Kappalite 3012LF vs. Delta 12LFA (please help)

[hobbes1]

Hobbes,

Given the pieces you have to work with perhaps it's worth looking at this a little differently. You would like better performance in the mid and deep bass than you are getting with the SB112. To accomplish this you have a 1.5 cf vented box, and the SB112: a 3 cf vented box with a oem version of the deltalite 2512, and a crossover (HP only?) and horn tweeter. Why not put the 2512 in the 1.5 cf box and look for a better performing driver in the 3 cf box (and probably retune). The improved performance you are looking for can be had from several available drivers in a 3 cf cab. Not sure how the OEM deltalite 2512 will perform in the 1.5 cf box, but a top quality driver in the 3 cf box may not even require the additional (1.5 cf) cab anyway.

Re: the sensitivity of the OEM driver. Given it's extended voice coil and (assumed) use of the same magnetic structure and magnet, its sensitivity MUST be lower than the standard driver. Based on the Eminence data sheet, it looks like around 97-98 db/w/m below the gradual 8db rise in the top of its range (above 1kHz). The OEM driver 'may' meet the claimed 98db if the spec is based on the sensitivity at the top of that rise. Otherwise, the OEM driver is likely closer to 90-93db/w/m (in the 200-1000Hz range).

Thanks AstroSonic. You make a valid point about that with swapping speakers. Dave at Avatar had told me that they "bring in the tweeter at 3900 Hz" but not sure what sort of crossover magic happens there.
So funny yet aggravating that every avenue of approach in speaker cab modding starts sprouting side trails of opportunity. Makes my mind cramp a little
Thanks for your help though, much appreciated!

 

[hobbes1]

I was emailing with Jerry McNutt at Eminence about the ports and tuning. He agreed that if use tom 1"x2" lumber to partially block off the port, I could change the cab tuning to be more in line with the published Kappalite 3012LF Med Vented Design cab on the Eminence website. At that point, I would think I'd have the best I could get out of that cab and that speaker and it would then be a matter of whether the amount of low end reinforcement at 250 watts (limited due to the max recommended for the Avatar SB112) into the Kappalite would be enough for me. Obviosly, the KL would be able to handle much more power but would be limited by the Avatar cab.

 

[bgavin]

Right at home, but will it meet the OP's goal of adding some tight low end to the SB112... It's not about differing driver sizes, but about differing amplitude and phase response, and dispersion.

The tightest vented response comes from the BB4/SBB4 group of alignments.
The price paid for this tighter bass response is a higher roll-off frequency and less bass extension than Flat or EBS.
The opposite of SBB4 is EBS where the cabinet volume is typically 150% that of Flat.
Then there is the corresponding flabby bass, reduced power handling and shelved response that is characteristic of EBS alignments.

In keeping with the OP requirement of tight bass, 1.5 cubic feet and 12" drivers, this leaves 3012LF in 1.69 cu.ft. as the obvious choice in Eminence drivers.

As to phase, etc, any dissimilar drivers overlapping in the frequency range will smear to some degree.
At low frequencies, this won't be readily heard.
If the OP is particular, bi-amping avoids the smearing and allows for individual gain control over Lows and Highs.

 

[hobbes1]

In keeping with the OP requirement of tight bass, 1.5 cubic feet and 12" drivers, this leaves 3012LF in 1.69 cu.ft. as the obvious choice in Eminence drivers.

As to phase, etc, any dissimilar drivers overlapping in the frequency range will smear to some degree.
At low frequencies, this won't be readily heard.
If the OP is particular, bi-amping avoids the smearing and allows for individual gain control over Lows and Highs.

bgavin: the 1.69cu ft. is nearly identical to the Med Vent box design on the Eminence website for Kappalite 3012LF (they specify 1.6 cu.ft).
Bi-amping isn't something I'd want to get into at this point (just want to stick with my Shuttle 6.0), so would have to see how much smearing there might be and whether or not it's unacceptable. Thanks for your thoughts.

 

[bgavin]

OP, your original post complained about 12LFa being too "middy".
Running this driver in 1.5 cubic feet net, at Fob=55 Hz, produces a pronounced hump at 100 Hz with an F3 around 60 Hz.

