Question about discontinued Bag End cabs

[Papazita]

I'm looking into a pair of older used D12E-D ELF cabs that came up for sale near me.
The ELF series has been discontinued by Bag End, and the cabinets do not come with the external ELF processor.
Is the external ELF processor (ELF-1/M/M2) required for the ELF series cabinets? Can the cabinets be used without the processor?

 

[Wasnex]

I'm looking into a pair of older used D12E-D ELF cabs that came up for sale near me.
The ELF series has been discontinued by Bag End, and the cabinets do not come with the external ELF processor.
Is the external ELF processor (ELF-1/M/M2) required for the ELF series cabinets? Can the cabinets be used without the processor?

ELF is not discontinued....years ago it was renamed INFRA. The ELF 1 processor has been discontinued for quite some while now, but I believe you can still buy the INFRA MXB or a Kairos KS26.

You could use the cab without a processor but it won't perform properly. The cab will roll off at 12dB per octave below about 80hz. Bag End uses a device called a Dual Integrator to create a 12dB per octave boost so the response remains flat.

The consequence of this strategy is the efficiency decreases by 12dB per octave below about 80hz. So while the cab may be theoretically flat to 8hz, it can not produce significant output in the lowest range, unless you have a lot of cabs and amps.

The spec sheet for the D12E is here: [Invalid or Expired Link Removed]

Relevant Specs:​

Sensitivity:
96 dB SPL @ 80 Hz (2.83 V @ 1 m)
Frequency Response:
60 Hz to 250 Hz ±3 dB
8 Hz to 95 Hz ±3 dB with external Infra™ integrator
Low Frequency Limit:
8 Hz
Maximum Calculated Continuous Acoustic Output: Half Space @ 1 Meter
10 Hz - 88 dBSPL
20 Hz - 100 dBSPL
40 Hz - 112 dBSPL
80 Hz - 123 dBSPL
Power Handling:
400 W continuous (AES)
800 W program
Recommended Amplifier Power:
400 to 800 W at rated impedance

If you are interested, you can still read the ELF white paper here: ELF-GUIDE-COMPLETE-V-1.3.pdf (bagend.com)

Years ago, I spec'ed a system with four compact ELF 18" subs. The compact version were about half as deep as the standard ELF 18. Each cab received 400W from a QSC PL 1.8. I chose them because I was designing a compact system to travel in a 7 passenger Learjet.

We only carried two of the subs in the jet.

When I configured the system I believe I cut off the subs at about 40hz. Running them lower seemed to reduce headroom too much and introduce audible, nasty sound artifacts. The system did sound pretty good, but the lows were not particularly powerful or loud.

If I did not specifically require very compact subs, I would have been better off with traditional ported cabs. In my experience, even a pair of fairly low quality ported subs will easily outperform the four ELF 18s. They may not necessarily sound better, but they will get way louder unless you buy absolute junk.

My advice is pass on the ELF cab, unless it suits some unique need.

 

[Wasnex]

FYI, per the specs, calculated SPL at 10hz is 88dB. I believe this puts the sensitivity at 10hz at about 61dB 1W/1m. This is 35dB lower than the sensitivity at 80hz, which is 96dB 1W/1m.

 

[BasturdBlaster]

Thank you Wasnex for your input, I've been curious as well about these cabs as I see a variety of used one's available locally, hehe
I believe all the "elf" cabs are sealed too vs.
the rear ported non-elf type IIRC

 

[Wasnex]

Thank you Wasnex for your input, I've been curious as well about these cabs as I see a variety of used one's available locally, hehe
I believe all the "elf" cabs are sealed too vs.
the rear ported non-elf type IIRC

AFAIK, all of the ELF/INFRA cabs are sealed. Sealed cabs roll off at 12dB per octave below resonance. This is a key characteristic of how the cabs operate and why the same processor can be used with all of them. The Dual Integrator provides a 12dB per octave boost, to compensate for the 12dB per octave roll off.

 

[BasturdBlaster]

So... what would the integrator sound like with the ported cabs?, hehe

 

[Wasnex]

@BasturdBlaster

Just checked the spec sheet for the S18E and Quartz-R subs. S18E is one 18 in a sealed 3 cubic ft box. The Quartz was four 18s in four separate 3 cubic ft sealed chambers.

Never heard a Quartz personally, but the review I read years ago suggested a pair with adequate power would bring down ceiling tiles. Then again, each cab weighed 237 lbs.

