Celestion 15" buyout and SEOS12/DNA360

I've got three of the woofs on order (and I'll check their function as soon as they arrive ), but I have a few questions before I start my build:

• I noticed in Bill's initial post that he used a 2 ft^3 box, but on the order page for the kit, a 2.5 ft^3 box is recommended. How will the extra 0.5 ft^3 impact the design and the sound quality? Are there any adjustments, eg. stuffing or crossover changes, required as a result of the slightly larger enclosure?

• How do I order the 2.5 ft^3 flat pack? I don't see it listed anywhere on the DIY site, other than the mention that it is an option.

• What is the crossover frequency?

• The crossover schematic lists either the DNA-350 or the DNA-360 as potential compression drivers ("CD"). Has an example of each been built and auditioned? I mention this because of Tuxedocivic's comments elsewhere of the difficulty in crossing over the DNA-350 below 1000 Hz.

• Which CD is in Erich's speaker?

• What interior treatments inside the box do you recommend for this kit?
  

Thanks in advance.

Mike

 

Sometimes Bill can be slow, so what ever he says trumps me, but I'll try to answer your questions cause it's been a day.

1. The size should be fine. The added volume won't change the XO design. You're welcome to go bigger and ported, or what ever will suit your needs. Try to keep the baffle dimensions the same.

2. This is the only flat pack I see that looks like it would work: http://www.diysoundgroup.com/flat-packs-1/seos-flat-packs/2-cuft-tall-seos-flat-pack.html

3. Bill would have to tell you. But I thought I saw 1100hz somewhere. Maybe that was something else.

4. The 350 does have a different low end knee. But they'll close. I'm surprised it's a direct substitute, but based on my FR measurements, I'd say they are close enough it would likely be fine. Personally, I'd go with what was used in the design process though. I managed to cross my 350 at 950hz, but it has very little protection.

5. Erich used the 350 I think. So if that's right, then it does seem suitable to substitute.

6. Fiberglass or what ever you like.

Hope that helps a little bit.

 

I wanted to follow up with you guys on my damaged driver.....received the replacement driver from PE today, in "absolutely perfect" condition. They did a much better packing job. Now I have a small dilemma.....

Driver #2 of my first shipment does not look "perfect".....you can see a small imperfect area in the cone around the voice coil close to the center (hard to describe, sort of a minute crease in the cone, probably can't capture it with a camera). The damaged #1 driver had a similar imperfection, but much worse, along with a bent frame, and it did not function properly (by WT-3). I noticed it when I first received it, but it tests fine with a WT-3, and I didn't have a "perfect" driver to compare it to. Since it may be a few months for my build, I don't want to take chances on that driver being less than what it should be prior to them selling out.

Can a driver perform incorrectly if the WT-3 readings are spot-on? At this point I can only test free air unless a makeshift box is built.

Thanks......

 

You don't have to return them?

I'd be worried the one with a bent frame will leak.

If you're interested in selling them at a discount, I'd be interested before June 10th. My folks leave Minnesota then. I'd even buy 1 cause I'd built a bass guitar cab or something with it.

 

I didn't have to return the first one. Upon further examination I see a few more things....it looks like the cone is a little off-center and the frame is slightly out of round, maybe 0.5 mm.

I will be calling PE tomorrow. I would be more than happy to send you one or both for the cost of shipping Tux....will keep you posted.

 

http://www.diysoundgroup.com/flat-packs-1/seos-flat-packs/2-cuft-tall-seos-flat-pack.html
That flat pack is for a 14.5" baffle. The buyout drivers baffle is 17.5"

 

Thanks for the response!
[list type=decimal]
[*]Good to know that box size is not so critical. I'll use whatever Erich has available. I plan to build a sub or two after I get these up and running with some surrounds (Fusion-8's ???), so low end extension is not a huge issue.
[*]What MAX said.
[*]My concern with questions 3-5 lies in what happens outside the X-Over band. I know there is still a lot of energy for an octave or two below crossover. I am worried the DNA-350 might introduce more distortion than the DNA-360, rather than gracefully roll off more quickly below its "knee". I've heard this mentioned with other, totally unrelated, designs, so I was worried it could happen with these drivers.
[*].
[*].

