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

[Zilch]

For 846B, just swapping the HF driver will likely result in a major improvement. I think that's gonna be my recommendation for Storm, who likes it kinda "forward" anyhow. We'll see, after he hears it.

What's the woofer model? Let's see if it's in BB6P. I also need the interior box dimensions. I forget if I've done this already, but no harm in a repeat....

[VTUBE6]

For 846B, just swapping the HF driver will likely result in a major improvement. I think that's gonna be my recommendation for Storm, who likes it kinda "forward" anyhow. We'll see, after he hears it.

What's the woofer model? Let's see if it's in BB6P. I also need the interior box dimensions. I forget if I've done this already, but no harm in a repeat....

Zilch,
I don't recall you doing this before, so I'll pull apart this evening and post. Personally, I don't really care for a "forward" presentation unless it's low listening volumes (late at night), so I may have to do something to bring it back down for better balance. That 19K spike is a bit concerning too.

[Zilch]

I'll start with what info I have in the meantime, maybe.

I haven't finished up 846B 'cause some stunning new JBL horns came in to mess with....

[hjames]

NO!

Tell us more...!

I'll start with what info I have in the meantime, maybe.

I haven't finished up 846B 'cause some stunning new JBL horns came in to mess with....

[Zilch]

NO!

Tell us more...!

I had to get the right hardware to assemble them, Heather. I'll put up some teaser pics in Q&D later today....

[Oh NO, NOT Q&D! Arrrggghhh! (Hee, hee....) ]

[VTUBE6]

For 846B, just swapping the HF driver will likely result in a major improvement. I think that's gonna be my recommendation for Storm, who likes it kinda "forward" anyhow. We'll see, after he hears it.

What's the woofer model? Let's see if it's in BB6P. I also need the interior box dimensions. I forget if I've done this already, but no harm in a repeat....

I believe the woofer is the 416-8Z. Interior dimensions are 27"x25"x14". I noticed that the top interior wall has nothing on it; I'm thinking that doesn't help with the ringing of the horn? I'm going to at least glue some 1" rigid fiberglass to it when I put them back together (unless I line the cabinet with something else) and will Dynamat the horn as well. I'm wondering if anyone else has replaced the interior 2" fiberglass with something a little more contemporary and with what results?

[Zilch]

My choices are 416-8B or 416-8C, unless someone can provide the T/S parameters for -8Z. For right now, I'm modeling with -8B.

The cabinet is 5.451 cuft gross, 4.522 cuft net, after deducting driver and port displacement, and 0.6 cuft for the horn and compression driver. The woofer is rear-mounted.

BB6P suggested tuning is 38.25 Hz, with 2 x 4" ports 5.496" long. If you'll measure the existing ports, I'll be able to tell you how close the stock tuning is to that.

416-8B is the same woofer we used for the Model 19 analysis. Does that make sense?

http://audioheritage.org/vbulletin/s...477#post138477

[moldyoldy]

... unless someone can provide the T/S parameters for -8Z...

416-8Z is the OEM equivalent of 416-8A, which isn't in most databases either.

416-8A (416-8Z equiv.)
Qts- 0.25
Qms- 3.55
Qes- 0.27
Vas- 29.673 (cu ft)
Fs- 23.9
Sens 98.13 (W/M)
Re- 6.58
Pe- 30W (cont)
Le- 1.26 mh
Bl- 13.94
xmax- 0.14 inches

[Zilch]

Thanks, Moldy.

I'm gonna make a more precise determination of the horn displacement today, as well; then I'll give the model a reiteration with the correct T/S parameters.

I still need the duct diameters and lengths from the stock 846B for comparison of the tunings, folks....

[sourceoneaudio]

Zilch,
I don't recall you doing this before, so I'll pull apart this evening and post. Personally, I don't really care for a "forward" presentation unless it's low listening volumes (late at night), so I may have to do something to bring it back down for better balance. That 19K spike is a bit concerning too.

