Has anyone ever measured a 32B horn?

**Old Guy** · March 13th, 2012, 10:31 AM

I use to use one of these to clean up throats. Been a while and can't remember what brand. USE WITH CAUTION! Too much enthusiasm is a bad thing.

Lisle Tools 10500 Brake Cylinder Hone | eBay

If you try this make sure pressure is adjustable and start with it backed off.

**martyh45** · March 13th, 2012, 12:31 PM

Originally Posted by Old Guy

I use to use one of these to clean up throats. Been a while and can't remember what brand. USE WITH CAUTION! Too much enthusiasm is a bad thing.

If you try this make sure pressure is adjustable and start with it backed off.

Cool idea

The problems I see are in the transition area. It looks like the boring tool was used as deep as it could be without screwing up the beginning of the bend area. What eventually transitions to the top of the horn looks and feels fine. The opposite side has a flash or excess weld material protruding into the horn with a sharp edge where the bore tool stopped. I think I will need to reshape just this area. In my case the brake cyl hone probably won?t work but in general is there a benefit to honing the inside of a throat beyond what is necessary to ease abrupt transitions?

**Old Guy** · March 13th, 2012, 01:57 PM

I say no. Really, want to polish, not hone.

**Altec Best** · March 13th, 2012, 02:20 PM

Originally Posted by Old Guy

I use to use one of these to clean up throats. Been a while and can't remember what brand. USE WITH CAUTION! Too much enthusiasm is a bad thing.

Lisle Tools 10500 Brake Cylinder Hone | eBay

If you try this make sure pressure is adjustable and start with it backed off.

Like this idea OG !

Originally Posted by martyh45

Cool idea

Me too. This looks like would be a good tool for this job.

**RonSSS** · March 13th, 2012, 07:23 PM

A small ball hone might be ok as well.
Either way, use a lot of lubrication so the alum doesn't mess up the stone. something thin like WD40 or even brake clean.

Shoot, I REALLY need to get my 9849's fired up!

**Geekstar** · March 14th, 2012, 05:24 PM

The pair I have ring like a bell when they are not mounted,

Is that 811s or 32A ringing?

I recently picked up a pair of plastic 32Bs. Played around with old metal 32A twenty years ago (WE 713C drivers) and I was under-impressed but at the time I had 1505s/288s and Lansing field coil gear set up, looking for the big fun. Now my goals are much more modest, as is available space...

I also know the 753 pretty well. That system used a phenolic 713 driver and did not have much highs but it is very natural. An optional PM tweeter was available for those who needed it.

Based on the crudest listening tests, a 32B with a tangerine 802 seems to be giving me about 10k highs through the horn. In the 9849, a HF EQ circuit was employed and I'll probably do the same thing. It is almost there as-is.

Also tried an 806...much more rolled on top. That would need a tweeter.

Overall effect is clean undistorted and a bit "soft"...but that's cool. None of the screech/ring of 511/811s. They have fans but I wonder how many of these fans have heard a good multicell Altec system??

I'm looking around for a pr of metal 32s to compare to the plastic units and measure.

Does anybody know if there is a difference in geometry between 32A and 32B?

**martyh45** · March 14th, 2012, 07:11 PM

Originally Posted by Geekstar

Is that 811s or 32A ringing?...

To my knowledge the only difference between the A&B is the driver mounting holes. There is some dispute as to which horn is which. The way I refer to them is 32A mounts the older WE drivers, 32B mounts newer 2 bolts. I don’t use the 32C I guess that would be what I call a 32B plastic. Anyway, I could be wrong, it is just a personal convention at this point.
My post above about ringing was about the 32B metal version. They ring like crazy un-mounted, I really can hear the decay just by talking into the horn.
The curves I found seem to show a gradual enough roll off that eq is possible. I guess that depends on how much headroom there is to burn before resorting to a bi-amp setup. The good news is the older I get the more HF extension I can trade for even power response and smoothness. As an aside, I have a pair of apogees that never seemed rolled off in the treble to me but they roll off pretty good after 10K according to the published measurements. Stinkin power hogs though, 100 Watts class A barely brings them to life.

**Geekstar** · March 16th, 2012, 03:49 PM

Despite my love for vintage ALTEC, I was thinking maybe the plastic ones are better, but I would like to check that assumption when I find a pr of cast metal 32s.

Hey I guess the plastic ones are vintage now too, huh? Time flies...

I have a "32C" out of a 1231 stage monitor that has molded reinforcement ridges on the bottom and it came with a metal plate bolted to those ridges. I suppose a loaded plastic 32 can snap like a potato chip if dropped off the stage.

MAYBE the 32C has ridges and the 32B didn't...I have seen pics of plastic 32B without the ridges.

Also have an identical ridged horn that came out a Model 15.

altec32c.jpg

**martyh45** · December 30th, 2014, 07:43 PM

Well I'm resurrecting a 4 year old thread to finally post some measurements for this horn.
These were done with 802-8G with light diaphragms. If I can figure out where to post FRD files I can get them up. I'll be back to the shop in the next few days to get Zma files for these and some others

Measurement setup is Maudio audiophile usb, Maudio audio buddy, pro calibrated measurement mic and REW.

**VolvoHeretic** · December 31st, 2014, 09:45 PM

The graphs of those horns that nobody loves sure look good to me.

I guess that putting a Piezo super tweeter that starts coming online at 4000 hz on top of my horns wasn't such a bad idea even though I am tone deaf and can't hear past 12khz.

I know that I love the sound of my 802-8D/pascalite or symbiotic/ aluminum 32B's in a smallish room.