Altec 406 - 8Y

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Built an Econowave using the 890C Bolero 406 woofers PRs and cabinet with a $10 JBL CD horn and Selenium DT-220-T CDs on top. Worked like a charm. Did not miss my Model 19s in the livingroom.

"Driven with high output impedance" means a tube amp for optimum dampening for the low Qts woofer.
 
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Just a note that info is for the Altec 406A woofer. Quite a bit different animal from the 406-8Y.

The 406A was a 2" VC, small Alnico slug motor and was crossed over in the 890A&B Speaker at 3Khz to an Altec 3000B multicellular tweeter.

The 408-8Y used in the 890C has s 3" VC, Altec 414 Alnico motor, and was used to 2Khz with a Hepner horn tweeter.

Pretty sure they do not measure the same.
 
Altec 406-8Y

Built an Econowave using the 890C Bolero 406 woofers PRs and cabinet with a $10 JBL CD horn and Selenium DT-220-T CDs on top. Worked like a charm. Did not miss my Model 19s in the livingroom.

"Driven with high output impedance" means a tube amp for optimum dampening for the low Qts woofer.

Hi Steve,

Thanks for sharing.

Did you use the existing Bolero cabinet? Is it the new compression driver that makes the difference? Is the horn/waveguide the same dimensions as the Heppner horn? Did you have to modify the crossover?

I would be driving with a Heathkit AA-151.

Best Regards,
Jeff
 
You're welcome!

Well, T/S specs says too low a Qts [< 0.312] for optimal venting, hence the PR, unless driven with a high output impedance to raise it [Qts'], so ideally would be in a large compression horn.

OB will work of course, though needs a helper woofer to fill in below its upper mass corner [fhm].

fhm = 2*Fs/Qts'

Qts' = Qts + any added series resistance: mh-audio.nl - Home

What I do, recommend for these type specs is a mass loaded [vented] TL = MLTL where net volume [Vb] = Vas, tuning [Fb] = Fs, which uses a TL to mass load the vent, improving the mid-bass some and allowing extension down to Fs, a real plus if driven with a high output impedance, so......

What are you going to use up high and assuming these will be used in a HIFI app, your average seated hear height or whatever height you want the HF at and I'll come up with a cab design.

GM


GM,

Your recommendation covered off on two of my criterion (lower bass, cleaner midrange). I really would be very interested if you could offer an ideal cabinet design for this woofer, and also a tweeter type/configuration, assuming a normal tweeter height for a floorstander (36-40"). My brother is a cabinet maker and could help me with the building of it.

Thanks,
Jeff
 
Hmm, almost missed this, didn't get an email update :(. Sounds like my default 38" will work then........ I can work up basic dims, but no drawing.

How tall, wide, deep can you tolerate? Cab will be around 7 ft^3 based on 3/4"[19] mm BB ply.

GM
 
You're welcome! OK, will try to get it done sometime this week [got to do it longhand, don't have Excel loaded].

Not really, I don't keep up with the rapid changes in drivers, just that the little horn's diaphragm is fragile and now with the death of the man that made them, don't know if anyone will continue. I used the nice sounding paper tweeter on a number of small speakers, but there's no direct replacement AFAIK, just cheap knock-offs like found in 'white van' speakers.

If still available, Scan-Speak has/had an alum. dome tweeter that was the only one out of all that I auditioned at several Atlanta DIY Meets back in the early 2000s save a very pricy ribbon.

Anyway, alum. domes, whether horn loaded or not seem to tonally sound best overall to me with Altec components, though a ribbon's 'air' tends to sound good with anything, so these are what I would research if the need arose.

The big problem is the driver specs 95+ dB eff., so the tweeter will likely need to be at least 92 dB and maybe have to match it depending on the room's impact on its wide range performance.

GM
 
Hi GM - Thanks again for all your help.

I have a couple "Morel" dome tweeters rated at 4 ohm/92db that might work (MDT29-4).

Also have a couple (monopole) Heil Air Motion Transformers - Not the big ones, but sound very nice. These too are 4ohm and appear to be quite sensitive (I don't have the specs).

Jeff
 
Here it is... finally :)
 

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Thanks! Don't recall these.

Regardless, got a sketch of sorts, now just have to find it........anyway, depending on whether my power gets knocked out and for how long before I can post it may be up to several days as my locale typically looses power anytime we get high winds due to living in a near forest of large trees.

GM
 
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