efficient cabs for low power tube amps

[will33]

It's only been recently (relatively speaking) where stuff like that Faital sort of lets us have our cake and eat it too, and even now, massive excursion/LF output/power handling still means you have to take a hit in other areas.

Refinements of the technology lets us do more with less, but there still is no, and never will be, a free lunch.

 

[beebassdude]

this thread ended when this phrase was typed.

"There is so much utter buffalo bagels talked on this site it's unreal."

its all downhill from here.

 

[Downunderwonder]

Bassmec, I'm listening. Thank you for sharing your obvious knowledge.

And me. Seems your humour is wooshing way over some peoples heads.

According to local wisdom a reconed E140 is as good as new. I mention E140 because afaik they are the only readily available recone in that JBL series.

 

[Korladis]

"love the sound of my 40 and 100 watt tube amps.
love the sensitivity of the older speakers, but they can be fragile.
i'm ok with a bigger box, if needed.
Any modern speakers that would get me there?"

It sounded to me as if the OP liked the vintage speaker and didn't mind needing a larger box for it, but he was under the false impression that the vintage drivers were fragile. Several TB members have vintage JBL drivers and we know that they are plenty tough to handle small wattage amps, such as the OP mentioned, and just as importantly, they don't require huge amounts of power to produce very large amounts of volume. I gigged for years with two D140F JBL drivers, which I still own, each driven by one side of a Peavey CS 400 amp. I had all the volume I could ever need, and the drivers never complained one iota. I and I believe others were trying to point out to the OP that he could have his cake and eat it too. FWIW. I'm sure some will want to argue the point.

Exactly. The tone of a JBL D140 is undeniably great.

But they're discontinued. Hence why I mentioned that ideally I'd like to have a single one for recording (paired with a low wattage tube amp), and the closest modern drivers currently manufactured, with high power handling, for live use.

I did pretty much the same thing with a pair of K140's for about 20+ years, used with amps from 400 watts to 1500 watts. The cab wore out before the drivers did. The title of the thread asks about " cabs ", so that's where I got the idea. The Faital 15 previously mentioned gets pretty close to the tone of a JBL K140, imho, but not quite the same " sheen " as the JBL. I was more concerned about copping that tone, than anything else, when Dave Green suggested the Faital. When weight became an issue, it was a no brainer for me, but, if I could, I would still be lugging around a 215 loaded with JBL's.

Yeah. For recording, I'd want that JBL "sheen," but live it wouldn't be as much of a concern.

And while old JBLs aren't "fragile" in an absolute sense, a Faital 15PR400 or Eminence 3015 is undeniably less fragile. That's a fact. I wouldn't feel comfortable cranking an SVT into two D140s, because a cranked SVT puts out well over 300 watts of power, and especially in terms of excursion, there's a good chance the vintage drivers won't take that, and if I broke them, well, that's it, that's potentially one less D140 in the world. They don't make them anymore (sometimes I wish I owned JBL just to reissue the 140 series). A pair of either of the modern drivers mentioned will handle a cranked SVT no problem.

Solid retort!



Sounds like you read what you want to read.

I think he's simply saying he wants the best cab he can get and size isn't a factor, because a lot of people (me included) do not have the means to carry large cabs.

I think the main point is even if the older speakers are tough it's more of a risk running a discontinued part (not saying obsolete). So if a newer speaker can achieve similar or better results and stay in the guys budget and size requirements why not? If technology developments have stalled then new drivers should be no better or worse right? Only you can order them right away if there is an issue.

Yeah, pretty much this. I feel better about gigging equipment that can be replaced if it breaks than equipment that can't.

It's only been recently (relatively speaking) where stuff like that Faital sort of lets us have our cake and eat it too, and even now, massive excursion/LF output/power handling still means you have to take a hit in other areas.

Refinements of the technology lets us do more with less, but there still is no, and never will be, a free lunch.

Yeah. And one of those hits is in the pocketbook, heh.

 

[Downunderwonder]

As an aside, should all this come up in a search for modern vintage tone, johnk_10 got some outstanding tone from replacing the stock 3015 dust caps with aluminium in his starliner.

 

[Korladis]

As an aside, should all this come up in a search for modern vintage tone, johnk_10 got some outstanding tone from replacing the stock 3015 dust caps with aluminium in his starliner.

Ooh, I didn't know that. Johnk_10 makes some awesome stuff.

Very cool to know.

 

[will33]

He put aluminum dustcaps on the Deltalite II 2512's in his V4 cab as well.