[*]OK. Just the walls or stuff the whole box (tight, loose, just right...). I'll do some searches on this topic.
[/list]Thanks again tux, I appreciate your time.

Mike

 

Hey Erich,

Do you have a 2.5 ft^3 flat pack that fits the baffle provided in the kit?

If so, how do I order 3?

Thanks,
Mike

 

I'm with Mike - if you've got flat packs, sign me up for three. Just don't tell my wife!


I don't mind cutting them myself if I need to, and I can figure it out, but I'd love to see a cut sheet for a box if anyone has one.


Fred

 

Paranoid that they'd run out of the woofers, I am buying my set of three right now. PE says there are backorder issues with a few of the parts for the XO:
The first one says in stock but has a warning about backorder.
015-5
The second and third ones say "backorder issue."
255-200
016-3
The warning is not that the order won't get filled, but that it may ship separately. I don't mind that, if that's what it is. Maybe that's common for PE.

Fred

 

There may be alternative XO parts that could work.

 

Well , Fred, I guess I am more paranoid because I bought mine last week for the same reason. :-[ The speakers arrived in good condition and each could play music and sounded similar.

I just received spandex material today for a new acoustically transparent screen, so I'll be buying the rest of the speaker parts after I decide between the 350 vs. 360 CD and my tax refund arrives (unless I'm under investigation by the IRS for my membership in a certain pro-2nd Amendment association...

As to stuffing the box...Wow, that seems to be a can of worms. The best recommendation seems to come from Bill Fitzmaurice who suggests you measure the speaker's impedance to target an optimum Q around 0.7 (is it significant or just coincidental that the target Q value is 20.5/2). I forget all the exact terms since I don't have the capability to do this, so I'm looking into inexpensive memory foam mattress toppers vs. bulk polyfill, both from the local Walmart. I may just let my ears decide

Mike

 

Hello,

Do you all think there will be a design using this woofer with the new forth coming SEOS 15"? I bought 3 of them and will pre-order the 15" SEOS as long as someone "Maybe Bill" will design a crossover for them.

Thanks,
Robert

 

One more vote for flat packs please! I can sand, glue, clamp, etc., and supply copious labor, but I have zero capacity to cut wood with any precision. These flat packs are absolutely fantastic for folks like me. I have everything in cart ready to order, but the project is a bust without that.

 

It's a good idea. If PE runs out of them quickly though, I doubt anyone would spend the time. Unless someone who already has the woofers and wants to make a design using the seos15. Hard to bank on though.

 

"That woofer turned out to be quite sweet. Very nice smooth midrange, well behaved before it rolls off naturally around 2kHz (actually easier to design with than the TD15M, which has a lot of junk to get rid of above crossover). I may like it better than the TD15, actually, but remember I'm not a high-volume freak-- TD15 may do better if you're wanting your neighbors down the street to hear it clearly."

if it really is that good, and given that the driver itself appears to be a completely unremarkable design, perhaps it could just be ordered from celestion in batches.

was there a distortion measurement on this guy anywhere?

 

Well,
I finally received my second undamaged driver today (they sent a total of 5). This time they double boxed it and stuffed it to the brim with packing paper. I'm sure mine are not the only ones being damaged in shipment. At this rate PE certainly will run out of stock prematurely.

 

I received my box today, and the one (of three) that I had a good chance to check looked fine. They did, as expected, omit the several components listed as back ordered. I'll just wait, I expect, instead of finding substitutes. You can see in the side of this image (which is sideways) the shipping box has been a little bit through the ringer - thanks to UPS.

