Altec 620 as a BR cabinet...?

[intercity125]

Hi,

Has anyone ever tried using the 620 cabinet as a low-frequency BR only enclosure for say, a 416-8C woofer, or something similar? I was just wondering if this cabinet design/size fares well for this task.

Willy

[speakerdave]

The 416 is used in the model 19 which nets even larger than the 620, so it should be just fine. You will need to calculate the porting, I believe. There are multiple Altec wonks on the Altec users forum who would eagerly entertain this question and could possibly help with the porting.

[intercity125]

The 416 is used in the model 19 which nets even larger than the 620, so it should be just fine. You will need to calculate the porting, I believe. There are multiple Altec wonks on the Altec users forum who would eagerly entertain this question and could possibly help with the porting.

Hey Speakerdave,

That sounds encouraging. I can do refurb and build cabinets, but when it comes to the 'technical' stuff, like figuring out port tuning, I get a little muddled. In all honesty, I've never done it. I suppose I should study up on the subject, but for now I'm hoping some of the guru's you mentioned will chime in with their expertise. Thanks for your reply.

Willy

[intercity125]

For anyone who is interested, Altec's own literature on the 620A states in the first paragraph that it can be used for either a 15-inch low frequency or coaxial loudspeaker. I'm going to read that as no further port tuning is necessary to switch between the two. Now, that's good to know!

[Alien_Shore]

Looking at the 1974 enclosure guide (http://www.lansingheritage.org/images/altec/plans/1974-enc-design/page12.jpg), it recommends a 7.5CF BR cabinet for the 416-8B.
Another valuable reference is Application Note #5 (http://alteclansingunofficial.nlenet.net/publications/techletters/AN-5_CustomizingAltecLFEnclosures.pdf), it mentions 416-8C but you can see specifics for this driver in three different enclosures.

The original 620 cabinet is about 8.89 CF, while the 620B/C are 9.0 CF, and as mentioned, you'd need to adjust the port size to tune for the 416's Fs. First step would be to actually measure the speaker you have, then make the calculations based on that. But sure, the 620 certainly will work well with that driver, you would just need a slightly smaller port.

[intercity125]

Looking at the 1974 enclosure guide (http://www.lansingheritage.org/images/altec/plans/1974-enc-design/page12.jpg), it recommends a 7.5CF BR cabinet for the 416-8B.
Another valuable reference is Application Note #5 (http://alteclansingunofficial.nlenet.net/publications/techletters/AN-5_CustomizingAltecLFEnclosures.pdf), it mentions 416-8C but you can see specifics for this driver in three different enclosures.

The original 620 cabinet is about 8.89 CF, while the 620B/C are 9.0 CF, and as mentioned, you'd need to adjust the port size to tune for the 416's Fs. First step would be to actually measure the speaker you have, then make the calculations based on that. But sure, the 620 certainly will work well with that driver, you would just need a slightly smaller port.

Alien Shore,

I stand corrected. That's a great little spec sheet; it explains quite a lot, and is very helpful. Thank you for posting it.

Willy