Look at my new babies...Altec 846Bs w/EV Tweeters!

[jackgiff]

Jack will measure your Valencias for you, in comparison to the other options.

Decide on the basis of what you see, hear and like best then....

But Jack is not going to spring for a $220 pair of Fostex tweets not knowing how or where they should mount, or how good they will really sound, or if Storm will buy them. Or if the added time alignment problems can be dealt with satisfactorily. I have recommended to Storm that the BMS drivers are the best answer I have heard. That is why I have ordered another pair of them. The next pair are the same as the 4550's except they have neodymium magnets, which have a slightly increased field strength. They don't have any mounting problems, nor any added time alignment problems. Quite simple, really. Why be confused?

Jack Gifford

[jackgiff]

He was confused before, he's confused now, he'll be confused then ...
if a cute little altec shakes its cone in his face he'll swear fealty for life and be off on another tangent ... Its inevitable!

Heather, those speakers in your avatar are not the L200 cabinets you just recently bought. They look awfully nice. You must be truly improving your home system. And all of the good JBL stuff is said to reside on the left coast. Not so?

Jack Gifford

[Zilch]

But Jack is not going to spring for a $220 pair of Fostex tweets not knowing how or where they should mount, or how good they will really sound, or if Storm will buy them.

Much as I'd like to hear them, I'm not springing, either.

It does present a more normalized choice for consideration, tho: Does one spend $220 for a pair of Fostex tweeters, or $230 for a pair of BMS drivers?

[Storm]

It does present a more normalized choice for consideration, tho: Does one spend $220 for a pair of Fostex tweeters, or $230 for a pair of BMS drivers?

Zilch -

You have to add on the $65.30 for parts, plus shipping. And then the time to install.

Should I just get the BMS drivers or what?

It is easier to just attach the BMS drivers to the horn or is there more steps than to take out of the box and install?

Thanks.

-Storm.

[Zilch]

Should I just get the BMS drivers or what?

What I said earlier today: http://audioheritage.org/vbulletin/s...&postcount=794

It is easier to just attach the BMS drivers to the horn or is there more steps than to take out of the box and install?

There is a small additional filter, maybe $50 for the pair. You can see it installed next to the driver in Jack's Vals here:

http://audioheritage.org/vbulletin/s...&postcount=784

[sourceoneaudio]

Much as I'd like to hear them, I'm not springing, either.

It does present a more normalized choice for consideration, tho: Does one spend $220 for a pair of Fostex tweeters, or $230 for a pair of BMS drivers?

That is kinda of what I was thinking. Did anyone hear the BMS b4 purchasing?? No I'm guessing. So yes this is a DIY speaker project, and improvement project from the start. Jack, I would also say the mounting pattern is very close too if not the same as the tweeter you chose. I have a couple of different ideas for mounting them, been dwelling on it all night. I think from reading the specs on the Fostex it is a very good choice, especially with the extended range it has. I also feel it will be a 10 fold improvement over the T-35 wanna be tweeter. This should be very fun and interesting.

J/S-S1A

[jackgiff]

Finally got the BMS drivers and horns swapped with the APT-80 set, so that Pix of BMS FR could be taken with and without grilles. Also cleaned up the wiring of the BMS set, and had to adapt my 1200 HZ crossover for the Altec woofers, which are obviously not the 16 ohms they are rated.

Any way, here are the pix of the BMS drivered units. The first pic is the left speaker with grille. Second is left without grill. Third is right with grille. Fourth is right without grill.

The fretwork grille does have a very small effect on the HF, increasing with frequency. Simply turning the LPad adjust should account for this minor difference.

Now it's time to go listen to them, and have a beer. How sweeeet it is.

Jack Gifford

[hjames]

Thanks - just got them home from a 3 state trip to PA ... set up in the living room tonight - fine tuning can come later ... they are not perfect, but - potential is high.

Actually, they were from "Right Coast Recording Studio" - that was really their name, no joke ... got a thread with more details elsewhere ...

