Best speaker for B15N Thiele cab?

**ddbassGA** · #1 05-03-2011, 09:49 AM

Setting up an early 70's black B15N with Thiele cab. Wondering what the best speaker would be. Have original CTS square mag, couple of different EV (DLX, L), JBL K140 and Altec 421 (?) to chose from. Oh and an Eminence Delta.

Actually the JBL and Altec need recone so I'd like to hear from anyone who has experience with the Thiele ported cabs before I invest. Im leaning toward the JBL and thinking 4 ohms at recone. Nutty idea?

Any power mods for the amp?

Jim C · #2 05-03-2011, 09:59 AM

Are you looking for the authentic sound (attenuated high freqs) or a more modern sound from a speaker swap?

Don't think there is much more clean power to be had unless you want to carve it up to include replacement of the output transformer.
With a tube amp the best results for speaker impedance is to match it to the output transformer IMO.

pgk · #3 05-03-2011, 11:04 AM

the altec would prolly sound pretty fab in that cab. i don't like an altec's strong mids in a small box, but in a thiele design you'd get deeper lows to offest them for what could be a very nice balance of attributes. personally i'd recone the Ev15L with a 15B kit, which has a thicker cone and is a little darker and much fatter sounding than a 15L. you can safely run with 4ohms. i would'nt but yeah you can. even jess oliver himself recommended doing that, tightens things up a skoch. you'll beat up your outputs a little harder but you won't hurt the iron, it can take it. for a modern speaker i'd go with an emi 3015 non-lf

4Mal · #4 05-03-2011, 11:21 AM

Great Plains Audio - have them recone the 421. It's the most efficient and to my ear the best sounding of the bunch. Personally I'd be thinking 8 - this amp is never going to knock the walls back so run it less close to the edge. Maybe put something like an Avalon U5 on the speaker out and send that somwehere else to get loud ...

Great Plains Audio

BTW - you can buy a recone kit from GPA and then have your local guy install if you want to avoid the freight and have a local guy you trust. Not all that expensive for the kit I would imagine. A 417-8C kit was $78 ... the GPA guys are super nice too!

JimmyM · #5 05-03-2011, 11:44 AM

i'd get the altec reconed, too. the extra mids of the altec will compensate for the slightly depressed mid response of the bigger cab.

BassmanPaul · #6 05-03-2011, 12:52 PM

Quote:

Originally Posted by 4Mal

BTW - you can buy a recone kit from GPA and then have your local guy install if you want to avoid the freight and have a local guy you trust. Not all that expensive for the kit I would imagine. A 417-8C kit was $78 ... the GPA guys are super nice too!

The advantage of having GPA do the re-cone is that they will also recharge the AlNiCo magnet back to where it should be.

**ddbassGA** · #7 05-03-2011, 02:09 PM

Re: GPA -- thanks for that advice Paul and 4Mal. I have requested a quote from them. Glad to know about them.

**ddbassGA** · #8 05-03-2011, 02:45 PM

While we're at it, where's the best place to have the JBL K140 reconed?

coreyfyfe · #9 05-03-2011, 03:33 PM

Quote:

Originally Posted by ddbassGA

While we're at it, where's the best place to have the JBL K140 reconed?

OC speaker seems to be the usual recommendation but they charge like $260 according to their price list (was looking earlier today because of this thread

).

Jim C · #10 05-03-2011, 04:26 PM

For the record, I have a Peavey 2x15 cabinet I bought new in the mid 70's and have since loaded with 421's. I'm sure it's technicaly wrong but use it at rehearsal once a week and love the tone.

4Mal · #11 05-03-2011, 04:58 PM

Surely there is someone closer than Orange County. Ask about the Atl scene, there has to be someone down there. Maybe Bernie at BLTSound has a recommendation. Bernie is good peeps and he's not that far away...

Email: bernie@bltsound.com Phone: 770-560-5155

BLT Sound
146 Highway 138, #118
Monroe, GA 30655

**ddbassGA** · #12 05-03-2011, 06:38 PM

Checked several and looks like $260-300 for the K140 using real JBL parts, plus shipping both directions. That's alot of mullah but since JBL doesn't make the parts anymore and these are NOS kits, I kinda feel like it's "last call".

With aftermarket parts the recone will run about half that, and as low as $131 at Parts Express. Just don't know what I'd get with the aftermarket stuff. PE reconed a BagEnd speaker for me and it doesn't sound the same as the new BagEnd speaker I ordered at the same time. I will say it sounds good, but not the same.

Thanks 4Mal, I will check with Bernie in Monroe tomorrow.

Bill Whitehurst · #13 05-03-2011, 06:54 PM

I think the stock answer for a B15 is JBL D140F.
They do sound great, but most folks that rave about vintage JBLs
just haven't spent any time with an Altec 421.

coreyfyfe · #14 05-03-2011, 07:02 PM

Quote:

Originally Posted by Bill Whitehurst

I think the stock answer for a B15 is JBL D140F.
They do sound great, but most folks that rave about vintage JBLs
just haven't spent any time with an Altec 421.

While it is true I haven't tried an Altec 421 the K140 in my double baffle sounds pretty darn nice. Not sure about in a thiele cab though.

JimmyM · #15 05-03-2011, 07:29 PM

mind you, this is based on my experience with the thiele and double baffle cabs, but i really haven't tried either the jbl or the altec. the thiele cab is upper mid shy with most "normal speakers," and everyone says the altecs have more upper mids than the jbl. plus the altec is what they came with as an upgrade speaker. so for that reason alone i'd go with the altec.

**ddbassGA** · #16 05-04-2011, 12:39 PM

Just got off the phone with Great Plains Audio and I'm stoked! They'll recone the Altec 421A for $125 + return shipping.

And they have a USA aftermarket solution for the K140 that they believe is as good as the NOS JBL kit: $65 parts + $40 labor. Wow! Do I really need to spend almost 3x that for the JBL recone kit?

**ddbassGA** · #17 05-04-2011, 12:55 PM

Alas, my Altec is a 418 not a 421. Smaller Alnico magnet, among other differences, higher resonant freq. Higher power rating.

What's the experience with a 418? Note this is NOT the series II but the original one with the 2 screws holding the stamped cover on the magnet.

Still worth messing with?

BillFitz, you out there?

4Mal · #18 05-04-2011, 01:31 PM

Quote:

Originally Posted by ddbassGA

Just got off the phone with Great Plains Audio and I'm stoked! They'll recone the Altec 421A for $125 + return shipping.

And they have a USA aftermarket solution for the K140 that they believe is as good as the NOS JBL kit: $65 parts + $40 labor. Wow! Do I really need to spend almost 3x that for the JBL recone kit?

nope. IME - the quality of the reconer is way more important.

4Mal · #19 05-04-2011, 01:35 PM

Quote:

Originally Posted by ddbassGA

Alas, my Altec is a 418 not a 421. Smaller Alnico magnet, among other differences, higher resonant freq. Higher power rating.

What's the experience with a 418? Note this is NOT the series II but the original one with the 2 screws holding the stamped cover on the magnet.

Still worth messing with?

BillFitz, you out there?

I would call back to GPA and talk to them. Those guy's know their Lansings ... they might also be or know of a source for a 421 and how best to dispose the the 418 if that turned out to be an attratcive option. The Altec fan community is pretty small and tight ...

**ddbassGA** · #20 05-04-2011, 01:56 PM

Called them back and they said they would recommend using the 418 as basically the same speaker, except for the magnet structure. Nearly identical flux from the smaller Alnico on the 418 as the larger Ceramic mag on the 421. Uses the same kit.

So I'll be sending it off to them.