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Low Down Sound 15/6.5 Cab
- Thread starter KJung
- Start date
Chef
In Memoriam
billfitzmaurice
Commercial User
- Sep 15, 2004
- 16,860
- 278
- 76
- Disclosures
- Owner, Bill Fitzmaurice Loudspeaker Design
Just my preference. I originally wanted the ports to go all the way down on both sides but Don said it's too much port area. He suggested closing off the middle area. I wanted ports up high too for the sub lows that come out of the port. I wanted pant flap and back flap which I think I/we achieved.
He reminded me that this was actually GB's X Port design on their 212V and has been wanting to do it for a while.
So far I'm diggin' the L pad just past noon for the mid, and I'm not a treble rebel. Perhaps the cab is tuned lower (41hz I believe) with more cu vol and that's why I'm able to turn up the mid past the 10:00 Ken stated he preferred.
The construction is top shelf as you already know from 1st hand experience Chef. The horizontal port shelf's just happen to add "free" bracing to the cab.
It feels very light weight for 50lbs. I need another one turned upside-down on top.
I actually wanted the cab to be 20.75". Don told me the ports would be too narrow with this width for this design. He suggested 21.5" which turns out is the exact width of the SKB rack.
With all the rounded off corners on the inside it almost looks like it's a one piece mold.
It looks great! Well matched to the rack....
Refresh us...What are the components and dimensions?
15"KLLF with an 18 Sound 6ND410 21.5"w x 25"t x 18"d
A light 50 lbs, I think it's because the cg of the handles is spot on, like everything else on this cab.
Thank you Kjung. I just got off the phone with Don. I had to call and personally thank him for doing such a great job on my cab. Everything is above and beyond construction wise and the sound is great. I can hear the speakers opening up as I continue to break the cab in.
I definitely want another one to run upside-down on top with the mid high passed at 800hz but still have the 15" low passed at it's 1300hz peak with a shallow taper. I'm just curious how it would sound. As is the 1300hz xover point sounds great for the mid.
Stroy05 came over with his old school Epiphani 212 vertical and we did some a/b'n. I heard more lows on the LDS156. The Epi212V has some serious treble extension with the tweeter. He was popping the g string hard and the tweeter wouldn't even cough.
The Epi cab was triggering the toms/snare to resonate more than the LDS156. I wanted to put the Epi on top and run them together
maybe another time.Don says he prefers my design and GB's design (a close 2nd
) best so far sound-wise.Don is actually going to build my design for himself with the blue Ampeg tolex. Should be cool looking. I think I may have stumbled on to an excellent design.
- Dec 18, 2000
- 13,201
- 340
- Disclosures
- greenboy designs: fEARful, bassic, dually, crazy88 etc
Thing is, and as Ken and I were talking earlier today, people got the impression that having that crossed-out spike in my graph further up in the thread would contribute to more output if the crossover included it on the woofer side. Not necessarily so. It just as easily sets up destructive interference/and cancellation in that range and, in that area, less intelligibility. It's not "free SPL".
On a related note, I've tailored crossovers as low as 500 Hz that sounded great (actually gone even lower but it was hard to compensate for the inherent rolloff and didn't have any good purpose but to know what the driver had to tell me about itself). I was using scads of power, and that midrange driver acts like "when are you actually going to pour it on?" ; }
Don says he prefers my design and GB's design (a close 2nd
He told me it was a matter of player preference ; } ...Actually I purposefully avoided a couple things your design incorporates just to have a more transparent palette in the midrange, so that even subtle EQ in the mid-cone range would be more likely to be reflected in final acoustic output. That includes
(1) not centering cone on the baffle so as to have shallower and diffused response valleys that get caused by baffle diffraction. Also has the benefit of placing better HF sections (wavguides!) on the baffle for those who want the gloss, sheen, sparkle, snarl, etc up above to be as good as is possible in that form factor.
(2) not centering the midrange chamber within the larger woofer space, to do the same for internal reflections within the woofer space - though this is more subtle given the intended crossover point. I did also try to keep the woofer away from the bottom and walls though, so I ended up centering it on the horizontal plane. In its passband it didn't seem to be adversely affected.
