Altec 803B woofer, 804A compression driver, N 800 D crossover - what to build?

[polaris26]

I am looking at purchasing a set of Altec drivers for sale near me which I believe are from VOTT systems. The drivers are 803B woofer (some say similar to 416Z?), 804A compression driver, N 800 D crossover, and not sure about the horns - they may be either 511B or 811B as I am trying to get more info from the seller - In any case, what sort of enclosure or configuration would do this combination justice, and what sort of performance would I expect? For reference, I was originally trying to purchase something like the Altec Model 19's, since I had those in the past and wanted to get back to that, but this lot of parts came up for sale locally and so I was wondering what the difference might be building a system with this lot of components (given an optimized enclosure) vs a stock Model 19. Any thoughts?

Dave

 

[bowtie427ss]

That's an Iconic load, would also be used in early 846 (before they named it Valencia), and there was a horizontal aspect cabinet as well, the name/number escape me at the moment.

The 803B is the same woofer as a 416A, 416Z would be the plain or OEM version which doesn't have the can covering the magnet structure. They changed the model number to end confusion created by the fact that they concurrently produced a multicell horn model 803B.

 

[malden]

yes, 846A or 846B type enclosures if you have the 811B horn. You could also build the A7 type enclosure if you have a huge room. I use my A7's in my workshop which is about 600 square feet and they really fill the room with quality sound.

 

[malden]

ALTEC PLANS

 

[polaris26]

I have confirmed that the horns are 811B. If I were to load this set of components into a Model 19 cab, would it give the same or similar performance to what came loaded in the Model 19 from stock? I am not familiar with all the models and years of drivers but am learning as I go. It seems there is little difference between these components and the ones from the 19 but maybe I am missing something (other than 16 ohm vs 8 ohm, and possibly a different crossover point?)

If I understand correctly, the 804A is similar to the 802D, but with a smaller magnet structure and slightly lower efficiency rating.

This system of components I am purchasing had an 800 Hz crossover point. Should I go with that if I had some new crossovers made, or would a higher point work better / allow for more power handling of the horns? This is a 16 ohm system. Would be curious as to suggestions for the best crossover for this system.

Dave

 

[bowtie427ss]

If I were to load this set of components into a Model 19 cab, would it give the same or similar performance to what came loaded in the Model 19 from stock?

Loaded question.

While same is clearly defined, similar is subject to a range of interpretation.

3+db difference in sensitivity is more than slight.

In early 1974 Altec was engineering a re-designed 802 alongside a re-designed 416. Once thoroughly shaken down they would be introduced across the 74/75 model year as 802-8G and 416-8B. Both the new woofer and compression driver would feature new magnet structures cast in a single piece from a special steel alloy. The 802-8G would feature the Tangerine radial slit phase plug.

The model 19 was completely engineered around these specific drivers, from it's dual resonant enclosure to the most complex crossover network Altec produced to date. To get the 19's signature sound, you need to use the same components.

 

[elitopus]

For what you would pay for that set of components, you’re probably at least half way to a pair of model 19. Just get the real thing if that’s the sound you want.

 

[polaris26]

Just a quick update - I have the drivers and crossovers, all in fine form! Now to work on cabinets...
Dave

 

[elitopus]

So are you building M19 cabs or something else?

 

[twiiii]

Altec Capistrano.

 

[polaris26]

So are you building M19 cabs or something else?

Not sure/open to suggestions...

Cabinet-wise, I think it boils down to:

1) "plain-jane" rectangular no-frills ported box, maybe around 8 to 10 ft^3. , horns sit on top in the open. Maybe with external crossover for easier tweeking. This would be the easiest to build, of course
2) 19 -style box, possibly with modified tuning (?) more complex to build, but more Altec-faithful
3) A full-on A7-style box (probably too large to transport and/or too complex to ask my cabinetmaker to build or transport)
4) Onken-style - complex to build, and is fairly large/heavy. Not sure what the advantages are for this design, but seems popular. I've seen someone selling plans for these online.
5) - Other possibilities/variants - smaller boxes, open baffles, closed box, etc?? Plus other mods like damping the outsides of the horns to make them less ring-prone? Etc....

P.S. - what is the deal with the time-alignment of the woofer/tweeter in these systems - the VOTT had the driver further back and more in-line and the 19 and a lot of other "domestic/studio" systems did not - not sure what effect this has on imaging, polar plots, etc - ?


Crossover-wise -

I suspect tweeking is in order to optimize this, and the original dividing network will probably not be sufficient. I may be mistaken but I believe the horn can be padded down in the mids to bring out the upper treble relative to the mids, and still match the efficiency of the bass driver. Is this what was done in the 19 crossover? Some adjustability would be nice as well. I understand the 804A is less efficient than the 802D but I would think it should still have some room to pad down relative to the 803B(?)

I think some measurements of the drivers are in order, but I currently lack any dedicated equipment other than basics like signal generator, scope, and multimeter. I know some/all T-S parameters can be determined with relatively simple equipment but of course computer-driven measurement systems are an option, and I might be tempted to invest.

Regards,
Dave

 

[elitopus]

If you think you might still get some M19 components, you could always build the M19 cabs now and use these components. Then switch them over later.

If it were me I’d build the 828 cabs. I just like the way they sound. I have not heard any Onkens, but yeah they seem to be popular.

There should be specs out there for all your drivers. Assuming the woofers have original cones and the HF drivers have Altec diaphragms. But if you could find someone local with DATS you could test all your drivers. Or just buy it. It’s only $130

 

[twiiii]

YES, 804 and 806 were 3 or 4 db below an 802. The 802 was a little flatter on the top end. Just like a 803 was 3 or 4 db below a 515 woofer. I always preferred two 414's to an 803. In the right size cabinet they could reach as low, handle more power and sounded better up into the midrange frequencies. Of course the later models with better magnets and cone materials have lower distortion and much less of the warmer bass fuzzies. Get the latest HF diaphragms for the 804 as it will improve things ,too.

 

[Lecta414]

If you have a small room, I'd think about losing the horns themselves, or you will be hoping the crossover will solve its issues, and the stock crossover was not meant for small room home listening, and is not great to my ears. But all altecs have this feature to deal with....I nixed the crossover and listen at low volume as a solution! not a fix for most, but the point is you will want to tweak the stock crossover no? or ideally have one designed which is costly. The other dirty fix is to try and EQ any issue on the final signal path, which is never perfect but can solve many issues for most listeners... as to the box, I ended up with a 3 sq fter for 414's, and feel like while its about right, one could probably get away with half that size perhaps..but not sure about the 416 variants you have.