fEarful™ 12/6 & 15/6 enclosure designs - FREE! (Part IV) On with the Madness!

greenboy · #1 10-01-2009, 10:13 AM

Mod Edit:
Continued from Part III

dug dog · #2 10-01-2009, 10:34 AM

Sweet.
I'm lovin' the depth of commitment to this project that's being exhibited by some of you guys. The "Cheap but Good" cross-overs are scratchin' me right where I itch.
Incidentally, I took delivery of a 3015LF and a ASD1001 this week. Still undecided on the mid. (I think I mentioned in the first thread that Loudspeakers Plus is the Canadian distributor for 18 Sound and they'll only ship UPS who, on top of their actual delivery fee, hit you with a $40 "brokerage fee". Ouch.)

dug dog · #3 10-01-2009, 10:45 AM

I haven't looked at that one yet, but I will. The option I've been pondering is the B&C as the distributor is only about 45 minutes away and he's also the Duratex distributor, so I'll be stopping in to see him one way or the other.

dug dog · #4 10-01-2009, 10:59 AM

I just got off the phone with the B&C distributor here in Canada. I thought they might have some off the required data, but no. I'll fire an email off to B&C this afternoon.

dug dog · #5 10-01-2009, 11:36 AM

Quote:

Originally Posted by dug dog

I'll fire an email off to B&C this afternoon.

Email sent. Let's see what happens.......

byoung · #6 10-01-2009, 01:27 PM

Quote:

Originally Posted by greenboy

But right now this looks a lot better than the Em for component consistency / power handling, system impedance, and on- and off-axis frequency response.

Greenboy, I'm not questioning your design, but I'm at the point where getting a crossover is necessary (going to glue in lining, and do final assembly shortly), and I would like to run this design. I just want to double check, since the previous design was pulled:

Should I run this design rather than an Eminence PXB2 (500 or 800)?

Curious as to feedback, I have the components sitting in my shopping cart at Parts Express. Pull the trigger?

rpsands · #7 10-01-2009, 03:01 PM

GB, have you ever tried a BBE DS24 before? Thinking of picking one of those up and rigging my cab for biamping, just to give it a go, since it'd give me a lot of extra eq options as well.

melodicly · #8 10-01-2009, 03:51 PM

"First, let me ask you this, melodicly: with your amp and with just the 12/6 set up whichever way you typically use it alone - either on the floor, tilted, or on a stand - how do you EQ?"

I go for the vertical stack to save stage room and get the sound up around my ears. I EQ as flat as possible according to the room. Cut a little bass, I use the mid knob on my bass to adjust for room weirdness and cut the treble just so there isn't any hiss or loud fret noise.

I am looking for a hi-fi modern sound. That nice mid punch without too much rumble. Think the guy from Jamiroquai (sp?) or MMW etc. Nice tight punch with enough clarity to play in the upper frets without being too bright. I use the low B quite a bit in this band so it has been a struggle to get that to sound decent enough without compromising everything else.

Eden is going to replace my speakers for me so I have to hold off a little while longer for the funds, but the more I think about it, the more I think, "why not another 12/6 vs 12sub?" Worse come to worse I can just put an L pad on them if it got too bright. My experience thus far has been very smooth and controllable mids and upper mids through the alpha6, so I'm not too concerned. I wouldn't imagine there would be any sonic advatages of a 12sub of another 12/6....

When I get a chance I am going to read up on this stuff so I don't have to keep asking basic questions from busy people!

Thanks again for all the help though.

BurningSkies · #9 10-01-2009, 03:56 PM

Quote:

Originally Posted by greenboy

Burning Skies,

You may have seen me mention I thought the Em 500 Hz crossover was a better choice for the 15/6 than the 800 Hz one. I hadn't had a chance to look at a total simultation of it but my reasoning was that the low-pass section would not do enough suppression of the horrible peak above 1K Hz that the 3015LF exhibits. That in itself would not be the problem. The problem would be how it summed at various listening positions. It would be all over the map, and at that frequency not especially pleasing in ANY position.

