Crossover Help Needed With ANOTHER Pair of ALTECS

[voice of the theater]

I need some help with the newest addition to my Altec family. I've mentioned in previous threads that gradually over the last couple of years I've sold all of the Altecs that I owned for my three stereo systems when I joined this community just over two years ago (a pair of 846 A Valencias (16 ohm), a pair of Heath/Altec AS-101's, a pair of Model 9's, and a pair of P.A. speakers --home made cabinets with various Altec VOTT drivers/crossovers installed--511B horns, 421 woofers, etc.....). Anyways, I still have the three vintage Altec stereo systems here in the house, but largely thanks to what I've learned from the good folks here, I've upgraded all the Altec speakers I listed above with the following (click on photos to enlarge)......

1)REC. ROOM stereo (mancave--finished basement) now has a pair of Model 19's instead of AS-101's.


2)RECORDING STUDIO (finished basement--the BIG room) now has a pair of Model 19's instead of the vintage Altec PA speakers in home-brew cabs.





3)LIVING ROOM STEREO--My latest purchase/upgrade. Just before the holidays, I bought a mint pair of Altec Model 14's from a guy here in upstate NY to replace the 846A Valencias that I had there.....





I'd been looking to upgrade the 846A's ever since I upgraded to Model 19's in my rec. room. These were the old 16 ohm 846A's with original diaphragms and caps (42 years old) which I'm sure could (should?) have all been replaced and upgraded. They just didn't get the high frequency extension or the deep thundering bass of the Model 19's. I did some research and of course read everything I could get my hands on here at this forum and scoured craigslist, ebay, etc. looking for something (preferably no more than a 12 hour drive round trip) that would fit the bill. One day, these Model 14's showed up on Craigslist. I read up on them, and called Bill at GPA to see if he offered recone kits and diaphragms for these speakers (in case I blew something in years to come, I didn't want to buy a pair of speakers that couldn't be serviced by GPA). He said yes they have the recone kits for the woofers and of course the diaphragms for the 902 h.f. drivers. While I had him on the phone, I told him I wanted to sell my 846A's because they just didn't get the high and low frequency extension that my Model 19's got and asked him if he thought the Model 14's would get better (deeper) bass and the extended H.F. response I wanted compared to the 846A's. I've been using Altec 15" woofers for so long, I admit I was skeptical whether or not I'd be happy with the 13.5" frame woofer in the Model 14's. Anyways, Bill said the 902 driver should be comparable to the Model 19 h.f. driver as far as high frequency extension/clarity, and he said the Model 14's used a really good woofer (I think he said it had a very deep voice coil?) and he said that the woofer, combined with the (more) modern tuning of the Model 14's cabinets (compared to the 846A tuning) does give them significantly better low end than the 846A's. I decided after talking to Bill that I needed to audition these Model 14's! I did a little additional research on the woofer and specs in the meantime and found from these specs that they do have a nice response on paper as well as what I heard from Bill (35-20,000 hz) and 95 dB at 1 one watt -- not quite as efficient as the 19's but still very efficient..... http://www.lansingheritage.org/image...l-14/page4.jpg

I also found this quote from Todd at the L.H. forum

The Model 14 woofer never had an official model number - only an internal Altec part number - because it was proprietary for the Model 14 and, as I recall, the 9842-8A/F Studio Monitor.

The Model 14 has really nice bass for a speaker it's size - if you are having problems with these in the Model 14 box, I don't think you'll find they work better in a different one.

If Bill and Todd spoke that highly of it, I was ready to audition these speakers! Drove 3 hours, cranked them up, saw and heard that they were mint (with nice crisp highs and deep thundering bass), and drove 3 hours home in Altec Heaven for the entire ride home!

TO BE CONTINUED..........

[voice of the theater]

OK, here's the part where I need help. In another thread here, I've been getting some great advice on upgrading my Model 19 crossovers. I plan on upgrading both pair of Model 19 crossovers--starting with one speaker--and once I do an A/B comparison to verify an improvement, then I'll do the other three Model 19's. Well, the thought occurred to me that my Model 14's aren't much younger than either pair of Model 19's and those crossovers could probably be upgraded with new caps etc. as well. I scoured the net and can't find a schematic for the Model 14 Crossovers anywhere. Does anyone have or know where I can find a crossover schematic for the Model 14's? These are the home version of the Altec 9842 Studio Monitors--exact same drivers and crossover in a similarly tuned cabinet. So, if anyone has a schematic for the crossover used in the Altec 9842 Studio Monitors--it's the same as the Model 14 crossover (Bowtie, do you have a pair of 9842's?).

