Driver replacement for Altec Valencias?

[Plink]

Hi folks...just picked a very nice pair of Altec Valencias from a very nice member here and I'm curious about a driver replacements for the horn so that I can get better HF response.

I just read a long and amazing thread on improving HF response for Valencias and it was suggested to use BMS 4550 or BMS 4552. Are there any others to consider? I was also advised to try Beyma and was told they were better than BMS. Looking for a quick drop in and improvement.

I drive my Valencias with a 300B SET amp which is plenty of power. Sound is very nice but I'd like something smoother and with better HF response. The rebuilt crossover is at 1.2 khz. I need to find out more about this crossover and am investigating.

I also have Model 19s but I will be listening to the Valencias while I work on the 19s.

Thanks!

[Zilch]

We will need to know whether they are 846A or 846B Valencias, specifically whether the 806 drivers are 8 or 16 Ohms.

Also, 1.2 kHz is not standard, so the details of the crossovers are important. Do they provide high-frequency compensation?

The most direct route to what you want to achieve using the stock drivers is to active biamp using Behringer CX3400 and push the "HF Comp" button, but that will only provide limited HF extension, as 806s cannot provide the HF performance of your Model 19s:

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=30131&stc=1&d=1198361465

Here's how they perform with the stock crossover:

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=30132&stc=1&d=1198361492

[Plink]

Hi Zilch, they are Altec Valencia 846B and the 806A drivers are 8 ohm per visual inspection. Reads on outside: N800-8K but this, of course, referred to the stock crossover there. The new ones are at 1200 hz and have a zobel network on the woofer, as I am told.

Here are some photos of the rebuild. Also, I have an email to the builder and am waiting on details. Thanks!

[Plink]

Hi Zilch, here is what I found about the crossover:

"Back to the crossovers, yes, I raised the crossover point to 1200hz, the stock crossover went down to about 780hz for the horn and about 1700hz for the woofer, pretty strange overlap, I did a 12db at 1200hz for both sections, I think it sounds better with less California sound (midrange emphasis). I'm going from memory on those old crossover points, I'd have to have the original cap values to verify them. Raisinf the crossover point to 1200 also raises the power handling to about 100 watts.

On the Zobel, it was tuned for the 416-8A woofer inductance, that's the LE figure for the driver, an Altec 416-8B or 416-8C could also be fine. The crossover just has the Lpad, no other compensation was done, I don't know what state the woofer alnico charge is in so if they lack bass at all they could be discharged some, I'd try swapping your model 19 woofers for laughs and see if there's a difference. "

[withTarragon]

Plink, Regarding the layout on the crossovers, there may be a couple of concerns.

1. The 2 inductors should be well separated from one another and not right next to each other. Also they should not be pointed in a parallel direction. IOW they should be a "right angles" to one another. Usually the layout for inductors should be guided by some measurement equipment.

2. The inductors appear to be mounted using a metal handle. Please use a magnet to find out of the metal is ferrous. IOW if it is attracted by the magnet then do not use it for a mount. Use brass instead.

I am surprised no one has caught these details.

Good luck,
-Tom

[sbjacob]

Plink, Regarding the layout on the crossovers, there may be a couple of concerns.

1. The 2 inductors should be well separated from one another and not right next to each other. Also they should not be pointed in a parallel direction. IOW they should be a "right angles" to one another. Usually the layout for inductors should be guided by some measurement equipment.

2. The inductors appear to be mounted using a metal handle. Please use a magnet to find out of the metal is ferrous. IOW if it is attracted by the magnet then do not use it for a mount. Use brass instead.

I am surprised no one has caught these details.

Good luck,
-Tom
Good call I also would have gone with Solen inductors.

[Plink]

Tarragon...thanks for your input

1. Looks like Altec aligned their inductors the same way. Did they determine it wasn't an issue or am I missing something?

2. I'll have to open things up tonight and see if they are metal.

[Baron030]

The Altec inductors are iron cored, so as a result they are not prone to inductor cross talk like air core inductors are.

