BMS Drivers

[ALTEC9846-8A]

To use a JBL driver you'd have to drill the JBL 3 bolt pattern in the 511 flanges, 500hz i'm not sure about.

Diaphragms delayed from GPA?

Yes. something about a gasket.The flanges are alum. so it wouldn't be hard if you had a 3 bolt gasket to use as a template. I woundn't want to have it get too complicated. Maybe someone else know if it would be worth it or should I just wait for the diaphrams.:scratch2:

 

[ALTEC9846-8A]

Could you use the jbl with a 500hz crossover. Would it be better than the 808 driver and what extra parts would I need to connect it to a 511 horn? I have ordered new diaphrams but they havn't shipped them yet. its been 2 weeks.:scratch2:

I justed checked my visa and great plains audio have debited it so my diaphrams must be on the way. I'm still curious if I could have used bms drivers. looked at some info on internet. Say they go down to 500hz but recomends 800hz crossover.

 

[skywave-rider]

OK boys, pony up. The shipment's in town.

 

[dgwojo]

OK boys, pony up. The shipment's in town.

Currently myself and two others have paid, I'm transferring the funds from PayPal to my bank for a money order to Assistance for the 1st six drivers, they want to ship 6 at a time, and they're now in stock in Utah, fresh from Italy, Dave.

 

[dgwojo]

Bump!!! Just two members haven't responded, one for the 4540's, and one for the 4552's, Dave. :worried:

 

[dgwojo]

Zilch,
Jack needs your mailing address, your drivers are being sent directly to you, he'll bill you separately but should still honor the discount, the other 12 are on their way to me now. No word or payment from member Spaceman yet so an extra pair might be available to someone else, maybe he's on vacation?? I'm fronting the funds for that pair, Dave.

 

[spaceman]

My sincere apologies to everyone, for slowing up the 2nd batch, my internet's been down. :sigh: dgwojo, your email's replied to.

 

[dgwojo]

My sincere apologies to everyone, for slowing up the 2nd batch, my internet's been down. :sigh: dgwojo, your email's replied to.

Not a problem, hopefully both batches were shipped to me today!! :yes:

 

[Zilch]

4540nds arrived here minutes ago, and Dave apparently has everyone's 4552nds.... :thmbsp:

 

[dgwojo]

4540nds arrived minutes ago, and Dave apparently has everyone's 4552nds.... :thmbsp:

All 4552ND drivers were shipped out this morning, I had them for 16 hours, man these look cool, all 12 drivers were exactly 6.1 ohms, now that's quality control!! I bought the 5mm screws for mine today, hope to check them out tonight, Dave. :yes:

 

[dgwojo]

I mounted my pair up to my Altec 511B horns, re-capped Eminence 18db high pass, 12 db low-pass 800hz crossovers, and Altec 515-8LF woofers, these sound excellent, I need to tweak the Lpad as these seem more efficient than the Altec 902's. These really sound sweet, I'm so glad I bought a pair. Some pics attached for comparison, these little drivers sure pack a punch, the treble is so nice I unhooked my super tweeters, yes!!! I think they will also sound great on 811B horns in the Model 19's, Zilch, thanks for the suggestion on these drivers, Dave. :thmbsp:

Altec 288, 902, 802, BMS 4552ND;

 

[spaceman]

Thanx for the update, dgwojo. :thmbsp: That sounds really encouraging, that you lost the super-tweets. I've never changed drivers on horns before, is there anything important to be careful of when I do it? I mean, obviously, I'll be careful of everything, but any tips would be greatly appreciated. :yes:

 

[Punker X]

Hopefully should be here today.... Dave what length 5mm's do you end up using?

Going to try them in the 19's, but was also looking to try them in my 9846's, has anyone crossed them over at 500hz? Due to the time alignment and the 411 woofer not going much above 500hz, I'd like to keep the 500hz c/o.

 

[dgwojo]

Thanx for the update, dgwojo. :thmbsp: That sounds really encouraging, that you lost the super-tweets. I've never changed drivers on horns before, is there anything important to be careful of when I do it? I mean, obviously, I'll be careful of everything, but any tips would be greatly appreciated. :yes:

I had my horns facing straight down, these drivers are so small the Altec mounting flanges are larger than the driver, so centering them takes a bit of patience, other than that, just be careful of the magets, I've never seen anything stronger than NEO's, I layed the project down on the floor and couldn't find the screws and washers, even though they were far enough away, the magnets still pulled them to the box and really held them there. Bottom line, just be careful of the magnets, I'm still uncertain of the polarity, it's marked but I'm hoping a positive signal draws the diaphragm forward towards the horn, that was my assumption for wiring them. I think you'll like them, get ready to lower the Lpads, these things are super efficient, they might just seem like they knocked your bass response down a couple notches, Dave. :yes:

 

[dgwojo]

Hopefully should be here today.... Dave what length 5mm's do you end up using?