Also, does anyone know if these crossovers would benefit from bypassing the ground lugs (connecting them with a wire) like people are doing with the Model 19 crossovers? Here's a closeup shot of the crossover (click to enlarge)......



In this photo I count what appear to be 7 (ground?) lugs--does anyone know if these should be connected with wire (or is it possible to tell from the photo?)? Thanks in advance again for any help/schematics anyone out there can give me on this upgrade.....

[cradeldorf]

Awesome collection Dude.

[GM]

Well, the thought occurred to me that my Model 14's aren't much younger than either pair of Model 19's and those crossovers could probably be upgraded with new caps etc. as well.

Might want to consider doing more than just switching out components:
Altec Lansing Fourteen's - Page 9 - AudioKarma.org Home Audio Stereo Discussion Forums

GM

[voice of the theater]

Might want to consider doing more than just switching out components:
Altec Lansing Fourteen's - Page 9 - AudioKarma.org Home Audio Stereo Discussion Forums
GM

Thanks for the link GM--excellent thread! I'm not an AK member so I couldn't access any of the AK links or the "quote" feature, but I read the entire thread and there was a lot of interesting info there--and some familiar names as well--Bowtie, Analog Addict, Zilch, etc.....

It seems most people who've heard or own the Model 14's love them:

quoting Bowtie (page 1 of thread):
"Probably the next best sounding speaker to the model 19 where the late model home series is concerned, they will even impress non-Altec fans."

quoting Richard C. (page 2 of thread) "My Altec 19's are downstairs, but my model 14's are my main living room speakers - cause they fit better! The sound is similar, and most people are impressed by my 14's sound."

quoting daWoofer (page 2 of thread) "I would be pumped also. I remember well 25 years ago when I heard my first pair. Wish I had still bought them then, and wish I could get a deal on some today. Have fun."

And there are some people later on in the thread trying to figure out how the crossovers work and they're not sure they approve of the design. But I've heard the same type of conjecture about the Model 19 crossover design and I really believe that Altec "got it right" when they designed the Model 14's (and 19's) so I'd like to duplicate the original crossover by replacing the old caps with new ones of equal value. I think if you heard these things (psychoacoustics), you'd agree. I really like the h.f. compensation in both crossovers (compared to the older Altec crossovers I've owned), combined with the 802G and 902-8A driver and the tangerine phase plug, tuning of the cabs etc,--a "magic" combination IMHO for both the 14's and 19's.

Now that being said, obviously nothing is absolutely perfect. In fact, a wise man once said,

Different strokes, but considering the popularity of the Iconic/Valencia and especially the M19 among the Altec cognoscenti that I don't share, I'd say I'm far more the odd man out than you. I just don't like using a 15" woofer this high up for vocals. Now a 9844 is a whole different ballgame.
GM

You're welcome!
Don't know if I have any technical explanation beyond a 15" output this high up is nothing but break-up modes which is technically called distortion. Mostly though, it's about how we hear which is the same, yet not so much. Disconnect the horn and listen to music to get an exaggerated version of how I perceive the woofer's underlying 'grunge' that the HF horn doesn't completely mask for me unless XO'd lower to a larger horn.
GM

After owning these Model 14's for a while, I can see the truth in your quotes. I consider Model 14's and 19's to be an apple and oranges comparison--not necessarily cut and dry better or worse. I'd say the high end in the 14's is easily equal to the Model 19's--the 902-8A h.f. drivers sound amazing combined with the Mantaray horn. And I have to admit, I've owned mainly 811B and 511B horns and was skeptical about the Mantaray--that is, until I heard it. It's sound quality in conjunction with the 902-8A is on par with the Model 19's, but it's dispersion characteristics are much better for my living room (where I have them located). I have a long couch and a love seat in that room--and you can sit ANYWHERE on the couch or love seat and the high end sounds amazing--there is a much wider sweet spot compared to the 811B or 511B Altec horns. Hopefully this doesn't sound like sacrilege to anyone--I'm not saying the 14's have a better high frequency response/sound compared to the 19's, just better dispersion characteristics (which is only beneficial in certain applications--like my living room since it's not a particularly huge room, for example).

As far as bass response, with all other things equal (acoustics, EQ settings on your amp/equalizer, etc.) IMHO, the 19's win. However, I've found that by adding a little extra EQ in the 30-40hz range, the 14's rival the 19's as far as low end sound quality at the volume levels that I listen to them at. I'm sure that if I were to crank them up to an extremely loud level, the 19's, having 15" woofers, would win over the 14's (with 13.5" frame woofers) at any EQ setting. I do crank them up to what I consider to be very loud on occasion, and even at those levels with a little extra bass EQ at the 30-40 hz range, they rival the 19's in bass "sound"/response. The "interplay" between the woofer, cabinet tuning, and crossover is that good.

