altec model 19....

**rontec** · December 20th, 2009, 01:27 PM

Hi everyone. I posted this on the Lansing Site and thought it would be helpfull here as well. A bit long, but I would be interested in your thoughts. Thanks...

I've been visiting this forum (Lansing H.)for the past six months and have found some very useful information. So, when I discovered something concerning my Altec 19's this evening, I decided to register and share this information with others. I hope this is the correct forum and that this information is not old news.
I've owned my 19's since 1985 and noticed in recent months that when comparing them to my ADS L1290/2s and my Energy Veritas 2.3's the high frequencies were not as outstanding as they used to seem, even though the dynamics and soundstage were still tremendous. Also, adjusting the HF and MF levels did not change the tone as much as it use to seem to do.
Anyway, I took the route of changing out the capacitors, but it made no improvement. Infact, I didn't like it as much. So, this evening I put the old capacitors back in and noticed that there are four ground lugs rivited to the crossover board. I began to wonder if oxidation had built up between the lugs and the board over the last 25 years. I soldered a common wire to all four lugs and then connected the wire to the negative side of the speaker wire, thus bypassing the lugs. Eureka!
The change in sound quality is unbelieveable. Everything improved, dynamics, soundstage, imageing. IMHO, if you have some 19's, before you do anything else, bypass those ground lugs by connecting them dirrectly to the neg. speaker wire. The magic is back!

**rontec** · December 20th, 2009, 01:36 PM

Part II ..... follow up to a quest.

TNTN-

I haven't tried the new capacitors since making the new ground connection. Infact I didn't even measure the resistance between the lug and the crossover board. Initially , when I saw the ground lugs, I thought of soldering the lugs dirrectly to the board. But because there was little room to do so, I used a common ground wire instead. I didn't expect such a dramatic change in sound quality.
After connecting a ground wire to the lugs of the second speaker there was again a dramatic improvement in sound quality as well. I believe that you can physically stress the ground lug to make a better connection but the wire will eliminate any resistance building up through oxidation between the lug and the board.
There are four ground lugs per crossover board. If any one of those lugs developes resistance then sound quality will be degraded! After reading so many post about HF lacking in model 19's I thought maybe I too needed new capacitors. Now I do not believe my original capacitors have dimished in any way. Now when I adjust the HF and MF levels, there is a much greater change in tonal intensity. The before and after is quite dramatic.
Now I'm wondering how many other mechanical connections in other pieces of equipment such as rivited ground lugs could be oxidizing and causing sound degradation after many years?
(at some point in the future I'll try the new capacitors and I'll remove the common ground wire and measure the resistance between the lugs and the board) ....sorry for the long post....

**RonSSS** · December 20th, 2009, 03:31 PM

Interesting and welcome!

I'm looking at a spare M19 (1201-8A) Crossover right now and indeed, the alum chassis is used as the ground. The rivets are steel, so corrosion is a definate possibility even if you can't see it.

Good catch!. I should have caught that when I was working on mine.

BTW....I also found that I preferred the stock caps. There may be some better ones, but a guy could spend a fortune trying the various different kinds.

The crossovers in my modded 904-8A are similar, but those I totally rewired.

Thanks,

Ron

Originally Posted by rontec

Hi everyone. I posted this on the Lansing Site and thought it would be helpfull here as well. A bit long, but I would be interested in your thoughts. Thanks...

I've been visiting this forum (Lansing H.)for the past six months and have found some very useful information. So, when I discovered something concerning my Altec 19's this evening, I decided to register and share this information with others. I hope this is the correct forum and that this information is not old news.
I've owned my 19's since 1985 and noticed in recent months that when comparing them to my ADS L1290/2s and my Energy Veritas 2.3's the high frequencies were not as outstanding as they used to seem, even though the dynamics and soundstage were still tremendous. Also, adjusting the HF and MF levels did not change the tone as much as it use to seem to do.
Anyway, I took the route of changing out the capacitors, but it made no improvement. Infact, I didn't like it as much. So, this evening I put the old capacitors back in and noticed that there are four ground lugs rivited to the crossover board. I began to wonder if oxidation had built up between the lugs and the board over the last 25 years. I soldered a common wire to all four lugs and then connected the wire to the negative side of the speaker wire, thus bypassing the lugs. Eureka!
The change in sound quality is unbelieveable. Everything improved, dynamics, soundstage, imageing. IMHO, if you have some 19's, before you do anything else, bypass those ground lugs by connecting them dirrectly to the neg. speaker wire. The magic is back!