 

[Papazita]

Thanks for the replies! I think I will be passing on those 2 I'm looking at.

 

[BadJazz]

@BasturdBlaster

Just checked the spec sheet for the S18E and Quartz-R subs. S18E is one 18 in a sealed 3 cubic ft box. The Quartz was four 18s in four separate 3 cubic ft sealed chambers.

Never heard a Quartz personally, but the review I read years ago suggested a pair with adequate power would bring down ceiling tiles. Then again, each cab weighed 237 lbs.

Pffft. Amateurs!

 

[J.Wolf]

Pffft. Amateurs!

View attachment 4926111

I think "Assault" is the operative word here. lol. Four 21's with infra processing to boost subharmonic content? I guess it's cheaper than a surgical bowel resection.

I was always curious about the ELF stuff from a conceptual standpoint, but honestly, spent enough time with the ported Bag End 15 and 18 "big cabs" which were substantially deeper sounding than the cubes with the same drivers that I cant imagine any more low end could be needed, appreciated or achieved (for electric bass) than what those things put out. I really liked the S15B-D cabs, which was still quick, but had a really nice pillowy low end, compared to the much more punchy and iconic S15D cab.

 

[Mike Marshall]

ELF is not discontinued....years ago it was renamed INFRA. The ELF 1 processor has been discontinued for quite some while now, but I believe you can still buy the INFRA MXB or a Kairos KS26.

You could use the cab without a processor but it won't perform properly. The cab will roll off at 12dB per octave below about 80hz. Bag End uses a device called a Dual Integrator to create a 12dB per octave boost so the response remains flat.

The consequence of this strategy is the efficiency decreases by 12dB per octave below about 80hz. So while the cab may be theoretically flat to 8hz, it can not produce significant output in the lowest range, unless you have a lot of cabs and amps.

The spec sheet for the D12E is here: [Invalid or Expired Link Removed]

Relevant Specs:​

Sensitivity:
96 dB SPL @ 80 Hz (2.83 V @ 1 m)
Frequency Response:
60 Hz to 250 Hz ±3 dB
8 Hz to 95 Hz ±3 dB with external Infra™ integrator
Low Frequency Limit:
8 Hz
Maximum Calculated Continuous Acoustic Output: Half Space @ 1 Meter
10 Hz - 88 dBSPL
20 Hz - 100 dBSPL
40 Hz - 112 dBSPL
80 Hz - 123 dBSPL
Power Handling:
400 W continuous (AES)
800 W program
Recommended Amplifier Power:
400 to 800 W at rated impedance

If you are interested, you can still read the ELF white paper here: ELF-GUIDE-COMPLETE-V-1.3.pdf (bagend.com)

Years ago, I spec'ed a system with four compact ELF 18" subs. The compact version were about half as deep as the standard ELF 18. Each cab received 400W from a QSC PL 1.8. I chose them because I was designing a compact system to travel in a 7 passenger Learjet.
View attachment 4925744
We only carried two of the subs in the jet.

When I configured the system I believe I cut off the subs at about 40hz. Running them lower seemed to reduce headroom too much and introduce audible, nasty sound artifacts. The system did sound pretty good, but the lows were not particularly powerful or loud.

If I did not specifically require very compact subs, I would have been better off with traditional ported cabs. In my experience, even a pair of fairly low quality ported subs will easily outperform the four ELF 18s. They may not necessarily sound better, but they will get way louder unless you buy absolute junk.

My advice is pass on the ELF cab, unless it suits some unique need.

As a long time Bag End user I have never used any of the ELF products I was under the impression they were for sound systems in theaters. I prefer a cabinet that is neutral sounding as possible and their 15" cabinets are perfect for that.

 

[brianrost]

Cool...nothing above 50 Hz!!! No need for D and G strings....

 

[bigthemat]

hey thanks for the info. I inherited two bag end cabs and that ELF device and have had no clue how to use it or what it is all for. I was hoping to use the cabs by themselves but looks like that's a no go. Is it easy/feasible to hook up the elf to an amp?

 

[Wasnex]

hey thanks for the info. I inherited two bag end cabs and that ELF device and have had no clue how to use it or what it is all for. I was hoping to use the cabs by themselves but looks like that's a no go. Is it easy/feasible to hook up the elf to an amp?

The processor is normally used to drive a power amp. You could probably run it in an effects loop of a bass amp, but the ELF/INFRA cabs are intended as subs only, so you probably won't like the results.

