HF driver and crossover recommendations for Altec 414A + Mantaray CD horn?

In my recent introduction post, I mentioned that I am beginning a 2-way build around a pair of Altec 414A drivers. I have really enjoyed going back through the archives and reading member posts about the 414A, and with a number of fans of that speaker here on the Haven I am looking for some guidance on how to proceed with my project.

For a few months now, I have had a lead on a pair of 32-style horns and 802 drivers out of a set of Model 15s, and if that deal materializes I would love to go the WE 753-inspired route that a number of members here have shared about. In the meantime, my 414A woofers are being reconed by a local shop with the GPA kit, and I would like to get them into a speaker to start experimenting. I have a pair of Mantaray constant directivity horns from a Model 14, and I am wondering if Altec fans would suggest starting with 902 drivers, with the Model 14 crossover to get the correct EQ on the CD horns, or if there is a better recipe out there. In reading about the Model 14, I see that there were 4 revisions of the crossover, and that some DIYers have updated it along the way. I would also be interested in running the 414As closer to full-range, which would change the crossover point from the original Model 14. I will be able to build my own enclosures, so I could go with a 614 cab with the HF unit on top, or something like the 3.4 cu. ft. design Altec had specified for the 414A with the HF unit mounted in the cab.

Any insight would be greatly appreciated, and thank you!

Mike
 

ICTWoody

No longer a junior member
I have a pair of Mantaray constant directivity horns from a Model 14, and I am wondering if Altec fans would suggest starting with 902 drivers, with the Model 14 crossover to get the correct EQ on the CD horns, or if there is a better recipe out there.

Welcome, Mike.

With that horn you'd be best served with the correct compression driver, the 902/908, since it's throat exit is actually 7/8" and not 1" like a lot of the small format horns. I have that combo and probably within the week I'll have my custom top-hats to mount them on top of my 614 boxes using a stock (but recapped) Altec N-3000 network.

I'll be updating my post soon... somewhere on here.

I like the MR HF section from the M14. It images very well and it's more modern sounding than the more laid back 32/802 combo.

- Woody
 
Just to complicate things for you, I will be posting an ad here at the Haven in the next day or two for two pairs of 32 horns—one pair plastic and one pair aluminum—and a pair of 802-8G with thin aluminum diaphragms. Also a pair of Emilar EH-500 horns with 1” adaptors.
 
Just to complicate things for you, I will be posting an ad here at the Haven in the next day or two for two pairs of 32 horns—one pair plastic and one pair aluminum—and a pair of 802-8G with thin aluminum diaphragms. Also a pair of Emilar EH-500 horns with 1” adaptors.

Go for this, and try Salectric's crossover too i found it a good improvement over the jelabs ones, the HF is noticably extended!
 
Welcome, Mike.

With that horn you'd be best served with the correct compression driver, the 902/908, since it's throat exit is actually 7/8" and not 1" like a lot of the small format horns. I have that combo and probably within the week I'll have my custom top-hats to mount them on top of my 614 boxes using a stock (but recapped) Altec N-3000 network.

I'll be updating my post soon... somewhere on here.

I like the MR HF section from the M14. It images very well and it's more modern sounding than the more laid back 32/802 combo.

- Woody

Woody,

Thank you so much for chiming in. I have seen a number of your Altec build threads, and I would love to hear your thoughts when you get the Mantaray horns on top of the 614 enclosures. Which compression driver (902 or 908) will you be using with yours?

Mike
 
The equalization components are the 3uf/5R pair and the .075mH/5R pair. These values come directly from the Altec 9849 crossover so I don't claim any originality. The 9849 used a 414 and 32/802-8G so the eq values are designed for these specific components. (The 9849 also includes a Zobel network on the 414 but I deleted that with the Jensen woofer.) Whether you use a 414 or a Jensen P15LL, the crossover network for the 802 sounds just fine. I have used this crossover with both the aluminum and plastic 32 horns.

I prefer discrete resistors instead of L-Pads to adjust the level of the 802. Using resistors means you are not stuck with either an 8 ohm or 16 ohm L-Pad. I took advantage of this to increase the effective load of my 802 from 8 ohms to something like 12 or 13 ohms, making it an easier load for the amp and more consistent with the 16 ohm Jensen woofer. If you use L-Pads on the 802, you will need to use different values for the actual crossover parts (7.5uf and 2.2mH are for the 12 or 13 ohm load); but the eq networks stay the same.

Some folks are using 16 ohm 802 drivers. The eq network as shown will NOT work as intended with them.
 

jmathers

Junior Member
Some folks are using 16 ohm 802 drivers. The eq network as shown will NOT work as intended with them.

Yeah, that would be me. Probably why I ignored this when perusing crossovers for my build. Thanks for posting it though. I'm sure it will help other folks. And the explanation helps a lot just as a matter of intellectual interest. I swapped out my L-Pads for discrete resistors (largely because of a comment you made in another thread here) and I'm liking the sound better.
 

ICTWoody

No longer a junior member
Woody,

Thank you so much for chiming in. I have seen a number of your Altec build threads, and I would love to hear your thoughts when you get the Mantaray horns on top of the 614 enclosures. Which compression driver (902 or 908) will you be using with yours?

Mike

Its got the loading cap, but aluminum surround diaphragms... so uhhhh. I guess 902’s? That’s are actually M14 horns and drivers I bought on eBay.

The top hats would have been done today, but my buddy messaged me and his guy rounded over all the edges. Oops. My 614’s he built me are all square. He’s having them kick out another set. I told him I’d sell the first set, sans finish, on here if anyone is interested. I’ll get them and post pics.

- Woody
 
Mike, I assume you have read Joseph’s latest blogpost (JELabs)...lots of good info.
I have 902s on my 32c horns and have found them a good match to 414z’s without a L-pad. I’m playing with 4-8uf caps from the 414z that is direct coupled to the amp. The higher caps are brighter and brings voice and high precussions into the room. Lower values are more laid back. Your choice.
 
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