Heather, those speakers in your avatar are not the L200 cabinets you just recently bought. They look awfully nice. You must be truly improving your home system. And all of the good JBL stuff is said to reside on the left coast. Not so?

Jack Gifford

[Zilch]

... here are the pix of the BMS drivered units.

As you predicted, the dip at 2.5 kHz is gone, and the compensation is now operating substantially as intended (below). There's likely more we can do to optimize the transition at crossover, but as is, they're suitable for listening comparisons.

The grille rolls off the VHF a few dB, but not so much as to be of concern. In fact, you may find that to be the more pleasant sounding of those two options.

The dip at 400 Hz is likely room modes at work, and I'd expect it to be different when you move them from the test space into the listening room.

Generally speaking, my own preferred balance would be with the HF attenuated a bit more overall from your present setting.

I look forward to your listening appraisal; you're now hearing these very much as I do here.

[Zilch]

1) Diminutive neodymium-magnet BMS 4552nd, smaller in diameter than Altec 811B horn flange, even, has 1 kHz minimum recommended crossover frequency, top.

846A/B highpass is actually 1.2 kHz, despite 800 Hz spec, so either 4550 or 4552 is useable in Valencia.

2) Frequency response of Jack's 4552nd pair:

a) Drivers only top (400 Hz highpass)

b) Drivers on factory 846A N-800-F crossover

c) With compensation filter, bottom

3) N-800-F attenuation adjustment range.

4) Filter schematic. Use same with either 4550-16 or 4552nd-16.

5) Parts list.

[jackgiff]

This is probably the most cost efficient way to add a tweeter to spice up the HF in your Valencias. We all love our Vals, and they really do sound good, but the HF end is lacking something, and a lot of bandwidth has been expended here seeking answers to the riddle of how to fix them.

The Eminence APT-80 Supertweeter is a moderately inexpensive device, and a decent performer. Zilch tested this tweet earlier in the thread, and found it capable enough to list as another possible fix. I tried it at a crossover frequency of 3.5 KHz and 5 KHz, but it didn't really sound like Altec's should sound. After Jeff used a Klipsch tweet high passed at 8.5 KHz and 18 Db per octave, I decided to try the APT-80 similarly high passed at 7.5 KHz at 12 Db per octave. Since the Altecs sound so good, trying to do anything other than filling in the missing HF response with an added tweeter will change the sound of them. The tweet needs to simply fill out the response curve where the Altec 806A isn't working.

The APT-80 does an admirable job of adding the HF without influencing the Altec sound for a cost of less than $100 per pair. The parts are all available from Parts Express, including the APT-80's, which are priced at $29.09 each. In post 385 of this thread, I showed where I had mounted the APT-80's in the middle of the 811 horn. This location gives excellent results without modifying the look of the Altec cabinet. Other tweeters are surely available which will fill the bill while maybe costing less, but be sure they are capable of producing the needed HF response up to 20 KHz.

The FR of one Valencia is shown with the HF LPad set in the minimum position (APT-80 out of circuit, so response is stock Altec), with LPad at maximum postion, and with LPad set at about halfway, which is where they sound most pleasant to me. The last pic is of the FR while listening to a CD labeled Monster Jazz. It is quite heavy on the cymbals, and you can see the HF that would be missing on a stock Valencia. The RTA is set to slow response with peak set at slow to capture the music as played on the screen.

Now, I am out in the garage listening to them and drinking a beer. How sweet it is.

Jack Gifford

[jackgiff]

Wish I had the RTA before setting up the comparo. They weren't ready then, but they are now. These pix show where the LPad was mounted for the APT-80 on the back panel, and shows the mounting of the high pass components. The .25 Mh choke is mounted between pins one and three of the Lpad, and the 1.88 Microfarad capacitor is mounted in line with the + lead of the connection from the speaker input to the Lpad. A 2 Microfarad cap will set the High pass frequency at about 7.3 KHz, which will work just as good, and be a lot easier than paralleling caps to get the right value.

Storm and Jeff, if you can get back to Prescott, you simply have to hear these Vals. And the APT-80's are playing through the fretwork grille on the FR pix in the previous post. Pretty impressive.

