Anyone Tried Legend CB15 Speakers?

ZiggyDude · #1 07-27-2011, 08:36 AM

It seems that my quest for speakers that will handle lots of power in large vented cabs is not complete yet.

Has anyone had any experience with the Eminence Legend speakers? I think the current version is the CB15.

craig.p · #2 07-27-2011, 09:40 AM

Ziggy, please permit me to challenge your acceptability criteria. Are you looking for drivers that will soak up lots of watts (which is another way of saying "will handle lots of power"), or are you really looking for drivers that will output the maximum possible SPL on a per-driver basis, assuming the frequency range you need is covered?

billfitzmaurice · #3 07-27-2011, 10:24 AM

Quote:

Originally Posted by ZiggyDude

It seems that my quest for speakers that will handle lots of power in large vented cabs is not complete yet.

Power is moot. What matters is frequency response, sensitivity and displacement.

ZiggyDude · #4 07-27-2011, 11:10 AM

Yup, yup, understand what you are both saying. I don't want to get too hung up on just that power thing - I am also curious on how the Legends "Sound". Despite the numbers - differ speakers are voiced differently.

If it helps where I am going with this. I have an Acoustic 406 wide cab. Tuned to about 31 hz, vented, 43x26.5x18". I found a set of Eminence 400 watt speakers that work just great. But, they don't make em anymore. I need more of the same. I tried the Kappa LFAs and they failed miserably - too much excursion. I tried a set of neo 15s that looked great on paper - better - but still failed.

I have had the same experieince with the vintage Sunn 215B cab. This is the one that I did the thread on TB where I rehabbed it. It also likes those Emmys - it simply came alive when I put them in.

I have one set of those speakers - would love more - but need what is being sold now. I have gone through Emmy tech support - nothing really came up.

One thing that I have noticed is that the speakers that work well are very firm when I push down on the cone excursion. Lots of resistance. When playing out they take everything I throw at them, I pin the 31 hz slider and power up and they do not even fart. I have used both the big power vintage Acoustic heads and also an SLM issue Ampeg SVT4-Pro (1400 watts). The cab was loud, clear, and projected. Yeah - I am not in the PA - we carry tops on poles only :-)

billfitzmaurice · #5 07-27-2011, 12:27 PM

Your only alternative, other than buying them and trying them, is learning how to use loudspeaker modeling software. As for the voicing of drivers, there's nothing the least bit mystical about it, and it's clearly seen on driver data sheet SPL charts. And as for 'too much excursion', there's no such thing. The longer the excursion the louder the driver can play, that's the only factor governed by excursion. The differences you heard would have been due to other T/S specs, assuming that in fact you don't want the driver to have the ability to play loudly and want it to clip at lower power input.

Battlemode · #6 07-27-2011, 12:33 PM

I've had a pair of the CA154's in an Acoustic 106 and I like them. I actually just yesterday switched them out for a pair of CB158's (for impedance reasons) but haven't got the chance to play through them yet. I'm expecting more of what I had with the CA154's, which is a good thing.

craig.p · #7 07-27-2011, 02:27 PM

To Bill's point, I SWAG'd the cab's internal volume at about 9.9 cubic feet, maybe a little less to account for internal lumber used for port shelves. BUT... you've got to tell us the porting arrangement. Long ago I had an Acoustic cab that had two fifteens but it was a "semi-shared" box. There was a vent between the two speakers, extended back some number of inches, but there also was a separator shelf that started at the back wall, bisecting the vent area, but not coming all the way forward to the baffle board. Is this what you have? I don't know how to model something like that. My biggest question would be who owns what air as you move from the rear of the port toward the front. Sorry for the crummy freehand but you get the idea:

Edit: Could someone please verify that porting arrangement. I've been running back through my memory and now I'm having doubts whether that arrangement was on my Acoustic cab or a V6B I once owned. Sorry if I got it wrong but this is what happens when you try to remember things from over three decades ago.