(3) not centering the midrange driver within its chamber so as to minimize and diffuse equal length reflections coming back through the cone - same principle as (1) and (2).
You have! A different flavor, and a good one - but please, a little credit where credit is due! ; }
Blues Cat, did Don mention any overall sound differences between the standard design and the side ports? Also, do you find yourself missing the tweeter or can the 6.5 cover the highs enough to make up for it?
I just talked to Don today by email for more info on this cab, it looks like a nice design.
I just talked to Don today by email for more info on this cab, it looks like a nice design.
- Dec 18, 2000
- 13,201
- 340
- Disclosures
- greenboy designs: fEARful, bassic, dually, crazy88 etc
If we are tuned the same, and using in the same enclosure internal volume (I don't think chuffing will be an issue with either even with mass wattage until you get into synthisizer sources) they'll be identical as for the port output sound. The two will also interact with walls and floors the same (as opposed to rear ports placed too close to walls). I almost went with sideporting for the 1212/6 because the two layouts function equivalently.
Indeed!
- Dec 18, 2000
- 13,201
- 340
- Disclosures
- greenboy designs: fEARful, bassic, dually, crazy88 etc
And for guys with really wide (tube) heads, Kindness's shorter, wider cab may appeal. It's also a little larger internally, so the bass voicing is subtly different - a little closer to my FeARB for F#0/E0-strung basses, and really nice with any bass as well.
- Dec 18, 2000
- 13,201
- 340
- Disclosures
- greenboy designs: fEARful, bassic, dually, crazy88 etc
Yep. Works great. Though it does kind of seem short and squat to me, personally, unless tilted back a hair. Two, stacked on their sides though - geddoudda town, loudie!!! ; }
Ooooh, you want credit.
Bro I thought it was inferred by specifying the 15"KLLF and 18 Sound ND410 together in the same cab. I don't think many would have thought to try those 2 different manufacturer's speakers mixed together would sound so good.
I bow to your OCD, for it is more O than my own.
Bro I thought it was inferred by specifying the 15"KLLF and 18 Sound ND410 together in the same cab. I don't think many would have thought to try those 2 different manufacturer's speakers mixed together would sound so good.
I bow to your OCD, for it is more O than my own.
- Dec 18, 2000
- 13,201
- 340
- Disclosures
- greenboy designs: fEARful, bassic, dually, crazy88 etc
Ooooh, you want credit.
Bro I thought it was inferred by specifying the 15"KLLF and 18 Sound ND410 together in the same cab. I don't think many would have thought to try those 2 different manufacturer's speakers mixed together would sound so good.
I bow to your OCD, for it is more O than my own.
Ah, probably sounded a little caffienated. It ain't you, my man! Anyway, I'd love to run some stuff by you on the phone that involves a superduper-SPL cab for "rilly rilly big shews" that I might never end up building but might interest you! Check PM.
He said in general that slot port cabs have generally more low end and that his round ported cabs have a more neutral sound not quite as deep.
There's no real standard design. I think up 'til a few months ago Don's 156 cab's had round ports @ 24"w x 24"t x 16"d to fit large tube amps. There's some pics of the one Ken tested.
I don't think I'll ever miss a tweeter, been turning them off for years. With the 6.5" mid turned up all the way there's plenty of high end that's smoother than a standard tweeter. I like 12:00 which is a testament to Ralf P's xover design imo because I have an equal amount to boost or cut. So a -3db pad was perfect for this cab it turns out.
With the mid cut all the way back it sounds very similar to rolling the treble all the way off on my bass and engaging the 2.5khz mid switch cut. Maybe the reggae guys would like no mid.
Don would love to build you another one of my cabs. As is blmeier I wouldn't change anything.
Look at the round off on the corner of the baffle/grill rail. He cut the grill to match the curve perfectly. Those little attention to details are all throughout the cab. Also notice that he routed out some of the vertical wood so the grill rail wouldn't have to be so wide.
Also look at the 2 grill spacers right above the 15", he cut about 25% of the spacer so it would butt up right against the 15".
He understands fully the capability of this next generation 15" (thank you GB) and builds the cab accordingly.