GM, here's where your two quotes come into play. As far as midrange, I have to give the Model 14's a slight edge (at least until I recap the 19's, then I'll have to compare again--although I plan on recapping the 14's as well!). I've got to think that it's because of what you said--which I roughly interpreted as meaning you're pushing the ("accurate/clean") upper frequency limits of most 15" woofers when your crossover point is 1200 hz. Yes, the 19's sound amazing, but there is a certain (subtle) clarity and presence that the 14's have over them in the midrange that is really only noticeable to me in certain recordings (it's a very slight/subtle difference as far as I can tell listening to mainly rock music--may be more or less noticeable with different genres of course). I've got to think it's due to the fact that the smaller woofer is more suited to reproducing the upper midrange frequencies (the Model 14's have a 1500 hz crossover point). In fact, in the AK thread that you linked me to people rave about the midrange "sound" from these speakers.

Quote from Moorden2004 (who started the thread when he had a line on some 14's, and then found the woofers needed refoaming) Page 7 of thread... "
My cross-over pots were fine - no scratching nor intermittents. The new surround kits were dead easy to install (who knew?). And, like you, I'm amazed at the quality of the sound field. Solo guitars seem to be so close you can touch them. The bass is so clean and controlled I've shut down my Yamaha sub-woofer. Not needed. But it's the mid and high range from those horns that captivate you -- clearly a well designed driver/horn combo."

Richard C "I especially like how guitar sounds on my 14's. Blues - Gov't Mule, Joe Bonnamassa, Clapton, Robin Trower, Dave Mason, etc. it cuts thru nice!"

Moordon 2004 "In my very limited experience with these 14's I can concur that guitar and solo voice are startling! You can almost reach out and grab them -- or so it seems. Placement is interesting too. In my room they do like the no-wall-coupling position. Mine are 10" from the wall behind them and a few feet from the side walls. This seems to be ideal. My senses can't tell the difference with and without my powered sub (Yamaha) on, so that alone tells me plenty."
Paul

Anyways, you get the idea. The people who listen to these speakers love them--hence my desire to not make any changes to the crossovers or drivers (other than "fresh" caps). Personally, if I were on a desert island (that had electricity!) and had to pick ONE pair of speakers, I'd pick the Model 19's over the Model 14's. They have an edge IMHO (and are big enough to be more easily converted into a life boat), but depending on the application I still think it can be an apple and oranges comparison. The highs are comparable (but the 14's have better dispersion characteristics), the mids in the 14's have a slight edge (probably the smaller woofer), but the 19's have a slight edge as far as low end unless you "tweak" your EQ for the 14's. I can honestly say, I prefer the 14's in my living room where h.f. dispersion is key due to the layout--the mids and bass sound great in that room as well. Downstairs, I love the 19's in my rec. room and in the recording studio. It will be interesting to see what new caps do to the h.f. response of the 14's (if I can get some help/schematic--HINT HINT!), and the h.f./mid response of the 19's (pretty much ready to go with their upgrade).......

[GM]

You're welcome!

So join!

Yes, the Mantaray CD horns have a much flatter power response over a wider arc than the antiquated rising on axis expo horns.

Right, all else equal, a 15" trumps a 12", so use two 12" to 'have your cake and eat it too'.

A 15" is beaming at 90 deg around 900-1000 Hz depending on its design, so for me this is its XO limit. For a 12", it's around 1350-1500 Hz, so as good as it may sound to some, the M19's ~1200 Hz XO is a 'make do' design to my way of thinking; but it's pretty obvious the designer(s) were given a tight budget, so all things considered, it's an excellent design. A pity they weren't allowed to switch to a Mantaray when the 416-8C was swapped in and drop the XO point.

I tried, Dick (Richard C., a local to me) drew up the stocker for both the M14 and M15 as well as his modded designs with the latter measuring more M19 like IIRC and posted it all on his web page.

GM

[voice of the theater]

I tried, Dick (Richard C., a local to me) drew up the stocker for both the M14 and M15 as well as his modded designs with the latter measuring more M19 like IIRC and posted it all on his web page.
GM

Thanks again, GM! Please let me know if/when you hear from him/obtain the schematic(s).....

[voice of the theater]

I just read through some of that thread at AK again, and it appears there were three versions of the Model 14 crossover that Altec used during the few years 14's were in production (mainly cap. value changes in the different versions). So, I'd still like to see a schematic, but I guess the only way to be sure I'm matching old capacitors with new ones of the same value is to read the values off of the old caps (go figure!). I still could use some assistance from anyone who'd like to offer it. Here's the photo of the crossover (click to enlarge)


Ok, I've looked over the caps and tried to read values off of them (and photograph them).

