Ideas or concerns about upgrading a pair of 9849A's

Hello,
I am new to the forum, and have obtained a pair of Altec 9849A Studio monitors.
The bass is fine, but I would like to enhance the upper end with 908-8B drivers.
Should the crossovers be rebuilt or redesigned? Do the enclosures need to be ported as in some of Altec's other models? Any thoughts on the pro's and con's of protecting these speakers with fuses? What is with the speaker wire terminals? Hard to believe there was nothing better off the shelf to equip these with in the mid 70's.
I have time off during the holidays to work with these speakers. I am building stands to get them about 18" off the floor, they sounded way too muddled close to the floor. They are currently on stands I built for Wharfedale Diamonds. ( I usually
tend to overengineer things whenever possible).
Thanks for your time, and Happy Holidays to all.

Hi Wolfenbit ! Welcome to the Altec User Board ! Are these speakers all original ? What are the HF drivers ? 902's I believe....

Hello,
As far as I can tell, the speakers are all original.The cabinets could use some TLC, they look as if they were pole mounted at one time.

I would start with the Crossovers first.They are nice little monitors ! If they have 902-8T's they should have nice HF.I think they got 414-8B's in them too.If they are 902-8T they will have loading caps in them.The recommendation on that is to remove the black loading caps and insert a piecs of 1/8" felt in the back cover.That should help in getting a smoother response.

Altec Compression Driver Rear Loading Caps

Greets!

Welcome!

New caps, yes, and since the few I?ve seen had 808-8B [Symbiotik] MI drivers, it probably will need a modded XO for later drivers.

Doesn?t hurt, but light bulbs would be my choice as you can see how much they?re being over driven.

??? They are ported. If you mean re-tuned, well, that?s a personal preference/app dependent choice. They are voiced to be wall mounted with the horn on bottom at/above ear height, so well away from any boundaries you may prefer tuning them higher or even sealing them off and using a separate sub system. For corner loading, you may want to tune them lower.

GM

HF is likely an 806A or 806-8A if you have the early sealed version.

In fact, if you have the early sealed version, much about it is quite unique and not like the later ported versions 9849-8A and 9849-8D.

Some pics would go a long way.

If you have the sealed version, some pics of the woofer and crossover would be very enlightening.

Once we see what you have, it may be possible to positively identify the components.

EDIT: apologies for the simulpost GM.

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??? They are ported.

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The early ones were sealed with a foam edged woofer and 900 hz XO.

http://www.lansingheritage.org/image...itor/page5.jpg

No need, stuff happens and I learned something as I don't recall a sealed version. The same basic info would apply though if these were voiced for mid-wall mounting also.

GM

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Originally Posted by wolfenbit

Hello,
I am new to the forum, and have obtained a pair of Altec 9849A Studio monitors.
The bass is fine, but I would like to enhance the upper end with 908-8B drivers.
Should the crossovers be rebuilt or redesigned? Do the enclosures need to be ported as in some of Altec's other models? Any thoughts on the pro's and con's of protecting these speakers with fuses? What is with the speaker wire terminals? Hard to believe there was nothing better off the shelf to equip these with in the mid 70's.
I have time off during the holidays to work with these speakers. I am building stands to get them about 18" off the floor, they sounded way too muddled close to the floor. They are currently on stands I built for Wharfedale Diamonds. ( I usually
tend to overengineer things whenever possible).
Thanks for your time, and Happy Holidays to all.

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Sorry for the delay, I had to build bookshelves for my daughter for Christmas. The speaker serial#s are 632 and 633. I am going to install the 908-8B drivers but need to verify whether they have loading caps or not. If so, how do you get them out? On the vintage Altec site, the pdf for the 9849A does not show them to be ported as the -8b's were.( That was the reason for my earlier question.) The woofers are definitely 414-b's, but the serial numbers are hard to read. Unsure what the older HF drivers are, the top end rolls off too early for me to believe they could be 902-8T's. ( I haven't a clue really.) The crossovers seem to be in good shape, but I am getting rid of the stock speaker terminals, and am going with a design to accept banana plugs. I took a few more pics which I will upload later.
Thanks for the feedback, you guys rock!!!

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Unsure what the older HF drivers are

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Look like 806-8A's to me.

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but I am getting rid of the stock speaker terminals, and am going with a design to accept banana plugs.

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Stock terminals are easily upgraded and i can think of many reasons to do so.

OTOH, banana plugs were designed for easy interchangeability of test leads on test equipment. I can't think of any good reason to use them for speaker connections. They are unreliable, and inconsistent for long term current transmission. Don't wait until one eventually vibrates out and shorts the speaker lead when you've stepped out of the room. My amplifiers all cringed watching me type this.:D

One of the best speaker connections you'll ever make is a lightly tinned bare wire firmly clamped down in a binding post. If you need something that looks fancy to impress your friends, use some gold plated spades and dress up their installation with some cable "pants" made from different colored heat shrink.

908 is Symbiotik, Altecspeak for an aluminum dome/synthetic surround. Can be identified by a brown ring around the dome.

http://i107.photobucket.com/albums/m...sympasfrnt.jpg


Image from Bowtie's photobucket


So in order...

Remove loading caps, add felt. You will need shorter screws.

Aluminum GPA frams.

Recap crossovers.

All of the above will improve HF dramatically. The only thing I could suggest beyond that is a crossover similar to the Model 19 with separate mid/high adjustments. It would raise the xover to 1200 Hz but that should not cause an issue.