Now I've had a chance to really examine it and it is indeed what I thought it was. So I've looked at the way to minimize this cheaply on the Em PXB2:800. It's simply to substitute a 250 volt poly cap (or two 12 uF) in place of the two caps that are currently supplying a 18 uF value on the low-pass side. IT's not as good as a tailored crossover of course, but it's a pretty good improvement (with your current padding and the 6ND considered of course).

Thanks Greenboy! I appreciate the extra time and thought on the crossover.

I think what I'll do is start with the stock PXB2-800 as it is, then test it and see how ugly it is. Then if it is indeed as ugly as you suggest I'll pull out the crossover and mod it or work from scratch on something. That's why I did indeed decide to mount the crossover and L-pad low and easy.

A big part of why I'll start stock is that I know that a weekend afternoon of time and things will be DONE...and I'm itching to finish and play this cabinet, since I've been looking at it for soooooo long now. That will also allow me to order in the few new components I'd need and have something to play while I wait for delivery. If anyone knows me, they know that if someone's suggested there's a way to make things sound better, I'll probably lose a few moments of sleep over it until I try. It would be easy enough to cut out the two caps on the board and solder in the replacements, or leads to a secondary board.

Also, for those interested in details of the woodworking aspects of my 15/6, my friend Andy as put up a more detailed description of his build process:

http://www.forums.woodnet.net/ubbthr...Number=4517456

Its interesting to see the amount of detail thought and extra finesse that went into the build. It makes me feel guilty that I went and covered it with Duratex...right up to the moment I look at the cab...

byoung · #10 10-01-2009, 04:00 PM

Quote:

Originally Posted by greenboy

Which fEarful and midrange driver?

Given your profile, I'm surprise you don't biamp. With these type of enclosures it's going to beat passives. I used to have an Alembic F1-X and still do have a QSC PLX3402.

12/6 with the Alpha 6.

The F1-X and 3402 are a semi-permanent installation at church; I have a Gallien Kreuger MB2 500 (350W into 8 ohm) amp I'll be using for this cabinet. I thought long and hard about bi-amping, but I'm not trying to wring every last drop out, this is essentially my home practice amp. It should certainly be able to keep up with a drummer and even a frisky guitar player.

I guess I could swap these amps (at least temporarily) to get up and running (cross over from F1-X into both sides of the 3402), and then do the crossover later.

I'm actually thinking of getting rid of the F1-X, it's a little old-school sounding for me (it pours that on like thick, buttery goodness, but I'm looking for a little more hi-fi in the EQ department).

So, pull the trigger now (at risk of spousal irritation if it needs to be changed), or wait? From my (admittedly amateur) crossover design capabilities,

Bradley

byoung · #11 10-01-2009, 04:11 PM

So, I'm supposed to line the woofer cabinet (which I did-- with a "mattress topper") and stuff the midrange chamber.

Can I stuff it with mattress topper, or do I need to go get polyfill?

I have the mattress topper in there, and it sounds pretty dead (by the scientific method of shouting into it). It does fill quite a bit of the volume of the enclosure (1 cm below the magnet, and I had to cut out clearance for the two close sides).

Thoughts?

BurningSkies · #12 10-01-2009, 04:15 PM

Quote:

Originally Posted by byoung

So, I'm supposed to line the woofer cabinet (which I did-- with a "mattress topper") and stuff the midrange chamber.

Can I stuff it with mattress topper, or do I need to go get polyfill?

I have the mattress topper in there, and it sounds pretty dead (by the scientific method of shouting into it). It does fill quite a bit of the volume of the enclosure (1 cm below the magnet, and I had to cut out clearance for the two close sides).

Thoughts?

The problem is that part of the 'stuff' instruction is that you want to loosely stuff it...not reduce the volume of the enclosure. Unless you're using a mattress foam that's of a lighter foam than I've ever seen. Of course, your wife/girlfriend/SO/roommate might not know if you pinched a bit out of the throw pillows in the living room...

Otherwise a small bag of polyfil is really cheap...or send me your address and I'll send you a handful of it.

byoung · #13 10-01-2009, 04:26 PM

Quote:

Originally Posted by greenboy

Yeah. I replaced mine with something that could do a lot more as well as being able to gnab all its tones for dimes on a dollar.

