9849-A studio monitor need help please'''??

[Old Guy]

Originally posted by GM:
WRT the 'more powerful' reference, I was referring to the 808's wasted increased efficiency due to its larger/stronger (more powerful) motor over the 804/806/807 series normally used in many consumer/prosound models, so I can see where this could be a bit misleading. My bad.

GM[/QB]

<font size="2" face="Verdana, Helvetica, sans-serif">Ahh, no problem. It's a little clearer what you were saying now.

Thanks for the clarification. I was starting to doubt my sanity.

I would have consulted the Redhead but she's been doubting it for years.

[GM]

Originally posted by gamalot:
Well, now you all know why I can't ID my drivers!
They measure 2 3/16" from cover mount surface to horn mount surface.

<font size="2" face="Verdana, Helvetica, sans-serif">Greets!

OK, last night I posted pretty much from a dim memory since I didn't have time to do any research of consequence, hoping someone would take up the slack, but apparently all I did was confuse, so after doing a little digging tonight I find my memory really ***** WRT time frames.

Anyway, according to Bill Eckle's chart, the 806-8A was used through '75, and from a referenced catalog, the 414-8C was also already available, so combined with your flange-flange dim. (which is 'close enough' IMO to the 2.13" dim. I reverse calc'd from various data)/alum.diaphragm, they have to be 806-8A except with a loading cap IMO (or what they should be from a performance/cost POV), so in theory would make these speakers '75 vintage, though if true, yours is the first '75 drivers I've seen with the later style rear cover.

This 'mod' makes me wonder if they are a year or two newer and Altec kept 'discontinued' stock to tide them over WRT existing speaker products until the 802-8G debuted, though I'm curious why they would even bother with it since the loading cap negates its primary function of sealing off the rear of the diaphragm.

GM

[gamalot]

OK, Now it is bugging me so I have both a known 802-8G on the left and the ones I am attempting to ID on the right.
Both are the same diameter.

802-8G with cover in place measures 3 13/16ths"

Other measures with rear cover 3 3/8ths"

Covers could interchange.
Note the stamped box on the white labels of the left driver. It has AL/80. on the right driver this same stamp has AL/60, don't have a clue if this means anything.







Thank you for all your help and I hope this could be the deciding factors. All internal pics are above in this thread.

Gary

[gamalot]

Based on all of the above, Ie; Loading cap with newer style rear cover.
Is it not redundant to have both the cap and cover?
Does it make sense to remove anything on these for optimum performance or should I use them exactly as they are.
The one difference I notice between the 802 and the 806 is the felt pad inserted in the cover of the 802 and no bakelite loading cap over the diaphram.
The 806 has the cap over the diaphram and no felt pad inside the rear cover.

How would you guys use these or what is best sonically?

I still have to check what Sledchick is refering to on the woofers but will do this from the speakers fronts rather then from the photos.
Gary

[GM]

Greets!

Right, this is what I was alluding to here: ".......since the loading cap negates its primary function of sealing off the rear of the diaphragm."

With no loading cap the felt is required to damp reflections back through the horn. The inside of the loading cap doesn't need it since the gap is so close that any reflections are well above the driver's passband, ergo so low in amplitude as to be completely inaudible.

Unless you're prepared to completely rethink/design the XO for whatever reason, leave it stock and might as well leave the rear covers on so you can't misplace them.

WRT improving them sonically, quality PIO capacitors are an obvious upgrade and FWIW I added a R/C network to flatten the horn's response when driven by a low output impedance amp, which typically was 8 ohms for an 8 ohm driver/1 uF bypass cap, though the cap value is somewhat room/personal preference dependent, so best to try a range of values with cheap ones first.

GM