 

[Bassmec]

Well I give in about recomending suitable loudspeakers for 50watts per coil.
So now we have to deal with running in the new drivers. Let's assume that we are going with the most sensitive modern contender the 3015ho, 450 watts RMS at a lowly 99dB per driver giving us circa 102dB spl the pair.
My recommendation is that as the op hasn't got anything like enough power to even begin to run the suspension in enough to get anything near the SPL spec. I would wire them in series for 16 ohms and plug them in the 110V mains for a bit while monitoring the temperature with an infra red thermometer.
If they get warm let them cool and run them again until they have done about 30 mins.
Then they might just compete for aparant volume with a single Altec 418-II at 100 watts.
You see the eminence pair will have far less speaker compression than the single ALtec running hard so the eminence pair will catch up a couple of dB.
By the way the ALtec figures are an average sensitivity, same as JBL and eminence IEC standard measurements.
This is a quality loudspeaker manufacturers measured spec nothing to do with the guitar centre or behringer.

 

[will33]

Yup.

The "performance" abilities of the newer drivers, when coupled to a "lowly" 100 watts leaves a whole lot laying on the table.

That means you are paying for a whole lot of potential output you will never, ever hear.

Same reason that though I love Fearfuls and their capabilities, I don't run one for my lower power, subwoofy-shy bass guitar tone. Not buying a bunch of capability I'll never hear. I am however gathering the funds for a pair if 3015LF's...to install in 15sub boxes.... to use for their righteous purpose......which is compact, effective subwoofers for my small PA system.....not my bass rig.....unless I send my kickdrum through the rig, drive the entire LF for the room from the backline, and consider that the subwoofer.

 

[CL400Peavey]

Well I give in about recomending suitable loudspeakers for 50watts per coil.
So now we have to deal with running in the new drivers. Let's assume that we are going with the most sensitive modern contender the 3015ho, 450 watts RMS at a lowly 99dB per driver giving us circa 102dB spl the pair.
My recommendation is that as the op hasn't got anything like enough power to even begin to run the suspension in enough to get anything near the SPL spec. I would wire them in series for 16 ohms and plug them in the 110V mains for a bit while monitoring the temperature with an infra red thermometer.
If they get warm let them cool and run them again until they have done about 30 mins.
Then they might just compete for aparant volume with a single Altec 418-II at 100 watts.
You see the eminence pair will have far less speaker compression than the single ALtec running hard so the eminence pair will catch up a couple of dB.
By the way the ALtec figures are an average sensitivity, same as JBL and eminence IEC standard measurements.
This is a quality loudspeaker manufacturers measured spec nothing to do with the guitar centre or behringer.

Actually read this post.

Ok so lets look at these drivers and compare them to some modern ones.

The 3015 has a sensitivity of 100.8 dB/w/m. It also has an xMax of 5.9mm. That is average sensitivity, and it peaks to about 104 dB/w/m around 2kHz. Oh and it weighs 7.9 pounds, and is very well regarded in terms of tone and response.

The Faital Pro is rated at 99 dB/w/m, conservatively as it also rises well above 100 dB/w/m in the upper mid range. It has an xMax of 5.75mm, and weighs 7.9 pounds. Tonally it is a dream either with low powered tube amps, or being driven by something bigger.

The JBL E130 is rated at[Invalid or Expired Link Removed], It is no more efficient in the lows than the Neo drivers. Those mids and upper mids are easy to get loud in. That sensitivity doesnt matter nearly as much as some want to believe. Guitarists have been cutting off heads in those bandwidths with single 12's since the dawn of electrified music.

The Link Removed and the Link Removed, Both also illustrate this rise in the mids/upper mids, and this is where their sensitivity figures are quoted from. I am going to go out on a limb here, and say that broad band, you are not going to have much increased sensitivity over something like the 3015, maybe marginally over the 15PR400, but if you can hear that 1dB difference, then you have some golden ears.

Actually read both the response curves. The sensitivity spec you are quoting for that altec, is not the average sensitivity, it is the peak. If that is the game you want to play, then the 3015 is rated at 104 dB/w/m. Which means it is all of 1 dB behind the 418B you love. So stack up two of each and you are looking at 107 and 108 dB/w/m respectivly. At 100 watts, barring power compression, which is going to be on the side of the 3015, you are looking at ~126dB and ~127db. Due to the linearity advantage of the 3015, if it doesnt surpass the 418, it matches it.


Invalid Link Removed

 

[DukeLeJeune]

... the op hasn't got anything like enough power to even begin to run the suspension in enough to get anything near the SPL spec.

They'll meet their SPL spec right out of the box. "Running in" the suspension system will lower their free-air resonance by a few Hertz, warming up the very bottom end a bit.

I would wire them in series for 16 ohms and plug them in the 110V mains for a bit while monitoring the temperature with an infra red thermometer. If they get warm let them cool and run them again until they have done about 30 mins.

