Reconing and fixing Woofers

I am wondering if there are any specialist you can recommend in Malaysia to fix a rubbing in my Altec 416-8C woofers. These woofers are about about 30 years and can do with a good service. Great Plains Audio, USA would be an obvious choice but the shipping and dutues would be too expensive.

I can "fix" the problem by placing my finger on the edge of the cone and it would sound OK, otherwise it would have some distortion on high-bass volume.

Any assistance are appreciated. Pls PM or contact me at 012 2236517 or mthoi@streamyx.com

Rubbing can only mean that either the voice coil has deformed, some rust/oxidation inside the woofer basket and its lodged between the voice coils and the stationary magnet or centre core, or the surrounding rubber has run off-centre, or a combo of the above.

Once u open them up, you can see if the voice coil has deformed or not.

If its just to recentre the cones with some new rubber surrounds, to do a good job, you might need certain jigs or custom DIY tools to ensure excellent cone centering.

If you love those speakers enough, it can be a worthwhile DIY project.

try PM Wang Yee Onn, he know a sifu who fixed a lot of those ALtec, JBL, Jensen..etc vintage driver..very experience guy..

mthoi wrote:I am wondering if there are any specialist you can recommend in Malaysia to fix a rubbing in my Altec 416-8C woofers. These woofers are about about 30 years and can do with a good service. Great Plains Audio, USA would be an obvious choice but the shipping and dutues would be too expensive.

I can "fix" the problem by placing my finger on the edge of the cone and it would sound OK, otherwise it would have some distortion on high-bass volume.

May I suggest that you try to re-align the magnet structure/motor of your Altec 416-8C first if the problem is not too serious?

This can be done by loosening the TORX screws at the back of the cone. Use a signal generator (if you have access to one) to generates a 4V,30Hz sine-wave signal or apply a 3V-4V (50Hz) a.c. source (direct from a small transformer) to the speaker; move speaker's basket (or the magnet structure) to realign the voice-coil assembly until the rubbing disappear.

Please give this a try....Write to me if you have question/s.

Thank you gentlemen for all your feedbacks. I have been in contact with Mr Oh's friend - Michael and he is kind enough to check out the problem with my Altec woofers.

The Altec 416 were recently fixed to my Altec A7 VOT. The bass are deep and clean. I just need to experiment with some damping material for the speaker cabinet and get the woofer fixed to make them a serious-sounding DIY speakers.

Hi Mthoi,
Have you manage to fix the altec speakers yet ?
How is the vocal and high with VOT ?
what about soundstage ?
It would encourage a lot of people here to diy speakers if you can post some pictures of the build !

cheers and happy diy
kp93300

Hi KP,
Michael did a splendid job in fixing my woofers. I would spend this long Labor Day weekend damping my speaker cabinets. Quite a few good suggestions from Wong SS and William Koh to damp the cabinet, which I would adopt.

Wikin and Wong SS came by last Saturday for a quick listen to the VOT, after about 25hrs of burn-in. They were very nice to say positive things about the clear mids and highs. I personally liked the large soundstaging for classical music. Bass was a bit loose at higher volume - which I hope to fix this weekend.

Wong SS also demo-ed his TDA1541/tube buffer/digital source and it blew me away with the clarity and sounstaging. An he did it all a very resonable cost. Beats my Meridian 506.20 anytime! More incentives to get my own TDA1541 DAC working!

And Wikin have an active crossover that I am keen to listen!

I have included some pics of the current Altec 828 VOT DIY. I hope there are more DIYs and certainly appreciate the comments and feedbacks.

Reg.

http://premium1.uploadit.org/mthoi1//DSC_0032.jpg
http://premium1.uploadit.org/mthoi1//DSC_0035.jpg
http://premium1.uploadit.org/mthoi1//DSC_0034.jpg

Hi Mthoi,
This is very impressive and nice and you have so many toys to play ! .
I can imagine that you have your own theater to play the music you like --sound like heavenly bliss!
The qls 550 with the i2s output is an over achiever. I use it with the monica and have no inclination to try anything new -- at this moment !. Even the spdif is also very very nice .
regards
kp93300

Yes, the key is I2S and the independent DAC (with tube output, current output).

It is easier to obtain good imaging and soundstage by using a separate DAC than a CDP with intergrated DAC unless the CDP is $$$$$.

In my case, QLS without i2S is just sound like DVD player with more queit background and slightly more analog. When shift to I2S it is day and night differences. 2 different beast.

My suggestion to those who use QLS 550 is at least doing the below:
1) Use I2S (priority) - more refine, analog, tigh bass, imaging, transparent and musical.)
2) Change the rubycons 470uf to blackgate. （better depth definition, soundstage, tighter bass, resolution)
3) use better power supply like batery and so on.

mthoi wrote:Wikin and Wong SS came by last Saturday for a quick listen to the VOT, after about 25hrs of burn-in. They were very nice to say positive things about the clear mids and highs. I personally liked the large soundstaging for classical music. Bass was a bit loose at higher volume - which I hope to fix this weekend.

Hi there,
Good effort to bring home a classic speaker and even place it in the hall. They'll serve as a piece of beautiful decorative furniture too.
Got a suggestion for you : Those white modern horn flares don't really gel. I'm used to looking at the black multicell classic horns; maybe you wanna spray them matt black ? ha ha.

Did you know that Brabusm is also a horn SET lover just like you and is staying a strong stone throw from your place.

Hey Brabusm, you there? Both of you should meet up and exchange notes.

cheers.

Hi mthoi,
Very nice set-up!

mthoi wrote:

http://premium1.uploadit.org/mthoi1//DSC_0032.jpg
http://premium1.uploadit.org/mthoi1//DSC_0035.jpg
http://premium1.uploadit.org/mthoi1//DSC_0034.jpg

Happy Labour Day.

Thank you for all your feedbacks. I tried convincing my wife to spray paint a snake coming out of the horns, but she was not keen for the idea. The white horn is a bit glaring.

I have the cabinet damped yesterday using Whurd car sound proofing material (courtesy of KK Lau Audio) and felt-covered fiber glass sound proffing material (Brothers). There is significant improvement in the lower register - what used to sound "fat" is now "leaner" and "sharp". The debate now is how much damping is enough? Lend me your ears!

Reg.

Hi mthoi,
I suggest you adjust the amount of damping material in stages and slowly over time to suit your music and ear.
This is the beauty of diy----tailored to your room, set up and your ears !
In the process you gain knowledge , experience and satisfaction.!

cheers
kp93300