in a flash.

GeeDeeEmm
 
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I removed the bug screens from my 802D and 802G drivers. The 802D's screens were dirty like yours. I noticed a nice improvement sans screens.
The 802G had cleaner screens. I noticed a slight difference removing those. Not huge but I would do it again.
I used some small needle nose pliers to remove mine
 
The circuit is rather simple, but I want to be sure I've wired it correctly - particularly since I'm using 16 ohm L-pads instead of the pot from the original design, and it isn't 100% clear to me if wiring the L-Pad to its published spec will yield the result of the original design, in which turning the pot "up" increased attenuation.
If it's simply a matter of rotation direction for increase or decrease, i'm pretty sure that can be reversed by simply reversing the outer terminals.

Also, at this point I have the original 20ohm resistor coming off the negative of the L-Pad, per the original N-800F schematic... I'm also not sure if this is correct, or if the addition of the L-Pad eliminates the need for that resistor.
I'm pretty sure it needs to be significantly reduced in value, if not removed altogether.

Please post pics............... we love pics! :)

I always cringe a little at the thought of removing bug screens. Having worked with lots of road gear i know what those things catch.

That said, any oxidation of the screen changes it's acoustic characteristics from the original spec, and that's not a good thing. 4 out of 5 screenless drivers will probably survive the next 30 or 40 years without any issues of intrusion. Which one of you fellas owns screenless driver number 5? The fear monger in me needs to know. :D
 
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