Questions about speaker building

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A pair of 12" woofers with a low 100-150Hz crossover frequency will deliver great floor-boosted bass and correct polar directivity when mounted side-side about 12" above the floor. Most woofer-generated cabinet vibration can be removed with proper counter-force internal side-side cross bracing. A shorter cabinet is possible. The example polar directivity plot illustrates why horns with a 90H x 40V polar pattern are popular for seated home listening.

.side-side counter-force example
.directivity model

Budget stuff: Design one great speaker and build one completed cabinet even if you have to leave a couple open DSA315-8 woofer holes until funds are available.
 

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I have determined that I need 4 4' by 8' pieces of MDF wood in total. 2 for each speaker. I am going with a length of 24" and from what I have learned, there is no reason to do exact calculations to end up with harder to work with numbers when rounding to an easy number like 24" won't make the graphs inside Unibox any worse. I will simply do the calculations to get the exact box volume and put that into Unibox to get a port length. I might need to get a smaller piece of MDF to make the doors for the wiring area or I might be able to use the piece I cut out...

I will go with all Dayton drivers and tweeters because Dayton provides the ready to go ZMA and FRD files needed to design the crossover. This means using this 8" midbass:

Dayton Audio PM220-8 8" Wideband Midbass Neo Driver

Not sure which tweeter to go with yet but this horn seems like the best choice:

SH402 1" Horn 7" x 17-3/4" Bolt-on

I would like to know the process of designing the midbass and tweeter section of the box. Do I use Unibox?

I think I'm going to use Jeff Bagby's crossover designer but if anyone knows a better software I can go with that.
 
What would be a better horn?

The 8" Dayton PM220 is tested in Sept 2013 edition of Voice Coil magazine.
http://www.daytonaudio.com/media/resources/PM220-8 Voice Coil Review - September 2013.pdf

With a 8" midrange, the 12" Dayton Audio H6512 waveguide + screw in Selenium D220Ti-OMF-8 would be a good match.
Flex Your PCD Mettle: -

Techtalk Speaker Building, Audio, Video Discussion Forum


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The discussed QSC 152i waveguide is identical to the $13 B-52 PHRN-1014 1" waveguide I have been recommending(and own).
You can find FRD/ZMA files with a complete PCD design for the Selenium D220Ti-OMF-8 compression driver on QSC 152i waveguide:
Flex Your PCD Mettle: -

Techtalk Speaker Building, Audio, Video Discussion Forum


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Still my favorites:
$13 B-52 PHRN-1014 1" Horn 10" x 14" Bolt-On waveguide
Model: PHRN-1014|Part # 299-2303
$34 Selenium 1" compression driver 2/3 Bolt . ( Proven Xover ckt available)
Selenium 8 Ohm Model: D220Ti-OMF-8 |Part # 299-2321
$130 Eminence Delta Pro 12A midrange 12"
$76 Dayton DAS315-8 (12" woofer need 2/speaker)
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$319 = $329 -$10 coupon + free shipping
$25 passives for each TM

$130 Adcom GFA-2535 4 Channel Power Amplifier USED on ebay
$40 stereo 2/3-way active Linkwitz-Riley Electronic Crossover ebay (analog opamps, just requires +/- 15V transformer)
----$860 total
 

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I thought I was building the crossover...
I think I can find an amp later when I know exactly how many watts I need but going on ebay might be a good idea if the amps I want are too expensive.

Just to make sure, these drivers and parts would go together well for a final build?

Dayton Audio DSA315-8 12"

Dayton Audio PM220-8 8"

Selenium D220Ti-OMF-8 1" Titanium Horn Driver 8 Ohm 2/3 Bolt

Dayton Audio H6512 6-1/2" x 12" Waveguide 1-3/8"- 18 TPI
 
40-Watts maximum power spec....
The Dayton Audio PM220-8 is a risky tech-music midrange partner for 240-watt capacity woofers.

My recommended Eminence Delta Pro 12A midwoofer has a 400W power spec. Rock and Roll is here to stay!
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Designing your own crossover is a great education, but you will need tech-articles, FRD ZMA measurements, free tools like Vituix, and help for great results. It is easily to spend $200 in L-R-C parts to optimize a 3-way Xover.
Research bi-amping, which direct connects the amp-woofer even with a steep slope Xover. Design a passive Xover for the tweet+midwoofer.
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If your new furniture arrangement supports a 22" wide cabinet, take another read of post #168 Maximus-18. One 550-Watt 18" woofer has more cone area that two 120-Watt 12" woofers, and is lower in cost.
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Some folks like big butts...
Some folks like big woofs..
--
I like big woofers and I can not lie
You other brothers can't deny
That when a speaker moves into your itty bitty place
And a round cone in your face
You get sprung
Wanna pull up tough
Cuz you notice that woofer was stuffed
Deep in the baffle it’s wearing
I'm hooked and I can't stop staring
Oh, baby I wanna get with ya
And take your picture
My homeboys tried to warn me
But that woofer you got
Make Me so horney
Ooh, motor with low inductance
You say you’ll sing with no reluctance
Well use me use me cuz you aint that average groupy
 
hahaha that was funny:D

Are you saying that I can buy a pre made crossover and make modifications to it?

Also I can't do 22" in width because on the left side it would barely fit but then there would not be any space for my JBLs on their stands (The left one would be uneven with the right one) And also with the tight fit they would be closer to the wall so they would run into the ceiling that is slanted (Ill attach a visual)

30.PNG
 
Ok without jReave I am not going to be able to finish an entire project. Maybe I can go with the Idea of making some powerful subwoofers and have the JBLs as the mid and highs. I can have the JBLs in the corners of the room with these. I would go with the same 2 woofer design with wiring on the bottom. Is a crossover necessary for subwoofers?

I think I can use this Dayton Audio RSS315HO-4 12" Reference HO Subwoofer 4 Ohm
 
Are you saying that I can buy a pre made crossover and make modifications to it?

He is suggesting an active + passive hybrid. I gave an example layout for how you'd set one up (post 180).

The mid-to-high crossover is relatively cheap & easy one to make passively, because the parts are smaller. That's why you'd do low actively, high passively.

Any reasonable passive XO will be OK, as long as you have some form of flexible eq (miniDSP OR multi band eq board OR software), because you can use that to flatten an imperfect response.

there would not be any space for my JBLs on their stands

Why use stands? I'd just build the woofer box to whatever height is needed, so that when the top box is plonked on it, the tweeter is at ~ear level.
 
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