# PA styled mains



## perceval (Oct 17, 2012)

While waiting to get my hands on a Sonotube for my DIY sub (not easy to get in my corner of the world, I'll need to scout some construction sites and try to scavenge a piece, no stores has them around me), I had fun and used my Yamaha PAs as mains for watching a movie last night.

My little Ushers are nice, but really, for HT, horn tweeters ROCK! I used to listen to music the most back in the days, but lately, 80% is HT. So, after hearing the power in the details that my PA can give me, I've decided to also add some PA styled mains to the show!

Following carmaniac13's thread, I've like the idea of using much bigger woofer, as in PAs, because my movie watching room is huge (4300 cubic feet). Still, design wise, I can't accommodate floor standing sets because just under the screen is a very wide table/shelf that is used for office storage and such (long story short: my house is also a school).

So, to get the ball rolling, I've been looking at compression drivers like the Dayton D250P-8. It looks like a great compromise between the sometimes harshness of tweeter horns and the power and projection of a horn. Another contender that is well reviewed is the Selenium D220Ti.

Now, I'd like to match that to a 10" or even 12" woofer. I was looking at the Dayton PA255-8, but really, I'm opened to suggestions, on both the tweeters and woofers.

Also, do you think I would need a mid range woofer, say 5", to help with the transition between the woofer and tweeter?


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## fusseli (May 1, 2007)

Based on the manufacturer's FR of the PA255, you might be able to stretch it without a midrange. You'd probably have better luck with the D250P to go with it since it can cross lower. Either way I'd be worried that if would sound a little harsh since the cone breakup on the woofer wouldn't be attenuated much. It might be doable though. 

If you don't mind the design complexity of a 3-way instead, I do think that'd be a better route for a better shot at the best sound with that woofer. Then aim for a 300-400 Hz crossover point for the low end instead of all the way up at 1.6 kHz. Choosing a midrange with sensitivity to match the other drivers would be the highest concern.


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## perceval (Oct 17, 2012)

I don't mind going to a 3-way to help spread the frequencies around and get a better sound... of course, I'll need help for that too! I don't know much about designing a crossover. I can build things, cut holes, look at stats, but electricity 101 was never my forte!

Is it better to stay with the same brand or can I mix'n'match tweeters and woofers from different companies?


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## fusseli (May 1, 2007)

Yes you can mix brands. Important factors for picking drivers to make a speaker system include similar (not necessarily matching) sensitivities, suitable frequency response, and impedance. Off-axis performance is another consideration for midrange and tweeters.


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## perceval (Oct 17, 2012)

Been looking high and low around here for some suitable drivers... not easy! My eyes are crossing from looking at so many web pages!

So far, I have few options.

There is a very local (taiwanese) company that makes drivers. A 15" is about $30, plus, they don't provide frequency graphs and only a limited amount of data, missing Xmax and a few others... I don't think I want to go there!

There is the auctions (like eBay) market here, but most stuff is from pulls of really old, rusted and parts, labelled "Vintage" and sold at a premium price, many times over the price of new item. Example, an Altec 515-8G CD, really nasty, dirty and in need of a complete overhaul, is over $1000... for one!

Usher audio is made in Taiwan. Some of their units are quite good and praised around the world in their enclosures. Their 10" driver is a sub, and only good up to 850Hz. They have a 12" that is a sub also but ok up to 1.6kHz, 86dB efficiency only. I don't know. I was hoping for 10" and use subs to cover the lower range.

The only imported company I found is 18sound. There's a 12ND830 that looks ok, I think, good until 2kHz and 99dB. At a little over $200 each, looks like a good option.

The compression drivers are really hard to find.

Again, there's the local company with no specs, or the 18sound ND1020, but it doesn't get favourable reviews. At least, a couple of compression drivers may be easier to ship! 

Then, there's the matter of the horns. That might be expensive to ship.
Not much is offered here, besides pulls from really old Altec and sold at insane prices.... 

I love where I live, but it is sometimes a pain in the &^%& to get stuff!


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## studiotech (Apr 27, 2009)

You could copy something along these lines:

http://www.quested.com/post-production.html

Substitute the Aurum Cantus 2560 for the ultra expensive Beyma TPL150 used in their design.

http://www.parts-express.com/pe/showdetl.cfm?partnumber=276-440

Or the CSS Planar 2:

http://www.creativesound.ca/details.php?model=Planar2

A nice high senstivity mid like the 18 Sound 6NDL430 and one or 2 10-12" woofers of your choice. Boom goes the theater!

Greg


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## perceval (Oct 17, 2012)

That looks nice!

The reason I started with a 2-way is because of my complete lack of knowledge regarding crossovers. I figured a 2-way may be easier to deal with than a 3-way.

I don't have the real estate space required by the Quested, but maybe something along those lines may work.

I do love clear and nice sounding vocals, so having a dedicated mid may be a plus. So I could go with a 10", a 5" or 6" mid and a tweeter (although in this case, I would have to let go of the horn to keep the speaker size reasonable, unless there's a clever design out there for that!)... 

or I wouldn't feel the need for the projection of a horn since I'd have a high power mid?


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## studiotech (Apr 27, 2009)

Have you considered more of a horizontal layout? This is a new studio monitor I'm working on right now. Please excuse the poor box. It is merely for prototyping. You could fit the CSS Planar driver and a nice 5-6" mid and then tuck a 10" next to it. Remember, if you choose higher sensitivity, pro style woofers, you will not get much bass in a smaller enclosure, so I assume you will need a sub for HT duty.