1.5 cubic feet is quite small for this driver, hence the hump.
If you want to experiment with the existing box, consider stuffing it with fiber fill (pillow stuffing) from a fabric shop.
1 pound stuffing per cubic foot, so 1.5 pounds stuffing.

Isothermal stuffing could raise your effective net volume to 1.8~2.1 cubic feet.
Stuffing will have to be kept out of the vent, and done with an RTA so you can see the effect and tuning changes.

You will still have the hump, but it will center lower at 80 Hz.
The 12LFa driver does not like small boxes, and always has a hump with BB4 tuning.
If you want 12LFa's full bass extension, move up to 4 cubic feet tuned at 44 Hz for Flat tuning.

You cannot stuff Dolly Parton into a "B" without a hump somewhere.
The 4012HO or 3012LF will give you more bass extension, and less mid-hump in this small box.

 

[ThisBass]

OP, your original post complained about 12LFa being too "middy".
Running this driver in 1.5 cubic feet net, at Fob=55 Hz, produces a pronounced hump at 100 Hz with an F3 around 60 Hz.

I would not tell that the hump is pronounced.
The modeling shows +1.5dB for the hump. That is nothing to talk home about.

There are some prof cab designers in the EU who consider those humps (appro +3dB) as a welcome benefit to accent the bass reinforcement.
Those humps are shown mostly by some eminence speakers.

So I would never point out that a little hump qualifies a speaker to remain out off small cab applications.


Modelings are nice tools but those tools cant reflect exactly the audible difference of different tunings.
Its a good idea to make at first a roughly estimation for the tuning. Lets say appro 55Hz.

The second step shall be different audio samples with different tunings. Lets say 50Hz vers 55 Hz vers 60Hz.
Probably the truth for the tuning is somewhere in the scale of 50..60Hz.

There are significant signs that are audible if the tuning is right ore wrong.

Tuning to low: audible lack in bass reinforcement and very tight precision
Tuning to high: boomy sound and audible lack in precision.

Tiuning at the sweet spot: balanced bass reinforcement and plausible precision.

 

[will33]

Some limited specs and commentary on the Avatar OEM Deltalites in this old thread for a little modeling/comparison.

http://www.talkbass.com/forum/f15/deltalite-version-i-vs-ii-800371/

I have some in 4ohm. Contemplating running a pair of them <400-500hz under a guitar driver...

 

[hobbes1]

OP, your original post complained about 12LFa being too "middy".
Running this driver in 1.5 cubic feet net, at Fob=55 Hz, produces a pronounced hump at 100 Hz with an F3 around 60 Hz.

1.5 cubic feet is quite small for this driver, hence the hump.
If you want to experiment with the existing box, consider stuffing it with fiber fill (pillow stuffing) from a fabric shop.
1 pound stuffing per cubic foot, so 1.5 pounds stuffing.

Isothermal stuffing could raise your effective net volume to 1.8~2.1 cubic feet.
Stuffing will have to be kept out of the vent, and done with an RTA so you can see the effect and tuning changes.

You will still have the hump, but it will center lower at 80 Hz.
The 12LFa driver does not like small boxes, and always has a hump with BB4 tuning.
If you want 12LFa's full bass extension, move up to 4 cubic feet tuned at 44 Hz for Flat tuning.

You cannot stuff Dolly Parton into a "B" without a hump somewhere.
The 4012HO or 3012LF will give you more bass extension, and less mid-hump in this small box.

Hey, actually, I was complaining that the Delta Pro 12a was too middy. Not the Delta 12LFA. I was trying to determine between the 12LFA and the KL 3012LF which would be the better fit in my existing 1.5 cu ft cab. The cab is lined with fabric batting on all sides (not the port) and it's about 1 inch thick.

 

[ThisBass]

Hey, actually, I was complaining that the Delta Pro 12a was too middy. Not the Delta 12LFA. I was trying to determine between the 12LFA and the KL 3012LF which would be the better fit in my existing 1.5 cu ft cab. The cab is lined with fabric batting on all sides (not the port) and it's about 1 inch thick.

I performed a modeling with extended frequency response.

The Delta shows a clear audible mid scoop around 500Hz and an audible resonant peak at 2kHz. Beyond 3kHz there is nothing to discuss.
So the total of sound should be a bit mid scooped with an accent at 2kHz but also a damped top end.