Here is a link that explains what inductor cross talk is and how to minimize it.

http://www.audioholics.com/education/loudspeaker-basics/inductor-coil-crosstalk-basics

Baron030:)

[Plink]

The Altec inductors are iron cored, so as a result they are not prone to inductor cross talk like air core inductors are.

Here is a link that explains what inductor cross talk is and how to minimize it.

http://www.audioholics.com/education/loudspeaker-basics/inductor-coil-crosstalk-basics

Baron030:)


Ah, I see and makes sense. Thanks. I will have to remount these and this should take care of issue 2 also. Glad I started this thread.

[Zilch]

I believe those conduit clamps are plastic. If so, not an issue.

I'm thinking about the rest of it.

What are the capacitor and inductor values, and the Zobel resistor? Also, which is the Zobel cap?

It looks like he made a symmetric crossover at 1.2 kHz, whereas N800-8K was asymmetric to tame the 806 mids, which he didn't understand, but even that didn't do it well enough. See below.

Even if we fixed that, 806-8A does not have the requisite HF extension.

I have an idea that I'll try to check out for you yet today. The 8-Ohm woofer simplifies this....

[sbjacob]

I believe those conduit clamps are plastic. If so, not an issue.

I'm thinking about the rest of it.

What are the capacitor and inductor values, and the Zobel resistor? Also, which is the Zobel cap?

It looks like he made a symmetric crossover at 1.2 kHz, whereas N800-8K was asymmetric to tame the 806 mids, which he didn't understand, but even that didn't do it well enough. See below.

Even if we fixed that, 806-8A does not have the requisite HF extension.

I have an idea that I'll try to check out for you yet today. The 8-Ohm woofer simplifies this....Was wondering what the DCR of the inductors are on this network?

[Zilch]

Here's the adjustable 8-Ohm version of the Altec 30923 bridged-T HF comp circuit lifted from the Model 19 crossover, and the performance of three alternative drivers that play VHF on M19. Build that circuit and add it on after your existing Valencia crossover. Like Model 19, you'll adjust the two L-pads, to achieve the flattest or most pleasing balance, the new one being the equivalent of HF adjust:

[Zilch]

If you're really ambitious, here's my version of the Model 19 crossover with the HF separated from the LF, and the original, bottom, courtesy of the Markwart website:

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=30595&stc=1&d=1200899899

[Plink]

Zilch, I'll have to find some time to remove the crossovers. With quick look, I cannot see the values with them attached. So, you're saying I should just put in a model 19 crossover and then try the BMS drivers? Or, keep my existing crossover, add the compensation and BMS, and let the chips fall where they may? Thanks. Btw, the inductors are mounted using plastic and not metal although they are mounted the same angle...which I will change.

[Zilch]

Zilch, I'll have to find some time to remove the crossovers. With quick look, I cannot see the values with them attached. So, you're saying I should just put in a model 19 crossover and then try the BMS drivers? Or, keep my existing crossover, add the compensation and BMS, and let the chips fall where they may? Thanks. Btw, the inductors are mounted using plastic and not metal although they are mounted the same angle...which I will change.I am saying, since you already have some Model 19 crossovers on hand, install Selenium D220Ti drivers ($90 a pair) in your Valencias and play them with the M19 XOs. If that does it for you, then build the HF comp circuit and add-on to your existing Valencia XOs.

No good? Titanium diaphragms too harsh in the VHF? Try a pair of DE250 drivers, then, which have Kapton diaphragms. We know BMS mylar works, but these are less expensive options. Also, if you like the performance on M19 XOs better, I've provided the info necessary to build them or my "improved" version of them.

We still need the info on your crossovers; perhaps there'll be additional suggestions, but your question was what driver options might work, and I've presented data on three that I happen to have on hand. I don't have any 811B horns, just 511As, but prior experience tells me 811B will perform about the same.

If you want to stick with Altec drivers, then you'll have to acquire those used in Model 19 to achieve VHF extension, which means Tangerine phase plug 802-8G or 902 whatever, with vintage "lite" diaphragms, preferrably, but those aren't without their own issues, either, and not cheap.