Jack Gifford

[jackgiff]

Since I had three pairs of Altec 846A Valencias, it seemed fitting that we tried a pair of BMS 4552's versus the 4550's which Zilch had picked as the most likely replacement for the Altec 806A's. They use the exact same LCR filter values as the 4550's, and the same 19 KHz dampener, if you care to use it. The 4552 has a neodymium magnet which reduces it's weight by roughly 2 pounds, and results in a much smaller driver. It has about a 10% increase in flux density which supposedly translates into a greater definition in the HF region. It isn't apparent to me after listening to both pairs for about a week, but can probably be measured, and may be apparent to someone who is more acoustically gifted. The 4552's cost about $34 apiece more than 4550s, and the extra cost of $68 per pair is not worth spending, in my book.

Both of the BMS fitted pairs reside in the master bedroom, and are providing a new appreciation for the Valencias. Never have we heard such HF from a Val, and the fact they are no longer completely Altec doesn't matter to us. I have previously presented RTA plots of the 4550's, and the 4552's are essentially identical, so will dispense with them here. If the fact that Altec parts have been replaced with non-Altec parts bothers you, maybe adding tweeters would be your best fix. The BMS drivers are my choice, because the change is easier to accomplish, adds no further time delay problems over the 806A's, and keeps the systems 2-way's.

Now that all three of my Vals have been fixed to provide frequency response out to 20 KHZ, and all of them do it relatively flat which is something a stock Val doesn't do, the next fix to them is obviously going to be in bracing the cabinets to eliminate flex, and adding to the internal padding which seems marginal. The Valencias have the potential to become really great speakers, some 40 years after their introduction.

I have tried both of the BMS drivers simply substituting them for the 806A's and adding the LCR filters as Zilch suggests, but have preferred to build new crossovers since the filter capactors in the N800F's are roughly 40 years old. My crossovers were calculated to use 3 Mh chokes, and 5.86 Microfarad capactors, but the 416 woofer in the Vals was still pumping out at over 2 KHZ, and increasing the cap across the woofer to 16 Microfarads brought it into compliance. This compares to the values of the N800F of 4 and 10.5 Microfarads. The N800F does the job quite nicely, and can save some bucks if cost is paramount.

At any rate, the two fixes proposed to the Valencias brings them up to standard at reasonable cost. Which one you select is up to you.

Good Luck with your Valencias.

Jack Gifford

[Gary L]

Thanks for the update Jack. I was thinking the interest died here.

Good to hear the fix is satisfying you and the Mrs.

Regarding the 4550 Vs 4552, I will eventually go with Zilch's guidance toward the 4552 because the 19 XO is crossed at 1200 Khz rather then the Vals 800.
My question to you is do I have to make any changes to the 811B horn to bolt on the 4552?

This thread has certainly been a "Long and winding road" and I am happy with the results. Like you, I prefer to keep my 19s as a two way system rather then to add an additional tweeter and updated XO components.

For all you Val owners, there has been some outstanding work, fun and commeraderee here and many members really did step up to the plate to make a very good speaker much better.

Thanks to all who gave of their time and efforts and it has been great being involved.

Gary

[jackgiff]

Regarding the 4550 Vs 4552, I will eventually go with Zilch's guidance toward the 4552 because the 19 XO is crossed at 1200 Khz rather then the Vals 800.
My question to you is do I have to make any changes to the 811B horn to bolt on the 4552?


Gary

There are absolutely no changes that need to be made to the 811B horn. Simply bolt either of the BMS drivers in place of the 806A. The mounting hardware is different (1/4-20 for the 806A, 6 mm for the 4550, 5 mm for the 4552). but is available at any hardware store.

The Valencia crossover is also at 1200 Hz, not the 800 Hz they advertise. The model 19 crossover has some extra compensation, which Zilch has gave info on in this thread. Either BMS driver will be a great improvement over the 806A's. Please let us know how you like them when they are installed, and you have had some time to enjoy them.

Jack Gifford