Just for scale, that pict is a 10" Scan Speak woofer and BG Neo8 that is about 8" high and Raal that is 4" high. The box is 14" high. Something like this with an even high sensitivity mid and tweeter could REALLY rock for HT!

Another idea that would be pushing the limits of the drivers, but still doable would be to stay with the Planar 2 or the Aurum Cantus and use a nice 8" for a two way and then add the sub to that. 

Greg


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## perceval (Oct 17, 2012)

Thanks for the idea, but I don't think a horizontal design will work in my case. First with the space available in front, and it would also need to be either raised or pretty high to have the tweeters at ear level.

I was trying to get some shipping info from http://www.diysoundgroup.com, but it looks like they are very busy and don't have time to reply to emails for the last week....

The other place that I know would ship to Taiwan is amazon.com. But I need to keep orders below $500 to be tax exempt... not easy!

The only known company that I can get locally is 18sound. I've seen some small Vifa tweeters too, mostly stuff for small bookshelf kits.

How does the combination of the 18sound ND1020 compression driver and the 12ND830 woofer sound?
Here are some specs:

*ND1020:*
Throat Diameter 1", 25.4mm
Nominal Impedance 8 ohm
AES Power Rating 30W (above 2kHz)
Sensitivity 108.5dB
Frequency Range 1600Hz-20kHz
Diaphragm Material Treated Polyethylene
Flux Density 1.8T
Magnet Composition Neodymium​
*12ND830:*
Nominal Diameter	300mm (12 in)
Rated Impedance	8 Ohm
AES Power	450W
Program Power	700W
Peak Power	1500W
Sensitivity	99dB
Frequency Range	53 ÷ 5000 Hz
Power Compression @-10dB	0,6 dB
Power Compression @-3dB	2,0 dB
Power Compression @Full Power	3,1 dB
Max Recomm. Frequency	2000 Hz
Recomm. Enclosure Volume	40 ÷ 100 lt. (1,41 ÷ 3,53 cuft)
Minimum Impedance	7,0 Ohm at 25°C
Max Peak To Peak Excursion	30 mm (1,18 in)
Voice Coil Diameter	75 mm (3 in)
Voice Coil Winding Material	aluminum
Suspension	M-Roll, Polycotton
Cone	Curvilinear, Paper
THIELE SMALL PARAMETERS
Fs	55 Hz
Re	5,7 Ohm
Sd	0,0531 sq.mt. (82,31 sq.in.)
Qms	5,15
Qes	0,296
Qts	0,28
Vas	72 lt. (2,54cuft)
Mms	46 gr. (0,10 lb)
BL	17,6 Tm
Linear Mathematical Xmax	± 6,5 mm (± 0,26 in)
Le (1kHz)	1,5 mH
Ref. Efficiency [email protected] (half space)	98,3 dB​


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## perceval (Oct 17, 2012)

And this from 18sound website:

Recommended speaker volume: 59 litres (2ft³), 62cm x 35cm x 27cm (about 24.5" x 14" x 10.5")

Here's the schema of their crossover, looks simple enough for me to build!


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## studiotech (Apr 27, 2009)

18 Sound drivers are generally very good, so that should get you started very nicely. Come back with pictures!

Greg


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## perceval (Oct 17, 2012)

Alright then,

So the plan is to use the 12ND830 as a woofer. 18sound gives out a plan for enclosure, crossover and mounting, but they are using a ND1090 driver. The ND1090 is unavailable (and quite more expensive too!) so I was wondering if I could substitute the ND1090 compression driver with the ND1020 and still use the same crossover design.

I asked 18sound support, but no answer...

Specs for both drivers and crossover... anyone foreseeing any problem or should it be a possible swap?

*ND1020:*

Throat Diameter 25,4 mm (1 in)
Rated Impedance 8 ohm
DC Resistance 5,8 Ohm
Minimum Impedance 6,5 Ohm at 5000Hz
Le (at 1kHz) 54 µH
AES power (1) 30 W above 2 kHz
Program power (2) 60 W above 2 kHz
Sensitivity 108,5 dB
Frequency Range 1600Hz ÷ 20kHz
Recomm. Xover Frequency	1600 Hz 12dB/oct slope
Diaphragm Material Treated polyethylene
Voice Coil Diameter	34,4 mm (1 1/3 in)
Voice Coil Winding Material	Edge-wound aluminum
Magnet Material Neodymium
Flux Density 1,8 T
BL Factor 6 N/A

*ND1090*

Throat Diameter 25,4 mm (1 in)
Rated Impedance 8 ohm
DC Resistance 5,3 Ohm
Minimum Impedance	7 Ohm at 4000Hz
Le (at 1kHz) 120 µH
AES power 50 W above 1,6 kHz
Program power 100 W above 1,6 kHz
Sensitivity ([email protected])	110 dB
Frequency Range 1600Hz ÷ 20kHz
Recomm. Xover Frequency	1600Hz (12dB/oct slope)
Diaphragm Material	Titanium - PEN
Voice Coil Diameter	44,4 mm (1 3/4 in)
Voice Coil Winding Material	Edge-wound aluminum
Magnet Material Neodymium
Flux Density 2 T
BL Factor 9,1 N/A

Crossover:


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## perceval (Oct 17, 2012)

Could someone help and tell me what the 1A box with a strikethrough line is?

Is this it?
http://www.tme.eu/en/details/fx100-30/tht-polymer-fuses/ece/#


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