Small Corner Horns

zingo

I just picked up this pair of nice, vintage corner horn speaker boxes. Holes are cut for 8" driver and front baffles slanted upwards; 3/8 " plywood, maybe birch. I think they might be an old EV design, but I'm going to find a full range driver for them that will benefit fron the back horn loading.

zingo

Any suggestions on 8" full range drivers? I have heard good things about Audio Nirvana, the Dayton Audio point source look interesting, and Tang Band for a little more money. Maybe a Goldwood with a whizzer cone?

mhardy6647

Well :- )

First off, I think the cabinets are EV Baronets (you've probably dug around and found this as well).



The Daytons do indeed look interesting if a tad pricey.
Ditto the Tang Bands (although I am not sure how sensitive they are).

My personal sense would be to avoid Audio Nirvana like the plague -- based on some of the proprietor's earlier forays in "high fidelity" (he being the guy who put Lowther drivers in bass reflex boxes)... but if you've heard 'em and liked 'em, perhaps they're a good choice after all.

The Goldwoods are OK but not spectacular. I have a pair here somewhere. They have plastic cones and paper whizzers (if memory serves) and they just don't get the magic of the paper drivers -- although they're not terrible (and they are cheap!).

In terms of vintage ;-) were they mine, EV fanboy that I am, I'd chuck a pair of EV "Wolverine" LS-8 twincones in there, posthaste. I have a longstanding affection for these; they "get the midrange right" in spades, and are extended enough at both ends (albeit barely) to be satisfying as "full range" (let's be honest, here -- "extended range") drivers.

EV SP-8 twincones (the next step up the EV ladder) would be a good choice too, as would the EV 8" coaxes (LT-8), although I've never seen a pair of either.

If you just want to play around with something in the short term in those cabinets (i.e., really cheap)... PM me.

Oh, and for best results :- ) please try 'em with a single-ended, direct heated triode amplifier (e.g., 2A3 or even a 45) if at all possible. Please ;- )

Please?!

mhardy6647

PS I'd love to stumble across a pair of those cabinets!

FWIW, I do have a pair of EV Coronets -- a simpler vented cabinet designed for 8" drivers (with a cutout and blank for a T-35(B) tweeter if desired) which I loaded with a pair of LS-8s. I think they sound pretty darned good.

EV Coronet by Mark Hardy, on Flickr

I don't have a good photo of an LS-8 so here're a couple of bad ones...
DSC_3770 by Mark Hardy, on Flickr
DSC_3773 by Mark Hardy, on Flickr

mhardy6647

(a la Lt. Columbo...)
ahhh... one more thing... ;- )

Another kind of interesting extended-range 8" driver was the Pioneer PIM-8 (PIM-20 for 20 cm or 200 mm)
http://www.audio-heritage.jp/PIONEER-EXCLUSIVE/unit/pim-20a.html

It's sort of a miniature version of the Altec "Biflex" drivers -- two different cone materials with an intermediate suspension for the inner cone. The inside cone is essentially a tweeter, and 'both' cones the woofer -- all driven off one voice coil.



The PIM-8 is a nice driver with an AlNiCo magnet (like the aforementioned LS-8).
They're not hard to find but they're also not inexpensive (i.e., for what they are) :- (

I actually have a single example of one, in its LRE SK-98 OEM morph. Wouldn't mind having two... but they're always too 'spensive for me when one turns up.

Pioneer LRE biflexes by Mark Hardy, on Flickr

zingo

Seems like EV did have a coaxial unit for these cabinets as well, so that doesn't seem like heresy. I'm guessing though by switching to a coaxial driver that the "single driver mid-range" would be lost?

mhardy6647

Absolutely not! :- )

My daily drivers are coaxes. The ability of a FR or coaxial driver to create a convincing stereo image is pretty much unparalleled, IMO (at least on a per-dollar-spent basis!).

plus...

There are very few (and some folks would say "there are no") 'full-range' drivers that are truly full range -- most of them are either quite rolled-off at higher frequencies, and/or they exhibit a very ragged response (even on axis) at high frequencies. I think the "tizzyness" of many FR drivers (often but not exclusively associated with "whizzer" cones) is precisely why many folks make fun of them.

A good coax does a much better job with the treble.

