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Building a superior 2x10 cab

#81
SWR Triad.
I just checked the specs.
Any loudspeaker builder with knowledge will know that these crossover points are a hell to get working correct passively. Crossing over at 100hz and 5khz with a 15" and 10" will not get you to nirvana. And they dare to call it studio sound? I want to see that crossover......
I can sum up several points why this can (and will) not work properly. Sorry SWR.

One other thing that makes me......
These specs of the Goliath junior 4ohm cab: 105 dB SPL @ 1W1M (-3dB @ 45Hz and 15KHz)
So they say that with 1watt/1mtr they can generate 102dB at 45hz, ha, ha, ha.............(maybe when placed in the corner of a room)
That's what I mentioned earlier, the manufacturers don't show correct numbers......
 
#82
The Xmax will not reveal all geometrical properties that determine excursion related distortion, as two drivers with equal Xmax might behave totally differently due to the total length of gap and voice coil. Some expensive woofers have" inverted" or underhung gap/coil geometry and often perform far better in some areas. Power compression can certainly be audible, too, and some manufacturers go to extreme designs to deal with heat. Look at Volt for instance.
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+1
 
#85
If I'm going to use the B&C I probably will dampen the 5.2khz resonance peak with an LCR network, just to remove the "sharp edge".
I hope the bandwith (up to 7khz) is enough to get the "studio" basssound on stage.
Passinwind, how low do you cross them?
I'm going to use a crossover point of approx. 700hz.
 
#86
Arjank said:
If I'm going to use the B&C I probably will dampen the 5.2khz resonance peak with an LCR network, just to remove the "sharp edge".
I hope the bandwith (up to 7khz) is enough to get the "studio" basssound on stage.
Passinwind, how low do you cross them?
I'm going to use a crossover point of approx. 700hz.
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Currently I'm at 635Hz, LR-24, with a DSP speaker management system. I am crossing to a 15 though. I cross to the tweeter (BMS4552ND) at around 3.2K, so that peak is moot in my case. I've used both the B&C and the 18Sound 6 without tweeters on top, but I only like that OK for my fretless bass guitars (nice for distortion without undue harshness), and not so much at all for my electric upright. I don't play fretted bass at all, but when I've heard them though my rigs the 6 alone sounded pretty darned good to me. As always, hard to know what someone else will prefer...;)
 
#87
Currently I'm at 635Hz, LR-24, with a DSP speaker management system.
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Pretty steep, so it's protected pretty well.

I'm really summing up the plus and minuses of both the 6"driver or the 12" tractrixhorn. Because I still don't know which one to choose.

6" driver from 700hz and up:
+ better off-axis response at the crossoverpoint
+ takes less space
- cone breakup
- frequency range only up to 7000hz
- worse off-axis response above 1500hz
- maybe the sensitivity is not enough

12" tractrixhorn+driver from 1200hz and up:
+ better off-axis response above 1500hz
+ very uniform off-axis response above 1500hz because of the tractrixhorn
+ frequency range up to 16000hz(depends on driver)
+ no sensitivity problems
+ no cone breakup
- worse off-axis response at the crossoverpoint due to combfilter effects of the 2 10" woofers (I don't think we need to overrate this, a 2x10 with a crossoverpoint at 3.5khz is much, much, worse and most of us live with that)
- takes more space
 
#88
Arjank said:
...I'm really summing up the plus and minuses of both the 6"driver or the 12" tractrixhorn. Because I still don't know which one to choose.
Click to expand...

Only you can determine what exactly you want from this cab. Personally, I could care less for anything that goes even up to 7kHz, much less higher than that. But that's me. If you like a lot of top end above that yet, then the tractixhorn would probably suit you more.

I don't really find much useful content up that high, but most bass cabs that employ woofers/tweeters often leave a hole in the upper mids and leave the highs sounding rather harsh to my ear...which is why I wanted to use a dedicated mid driver as opposed to the woofer/tweeter. It sounds smoother to me, throughout the range I like to hear.

I built my two way cabs for kind of the same reason you are building yours...wanting more of a studio/less colored tone from the cabinet itself so I could hear pretty much the same tone I hear out of our PA. Not perfect really but the tone I get from my cab onstage sounds almost identical to the tone coming through the PA from my amp's DI. Of course we run our own PA and I have control over what comes out of the PA, but in instances where I've played with others and their PA I'm still getting similar tone. I don't think any cab is truly neutral or flat and all add some coloration, but I'm pretty happy with the two-way design.
 
#89
Arjank said:
I'm really summing up the plus and minuses of both the 6" driver or the 12" tractrixhorn. Because I still don't know which one to choose.
Click to expand...

Which best fills a niche that isn't being filled? Which would you choose to own? Which do you most strongly believe in? Strong - even passionate - belief is needed to get you over the obstacles that will arise.

If questions like that don't help, you might consider building competing prototypes.
 