The KL shows a flat lined response and a peak at 1.5kHz.
Beyond 2 kHz the response shuts down.

If the Delta is too middy for your taste so the KL will probably do that middy sound all the more.


The response of the Delta looks not so bad. Some hump around 100Hz combined with some mid scoop should provide a nice vintage colering. Just this moment I don't have an exact imaginary how the resonant peak at 2kHz deals with the roll off at 3kHz but probably this sound equals to a passive instrument where tone blend is turned to the off position a little bit.

In total I point out that the Delta isnt a speaker that prefers strong accent at the mid band.
May be your Delta lacks off in performance due to some damage of the voice coil.
Damage of the voice coil very often impacts the performance of the frequency response.

 

[hobbes1]

I'm talking about the Delta Pro 12a being middy...this is not the same as the Delta 12LF...which Delta are you modeling? Looking again at the graphs on the Eminence site, I think you guys are talking about the wrong speaker here. I already have the Delta Pro 12a NOT the DELTA 12LFA (two very different speakers).

 

[ThisBass]

I'm talking about the Delta Pro 12a being middy...this is not the same as the Delta 12LF...which Delta are you modeling? Looking again at the graphs on the Eminence site, I think you guys are talking about the wrong speaker here. I already have the Delta Pro 12a NOT the DELTA 12LFA (two very different speakers).

Try to give the Delta pro 12a a fb tuning around 60..65Hz.

55Hz would be a bit too low (to my taste) and would give more accent to the low mids.

By the other hand take care with high fb tunings like 60..65Hz combined with 5-strings and EQ settings.

 

[hobbes1]

Hi ThisBass. Yes, I play 5 string active bass all the time. This is mainly why I want a subwoofer to reinforce the low end. I don't want to go with a higher tuning or use the Delta Pro 12a. It's spectrum of sound goes up to almost 5KHz...I have that covered with the Avatar and want more on the low end, hence the 3012LF or Delta 12LFA. ultimately, given what I have to work with (cabinet) you would agree that the 3012LF is the best choice (although it will not be perfect)?

 

[ThisBass]

Hi ThisBass. Yes, I play 5 string active bass all the time. This is mainly why I want a subwoofer to reinforce the low end. I don't want to go with a higher tuning or use the Delta Pro 12a. It's spectrum of sound goes up to almost 5KHz...I have that covered with the Avatar and want more on the low end, hence the 3012LF or Delta 12LFA. ultimately, given what I have to work with (cabinet) you would agree that the 3012LF is the best choice (although it will not be perfect)?

The 3012LF works best for sub applications. This speaker isnt meant to be used in full range applications.
The frequency response cuts off everything beyond 2kHz. Thats a full octave missing compared to your delta.

I think I know what you are asking for. Playing the Low B lacks lacks a bit of the feeling of fundamental frequency response.

There are some 12s speakers on the market with a comparable performance like the 3012LF but extended frequency response at the top end.

I myself use this one:
Link Removed
fb 55Hz at 1,5 cu ft should give you what you are looking for.

As far as I know this speaker is out of production in the meanwhile but never the less should be still in stock at some stores.

 

[will33]

IMO, your 1.5 cu.ft. box isn't big enough to get real bass extension even out of these drivers that are capable of giving it in a suitable box.

IMO, the Kappalite is way too expensive to be putting in a box not purposely designed for it. The D12LF, tuned with a midbass hump would add perceived bass to your overall sound and do it without blowing a bunch of money on a premium driver only to neuter it.

Once the cost gets above what you could find another Avatar 112 for, getting another Avatar makes more sense. You'd have twice the drivers running, without any mix/match crapshoots, and they'd better handle adding in some more lows (or better cutting a little upper mid to bias the sound towards the bassy side.

 

[ThisBass]

IMO, your 1.5 cu.ft. box isn't big enough to get real bass extension even out of these drivers that are capable of giving it in a suitable box.

Link Removed
This speaker is designed to work very well in small cab designs.

fb 55Hz at 1.5 cu ft gives F3=58Hz.

In general I suggest linear response for the 2nd Harmonic which means F3 around >50Hz for the B-string.
But this means a 212 cab at least if the speakers shall be used as a full range application.