Here's a close up of one of the caps



It says 470 uF on it. I asked my friend about the extremely high uF value of this cap and he said (more or less): "Don't replace this cap. A cap of that high of a value is going to be in the "shunt" / parallel circuit (which is around the series, not in the series). Therefore, the audio signal doesn't even pass through this capacitor and because of that it's value should still be at least close enough so as not to affect the sound. He told me to replace the smaller value capacitors in this particular crossover design as those caps are in the series (in line) and sound actually passes through them and is greatly affected by them if their values start to change (even a slight change can be bad in those caps)." Does this (Greek) make sense?

BTW, just noticed this discussion of the 470 cap on the AK thread. Quoting Morden2004 (page 6) "I pulled a cross-over and I see there is just a single electrolytic; a 470 uF 50 VDC standard cap. I think I'll replace them both with Polypropylene capacitors. Any thoughts on this?"

Quoting Richard C on page 6 "They are part of the power limiting protection circuit. Think of those as power supply filter caps that charge up "only" at high volume levels, from the voltage delivered to the loudspeaker. I doubt anything will be gained from changing these out.
Do you know how much 470 uf of polypropylene cap would cost AND how big it all would be?
Richard C. "

OK, here's the next two capacitors up close.



I could make out 2 uF on one of them and 10 uF on the other one. These are both capacitors right? (and could be replaced with Solen 400VDC "fast caps" with values of 10 uFand 2 uF)? It was very hard for me to read what was written on them other than the 10 uF and 2 uF--there's no chance they're anything other than capacitors is there (I'm the first to admit I'm a complete novice at replacing/identifying components like these)?

Next Two Photos (click to enlarge)





What is the rectangular "thing" in these two photos (please excuse the highly technical terminology I'm using) Not a capacitor, right? Leave it alone, right?

Last photo



What is the big black thing in this photo? Not a capacitor, right? Leave it alone, right? So, if I have figured this out correctly (hmmmm), I really just need to replace the 2 uF and 10uF capacitor in each Model 14 crossover (judging by my first photo that shows the whole crossover)? Can anyone chime in and let me know if I'm even close to being right here?

Lastly, the capacitors in my Model 19 crossovers are soldered to a "post". I'll be replacing all of the capacitors. It looks like it will be easy to "unsolder" them and solder in the new caps. If you look at the first photo in this post, the leads on the capacitors in the Model 14 crossovers come through from the other side of the circuit board. I'm not comfortable soldering directly to a circuit board. That being said, is it acceptable (although I know it's probably not the best way) to just clip the leads from the old caps while being sure to leave enough of the old leads to allow me to just solder the new caps to them (solder the leads of the new caps to the portion of the old leads I leave intact/attached to the board)? BTW, I'll be using 2% silver solder with tin and lead in it for the soldering--is that ok? Thanks again in advance for any help--the lives of innocent Altecs are at stake.....

[westend9]

Seems like you have a pretty good handle on the capacitor replacement. The "big black thing" is a resistor and looks to be well made.
I would definitely try to mount the new caps in the through holes. If you haven't had at it with solder wick, this is probably a good learning platform, lot's of free space, lead count low, and I would assume the board is amenable to the work.
If it was me, I'd check the values of all the resistors just to be on the safe side. That might mean lifting a lead from each one so may be more work than what you're willing to tackle.
I would also replace the electrolytic caps because of their age and the low price for quality replacements.

I've been using these Axon True Caps and they seem to work fine (built by Solen). I've only used them in a couple of situations but they are as good as any other film cap I've used and the price is right.

Good luck with the crossover rehab!

[Earl K]

Richard C is certainly the man when it comes to practical Model 14 info .

Unfortunately his personal web-page is no-more .
He still maintains a photo-bucket account ( with good info ) , here !


He has stated there were 3 basic M14 crossovers ( and then nicely provided proof with this pic ).



His comments about the M14 sounding like his M19s were made after he redesigned the original crossover to this ;




- ( it's no surprise the "voicing" of the M14 became closer to that of the M19 /// his schematic clearly owes its design origins to the M19s network )

- FWIW, previous to his new networks being implemented ( he commented that ) he found the sound of the stock M14 to be fairly fatiguing ( according to some posts I read ) .

- Based on his experience, ( & if these were mine ), I'd be building up a pair of fully new crossovers ( not just recapping ) .

<> EarlK

ps ; here's the same schematic showing voltage drive ( for the HF section ) of Richards redesigned network ;