I would not recommend that. Loudspeaker thermal power ratings are not based on sine-wave input.

 

[Stealth Fighter]

Solid retort!



Sounds like you read what you want to read. Much better than reading what I don't want to read.

I think he's simply saying he wants the best cab he can get and size isn't a factor, because a lot of people (me included) do not have the means to carry large cabs.
No. He said this: "love the sound of my 40 and 100 watt tube amps.
love the sensitivity of the older speakers, but they can be fragile.
i'm ok with a bigger box, if needed.
Any modern speakers that would get me there?"
I see nothing about wanting the best cab he could get. Even if he had, the best cab for a 50 to 100 watt head would not be a F______, as some have suggested. That would be a waste of money.

I think the main point is even if the older speakers are tough it's more of a risk running a discontinued part (not saying obsolete). Why? Where is the risk? It's not like he's going to fall over dead if the driver blows. So if a newer speaker can achieve similar or better results and stay in the guys budget and size requirements why not? Well, first off, the op did not state a budget. Second, in the ears of many, the modern driver does not equal the vintage driver, in terms of tone quality, nor are they a match in sensitivity. The op stated explicitly that he loved the sound of his tube amps and the sensitivity of the older speakers, which in my opinion are part of the sound of the old amps. If technology developments have stalled then new drivers should be no better or worse right? Only you can order them right away if there is an issue. As he still can if and when his vintage driver, Heaven forbid, ever breaks.

At least I don't make stuff up.

 

[Bassmec]

Actually read this post.




Actually read both the response curves. The sensitivity spec you are quoting for that altec, is not the average sensitivity, it is the peak. If that is the game you want to play, then the 3015 is rated at 104 dB/w/m. Which means it is all of 1 dB behind the 418B you love. So stack up two of each and you are looking at 107 and 108 dB/w/m respectivly. At 100 watts, barring power compression, which is going to be on the side of the 3015, you are looking at ~126dB and ~127db. Due to the linearity advantage of the 3015, if it doesnt surpass the 418, it matches it.


Invalid Link Removed

The only spec I have which I am directly quoting from is posted way back in this thread, its a catalog page which is hard to read and the speaker I am referring to Is not the same loudspeaker you are talking about, Its not the 418b or 421a it's the much larger stepped alnico magnet structure extended frame 418-series two driver.
I think it quotes 150 watts the spl at 103, Correct me if you read it differently, I have no reason to suppose its a lie and I have no reason to suppose any of the other figures quoted by other respected loudspeaker manufacturers and JohnK10 are inaccurate.
I believe the 418b to be 100 watts at 98dB Spl. I have been unable to find a graph referring to the loudspeaker I am talking about
Perhaps you could show me the one you are quoting from so I can check which loudspeaker it refers to.

 

[Bassmec]

They'll meet their SPL spec right out of the box. "Running in" the suspension system will lower their free-air resonance by a few Hertz, warming up the very bottom end a bit.



I would not recommend that. Loudspeaker thermal power ratings are not based on sine-wave input.

Interesting when I worked at celestion we where told in no uncertain terms to run in drivers before SPL testing in our anechoic chamber.
I only tested after they were run in as instructed, I just supposed there might be an effect on excursion as it seems logical that if it was a bit tight in one way it might effect it in another.
We used to use an old crown dc 300a to abuse them running in suspensions, perhaps it would be better to see if the
OP can borrow an amp powerful enough to reach X-Max for a bit.

 

[jnewmark]

Exactly. The tone of a JBL D140 is undeniably great.

But they're discontinued. Hence why I mentioned that ideally I'd like to have a single one for recording (paired with a low wattage tube amp), and the closest modern drivers currently manufactured, with high power handling, for live use.


Yeah. For recording, I'd want that JBL "sheen," but live it wouldn't be as much of a concern.

And while old JBLs aren't "fragile" in an absolute sense, a Faital 15PR400 or Eminence 3015 is undeniably less fragile. That's a fact. I wouldn't feel comfortable cranking an SVT into two D140s, because a cranked SVT puts out well over 300 watts of power, and especially in terms of excursion, there's a good chance the vintage drivers won't take that, and if I broke them, well, that's it, that's potentially one less D140 in the world. They don't make them anymore (sometimes I wish I owned JBL just to reissue the 140 series). A pair of either of the modern drivers mentioned will handle a cranked SVT no problem.


Yeah, pretty much this. I feel better about gigging equipment that can be replaced if it breaks than equipment that can't.


Yeah. And one of those hits is in the pocketbook, heh.

