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Old 7th February 2013, 04:08 PM   #21
maxo is offline maxo  United States
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Location: A Hole in Texas
Quote:
Originally Posted by jbell View Post
If you really want a PPSL instead of a TH, like a SS15, I can whip up drawings a dual 15 on something cheap, like the dayton pa380, or something like that, in 200liters tuned to 40hz. It should do low to possibly mid 120's. The push pull slot load would be a ton cleaner than just a basic reflex cabinet, but not much more involved in construction.

You have a budget for neo drivers? and are planning on using one channel of your amp for subs, and one channel for your pair of tops?
Ohh that would be nice ,
i want neo drivers , to save total weight, 1/2" , auraco or baltic birch
3/4 is too heavy
i will start with one and i dont know if that can be fitted in a community 15" push pull type of box i posted, or dual 12's to save some space
i need to fit one of those in the back of my car, 48" max height , 20" width and 22 deep .

im choosing PPSL because you suggested and the build is just straight cuts
much easier than a tapped horn

so ppsl is more efficient than single driver tapped horn design ?

also, if for example we use the 3015lf or 3012 lf
and it is rated at 450w rms, means that paralleled i can feed them
900 w rms right ?
since my amp is not that powerfull, i will keep bigger power drivers when later i upgrade to another amp in bridge mode just for that
but at least i will have a low end missing now from my current speakers
and yes, i have only a crown XLS drivecore 2000
so ch1 for the sub and ch2 for 2 tops

Last edited by maxo; 7th February 2013 at 04:11 PM.
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Old 7th February 2013, 04:44 PM   #22
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Quote:
Originally Posted by maxo View Post
im choosing PPSL because you suggested and the build is just straight cuts
much easier than a tapped horn

so ppsl is more efficient than single driver tapped horn design ?

also, if for example we use the 3015lf or 3012 lf
and it is rated at 450w rms, means that paralleled i can feed them
900 w rms right ?
You suggested BR, Jbel suggested the PPSL variant of BR.
PPSL is really no more efficient in LF output than BR, it just reduces even order distortion.
TH is more efficient, but requires a larger box to go as low as BR and maintain an efficiency advantage.

The 3015LF is rated for 450 watts AES, which uses a compressed pink noise signal with 6 dB dynamic range. A pair driven with an amp capable off 900 watts in to 4 ohms would be a reasonable amount of power.
"Watts RMS" would imply sine wave, which has only 3 dB crest factor, double the average power of the AES rating.

Art
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Old 7th February 2013, 04:56 PM   #23
maxo is offline maxo  United States
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Location: A Hole in Texas
Quote:
Originally Posted by weltersys View Post
You suggested BR, Jbel suggested the PPSL variant of BR.
PPSL is really no more efficient in LF output than BR, it just reduces even order distortion.
TH is more efficient, but requires a larger box to go as low as BR and maintain an efficiency advantage.

The 3015LF is rated for 450 watts AES, which uses a compressed pink noise signal with 6 dB dynamic range. A pair driven with an amp capable off 900 watts in to 4 ohms would be a reasonable amount of power.
"Watts RMS" would imply sine wave, which has only 3 dB crest factor, double the average power of the AES rating.

Art
so that means i will need a 1800 watt amp to double the aes of 900 ?
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Old 7th February 2013, 05:03 PM   #24
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Quote:
Originally Posted by maxo View Post
so that means i will need a 1800 watt amp to double the aes of 900 ?
Yes, 2x900 =1800 .
The 3015LF cones already flex quite a bit at 450 watts, probably why jbel suggested a distortion reducing cabinet design.
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Old 7th February 2013, 05:04 PM   #25
jbell is offline jbell  United States
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I realize you are conflicted on what to build, you've looked at several different options.

In "General" but certainly not always....
A TH can and is usually more efficient that any reflex design. aka, more spl per watt.
A PPSL can be smaller than the above TH, and can match the output of a TH, but at the expense of double drivers, double power.

SO, I think the best thing I could do for you right now is help you define what you want, and as the saying goes, loud, low, small -- pick 2. ONLY 2... that's where the trade off's start...

AND, this doesn't even factor in cheap vs expensive.

So your highest priority sounds like small.... so that eliminates the more efficient designs... and means you need more power to achieve the same spl.... but you are limited on power too.

small, efficient, and loud is the holy grail and doesn't really exist....

So, help us out. What is the maximum size and weight cabinet you can accept. Start there. Then what is the max voltage your amp channel(s) that you are going to dedicate to your sub(s) can long term produce. Then you evaluate the options that fit the first two, and see which one produces the cleanest spl for your application.

If it's something you can easily build -- it's a winner
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Old 7th February 2013, 06:50 PM   #26
maxo is offline maxo  United States
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Jim,

48" max height , 20" width and 22 deep, low extension i dont care , i mean 40hz or 35 hz low is the most i want, it is for PA not for cinema

weight i dont care for the given dimensions, altough light magnet drivers are a plus, so i will like to have both options in case i want to go with the more expensive route

Now, i was thinking instead of a dual 15 or dual 12 , singles like the SS15
but smaller at the expense of injecting more power to them
what about a mini SS15, with dual 12 drivers or single 12" driver
Lab 12's i heard a lot or 3012LF,

another tought is the 3015 Tqw that bjorno posted
the size is perfect
but can that thing be fitted with dual 12 to get some more spl out of them
or i just a plain no and you need just a more powerful 15" driver

some ideas i just come up with
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Old 7th February 2013, 07:16 PM   #27
tb46 is offline tb46  United States
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Hi maxo,

Jbell is the one to ask, but I think a SS15 style TH using the 3015LF should fit into your dimensions. It would even give you a longer horn path for a slightly lower response. That's a sub with a single driver, doesn't need outlandish power, and should go plenty loud.

Regards,
__________________
Oliver
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Old 7th February 2013, 08:57 PM   #28
maxo is offline maxo  United States
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Thanks Oliver
now that i am looking at all this thing from a broad point of view
and i think i will return to my starting point
that is an SS15 then another one for a pair

Jim
can the dimensions be changed to make a slimmer version of it and maybe taller
to conserve the volume of the enclosure
that is just for easy of transportation purposes
as i have a 20" by 20" rack and it is hard to get the sucker in the back seat
because of the opening shape of the backdoor

so can a "slim" ss15 would be possible ?
so instead of 22x24x30 as stated in the cut sheet drawing
maybe a 18 x 24 x (34....40 )
and if that is feasible, does it affect the response of the cab
?

Also a "slim" ss15 will outperform the Bjorno 3015LF TQWTH ?

i like the 3015LF and B&C 15NDL76 to say some drivers
i need a little truck but as of now that i not possible
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Old 7th February 2013, 10:28 PM   #29
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Quote:
Originally Posted by maxo View Post
48" max height , 20" width and 22 deep, low extension i dont care , i mean 40hz or 35 hz low is the most i want, it is for PA not for cinema
The Keystone TH sub is 45 x 22.5 deep x 26.5 wide. It could be made to 22" deep and 20" wide and still go to 35 Hz, but would loose a bit of efficiency from the "full size" version.

Keystone Sub Using 18,15,&12 Inch Speakers
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Old 7th February 2013, 10:44 PM   #30
maxo is offline maxo  United States
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let me look at it, hope is not a nightmare to assemble and cut the wood
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