The only 8" coax that EV made (at least, to my knowledge) was the Wolverine LT-8 -- a beautiful driver... but I've never seen nor heard one in the flesh (so to speak). I like its bigger brother, the LT-12 (quite a bit, actually) so I reckon it'd be pretty good, but they're not common (i.e., they're probably not cheap).

There is at least on "popularly priced" 8" coax driver (still) on the market today. I haven't heard these, either, but the prognosis would be pretty good for 'em, I would think. http://www.parts-express.com/eminence-beta-8cx-8-coaxial-driver--290-500
It's built like a Tannoy coax -- the HF 'horn' is (apparently) formed by the woofer's cone.

http://www.eminence.com/pdf/Beta_8CX.pdf



Note that the price doesn't include the compression HF driver nor XO. The Eminence APT-50 is, I think, reputed to be a pretty good choice for the tweeter & is... well... cheap: http://www.parts-express.com/eminence-apt-50-super-tweeter-horn-driver--290-530

I see that Beyma makes some nice looking 8" coaxes, too -- but at their price point, you might want to try the Dayton or Tang Band twincones!
http://www.usspeaker.com/beyma 8cx300fe-1.htm

And now, with that segue, some final (?) twincone/FR thoughts:

I like some of the Fostex FRs... but some are much smoother (to my ear) than others, and they tend towards the expensive nowadays.

The FE-207E was a nice sounding and reasonably priced driver, but is no longer in production, unfortunately.

DSC_3316 by Mark Hardy, on Flickr

mhardy6647

PS -- I do hope someone besides me will chime in to this thread! :-P I do realize that the Polk Forums isn't exactly a hotbed of interest in FR/high-sensitivity loudspeakers... but, still, you should get some other input besides me foamin' at the mouth!

voltz

I loving this thread, cant add anything just here getting my learning on!

Doc already push me down the crossover less full range driver road

heck you had me all over the internet this morning reading up on all those drivers

this is what I am currently power my DIY Full range with:

mhardy6647

^^^ I have no idea what those are -- but they look like they'd be a good choice :- ) Are those 300B outputs?

voltz

yes it a Dared SL-2000a preamp - and 2 Dared VP-300B Monoblocks at 9 wpc! wasn't sure what to go with so my 300b's are Genalex Golden Lions

zingo

The Beta CX8 + APT50 looks like a pretty interesting combo, especially having used the APT50 for another project. Bob Crites has documented testing this combo before with a miminal crossover with good results.

Whether full range or coaxial, I just want to make sure that the woofer has appropriate specs for the horn cabinet.

CoolJazz

Small corner horns? What if you have a BIG corner???

I think I have a pair of EV 8's that are coax, so I'm pretty sure their are some around.

I've played with a ton of 8", full range as possible drivers, and I still think a cream of the crop is the Tang Band. Not the cheapest (or most expensive) but well justify the $200 each entry ticket!

CJ

mhardy6647

Big corners are good for K-horns... or these...

DSC_5746 by Mark Hardy, on Flickr

plans and photos of a much prettier pair (the designer's) at:
http://www.wardsweb.org/Billfort/

OK they're not horns, but a vented enclosure tucked away in a corner does indeed make a corner horn of fairly impressive dimension (and, thus, respectably low cut-off frequency).

zingo wrote: »

The Beta CX8 + APT50 looks like a pretty interesting combo, especially having used the APT50 for another project. Bob Crites has documented testing this combo before with a miminal crossover with good results.

Whether full range or coaxial, I just want to make sure that the woofer has appropriate specs for the horn cabinet.

That's a good question -- basically, a driver well suited to a horn will have low Qts (e.g., ca. 0.3 or less). According to the PDF at http://www.eminence.com/pdf/Beta_8CX.pdf , the Eminence coax's woofer has a Qts of 0.29 so it should be reasonably happy in a BLH (back loaded horn).

zingo

I think I want to try full range drivers with these first to explore that sound.

zingo

What about installing a pair of 6.5" drivers in these? Not physically of course since I could just cut a new baffle board, but could a smaller driver interact well with this back-loaded corner horn? I like the idea of a 6.5" full range for it's HF potential.

mhardy6647

A 6.5 inch driver with a baffle reducer and suitable T-S parameters should :- ) work fine. It will not have the LF extension of an 8" driver as the Fs will almost certainly be higher. The horn-loading will add bass reinforcement (extension) but it cannot work miracles (not dissimilar to Star Trek's Dr. McCoy!).