I assume you've found both the Valencia "Babies" thread and Skywave's 9844-8B one, where we tested out these options....

[Plink]

I don't think I've seen all those threads so I'll go back and search. I don't remember discussion about the Selenium D220 but perhaps my memory is poor. But, I now see them in your graph. Thanks for your suggestion.

Cheaper is better in this case because my main speakers are really going to be the 19s. I'm working on the 19 crossovers now so trying them in the Valencias will have to wait.

[Zilch]

Yeah, we did the Selenium stuff in another forum:

http://www.audiokarma.org/forums/showthread.php?t=147170

[tomee]

Yeah, we did the Selenium stuff in another forum:

http://www.audiokarma.org/forums/showthread.php?t=147170

there's also the 59 pages here ...
http://audioheritage.org/vbulletin/showthread.php?t=14690

[rustnrot]

If you're really ambitious, here's my version of the Model 19 crossover with the HF separated from the LF, and the original, bottom, courtesy of the Markwart website:

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=30595&stc=1&d=1200899899

I've been lurking for awhile and think I have found what I am looking for. I have a set of Heathkit AS-101's that have not been modded and I want to improve them. I want to use the Selenium D220Ti drivers. I also want to upgrade the crossover (this needs to be done regardless as the caps are over 30 years old so why not a new crossover).

Is the crossover circuit above the latest recommended one to try?

Has anyone else built it and used it for this same purpose, i.e 811b horns with the AS-101/ Valencia woofers/ enclosures?

I can certainly do a take-off of components but if someone else has already prepared a bill of material, where is it?

Also, please explain how to adjust lp1 and lp2, thanks.

[Zilch]

There is no B/M, though I have all the parts in a "kit" and could probably make one up.

Submit yours here, and I'll check it. All components came from Parts Express.

Member Skywave-rider built the crossover in his 9844 thread.

How it works is also documented there, and the stock M19 crossover in another thread.

L1 establishes the slope of the HF compensation, and L2 balances it with the woofer....

[rustnrot]

For the chokes I tried to match the DC resistance as close as possible. How critical is that? For the caps, I went with 10% as good enough, subjective of course.

Please let me know what needs to be changed.

I may decide to build this if I do not biamp, thanks.

[Zilch]

Nix to NPE.

For C1, use 15.0 + 6.2 or 18.0 + 3.0 Dayton, or 12.0 + 9.1 Solen

C2 is 8.2 or 4.7 + 3.3 Dayton

C3 there's a 16 uf Solen, or 12.0 + 4.0 Dayton

C4, a pair of 3.0 Dayton

C5, 3.9 Dayton. No NPEs

L2 I bought 0.8 to unwind a bit

LP1 & LP2 are both single-gang. LP1 uses only one of the windings.

My sketch suggests I'm hoping to get it on a 6" x 6" board.

[Dubious.... ;) ]

[rustnrot]

I haven't done this in over 30 years. Last time I wound my own chokes on a lathe at slow speed. Why no nonpolarized electrolytics recommended these days?

LP2 has one wiper and one winding, 3 terminals?.

[Plink]

I am saying, since you already have some Model 19 crossovers on hand, install Selenium D220Ti drivers ($90 a pair) in your Valencias and play them with the M19 XOs. If that does it for you, then build the HF comp circuit and add-on to your existing Valencia XOs.

No good? Titanium diaphragms too harsh in the VHF? Try a pair of DE250 drivers, then, which have Kapton diaphragms. We know BMS mylar works, but these are less expensive options. Also, if you like the performance on M19 XOs better, I've provided the info necessary to build them or my "improved" version of them.

We still need the info on your crossovers; perhaps there'll be additional suggestions, but your question was what driver options might work, and I've presented data on three that I happen to have on hand. I don't have any 811B horns, just 511As, but prior experience tells me 811B will perform about the same.