#90
I would choose better behavior at the crossover point over better behavior at the upper octaves but that's just my opinion. It makes sense to me though that the smoothest transition possible (on and off axis) at the crossover would make the drivers a more cohesive unit and not sound like there are any holes in response off axis. The upper octaves, by comparison, don't seem to be as relevant for bass guitar reproduction.

You could always have the best of both worlds and go 3-way! :eyebrow:
 
#91
Arjank said:
Sundogue's approach keeps me thinking.
I did build something like that before (post #27) but the 5" drivers back then were not very sensitive.

But now I found this driver Link Removed
It looks like a good candidate, it's spl in the usable range (700 - 9000hz) is about 95-100dB. I would not use it below 700 because the distortion starts to rise. The Beyma 605nd also looks good, it has a slightly higher spl but it has more H3 distortion, bummer.
700hz is good because I (allmost) get the pointsource I'm after and I can (probably)keep an airinductor for the lowpass.....
Click to expand...

You may also want to check out the B&C 6PEV13-8. If you can make it work, IM me, as I have a couple sitting around the shop.

[Invalid or Expired Link Removed]
 
#92
I believe the most in the solution with the 12" tractrixhorn since I think that 1200hz will be low enough to have no audible effects at the crossover point in the real world. But, I wanna know for sure so I'm gonna make a testbaffle with these 2 woofers on it and measure them at 1mtr distance under different angles. The measurement point will be approx where the position of the tractrixhorn will be. With this test I can see the effects.

When the effects are audible I will dump the tractrixhorn idea and go for a 6" mid.

You may also want to check out the B&C 6PEV13-8. If you can make it work, IM me, as I have a couple sitting around the shop.

Invalid Link Removed
Click to expand...

I did see those, and they look like good candidates. But the best B&C is probably the 6MD38 (check at zaphaudio.com). According to Zaphaudio it's also better and has a bit higher sensitivity then the Beyma 6MI90.
 
#93
Gentlemen, since you are so knowledgeable and I know ZIP about this stuff, other than how to plug em in and calculate ohms, may i ask a question?

I am on a budget and ordered a Peavey Headliner 210 to add to my Traynor 115. Will the 210 have a crossover? It has no tweet, dont want one anyway! I don't expect it will have a xover since there is no tweet. I'm stupid.
 
#97
That makes sense
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It definitely does.
This way I could even drop the crossover point to approx 500hz. This is the only 2x10 construction that can give me a real point source with full range capabilities and a smooth off-axis response in all directions.
It will only cost me a 150 bucks extra, 100 for the coax and about 50 for the extra crossover components. Talking about crossover, this will get pretty tricky since I need to add two impedance correction LCR's to get the low pass of the woofers and the highpass of the 8" mid to work correctly. But I think it will be worth it.
The only thing is that I will loose about 2dB sensitivy because of the coax. That is, on-axis, off-axis I will loose less dB's because of the better dispersion. So the power response will be very good.
 
#98
Regarding mid without tweeter; There is a very noticable difference in sound if I turn down the tweeter in my 3-way cab that uses an Alpha 6 for mid. (HP filtered at about 400-500Hz, 12 dB/octave and no LP filter.) Even with an old Squier JV Precision + SD pickups, played fingerstyle, the sound is not quite right without the 3/8" horn. Eminence's specification seems right, the Alpha 6 does not put out a lot over 5 kHz.

edit:
There are better mids than the Alpha 6, though. But just like a good horn + driver combo, a better cone mid is also costly.
 
#99
Regarding mid without tweeter; There is a very noticable difference in sound if I turn down the tweeter in my 3-way cab that uses an Alpha 6 for mid. (HP filtered at about 400-500Hz, 12 dB/octave and no LP filter.) Even with an old Squier JV Precision + SD pickups, played fingerstyle, the sound is not quite right without the 3/8" horn.
Click to expand...

That's what I also thought myself, there are these small details in the sound that you will get not with a mid that goes up to 5-7khz. Maybe it's also because such a driver has a lot more "beaming" then a dedicated tweeter. This means that the power response(say 30 degrees off-axis) will drop significantly after about 3khz.
I emailed the Oberton distributor to see if they can make me a custom 8"coax thats based on the driver 8NM200 instead of the 8NB201. This will give me the extra sensitivity I need in the midband.
 
#100
Ok, the 6" mid will be off my list.
Now I have to choose between the coax or the tractrixhorn.
The tractrixhorn combo will have like 2dB more in the midband. But I think that will only be the case on-axis. The coax will have a slightly better power response.

So I think my choice is made, it's going to be a 3-way 2x10 with an 8"coax.

A custom coax is possible, but then I will have to buy 50 pcs :D
I'll stick with the "regular" Oberton coax. The bandpass filter will add a bit off extra sensitivity in the midband so I think I'll get the frequency response I want.
For those in the US, Oberton loudspeakers can be bought directly from the factory (they told me that)
 

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