FuzzBoxVoodoo · #8 07-27-2011, 02:48 PM

I put a set of CB115 Legends in a Narrow Peavey 215 cab and they sound good to me,not what you would consider a hign power sub cabinet but does well for a standalone bass cab.

ZiggyDude · #9 07-28-2011, 06:22 AM

Hi Craig

That is the cab – very clever drawing by the way! The difference is that the separator that comes from the back of the cab does not go between the two planks from the front. I wish they did - with a bit of a V shape - but there is actually about 2 or 3 inches where you could look down and see the bottom of the cab from the top – my not as talented drawing. The (__ ) is just dead air - the web software takes out leading spaces or extra spaces and tabs it seems

-------
(______)--------
-------

Regarding the other comment by someone on speaker excursion. I honestly do not want to argue - but even the Eminence documentation talks about it - they want some hi pass filter to prevent it. It is on their website for the cab design sheet - I am not making it up. Wish that there was no such thing as when the speaker does over travel it shorts and blows the output transistors - like what happened to my 320 head :-( That was money....

craig.p · #10 07-28-2011, 08:22 AM

Ziggy, thanks for straightening out that porting scheme for me. The way it is in that cab, it might not be that tough to model.

On the excursion thing, what Bill's saying is that there's nothing wrong with a speaker's ability to move its cone long distances SAFELY. He's not saying there's nothing wrong with too much excursion relative to the speaker's specified limit. You're both actually agreeing -- you just don't realize it.

I'm glad you brought up high-pass filters. The dirty secret of bass amplification is that lots of bass amps do nothing to prevent (or at least forestall) subsonic energy reaching from the speaker outputs, unless it happens to be a by-product of low-end roll-off in an output transformer, or benign high-passing in stage-to-stage coupling, or both. Here's a good test. You'll need to be able to see your cones, first of all. Set your amp to its typical stage volume and tone, i.e. as loud and low-voiced as it'll ever be set on stage. Same with your bass, including its active tone circuits, if any. Now take your E (or B) string between your thumb and forefinger, and wiggle it as fast as you can. If your cones move, there's a subsonic problem and it should be addressed. Some people say this can be done with a 1/3 octave equalizer. This is not correct, unless the equalizer goes down to 0 Hz. I've yet to see one. Some equalizers, though, have switchable/variable subsonic filters that do the job well. I'm especially impressed with Carvin's implementation, where the knee frequency is variable over a wide range. Of course, for those who've done simple kitting, hacking together a simple high-pass filter and shoving it into a small Bud box is a trivial job. There are also those passive subsonic filters that work well as long as (as Bill F has pointed out elsewhere) the input impedance of the power amp is what the filter expects it to be. But even if it's not, a different ("incorrect") knee point can be selected to compensate for the "incorrect" impedance.

Sorry for the OT......

billfitzmaurice · #11 07-28-2011, 08:56 AM

Quote:

Originally Posted by ZiggyDude

Wish that there was no such thing as when the speaker does over travel it shorts and blows the output transistors

There is no such thing. You need to do quite a bit more research into how speakers and amps actually work, as there's no engineering basis for this conclusion. As for the need to high pass a driver, that's because it lacks enough excursion capability to be run at high power/low frequencies, not because it has too much.

craig.p · #12 07-28-2011, 04:05 PM

Hey Bill, what if the voice coil got hot enough to deform, then its windings on the opposing high sides began scraping against the magnet, then the insulation began gradually to wear off, allowing the magnet's metal to provide a lower and lower resistance electrical path over time?

Or have I just invented a Bizarro World scenario that never occurs? (I'm not a driver designer, don't know whether voice coils ever go out of round, don't know how tight the gaps they run in are, etc.)

4StringShooter · #13 07-28-2011, 05:17 PM

Quote:

Originally Posted by ZiggyDude

It seems that my quest for speakers that will handle lots of power in large vented cabs is not complete yet.

Has anyone had any experience with the Eminence Legend speakers? I think the current version is the CB15.

