B-15N cab audio shootout---double baffle vs. Thiele

JimmyM · #1 04-10-2008, 01:31 AM

A lot of talk about the different B-15 cabs lately. A lot of us have B-15's, a lot of have scored one recently, etc. I have two of the three different cab designs as of a week ago, so I thought it would be fun to record them and compare and contrast. As you will see, there are a LOT of comparisons and contrasts.

But first, the speaker was mic'ed on axis with a Shure SM-58 (don't like it? Buy me an RE-20) into an old ART Dual MP tube mic pre (don't like it? Buy me a Neve clone) and into a M-Audio Audiophile 2496 soundcard (don't like it? Buy me a Studer 24-track...please!). The bass used was a nifty new SX PJ with fairly dead roundwounds. Not the most expensive bass ever, but sounds like any other PJ. The head was the 1977 head I got last week, plugged into the normal channel. Believe it or not, the recorded sound is very representative of what these cabs sound like in person, and I thought the 58 did a great job of capturing the tone. Maybe after you hear this, you folks may actually quit poo-pooing the 58 as a bass cab mic, because to my ears, it's great. I played 3 identical lines, a walking line, Stevie Wonder's "I Was Made To Love Her," and a simple little slap line.

First is the original double baffle cab, designed by the great Jess Oliver in 1959. It's a Fliptops exact replica loaded with an Eminence Delta 15A (I would have used the 66 CTS in my original 64 cab but the Delta sounds almost identical and it was easier to use since I need a 4-pin adapter for the 64):

http://www.worldnotemusic.com/B-15N-...ta 15A, PJ.mp3

Next up is the Thiele cab, designed by who the heck knows based on a port design by Thiele, and loaded with the original 1977 CTS driver:

http://www.worldnotemusic.com/B-15N-...77 CTS, PJ.mp3

Quite a difference, huh? The Thiele is extremely subdued with almost all low end and no highs, while the double baffle is quite bright for a 15" with very prominent upper mids. But since these speakers are voiced so differently, I swapped them out. The 77 CTS sounded so bad in the double baffle cab that I didn't bother to record it. Totally boxy with no character whatsoever. But here's what the Thiele cab sounded like with the Delta:

http://www.worldnotemusic.com/B-15N-...ta 15A, PJ.mp3

As you can hear, a lot of the differences in the two cabs get minimized, but not entirely. The Thiele cab is still more subdued, with lots of warm fuzzies in the mids and a very pretty high end complemented by slightly deeper lows. The lows aren't quite as apparent on the recordings as in person, but if you listen closely, you can tell.

I have listened to these clips over and over trying to decide which cab I like better, and I think I have to give a slight nod to the double baffle cab. With the Delta, the Thiele is definitely prettier sounding, but without having the benefit of having played the Thiele on a gig, I am pretty sure that the the double baffle will cut through a mix better. And with the CTS, the Thiele cab might as well be a subwoofer. If you're into the bass being a really deep dark sound with very little treble, then you would love the Thiele with the CTS. Like someone who plays a lot of hip hop, old school R&B, or dub would really dig it.

A lot of people say that the B-15 got its modern-day reputation as THE studio bass amp because of the Thiele cab. I have no clue if that's true or not, but judging from this little test, I think the double baffle would be better in the studio because it's got plenty of low end plus more mids so you can feel it AND hear it. But that's just me. Tons of people swear by both of these cabs (and even the much-maligned single baffle cab of 1965-68), and there isn't a bad tone to be had by either. I think they're the number one and two best-sounding 15" cabs of all time.

I'm interested to hear everyone's comments and see what the rest of you think. I'm also interested if people who own either of these cabs thought the recordings I did were a fair representation.

Vin_MM_Sabre_79 · #2 04-10-2008, 07:00 AM

Hey nice. What head are you using here? if it's the '65 B15 what volume did you have it at?

billfitzmaurice · #3 04-10-2008, 07:15 AM

The double baffle and Theile versions are both bass reflex cabs that operate the same way, they just look different. OTOH the double baffle version is a 'seat of the pants' design, so it's not tuned the same as the Theile version and that, along with the different drivers, explains the different results.

joelb79 · #4 04-10-2008, 07:26 AM

Really they both sound good. To my ears the Theile would be better for recording. The double baffle would be better for live use and boomy stages.

morebass! · #5 04-10-2008, 08:45 AM

Nice sounds and playing! I have a '64 with the original speaker. To my ear it sounds warmer than any of the recordings but that could just be the headphones I'm using here at work. Or the fact that I roll off some highs at the bass. If I had the gear I'd make some recordings. Lots of low mid ummpphh, sweet all the way through the spectrum. I've been trying to duplicate the tone in a louder amp for years without much success.

JimmyM · #6 04-10-2008, 09:41 AM

morebass, thanks, bro! What is the original speaker in yours? Mine is not the original CTS, but I have heard conflicting info that the 64 B-15NC had either the CTS or a Jensen P15N with the JBL D140 as an upgrade speaker.