The ELF/INFRA processor is intended for biamp applications. So it will have a low output for the subs, and also a mid/high output.

 

[fdeck]

When I was first learning about speakers, there was a design type called equalized reflex, which was a fairly conventional speaker with an electronic filter that flattened its response. Also, integrator would be the correct term for the mathematical equivalent of a filter that produces such a correction below the cutoff of a typical speaker. It's a dual integrator because a single integrator produces a 6 dB/octave slope.

I think the original Bose 901 was an equalized reflex.

The drawback is that once a speaker is flattened in this way, the maximum SPL at the lowest frequency becomes the maximum SPL for the entire system. So it's a way to get low end reproduction, but not a free lunch in terms of the Iron Law.

 

[winston]

I've owned both the big and little Bag End 15" cabs, plus I worked for a PA company with a Bag End ELF system.

tl;dr - ELF/INFRA is overkill for a bass rig unless you are playing large stages or maybe doing live electronic music with DJs. Sound people will (justifiably!) hate you for putting that much low end on stage, especially indoors on smaller wooden stages. They really do go flat down to 8 or 18hz.

The ELF/INFRA stuff is truly game-changing in terms of getting deep low TIGHT bass because you're using sealed cabs operating below the cabs' resonant peaks, there's no phase shifting because ELF/INFRA isn't a filter, and the low end Concealment is brilliant (rather than a brickwall limiter, they dynamically raise the low cutoff frequency). No other system at the time (early 2000s) came close to the low end - and I'm talking vs. actual world-class Meyer Sound, Adamson, Martin, TurboSound (pre-Behringer) systems I heard up close let alone pro-sumer QSC, JBL, EV, Genz Benz rigs other sound companies ran.

And because they ELF/INFRA uses sealed cabs operating below resonant frequency, they are extremely inefficient. For small gigs we never went below 2 18 cubes per side, on big ones we had maybe 6-8 of the single 18 cubes per side and sometimes added 2 of the 4x18 boxes (the mini Bassault, either the Quartz or Crystal) fed by multiple banks of QSC power amps. I'll also say that I was never as crazy about the Bag End mid/high components, they sounded excellent - but not quite as sweet as the Meyer Sound stuff up top.

 

[winston]

@fdeck - interesting about the Bose equalized reflex. Around the same time I worked on the ELF rig, I played in a mostly acoustic gypsy ethno-jazz combo. The best sound we ever got was at a gig with two Bose 802s plus 2 or 4 Bag End ELF 18s per side. Smooth and deep, just like the band but louder.

 

[agedhorse]

How is the integrator not a filter? An integrator and differentiator are both filters:
Here's an integrator bode plot, it's a low pass filter with continuous slope and a 90 degree phase shift.

 

[agedhorse]

When I was first learning about speakers, there was a design type called equalized reflex, which was a fairly conventional speaker with an electronic filter that flattened its response. Also, integrator would be the correct term for the mathematical equivalent of a filter that produces such a correction below the cutoff of a typical speaker. It's a dual integrator because a single integrator produces a 6 dB/octave slope.

I think the original Bose 901 was an equalized reflex.

The drawback is that once a speaker is flattened in this way, the maximum SPL at the lowest frequency becomes the maximum SPL for the entire system. So it's a way to get low end reproduction, but not a free lunch in terms of the Iron Law.

I have used this concept to some degree over the past 30+ years in processing driving reflex designs, combined with high pass filters. There is no free lunch for sure, but with the right compromises the results are often a clear net improvement for most players.

 

[Wasnex]

When I was first learning about speakers, there was a design type called equalized reflex, which was a fairly conventional speaker with an electronic filter that flattened its response. Also, integrator would be the correct term for the mathematical equivalent of a filter that produces such a correction below the cutoff of a typical speaker. It's a dual integrator because a single integrator produces a 6 dB/octave slope.

I think the original Bose 901 was an equalized reflex.

The drawback is that once a speaker is flattened in this way, the maximum SPL at the lowest frequency becomes the maximum SPL for the entire system. So it's a way to get low end reproduction, but not a free lunch in terms of the Iron Law.

I don't remember if the 901 processor equalized the low end. I am pretty sure it equalized the highs.

The EV TL cabs in stepdown mode required 6dB of corrective EQ for flat response.

Pretty sure EV used to publish plans so you could roll your own. They also made various processors that could be configured to provide the proper boost at various frequencies.