Going to try them in the 19's, but was also looking to try them in my 9846's, has anyone crossed them over at 500hz? Due to the time alignment and the 411 woofer not going much above 500hz, I'd like to keep the 500hz c/o.

Mike, Whatever I bought is too short after going through the horn flange and washer, I think they were 12mm long, they don't cut it so I'm replacing those today with black allen heads, maybe 20mm long, the thread is very deep on the driver so there's some buffer. Don't know about the 500hz XO point, they are rated to go that low though, regarding time alignment, the difference in sound when swicthing polarity was very subtle, I.E. seemed to make very little difference!! I don't know if your voice coils are "in-plane" mine are so I'm running the red as positive, Dave.

 

[Zilch]

I mounted my pair up to my Altec 511B horns, re-capped Eminence 18db high pass, 12 db low-pass 800hz crossovers, and Altec 515-8LF woofers, these sound excellent, I need to tweak the Lpad as these seem more efficient than the Altec 902's. These really sound sweet, I'm so glad I bought a pair. Some pics attached for comparison, these little drivers sure pack a punch, the treble is so nice I unhooked my super tweeters, yes!!! I think they will also sound great on 811B horns in the Model 19's, Zilch, thanks for the suggestion on these drivers, Dave. :thmbsp:

Cute little buggers, aren't they?

Heads UP, guys and gals, get the requisite Faston connectors at the hardware store when you buy the 5mm screws if you don't have them, 1/4", I believe. If you get the terminals too hot soldering to them directly, you'll soften or melt their mechanical mounting to the diaphragm rear loading cap.

Yes, they're substantially more efficient than the vintage Altec drivers, and thus require L-Pads, fixed or variable, to balance with most low frequency systems. Find those 30923s, Dave, or build new ones, to provide the requisite passive CD compensation, adjusting R-2 for the flattest response. They'll play flat and smooth out to nearly 20 kHz without tweeters.

It's the Mylar diaphragms making the sweetness and detail, largely, I believe. Model 19 crossovers will provide adjustable compensation, albeit at their higher crossover frequency. You may have to add a supplemental L-Pad to them, as well, to lower the sensitivity into the "Optimum" range.

500 Hz is pushing their lower limits, but they'll certainly do 800 Hz on 511 horns. Several members have now confirmed the assessment that 811s are best used above 1 kHz, independent of the driver. 4552nd works nicely on those at Model 19's 1.2 kHz.... :thmbsp:

Note: Could a Moderator please move this discussion subsequent to the arrival of the drivers @ #33 over into a new thread the Speakers Forum? With so many members soon working with them, I suspect there'll be considerable interest in these application details and everyone's comparative experiences.... :yes:

 

[skywave-rider]

Cute little buggers, aren't they?

Heads UP, guys and gals, get the requisite Faston connectors if you don't have them, 1/4", I believe, at the hardware store when you buy the 5mm screws. If you get the terminals too hot soldering to them directly, you'll soften or melt their mechanical mounting to the diaphragm case.

If the terminals are the same as on 4550 (1/4"), RatShack part #64-3133, package 5male/5 female.

 

[dgwojo]

Home Depot had the correct bolts, 5mm x 16mm, the 5mm x 20mm were too long. I lowered the Lpads to the 9:30 position and they seem to be blending very well with the woofers now, it's weird for me to be able to hear all that treble with the Lpads that low, I'm pumped!! Dave. :yes:

 

[Punker X]

Got mine ok. Didn't get a chance yesterday to get bolts and need to see if I got some lugs to fit the spade connections. I have the gold pins on my wires for the Altec push pins.

 

[dgwojo]

Got mine ok. Didn't get a chance yesterday to get bolts and to need see if I got some lugs to fit the spade connections. I have the gold pins on my wires for the Altec push pins.

Darn, I wish I would have thought about it, I have a few hundred of these from work (dumpster diving at its finest), they're Belden Wire brand, Dave. :tears: