Altec 816A & 3156 in close range listening

[Eino]

Hey everyone,

I recently managed to rescue two pairs of weather-beaten 816A-cabinets loaded with 3156-woofers. They had served their time stacked in open-air events, which might explain the supposedly odd cabinet-speaker pairing. However, I’d hope to restore one pair for a listening room setup, along with unidentified midrange horns hooked on HH Acoustics CD400 drivers. But before getting ahead of myself, I'm keen to hear your thoughts about gear's suitability for the intended use.

By judging from your personal intuition, how fitting a 816A-unit is for close range listening? And charging from the woofers' perspective, will I get a full potential out of a 3156 from a low-powered amp / on relatively low volumes? I'm still new to the horn game here, so any related thoughts regarding fitting amplifying, speaker positioning or general acoustics will be very much appreciated.

Thanks for the add to the forums, and thanks for your time in advance.

Best regards,
Eino

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Edit: Images embedded, cheers Rob!

[Robh3606]

Please post the images on the forum. I won't open them from there and when those links no longer work the thread will have no context.

Rob

[RMC]

Hi Eino,

Welcome to the Lansing Heritage. This is an interesting find you got and should lead to a nice restoration project.

The cabs look like DIY made, probably not factory built since i can't recall seeing brown ones, unless repainted.

I don't intend to rain on your project but the 3156 driver is more suitable for vented box use as indicated on both 3156 tech sheet versions (Altec and Great Plains Audio). As far as i know the 3156 was never recommended for horn use, nor for the 816A.

Altec's 31 series drivers were mostly developed for vented box use. Driver EBP here (Fs/Qes = 131) also points in that direction.

Altec's own 816A driver recommendations were 416-8A, 421A and 515B. Among Altec's 31 series drivers the 3156 could be the closest one, though not the right one.

I wouldn't be surprised the cabs were loaded with 3156 because of the lack of the exact drivers or difficulty/price to get the real thing. Therefore what you have is sort of a second best driver in terms of suitability for 816A.

It will still produce sound, no doubt about this, but just won't be optimal. Its important that you know, however it may not be necessarily critical. My impression is that you may get more boomy bass from the cabs.

RE "for close range listening?" Such horns are not intended for close range listening but rather to project sound at respectable distance, their coverage pattern is designed for that purpose. Regards,

Richard

ALTEC 3156_lf_speaker.pdf

EDIT: File size for the 816A cab is slightly too large to be posted here says the LH software... If you send me a PM with an e-mail address i can forward it to you, along with the 3156 GPA version of the tech sheet.

[Eino]

Hey Richard,

And thanks a million for taking the time to write such a thorough response. I could not have hoped for more valuable input and advice you’ve provided here.

The reason behind the curious speaker loading might be exactly what you’ve suggested here. I tracked the cabs origin down to eastern Finland, where they had been put together by a couple of chaps who allegedly used to import and install licensed Altec systems to neighbouring countries. This dates back to late 1970s, so I haven’t got a doubt there has been a shortage both on equipment, and well, quality control. It’s still rare to come across any Lansing-gear from that era around here.

Despite the fact the cabinets are likely locally made, the woodwork is solid and worth restoring. It looks like I should begin by finding out whether the previously installed drivers will provide anything close to a satisfactory output, and if not, I’ll have a better understanding why. Same applying to the mid-range.

Since I have the luxury of owning two pairs of 3156s, I could put the first one in use while building more fitting vented cabinets for more critical listening for the second — I suppose that would be a 8156 then.

I’d be happy to study that 816A spec sheet as well. I’ll DM my details to you soon.

Again, thanks for the extremely helpful response!

Best,
Eino