I know you run the Roland V-Bass; is that what you're referring to? I'm interested in hearing about other options if you're running an actual pre-amp.

Quote:

Originally Posted by greenboy

Anyway, Bradley, my crossover sure appears to be good to go. I've checked everything umpteen times on a number of different criteria and compared it to a fair number of known examples.

Alrighty then, credit card is armed and firing.

melodicly · #14 10-01-2009, 04:45 PM

Cool. The only reason I'm getting the Eden fixed is it's still under warranty and I can get more out of it when I sell it. Don't get me wrong this is the best 2x10 I've ever come across, but even in top shape it's nothin' compared to this 12/6! I am going to use it alone at practice tonight and now that the speakers are good and broken in I'm going to really push it! :laughs maniacally:

BurningSkies · #15 10-01-2009, 07:46 PM

Quote:

Originally Posted by greenboy

Sure. Do realize though that some of these kinds of things are not what you might zero in on right away as being about that specific frequency range. But they do affect tonal balance and can cause EQ problems and as you acclimitize it becomes apparent. And regardless of YOUR listening position and enclosure placement/angle they are nevertheless causing problems of tonal balance over a wider variety of listening positions - ie the venue coverage is way more unpredictable than it needs be.

Great! I just skimmed it for now, but I did notice his mention of butt joints. But (!) I've always said I designed the plans so that anyone could choose any type of joinery they thought they could pull off. Also, he makes reference to a weakness where the spine brace meets the port divider in back. Doesn't he realize that there's no stress to speak of on that point in the first place because of (1) its distance from panel centers (2) the incredible strength provided by the glue join between back panel and spine brace, once the back is put on?

This reminds me of those who put a lot of bracing in the corners where none is needed and neglect the open areas of the panels as you get closer to the center of each, where they are considerably less rigid ; }

But nice of him to put the blog up : }

I certainly will keep it in mind, and I'll probably order in the parts with the idea that I'll be making the change.

Now, here's a question for you...I squash my signal extremely on the mids and highs for my gigging band. With the low passed at 800 (and I know that it's a slope), and the fact that I most of my signal rolled off above that point, will this be less of a concern for me, or will this be 'coming out sideways' in terms of my low end?

I'll probably find out fairly soon myself, I'm guessing.

Also, on a side note, I did find adhesive rubber foam of 3/16 thickness at an automotive store. It's fairly dense closed cell and black in color. It is 1&1/4" wide so I'll be cutting it down to the correct width.

X Ray · #16 10-01-2009, 11:18 PM

Does the Alpha6 have enough output to be used with the 3015LF? I've never seen a crossover diagram for this.

Anybody?

X Ray · #17 10-02-2009, 12:36 PM

byoung · #18 10-02-2009, 12:42 PM

Quote:

Originally Posted by X Ray

Does the Alpha6 have enough output to be used with the 3015LF? I've never seen a crossover diagram for this.

Anybody?

No, not really.

rpsands · #19 10-02-2009, 12:58 PM

Quote:

Originally Posted by X Ray

Does the Alpha6 have enough output to be used with the 3015LF? I've never seen a crossover diagram for this.

Anybody?

While it doesn't have enough output to be balanced, it probably does have enough output to sound good to a lot of ears. It'd be pretty dark, but lots of people like that.

You could also, if you had room, use a pair of 6a's for still quite a bit less than a 6nd410, if you were trying to cut down on cost.

I'd say it would sound better with a 6a than with a straight cross to a tweeter, but that's just this man's opinion

NickRich · #20 10-03-2009, 06:47 AM

Quote:

Originally Posted by BurningSkies

Also, for those interested in details of the woodworking aspects of my 15/6, my friend Andy as put up a more detailed description of his build process:

http://www.forums.woodnet.net/ubbthr...Number=4517456

Wow, great resource ! Think of Wood Working 101. It will sure help when I'll be tackling this project.

And your friend sure took this building seriously. It's great to see all the little details he put together on this one.