I have long felt that the "optimum" size for a FR driver (combination of LF extension and HF dispersion) -- if there is one! -- is 8".

Ya pays yer money & ya takes yer choice.

... and I (still) owe you some info :-P
Got busy doing some grandpa stuff today.

pkquat

On a wild shot I'll toss out the idea of a KEF uni-Q driver, if you can find one used (with a working tweeter or can fix it) and the parameters are close for this box. I saw a home built folded horn that used an old KEF may years back. I don't think it was a corner design. There was some foam and maybe some poly-fil in the box. The end result supposedly had great mid-bass to high frequency, and a good bottom end with a little dip in between, although the lower bass was a little boomy and peaked. Initially there was a significant mid to lower bass hump which I am guessing was what the foam was for.

zingo

Oh good idea on the Uni-Q! I would enjoy finding a pair of Kef SP-3136 8" coaxial drivers as I really like the Kef sound from that era.

leftwinger57

To bad I have 2 10'' cloth surround speakers pulled from my long gone ADC 303ax. The confusing thing w/ these the tweeters tied into these when they were a working pair.

leftwinger57

Of course I forgot to mention that they have these big square honkin what I believe are Alnico magnets. Also is a shot of the terminal posts I thin Mark"doc "Hardy would know these.

mhardy6647

Those are AlNiCo 8" woofers made by CTS -- nice drivers (there's one or two here, in fact). These were widely used in sort of second-tier US speaker systems in the 1960s/70s -- and, by and large, many of those systems sounded surprisingly good (e.g., the HH Scott S-15 three way). CTS made the woofers to their clients' specs, I am pretty sure, but most of them I've encountered were for sealed box alignments.

The one in the photo above was made the 14th week of 1972 :- )

leftwinger57

Mark I just measured outer rim diameter and they are 10''. To be sure I then measured my Advent Prodigy 8'' diameter and sure enough came up to 8''.I just ran a mm to them and both are either 5.9 or 6ohm even. Scroll down and dude even says they are 10'' drivers.

http://www.classicspeakerpages.net/IP.Board/index.php?/topic/3342-adc-303ax/

mhardy6647

Yes, you're right -- 10 inch all the way. Dunno why I typed "eight" :-P
Sorry!

The same driver (at lest phenotypically) used in the Scott S-15.

scotts-15drivers by Mark Hardy, on Flickr

leftwinger57

Finally I should get the apple that goes to the teacher. This I was so positive on I whipped out the ole tape measure and viola. Glad that's settled and I know this is not for here but if one needs 2 10'' cloth surround woofers p/m me.

mhardy6647

Kudos to you :- )

(and, in all seriousness, those are nice general purpose woofers)

zingo

So those are not a full range driver? Although they do have a great look to them!

mhardy6647

The CTS drivers? No, they're woofers -- or, as the Craigslist denizens might refer to them, "subs" ;- )

zingo

There is a local pair of EV 808 2312 8" drivers. The seller claims they are full range, but weren't these mids in a 3 way design?

mhardy6647

Yes they might have been - but they're probably either LS8s or SP8Bs and fully capable of "full range" use. Those EV part numbers aren't as well known (at least to me) as the 'standalone' versions' model numbers. Based on a quick Google search, they're probably SP8B fullrangers -- and the perfect (from EV's perspective) drivers for your cabinets!

EV had a line of consumer (sealed box) loudspeakers that used their fullrange 8" drivers as midranges -- because (I think) EV, like I, thought that "getting the midrange right" was Job 1! :- ) These speakers basically were "augmented fullrange" designs, with the LF and HF limitations of the 8" FR drivers augmented with a woofer and a "super" tweeter. I have pair of the EV "Esquires" and I think they're quite good (FWIW). The Esquire used the LS8 as its MR driver.


Do you have a photo of the drivers for sale that you're looking at?

zingo

Seller states these are ELECTRO-VOICE 808-2312 8" dual cone, full range drivers (SPK126) DCR's measure 3.4 & 3.4 after being pulled from a pair of Regal 300 speakers.