Kappalite coaxials!!

[agedhorse]

Is there much of a difference in ideal box sizes or are they all similar requirements?

Much of this is due to the trade-offs made within the driver's design itself.

 

[PraiseBassing]

Much of this is due to the trade-offs made within the driver's design itself.

Right, what I was referring to was a reason someone may chose the CX over the others. I haven't done a lot of modeling for them, but it seems to maybe reach a little lower in a smaller box. Of course that's relative. If you lose 3 dB from the beginning, you can be behind already where that more efficient speaker has more potential to catch up, or surpass. Interested to see Eminence's Box design's when published to see thermal and mechanical limit numbers.

 

[5StringPocket]

I have built 212 cabs with both the 3012HO and KL3012CX drivers. Being from the same Eminence family their voicing is pretty similar. The 3012HO is a bit louder in the mids but not as much as the graphs might suggest. For a 4-string tuned to low E either driver is a good choice, but for basses tuned to low B the KL3012CX offers substantial improvement in low end response. This comes from the CX having a larger X-max (7.47 vs 6.2 mm) and lower resonant frequency (Fs 42 vs 51.5 Hz). All my basses are 5-string with low B and I've been very pleased with the dual KL3012CX cabinet and an 800 watt amp.

 

[5StringPocket]

Awesome work as usual! Very interested in your thoughts on the CX15 vs your CX212 cab.

The voicing is a bit different between the two as can be seen by their RTA frequency responses. The 3015CX has more pronounce upper bass and a mid dip around 400 Hz which gives it a more vintage vibe while the 3012CX has a mid hump around 3500 Hz which makes it sound brighter. The 212 is louder (no surprise) with two vertically arranged drivers but the 115 would definitely bring more than a 112. The 15 degree tilt-back on the upper 212 driver noticeably improves vertical dispersion when standing about 5 feet back from the cab.

Here is a gratuitous pic of the 115/212 stack. Don't know when I'd actually need to use this but the Forte HP headroom is intoxicating.

 

[3rdcurve]

The voicing is a bit different between the two as can be seen by their RTA frequency responses. The 3015CX has more pronounce upper bass and a mid dip around 400 Hz which gives it a more vintage vibe while the 3012CX has a mid hump around 3500 Hz which makes it sound brighter. The 212 is louder (no surprise) with two vertically arranged drivers but the 115 would definitely bring more than a 112. The 15 degree tilt-back on the upper 212 driver noticeably improves vertical dispersion when standing about 5 feet back from the cab.
View attachment 3735132
View attachment 3735133
Here is a gratuitous pic of the 115/212 stack. Don't know when I'd actually need to use this but the Forte HP headroom is intoxicating.
View attachment 3735147

Oh man, that stack would crush! How do you like the HP vs the WD-800? I currently have a WD and a BB800, and have been thinking about moving one to pick up an HP.

 

[5StringPocket]

I used to have the BB800 and much prefer the WD800. I'd move the BB800 and invest in the HP. So many good tones on tap...

 

[agedhorse]

There's something wrong with the low end of those RTA curves, either boundary contributions or low frequency noise because there's no way the speaker represented by the bottom curve is only (~) -7dB below 32Hz, the shape and slope of the bottom is wrong.

 

[5StringPocket]

These are just simple at home RTA snapshots from my iPhone. I'm sure there are boundary conditions and other imperfections. My Eminence Designer models show -10dB at 42.7 Hz for the 3012CX and at 40.0 Hz for the 3015CX. I don't put credence in most measurements below 40 Hz. They are difficult to measure accurately. I'm more interested in 50-8000 and always use a HPF to keep the low end tight but like it full. What's impressive is that neither driver is excursion limited at 40 Hz at full rated power. Fartout is not a problem and they appear to be thermally rather than excursion limited.

 

[agedhorse]

Anything measurement-wise below 200Hz is a challenge. I was pointing this out so the guys who are "positive" they can beat well designed commercial products and get -10dB at 20Hz performance based on an inaccurate measurement don't get too excited about the prospects of gaming the system.

A true half-space measurement (without additional boundaries or room gain) is what most (honest) commercial speakers are based upon. This is generally accomplished outdoors or in an anechoic chamber with reasonable agreement to (well modeled) predicted response. If there's not agreement, something is wrong with either the measurement or the model.

 

[kringle77]

5stringpocket, great job on rhose cabs, they look like real gig machines. The 2x12 looks like a similar voicing to the barefaced supertwin. The 15' driver looks like a bagend sort of voicing. Id like either, but probably prefer the15.

 

[5StringPocket]

I bought a DATS v3 from Parts Express and used a speakon adapter to run impedance sweeps on several of my DIY cabs to verify tuning frequency. The KL3012CX slant twin was 48.4 Hz which agreed with the Boxsim model as expected. The KL3015CX single was 42.7 Hz with the ports open and 65.7 Hz with the ports plugged. It’s a guess how much damping to account for in Eminence designer and Boxsim. This DATS v3 is a handy tool to get an accurate value.

 

[DonaldR]

I have an old (but in great condition) Peavey 1516 bass cab. I also play guitar with a modeller (Avid Eleven Rack) and was thinking changing the speakers in the cab and create an (almost) FRFR.
The cab has 1x15" 4ohms Black Widow and 2x8" Scorpions connected to passive crossover. Would it be better to:
1- Upgrade the 15" with a coaxial Kappalite and keep the 2x8"?
2- Leave the 15" Black Widow and upgrade the 2x8" with one coaxial Beta 8CX" and one Beta 8A?
3- Forget about it
Was thinking of using a Crown XLS1500 and using one side for the 15" and the other side for the 2x8", using the active crossover in the Crown.

Edit: Forget to say that internally the 15" and the 2x8" are in there own enclosure.

 

[agedhorse]

What about leaving it as it is?

 

[DonaldR]

Because it's missing some high when playing guitar and not enough money to buy an Accugroove Latte (around $2000CAD + $500CAD shipping).

 

[SeayBass]

I recommend option 3. The 1516 is an iconic Peavey cab with a unique tone profile. It ain't broke so don't fix it.
On the other hand speaker building and modding and designing is an awesome fun hobby that will occupy your attention through this global pandemic and beyond. If you want flat response, find a proven design and build that instead of retro fitting a cab that was never intended to be FRFR.

sell the peavey and use that money to support your speaker building habit

 

[agedhorse]

Agreed, you will be better off finding a cabinet that you can try out to see how it works for your more unique needs.

Otherwise, everything is just a guess and nothing more.

 

[DonaldR]

Thanks @SeayBass and @agedhorse. Don't have the talent to build a cab, that's why I was looking to mod the 1516 as the sound was more toward FRFR (or at least way more usable for guitar modeller) than expected.
Will sell the Peavey cab, my Peavey head and take that money probably toward a Tech21 Power Engine.

 

[SeayBass]

that's a good one. Headrush 112 is probably the cheapest. You could buy one of those at guitar center using their 30 return as a trial period. It will demo the FRFR thing. I have a friend who did that- it worked great for his modeler thing. But then he decided he didn't want to be in a modeler all the time, so back it went, and he's back on his conventional genz benz shuttle combo still killin @agedhorse

 

[DonaldR]

I already have an FRFR setup: EV ZLX12P top with EV ZXA1 sub. Working very well, but 2 components instead of one and ugly as hell as a backline.

 

[DonaldR]

Maybe I will try replacing one of the Scorpion 8" with an Eminence Beta CX8 with a tweeter just for fun (if I can find a used one in my area).