New project, need assistance please

[Satansfx]

Hey guys....

Im good with coming up with ideas, but the technical part is where I am lacking right now... graphs, charts, imps, freqs.... yea... mm hmmm.

I have been reading DIY speaker forums for over a year now.... I have gotten somethings down pat, but other things im still lacking in.... namely because I can't seem to get speaker workshop to work correctly... and i've given up LOL

so, I came here.... groveling.... looking for help with my idea, so if someone, anyone can chime in and help a stuck DIY'er and offer assistance please??

Idea....

Highs 1 per - Dayton PT2C-8

Mid 2 per - Dayton RS150S-8 6"

Lowend 1 per - Dayton RS270S-8 10" (down firing + ported)


So a 3-way design using those drivers... and I was planning on "stealing" the x-over design from the WMTW since it also uses the RS150-8 ohm driver.... but I wasnt sure on how it would work with 2 of them in 1 cabinet on the same x-over.... would this be a problem?

Second.. Im not even sure on the cross point on the PT2 and how well this works with the RS150...

Third... the 10"... another hurdle to work out with the freq resp.

advice? lol.....

This is a project in the making.......

[Hdale85]

You can't just use a crossover from another speakers. Crossovers are designed to match a cabinet along with the drivers and then there is BSC and everything. You can't just slap a 3way together in a tower and just use someone elses crossover its just not going to work very well. If you want a nice 3 way look into something thats in the misson accomplished section as there are some very nice designs there. I'm not sure what your budget is but the RS 3 Ways are very promiseing at about 700 in parts for the pair I believe and in a TMWW configuration. There are lots of other designs there.

[Satansfx]

what I meant about stealing the design was that I was going to use that as a starting point... the rs150 in that center design is in a sealed chamber, so I was assuming that if I did the same I could model something along those lines... kinda like reverse engineering the whole thing.

I know there are designs over in the other section, I just don't prefer the 3 way design there.... I'd like to go with the PT2, and the 150's.... but I can't seem to find any designs with them incorporated.

Im looking more for a starting block advice on which way to turn.

[Hdale85]

Well your going to need measureing equipment. And probably read several books on speaker design like Loud Speaker Cookbook I beleive its called. If you search people have asked this question several times a week in a new thread.

[ThomasW]

It's going to be virtually impossible to get a good smooth transition from a down-firing woofer to the RS150. Downfiring drivers are primarily used around 100Hz, and that's really a no-go for the little RS150 if you want any usable output.

The second problem is the planar tweeter. Although some use these as "tweeters" they're really best used as supertweeters.

Looking at the FR plots of these drivers

http://www.partsexpress.com/pdf/295-362g.pdf

http://www.partsexpress.com/pdf/275-085g.pdf

You might be able to force a 3.5kHz XO point, but who know's how it's going to sound?

You really need to have an operational measurement system to do any meaningful work on a system like this....

[PoorboyMike]

FYI, Loudspeaker Design Cookbook, Sixth edition, is on clearance at Madisound for $11. Edition 7 is out now, but I figured I'm so far behind anyway than I might as well save the $25 and go with the old one. :B

Starting out with Jon's xover for what you want to build is about as far away from being right at starting with nothing. Also, from what I've read, the Dayton planner isn't a good tweeter at all. If I was trying to do a planner design, I would consider the B&G Neo3PDR, which Zaph says is as good as the high end domes for the most part.

BTW, way can't you get Speaker workshop to run on your computer?

[cjd]

The tweeter and the RS150 aren't really going to reach each-other as far as frequencies covered goes. Almost an octave between their realistic crossover points.

I'm assuming your intent was to wire the RS150's in series for the power handling given the low low crossover point required by a down-firing woofer. Then too, the sensitivity of that single 270 suggests you'd need to do this. This portion of the system *might* work if you put a more reasonable tweeter in there. But there's no starting point for such a system either. You'd really be running this as a 2-way plus sub, except that your "sub" isn't a sub... That does, however, suggest the more sensible path to take here.

C

[Satansfx]

PoorboyMike - i can get the program to work, the wallen II jig checks out 100%... metered wise...

But I think it has to do with my DIY mic and pre-amp... since I just built a small phantom power, or my soundcard... im not sure... and since no one posts in those forums anymore, and ppl have stepped up to LEAP and other programs... seems no one cares about t/shooing Speaker workshop

I also have 6th and 7th edition.... they read like brain surgery lol




cjd - kinda was the idea. I dont want to have the 10" running as a "sub" but rather just low end... 100-500 hz somewhere in there. But yes thats kinda the idea on the wiring


ThomasW - the only reason I wanted to downfire an port was to "fit" it into the cabinet. It's about the "look" I know someone else has a design like it, but I was trying to change a few things about it... so I was trying to figure out how to squeeze those drivers into this cab. Or drivers "like" that

I'll elaborate on this a bit more once I make a crude crayon drawing of this lol


Dougie085 - yea, im working on that too lol

[Hdale85]

I think Thomas was thinking you meant a down firing 10" not the port. But sounds like you just want a downfiring port which a lot of people do this.

[Satansfx]

Doug,

I had a typo in there.... no, i really do want a downfiring 10-12" driver.... and ported to the back/front/side/top, hell I dont care where the air goes lol

it's all for looks, and to accomodate the space that I have.... yes i know... dumb reason building a cabinet for the looks :P



**inserted crude of said cabinet**

[Dennis H]

Aside from the crossover problems with the planar tweeter, it's just a bad tweeter. It's a very similar if not identical OEM to the Silver Flute Zaph tested. Zaph said "it may be the worst tweeter I've ever tested" which isn't exactly a ringing endorsement.

http://www.zaphaudio.com/nondomes/

[Hdale85]

Well then a 10" Mid Bass is not going to work well down firing.

[ThomasW]

i really do want a downfiring 10-12" driver.... and ported to the back/front/side/top, hell I dont care where the air goes lol

Then you need to choose midrange drivers that have solid output to 100Hz or lower, since what you're actually designing is a 2-way with a sub.

[Satansfx]

Thomas,

Would that be considered a 2 way + sub? so would the sub need to be amp'd?

[Satansfx]

Then you need to choose midrange drivers that have solid output to 100Hz or lower, since what you're actually designing is a 2-way with a sub.

something along the lines of?

HiVi M6a 6"

[ThomasW]

3.5mm of Xmax doesn't go a long way when trying to do 100Hz at any reasonable SPL

Look to the Modula TM or the older M8a-MKIV design for an example of what's realistic with regard to a woofer in a 2-way.

[cjd]

I mentioned the 2-way + sub thing too. The reason is you don't want to cross a downfiring woofer *higher* than about 100Hz.

C

[PoorboyMike]

I also have 6th and 7th edition.... they read like brain surgery lol

You can say that again! I'm pretty sure I'll be reading this a second time.