 

Regarding that parts list: Is this correct, as I see one part listed twice, the 027-436:

+++ 20uf - 027-436

1.5uf - 027-412

+++ 20uf - 027-436

.4mH - 255-032

.05mH - 255-200

1.5mH - 266-552

5 Ohm - 015-5

12 Ohm - 015-12

6.2 Ohm - 015-6.2

7.5 Ohm - 015-7.5

3 Ohm - 016-3 (as of today 06/09/13 that part is listed as a backorder on PE. Suggestions?)

woofer - 299-418
+++++++++++++++++++++



This is my first build. I'm ready to pull the trigger on this project, via SEOS flat pack 2.0 . I have some questions I don't have the answers to.

That flat pack is for a 14.5" baffle. The buyout drivers baffle is 17.5" (maxphan)

1) I now have the same question, is there something about the baffle I need to know, or need to order? I thought this was a sealed design, so is there a baffle (port)?

2) When ordering, there is an ordering option where I have to choose if I want "roundovers" on the baffles. I don't know what the default answer is, and I certainly don't know what I need. I would prefer someone give me their suggestion, and I will go with it.

3) Eric question: Regarding the CD, there is a DNA-350 for about $58, and a DNA-360 for $78. It looks like the DNA-360 is a better item for an extra twenty bucks and will interchange with no problems with the DNA-350. If I should NOT do this, please let me know. If I CAN do this, how do I put the upgrade into my order?

4) Are there any other materials I will need to complete the project, such as a special type of wire or size for the crossovers to the speakers?

I didn't see any reference to this, but I DO hope the kit comes with instructions?

 

I can answer a few of those questions.

Yes there should be two of those 20uF capacitors, one goes with the woofer circuit and one on the cd.

The 3 ohm - 10 watt resistor 016-3 on backorder can be replaced with two 6.2 ohm - 5 watt resistors in parallel part 015-6.2.

The design using the included baffle is for a sealed enclosure, no port tubes. I think roundovers are standard on the baffle. The rest of the enclosure must be cut and built I believe the size was 17.25" wide, 26" tall, and 16" deep.

Any speaker wire 18awg or larger will do, even lamp cord if that is what you have. Don't forget to pick up some terminal cups or binding posts if you don't already have any.

 

Thanks Mr. MTG, that answered all but a couple of questions (substituting the 350 for a 360 CD).

You unknowingly unleashed the true nature of my OCD; I now have questions about resistors. I had hoped it would never come to this for me. :'(

The first thing I found out is that I can get that resistor from PE for about 70 cents, and Sears is willing to sell me the exact same one for about 11 bucks. Such a deal.

But there really are better and worse resistors, and for about $2.50 I can get a good Metal Oxide resistor made by Mundorf. Surely I can't hear the difference, right?

And one last question; what would the effect be if instead of the 3 ohm model, I used the 3.3? Or the other way, the 2.7?

This is all the stuff I really don't want to think about. I just want the smart guys to tell me what I need so I can get on with my life without unlimited research on every nuance of my equipment. :

I trust you. Really.

 

Well lets just say you can't measure the difference besides maybe the tighter tolerances of the Mundorf. Whether or not you can hear the difference is something I am not qualified to answer. If I had to guess I would say no.

Going with the 2.7 or 3.3 is only a 10% difference, should be perfectly acceptable for that one.

 

1) Correct - no ports on the current baffle
2) Get the round overs! They look better, and you would need a router to do them yourself.
4) There are several things you'll need. I use old lamp cord, speaker wire or extension cord for the wire from the speaker terminal thru the crossover. The terminals on the site are nice. Get the threaded binding posts and you only have to drill holes. If you get the terminal cups, then you need a saw to make the opening.
No instructions, just the crossover schematic. The folks on this site or several others will pitch in to offer custom help!

 

Hey guys,

this is my first diy audio project and I'm a little clueless when it comes to interpreting a crossover schematic (to put it lightly). Here's what I have so far (had to substitute part# 266-798 for part 255-200 and part# 005-3 for the 3ohm resistor....hope that's acceptable). If I'm reading the schematic properly I need to wire everything together with arrow facing south as a ground? Does anyone have a picture of a completed crossover that those in the same boat as me could oggle? Thanks in advance