 

[ThisBass]

Once the cost gets above what you could find another Avatar 112 for, getting another Avatar makes more sense.

May be you are right.
Charging appro $200 into one single speaker must to be a deliberate choice anyway.

 

[bgavin]

I'm talking about the Delta Pro 12a being middy...

I looked at the heading of the message...
Kappalite 3012LF vs. Delta 12LFA (please help)

Then looked at charts...
The Delta 12 LFA curve

Then various posts from members:

Charlie:
The curves you need to look at are mainly Max SPL and Max Power. Here's a (very) quick and dirty comparison of Max SPL, purple is KL3012LF and green is D12LF, both in 1.5cu ft and tuned to 55Hz:

RPSands:
Hell, this guy is cheaper than the eminence 12LFA by a ton and comparable in the lows...

* * *

As you can see above, this is where I was operating on 12LFa being the topic of conversation.

 

[Minussss3db]

The Dayton Audio ST305-8 12" Series II Woofer Link" $95
[Invalid or Expired Link Removed]

and spec sheet here:
Invalid Link Removed

is likely going to give you a good solid thump in that 1.5cuft box, yes is a little less sensitive, but has a natural +2.5 hump in 50-70hz region which puts it very close.
It does not have too much high end, rolling off at 1.5khz or so....
Xmax = 8 mm /275w
Fs = 30hz
Qts = .35
Vas = 128L/4.52cuft

it comes in Fb = 42 hz, f-3db = 52hz

port Diam = 3.5"id, 7.125"length...

this is very close to what you want: I think if you ask one of the other posters with better software than me to get you an SBB4 solid hitting alignment for you ...I think it is close to possible in this box. You would have to as before, close the existing port, use a hole saw to cut a new port, but you would be close.

Good Luck,
-3db

And I really want to acknowledge Astrosonix for really thinking "out of the Box"...yes

 

[hobbes1]

I looked at the heading of the message...
Kappalite 3012LF vs. Delta 12LFA (please help)

Then looked at charts...
The Delta 12 LFA curve

Then various posts from members:

Charlie:
The curves you need to look at are mainly Max SPL and Max Power. Here's a (very) quick and dirty comparison of Max SPL, purple is KL3012LF and green is D12LF, both in 1.5cu ft and tuned to 55Hz:

RPSands:
Hell, this guy is cheaper than the eminence 12LFA by a ton and comparable in the lows...

* * *

As you can see above, this is where I was operating on 12LFa being the topic of conversation.

[/QUOTE]OP, your original post complained about 12LFa being too "middy".
Running this driver in 1.5 cubic feet net, at Fob=55 Hz, produces a pronounced hump at 100 Hz with an F3 around 60 Hz. [/QUOTE]


hey, it's all good. but the second sentence of my original post is where i specifically called out the delta pro 12a as the problem (being too "middy"). seems to me you misinterpreted my meaning the delta 12lfa as being too middy. not the case at all. i've not tried the 12lfa yet and seeking opinions. hence me soliciting opinions as to which of the two (KL 3012LF and Delta 12LFA) would be best.
i do appreciate your input though

 

[hobbes1]

The Dayton Audio ST305-8 12" Series II Woofer Link" $95
[Invalid or Expired Link Removed]

and spec sheet here:
Invalid Link Removed

is likely going to give you a good solid thump in that 1.5cuft box, yes is a little less sensitive, but has a natural +2.5 hump in 50-70hz region which puts it very close.
It does not have too much high end, rolling off at 1.5khz or so....
Xmax = 8 mm /275w
Fs = 30hz
Qts = .35
Vas = 128L/4.52cuft

it comes in Fb = 42 hz, f-3db = 52hz

port Diam = 3.5"id, 7.125"length...

this is very close to what you want: I think if you ask one of the other posters with better software than me to get you an SBB4 solid hitting alignment for you ...I think it is close to possible in this box. You would have to as before, close the existing port, use a hole saw to cut a new port, but you would be close.

Good Luck,
-3db

And I really want to acknowledge Astrosonix for really thinking "out of the Box"...yes

yes, i will consider that one too
as far as port, I could block off the existing port and thus modify it to being close to that dimension....
Thanks for your thoughts