No, but I DID use RCF s for quite a few years in my Traynor 2-15 Cab. I liked them. At the time, they set me back $540.00 for the pair. Sensitivity was 108db @ 1 watt meter.

billfitzmaurice · #14 07-28-2011, 08:10 PM

Quote:

Originally Posted by craig.p

Hey Bill, what if the voice coil got hot enough to deform, then its windings on the opposing high sides began scraping against the magnet, then the insulation began gradually to wear off, allowing the magnet's metal to provide a lower and lower resistance electrical path over time?

If the coil gets hot enough that scenario can play out, but the time period from the start of the process to the appearance of magic smoke would be at most a few minutes.

Quote:

I DID use RCF... Sensitivity was 108db @ 1 watt meter.

No cone drivers are capable of that sensitivity. The most you can get from a fifteen is about 98dB, unless it has very low Q. That can get you up to about 101, maybe 102, but at the expense of choked off low frequency response.

ZiggyDude · #15 08-02-2011, 08:45 AM

Bill - as far as the term overexcursion - we are probably talking the same thing but using a different term? This is a link to the Eminence spec sheet. They clearly use the term and warn about the problem.
http://www.eminence.com/pdf/Kappa_15LFA_cab.pdf

I guess you can argue the point with the Eminence engineers - I just know that I had the problem and their tech support guys understood it.

Actually - I got the problem with the speaker as soon as I plugged in or after several sets - so heat was not the problem.

I don't want to drift to far away from wanting to learn about the Legends though.

Hey Battlemode - how did the CB15s work? Also FuzzBoxVooDoo - how would you describe the tone?

Battlemode · #16 08-02-2011, 10:05 AM

I finally got the chance to really try them out yesterday. They sound good to my ears - articulate, good lows and highs. More of what I had with the CA154's, and I got a lot of compliments on my sound using those speakers (in various boxes). In trying them out, I tried everything from only running ≤ 300 hz from my head's crossover to cranking the treble and they seemed to handle everything. For my sound - bright cleans, black Russian Big Muff on 2/3 of the time - I was very pleased, and the cab sounded good by itself and as the bottom of a bi-amp setup. I'm sure there are better speakers out there (probably for more money), and I haven't modeled the cab with the speakers in WinISD or anything, but they're the right price, sound good to me, and will be more than capable of doing what I need them to do. I can't speak for how they'll work with your bass/head/cab, but I'm happy with them.

billfitzmaurice · #17 08-02-2011, 10:05 AM

Quote:

Originally Posted by ZiggyDude

Bill - as far as the term overexcursion - we are probably talking the same thing but using a different term? This is a link to the Eminence spec sheet. They clearly use the term and warn about the problem.
http://www.eminence.com/pdf/Kappa_15LFA_cab.pdf

That warning is exactly the same as what I said. It has everything to do with protecting the driver from physical damage, and nothing to do with protecting the amp.

Battlemode · #18 08-02-2011, 10:18 AM

As a side note, the only hassles I had with them were mounting/wiring issues. My cab is front loaded, and I need to use spacers on the bolts sticking out of the baffle to mount them properly. The frames of these speakers are a hair thicker then on the CA154's, making my old spacers too long and the only other size I've been able to find locally too short. I'm going to have to order some, but it might not be an issue with you. Also, the speakers have binding posts instead of the quick-disconnect style terminals every other of my speakers has had. I actually prefer the posts, but I did have to make a run to the electronics store and throw together some banana plug jumpers.

ZiggyDude · #19 08-02-2011, 11:02 AM

Thanks BattleMode!

If I may ask, what cab and amp did you use?

johnk_10 · #20 08-02-2011, 11:24 AM

Quote:

Originally Posted by 4StringShooter

No, but I DID use RCF s for quite a few years in my Traynor 2-15 Cab. I liked them. At the time, they set me back $540.00 for the pair. Sensitivity was 108db @ 1 watt meter.

i've never heard of a 15 having sensitivity specs that high. AFAIK, the most sensitive 15 that i've ever used is a JBL K130. it's 103db @ 1w/1m, and i believe it to be the most sensitive 15 ever offered. IME, it even makes an 85 watt Fender Showman sound/feel pretty powerful.