**Russnohio** · December 20th, 2009, 04:43 PM

rontec, thanks for that tip!

Last time I had my crossovers out I never even considered this. My crossovers are still stock BTW except for some replaced wiring.

The HF of my 802-8g's still sound great so perhaps mine are not (yet) oxidized or giving resistance. In any case....your info is something I'll keep in mind.

Russ

**Altec Best** · December 20th, 2009, 05:21 PM

I had mine done also but I can't stress enough if your caps are 25 years old or older they should be changed.A friend (Dave Wojo) did the same thing for me he made ground jumpers from lug to lug so they were grounded directly with wire to ensure a good ground after all they are only rivets nothing beats soldering the grounds.The caps and resistors were changed 1 resistor was out of spec so they should be checked/changed also, he used Solens and the differance was like night and day.They sounded so much better when I put the rebuilt Crossovers in they sounded fantastic I highly recommend changing the Caps/resistors especially if they are original and from the seventies they should be changed you won't be disappointed.I couldn't be happier with the change.

**Old Guy** · December 20th, 2009, 06:08 PM

Very good insight...if I could add, a corroded connection may well have capacitance too....and even if the crossovers are in good shape, your wiring idea holds water...copper is a better conductor than aluminum or steel....

**rontec** · December 20th, 2009, 06:31 PM

Thanks for all the comments.

Altec Best- I agree that changing the caps and the resistors may improve sound quality. However, I stress to first connect the ground lugs together. Then any changes to the crossover componets can be varified. Great that you've got your 19's at optimum levels!

Russnohio- I didn't think there was anything wrong with my 19's. I was comparing them with my ADS L1290/2 and my Energy Veritas 2.3's. (good speakers) But after connecting those ground lugs, there now is no comparison. It's like going back 30 years to when I first heard a pair of model 19s!
Even a friends B&W 801 matrix II's doesn't seem so superior any more. (I know..this is very subjective)But... Infact the 19's at lower volumes seem hard to beat. And at high volumes where the 801's are just starting to breakup, the 19's are just cruising along. ( Model 19's seem to be a very forgiving speaker with less than perfect recordings) But again this is "after" correcting the problem with the lugs!

So , if you have any Altec crossovers with rivited ground lugs, you owe it to yourself to connect them dirrectly to ground.
I believe in most cases there will be a very pleasant suprise!

**Panomaniac** · December 20th, 2009, 07:47 PM

Good one! Thanks for posting that.

90% of all problems in audio seem to be bad contacts.....

**Altec Best** · December 21st, 2009, 01:57 PM

Thanks Rontec, For the post.I pulled one of my 19 Xo's to show the jumpers on the ground lugs.I should also add that he upgraded the wire gauge to thicker.The first thing I noticed when I installed was the bass response was awesome much improved.I wanted to keep my original Xo's original so I bought an extra 2 sets from ebay.Had 1 done by Dave and hoping Todd can get to the 2nd pair after the Holidays and maybe use different caps to experiment alittle will see.Regards ~ AB

Happy Holidays to You and Yours !!!!

**Russnohio** · December 24th, 2009, 04:14 PM

Would it be possible I wonder for someone to put up a photo (closeup) of exactly what & where these 4 ground lugs are on the board, and how the wires are bridged?

.....I'd want to have an unmistakable ref to look at if & when I pull mine out again and I'm not sure I'm looking at the lugs discussed in AB's photos.

Thanks, Russ