If you want to stick with Altec drivers, then you'll have to acquire those used in Model 19 to achieve VHF extension, which means Tangerine phase plug 802-8G or 902 whatever, with vintage "lite" diaphragms, preferrably, but those aren't without their own issues, either, and not cheap.

I assume you've found both the Valencia "Babies" thread and Skywave's 9844-8B one, where we tested out these options....

Hey Zilch, big apologies for the long delay in getting back to you. When I get my Altecs rebuilt, after testing in the 19, I'm going to try in the Valencias. Then, I'll decide what to do - be it your improved version or simply the 19 version with likely BMS drivers. I suppose I should get crackin' on buying some drivers because I could try them on the 19s as well. Big thanks!

[Zilch]

I haven't done this in over 30 years. Last time I wound my own chokes on a lathe at slow speed. Why no nonpolarized electrolytics recommended these days?

LP2 has one wiper and one winding, 3 terminals?NPEs are not suitable for use in crossovers, generally. There are exceptions, but this isn't one, as suitable foil caps are available.

There are two windings in an L-pad with three terminals. LP2 uses both of them, and LP1, just one and two of the terminals only.

[Mr. Widget]

NPEs are not suitable for use in crossovers, generally. There are exceptions...They have always been suitable and were used frequently by all manufacturers in the past. In the '70s JBL and others used mylars when possible due to their better sonic qualities and today the newer large value film and foil type are sonically the better choice, but are no more suitable... NPEs are still used by JBL and others when very large values are needed, especially on woofer circuits.


Widget

[Zilch]

Congratulations on achieving post #10,000, Widget! :thmbsup:

Over the years, I have accumulated a substantial stash of "suitable" NPE caps ripped out of vintage speakers when I recapped them with foil types.

Next time you're over, I will make a formal presentation of this prestigious award.... :p

[Mr. Widget]

What are you talking about? ;)

Oh, thanks for the offer on the NPEs... I haven't used them in decades, though there are plenty of perfectly decent speakers that use them and more than a few terrible sounding speakers with film and foil caps.


Widget

[grumpy]

cool... the odometer rolls over after 10,000 posts ?
Doesn't appear one gets the benefit of all past posts
rolling off as well though. ;)

[Mr. Widget]

cool... the odometer rolls over after 10,000 posts ?
Doesn't appear one gets the benefit of all past posts
rolling off as well though. ;)Naw... I just reset mine to zero... I just don't see the point of post counting.


Widget

[grumpy]

figured as much... wishful thinking. carry on.

[Zilch]

Naw... I just reset mine to zero... I just don't see the point of post counting.VERY clever, but yer STILL gettin' the 10K award.

[As you know, the dumpster's just outside the door.... :) ]

[rustnrot]

Back to the Valencia 846B or Heathkit AS-101 driver replacements.

First the link to the Heathkit AS-101 assembly owners manual as I have not seen that posted to this forum before.

http://www.z-audio.ru/readme/hk/s1.htm

It appears to be a Russian site and I have downloaded the individual .jpgs of each page. I can post these .jpgs separately in the name of posterity if desired.

I have decided for now to use Selenium 220Ti drivers for my 811b horns in my AS-101s. I will recap the existing crossover and replace the HF pot with an l-pad. I have spent some time looking at many threads on many forums and there has been alot of work with new drivers and crossovers for the 811b horns.

It doesn't appear (or at least I have not found it) that there is, as of yet, no "finalized" "simple" fix for the existing 846b / AS-101 N800-k crossovers utilizing the D220Ti drivers in 811b horns.

Looking at all the work that has been done, it appears that the D220Ti requires HF compensation, but to a lesser amount than the BMS 4550 / 4552 drivers on the 811b horns which has been tested and documented.

Therefore, in addition to the recap and l-pad it appears that a modest 3 db HF compensation is all that may be required as an addition to the N-880-k crossover so I propose this:

Please comment.

[Zilch]

http://www.parts-express.com/pdf/264-270s.pdf (http://www.e21.com.br/selenium/forceDownload.php?fdown=mercado_interno/profissional/drivers/Titanio/D220Ti)