Here is a link to the parts I used for the binding post.

http://www.partsexpress.com/pe/pshow...TOKEN=10721370

As far as the spike at 19kHz goes. Depending on your age you probably will not notice. The real test, go get hearing test performed. Near Field test in a booth only go up to 8k, and UHF test are done with headphones. At age 40 and up the odds of you hearing that spike are unlikely. Also depending what you have been exposed to over time will have an affect on what and how high you can hear.

J/S-S1A

[VTUBE6]

My choices are 416-8B or 416-8C, unless someone can provide the T/S parameters for -8Z. For right now, I'm modeling with -8B.

The cabinet is 5.451 cuft gross, 4.522 cuft net, after deducting driver and port displacement, and 0.6 cuft for the horn and compression driver. The woofer is rear-mounted.

BB6P suggested tuning is 38.25 Hz, with 2 x 4" ports 5.496" long. If you'll measure the existing ports, I'll be able to tell you how close the stock tuning is to that.

416-8B is the same woofer we used for the Model 19 analysis. Does that make sense?

http://audioheritage.org/vbulletin/s...477#post138477

Thanks! That's interesting and it's close. My actual measurements are (x2 ports), 4 1/4 W x 6 1/4 L. When I get my drivers and put these back together, I'll measure my bass response, it will be in room. I think I was pretty close to that advertised 40Hz before I broke the speakers apart. Maybe that's all I can reasonably expect. Hmmm...

[VTUBE6]

Here is a link to the parts I used for the binding post.

http://www.partsexpress.com/pe/pshow...TOKEN=10721370

As far as the spike at 19kHz goes. Depending on your age you probably will not notice. The real test, go get hearing test performed. Near Field test in a booth only go up to 8k, and UHF test are done with headphones. At age 40 and up the odds of you hearing that spike are unlikely. Also depending what you have been exposed to over time will have an affect on what and how high you can hear.

J/S-S1A

Thanks. I already have some good quality individual posts that I am going to use. I am over 40, but I know what my brain perceives to hear over 15k or so. I've used super tweeters (modified Ravens from Tonian Labs) x'd to play 15K to 35k, and let me tell you, they make a difference! They add air and perceived micro dynamics that is hard to describe. You really have to "hear" it to believe it.

[sourceoneaudio]

Thanks. I already have some good quality individual posts that I am going to use. I am over 40, but I know what my brain perceives to hear over 15k or so. I've used super tweeters (modified Ravens from Tonian Labs) x'd to play 15K to 35k, and let me tell you, they make a difference! They add air and perceived micro dynamics that is hard to describe. You really have to "hear" it to believe it.

The remaining chokes arrived today, and I got the final bits of the filter Zilch designed to flatten the midrange of the BMS drivers and knock 2 db from the big peak at 19 KHz. Here is a picture of the 1200 Hz crossover I built to replace the N800F's mounted on the side of the cabinet, and the filter PC assy mounted on the top. Needless to say, the Val is upside down for this pic.


A friend who has a pair of Flamencos (Roughly same cab, same drivers, different style grille) listened to them a couple days ago, and he preferred the tweeter fix. I will call him back over, 'cause he may change his mind. I really liked the BMS fix best without the filter, but now they seem pretty much similar, which totally baffles me. I will get them in the house tomorrow, and try them on the carpet in the living room. As Widget suggested, that should be a lot softer environment to compare speakers.

So why get rid of a 2db spike at 19k? Jack liked the way they sounded b4 the filter.
You also might like it better?

J/S-S1A

[Zilch]

The filter is compensation, and only minimally mitigates the spike.

It's more like 8-10 dB, actually, though I don't have time to check that now 'cause I'm about to dunk a driver and horn in a tub of water to determine the displaced volume.

[I ain't sayin' WHOSE driver it is, tho.... ]

[VTUBE6]

So why get rid of a 2db spike at 19k? Jack liked the way they sounded b4 the filter.
You also might like it better?

J/S-S1A

Good point, I otta just listen first. What a concept.