Vin, I used my 77 (the 64 head had to go back to Jess for a shipping incident), the volume was at 11 o'clock, and the tone controls at 12 o'clock, which is flat for Baxandall tone controls.

Interesting comments so far...keep 'em coming!

pedro · #7 04-10-2008, 10:19 AM

Hey Jimmy I can't wait to listen to this at lunch and compare w/ my B15s. FWIW, on my B15 I set straight up and to 'Flat'.

**barebones** · #8 04-10-2008, 10:33 AM

I think I like the dual baffle with the Delta best. Has an aggressiveness the other samples don't really convey. It's kind of like choosing flavors of ice cream, though--whichever you choose, hey, you're still eating ice cream!

Thanks for the shootout.

Matt

BartmanPDX · #9 04-10-2008, 10:35 AM

I prefer the double baffle/Delta, though the Thiele is mighty nice, too.

I pretty much agree with the OP's characterization of things.

I was surprised by the high mids/treble coming from the double baffle/Delta. I didn't think you would get that kind of tone from a 15.

morebass! · #10 04-10-2008, 11:22 AM

Not sure the make of the speaker. It's got a smallish square magnet on it. Back in the 80's I put a JBL (k140?) in it and it sounded bad so I put the original back in there - instant mojo.

hexbass · #11 04-10-2008, 01:28 PM

I've probably played 15 or so different b15ns and I really like the Thiele design best. I have a 74 that has the original Eminence in it that I was going to sell, that is until I plugged my Fbass into it, and heard the magic.

pedro · #12 04-10-2008, 01:52 PM

Could be the difference in bass and bass strings but to my ears none of them sound like my b15. Much more modern sounding and way more high end than I would've expected.

BTW, can someone explain to me what theile cabinet is and how do I know if mine is one or double baffle. (pedro clueless as usual.)

vintageampeg · #13 04-10-2008, 03:02 PM

great stuff here - thanks for posting!

hexbass · #14 04-10-2008, 03:32 PM

I'm pretty sure all the Thiele cabs look like this

pedro · #15 04-10-2008, 03:50 PM

Looks like mine. What does thiele mean?

Quote:

Originally Posted by hexbass

I'm pretty sure all the Thiele cabs look like this

JimmyM · #16 04-10-2008, 04:09 PM

Pedro, A.N. Thiele is a guy who came up with the modern system for rating speakers according to their performance and designed porting systems in cabs. The B-15 cab of the 70's is based on his work. I wonder if the differences you're hearing are because of you having a B-15S. In all honesty, my two B-15's are the only ones I ever have played so I don't know what the S sounds like. I hear it's tighter and a little less tube saggy at higher volumes.

4Mal · #17 04-10-2008, 04:09 PM

Thiele and Small were just a couple of (very smart) engineers who came up with the following parameters to be used for speaker enclosure design. These have become the industry standard.

cut from the net ...

Generally a TS box from that era would be a slot port design with the area and depth of the slot and shelf determining the tuning of the box. It wouldn't have to be a shelf and slot arrangement but most often it was.

JimmyM · #18 04-10-2008, 04:14 PM

Quote:

Originally Posted by morebass!

Not sure the make of the speaker. It's got a smallish square magnet on it. Back in the 80's I put a JBL (k140?) in it and it sounded bad so I put the original back in there - instant mojo.

The CTS magnet is square but it's gigantic. I'd guess it's probably the Jensen. Any chance of hearing a recording of it in the near future?

EDIT: Sorry, I was wrong. The Jensen has a round magnet. So do the JBL D140's. Now I'm not sure what it is. Maybe an earlier design of CTS?

pedro · #19 04-10-2008, 04:17 PM

Quote:

Originally Posted by JimmyM

Pedro, A.N. Thiele is a guy who came up with the modern system for rating speakers according to their performance and designed porting systems in cabs. The B-15 cab of the 70's is based on his work. I wonder if the differences you're hearing are because of you having a B-15S. In all honesty, my two B-15's are the only ones I ever have played so I don't know what the S sounds like. I hear it's tighter and a little less tube saggy at higher volumes.

Thanks Jimmy. I had no idea where the name came from or what it stood for.

I've never had a chance to A/B the B15s w/ the B15. I would've expected that the B15n to be softer (for lack of a better term). But to me those clips, especially the first one was surprisingly bright.

P.S. Were you using a pick?

JimmyM · #20 04-10-2008, 04:21 PM

Nope, just fingers. The Delta is a bright speaker but very much like the 60's CTS. If you put the 70's speaker in the double baffle, or you mic it off axis, you can tame those highs down (sounds like crap to put the 70's speaker in it, though...too boxy). Also, the 58 has a hump in those freqs, so they might be a tad over-accentuated on the recording. But you can definitely hear the edginess of those freqs in person.