Don't want to harp on old JBL's, but they, ( at least the K140 and the E140 ), can certainly be replaced, and reconed. I have had no problem doing this at all, even locally when it comes to a recone job. Those drivers pop up all the time on Ebay. If you can put up with the weight, I don't see how a 40 -100 watt amp is going to harm them much, if they are loaded in the correct cab for their specs.

 

[DukeLeJeune]

Interesting when I worked at celestion we where told in no uncertain terms to run in drivers before SPL testing in our anechoic chamber.
I only tested after they were run in as instructed, I just supposed there might be an effect on excursion as it seems logical that if it was a bit tight in one way it might effect it in another.
We used to use an old crown dc 300a to abuse them running in suspensions, perhaps it would be better to see if the
OP can borrow an amp powerful enough to reach X-Max for a bit.

Twenty-five watts at 10 Hz will push the 3015 (non-LF) to its linear excursion limits in free-air, breaking it in as far as resonant frequency goes overnight with no thermal stress on the voice coil or amp... but it's not going to flex the cone and "run it in" to achieve a certain tonal sweet spot, which is what I would guess was part of the goal at Celestion.

I'm under the impression that many electric guitar players really like the tone of an old speaker, probably because they aren't quite as peaky as the new ones because the cone has softened up a bit with use. Does that sound right to you?

 

[Korladis]

Don't want to harp on old JBL's, but they, ( at least the K140 and the E140 ), can certainly be replaced, and reconed. I have had no problem doing this at all, even locally when it comes to a recone job. Those drivers pop up all the time on Ebay. If you can put up with the weight, I don't see how a 40 -100 watt amp is going to harm them much, if they are loaded in the correct cab for their specs.

That's the thing, though. They can't be replaced in the sense that I'm talking about.

Yes, I myself, if I wreck a JBL so badly that it can't just be reconed (and even if it can, there aren't infinite recone kits), can find one on ebay.

However, that is still one less old JBL that exists in the world. They are not still being manufactured.

 

[Bassmec]

Twenty-five watts at 10 Hz will push the 3015 (non-LF) to its linear excursion limits in free-air, breaking it in as far as resonant frequency goes overnight with no thermal stress on the voice coil or amp... but it's not going to flex the cone and "run it in" to achieve a certain tonal sweet spot, which is what I would guess was part of the goal at Celestion.

I'm under the impression that many electric guitar players really like the tone of an old speaker, probably because they aren't quite as peaky as the new ones because the cone has softened up a bit with use. Does that sound right to you?

Yup actually the speaker I am referring to has an odd chamfered voice coil gap in order to soften its tone a bit without having to do so much cone distressing, in fact Marshall made a big sales thing of wirewooling cones on their 18 watt blues breaker combo reissue.
PS I thought a puny 726 odd USA RMS watts - speaker cable losses at 60 Hz sine wave might be about right for running in a pair of series wired drivers rated at 900 watts rms total. What sort of power do you recommend at 60Hz sine wave before the coil comes out of the gap in these bad boys?.
PPS Actually thinking about it, it might be a bit loud, running it in at 60 Hz in a suburban garage for a couple of hours.

 

[DukeLeJeune]

Yup actually the speaker I am referring to has an odd chamfered voice coil gap in order to soften its tone a bit without having to do so much cone distressing, in fact Marshall made a big sales thing of wirewooling cones on their 18 watt blues breaker combo reissue.
PS I thought a puny 726 odd USA RMS watts - speaker cable losses at 60 Hz sine wave might be about right for running in a pair of series wired drivers rated at 900 watts rms total. What sort of power do you recommend at 60Hz sine wave before the coil comes out of the gap in these bad boys?.
PPS Actually thinking about it, it might be a bit loud, running it in at 60 Hz in a suburban garage for a couple of hours.

In free air, the 3015 (non-LF) reaches x-max at 60 Hz with about 250 watts input... ten times the wattage it takes to get there at 10 Hz. That's still too much sine-wave wattage, from a thermal standpoint.

The reason I would never recommend hooking a woofer up to a wall outlet (to break it in) is because of the thermal stress on the woofer. Sine waves are thermally brutal because the average power level is so much higher than the average with music. RMS power handling is either 2 or 3 times the sine-wave thermal power handling (I can't remember which), so if a woofer is rated at 450 watts (granted that's AES not RMS), I would never want to put anything approaching that much sine wave power into it for any longer than a brief burst. And 120 volts into 16 ohms (two 3015s in series) is 900 watts, imo likely to fry both woofers in a few minutes at most. By the time you smell it, it's been damaged... something has overheated.

AC vs woofers video clips (the series-wired pair of 3015s would last longer, but the end result would be the same):

 

[AstroSonic]

I watched an episode of 'Big Bang Theory' prior to checking on this thread. I was amused to realize that this thread has taken on a more than passing resemblance to that program. Well, it's all fun.