What to do with Altec 515b and 288-8g on 805b horns

[eestrera]

Good day,

Am a newbie here. Im from Manila, Philippines. Need some help from the gurus here who are knowledgeable on Altecs. Recently (and cheaply)got a pair of 515b drivers (16 ohms) and a pair of 288-8g (8 ohms) on 805b horns. Can anyone suggest what cabinet design and crossover design is suitable for the mentioned drivers. I'm not so sure if the Altec A5 (828b or 825) enclosure design would do. Also what dividing network will work on this? Im a dimwit with technical stuff but I do have good hands for cabinet making.

Another question is, since the HF driver is 8ohms and the LF driver is 16ohms, what can I do about it? My guess is is that the pair 515b drivers were initially just for one speaker connected together to make it 8ohms. The other pair must have been sold somewhere else. Is there a way to use the LF and HF driver with different impedance?

Would appreciate your help.

Many thanks,
Earl

[bowtie427ss]

Please be kind to the new fella, i steered him here for the premier in Altec guidance.

Welcome eestrera! :welcome:

[eestrera]

Please be kind to the new fella, i steered him here for the premier in Altec guidance.

Welcome eestrera! :welcome:

Thank you very much sir. :thankU:

[aeyb701]

Hello Earl and welcome.
I'm no expert but have s similar set of drivers and use them in an A-5 configuration, with readily available (epay, CL, Kijiji) 828/825 cabinets.
The impedance differences could be addressed by swapping out voice coils in the HF units to match those of the woofs, or by bi-amping into an electronic (active) crossover.
Series or parallel resistors of the appropriate value coukld be placed around/in-line with the 16-ohm units so the amp "sees" equal nominal impedances on each driver if still using a passive network.
Others may jump in here to correct me or offer more specifics, but I have a good sounding setup of A-5's with 515-8G's, 288-8L's, and 1005B horns, through N-1285 networks. Sounded really nice this Wednesday afternoon past at my clinic's summer BBQ at my place. Low volumes but effortlessly portrayed outdoor musical imagery from 200 feet away.
Jon Archibald
Ontario, canada

[analog addict]

Again, location would be helpful.

One of my local friends has several A7/A5 type cabinets he's trying to sell.....

[Altec Best]

First off Welcome to the board Earl, :welcome: I think you maybe right that there was another set of drivers.Is picking up another pair of 515B's an option for you.You can hook up a pair of 16 ohm drivers to produce an 8 ohm load.The 288's with a single woofer configuration can overpower the woofer quite easily.It is an ideal situation to use 2 woofers with a 288-8G per side.Is cabinet size a restriction.Or do you have space requirements/restrictions.The more detail you can provide the better your questions can be answered.Be patient there are many knowledgeable and good people here.

Kind Regards ~ AB

[eestrera]

First off Welcome to the board Earl, :welcome: I think you maybe right that there was another set of drivers.Is picking up another pair of 515B's an option for you.You can hook up a pair of 16 ohm drivers to produce an 8 ohm load.The 288's with a single woofer configuration can overpower the woofer quite easily.It is an ideal situation to use 2 woofers with a 288-8G per side.Is cabinet size a restriction.Or do you have space requirements/restrictions.The more detail you can provide the better your questions can be answered.Be patient there are many knowledgeable and good people here.

Kind Regards ~ AB

Thanks for welcoming me on the board. Getting another pair was my first instinct. However, after doing some research and seeing the photos and measurements of the cabinets with the dual 515bs, I think my wife will kill me. And I don't want to be sleeping in the garage. My listening room is rather small at around 15ft wide and about 18ft long. Aside from the size, the prices on the 515b's here in my location are priced around 30x more the price I got it for. I've shown her the A5 dimensions and it seems passable to her for now. I'm slowly getting her into this hobby so WAF is a big consideration. Once shes addicted, things will be easier

If the 288 horn with a single 515b configuration is to overpowering, can this be fixed by havng an active equalizer?

Thank you for help. WOuld love to hear more from you guys.

Thanks,

Earl

[Panomaniac]

Yes, the horn can be EQ'd actively or passively. You'll want to...

For a bass box you might also look at the Onken box. It works very well with the 416. Should do OK with the 515. GM might know. I can send you the plans, if you don't find them. No horn flare, so easier to build then the Altec box. Looks cool, too.

The Onken looks like this. Onken Box

[Panomaniac]

Again, location would be helpful.

Earl is in the P.I.

[eestrera]

Hello Earl and welcome.
I'm no expert but have s similar set of drivers and use them in an A-5 configuration, with readily available (epay, CL, Kijiji) 828/825 cabinets.
The impedance differences could be addressed by swapping out voice coils in the HF units to match those of the woofs, or by bi-amping into an electronic (active) crossover.
Series or parallel resistors of the appropriate value coukld be placed around/in-line with the 16-ohm units so the amp "sees" equal nominal impedances on each driver if still using a passive network.
Others may jump in here to correct me or offer more specifics, but I have a good sounding setup of A-5's with 515-8G's, 288-8L's, and 1005B horns, through N-1285 networks. Sounded really nice this Wednesday afternoon past at my clinic's summer BBQ at my place. Low volumes but effortlessly portrayed outdoor musical imagery from 200 feet away.
Jon Archibald
Ontario, canada

Thank you for the warm welcome and thanks for the tips. Just some q's sir, . I wanted to keep the drivers as original as possible, (Im a nostalgia freak and love vintage audio) would swapping the voice coils in the HF driver change the original t/s parameters? The active crossover looks like a better alternative for me but am open to options.
The series and parallel transistors also seem to be less intrusive.

Do you have a photo of your current A5 setup? Would love to see it.

Btw, I've read that these drivers can be powered by flea powered tube amps, do you think its possible to run them via triapath t-amps?

Thanks,
Earl