Suggerstions for subs doing 50-350Hz.

[swak]

I will be using Audax pr17 mids and Aurum ribbon tweeters, and I need a solution for two subs on separate enclosures to do the lowest frequencies. Size is important and should be small, I guess around 50 liters. I am doing these speakers for a friend who needs them quickly, so a project floating around would probably be the best.

I would appreciate any suggestions.

[Cal Weldon]

Hi Swak,

Are those figures correct? 50hz is the bottom cut off?

If so you may wish to look at PA woofers. They don't go deep but they perform well down to 50Hz.

What size are you looking for?

[swak]

Cal, thanks for responding.

Actually they should do lower, I´d say an f3 of 35Hz or thereabouts, anyway with SOLID 50Hz. I think he will complement these speakers later on (1 year or so) with another sub when extending the system to a HT.

The size, i guess 12". I´ve been tempted to try the madison PA woofers, but for the quick solution for this friend I am tending to build something already available as cut and paste (more or less) project. I dont care if sealed, vented.

[mashaffer]

How much money can you spend? Just a quick perusal of the Parts Express drivers I come up with several options. Your 50l comes out to about one and a half cubic feet. A Dayton HO 12 inch easily gets you there in a sealed box as 1 cubic foot still gets nice output down to 40Hz not counting room gain. The sealed enclosure is nice since you need to do it in a hurry and you won't have to do any diddling with tuning.

The cheaper Quatro 10 doesn't really do it sealed but a 0.7 cubic foot enclosure would work if you ported it.

Now here is the real bargain. The PE

HD Paper 12 inch buyout is less than $20 each and will give nice output down to 30Hz or below in a 1.4 cubic foot box. I bought one and stuck it in a 3 cubic foot box just to see how it did and have been quite pleased. I am sure that the distortion is much higher than the $150+ drivers but the extension and output was quite good.

I will be using it in about a 4 cubic foot sealed enclosure made from an electric fireplace frame.

So there is quite a range of possibilities. Mostly you are looking for a fairly low Vas, moderate Qts (e.g. 0.4x) and reasonably low fs. That way you can use a simple sealed enclosure to good effect. Too low of Q is going to make good extension difficult in a sealed box and too high of Vas will make the required box too big.

Hope this helps.

mike

Oops. Just noticed that the buyout is now sold out. I could have sworn it was there just a few minutes ago. Anyway look for similar specs.

[swak]

Mike thanks for your advice.

Too bad the woofers are sold out! I was looking today at much pricier candidates, the 10" Aurasound NS12-513, the 12" Rythmic, and the 12" dayton rss315.

All seem very good, the cheapest being the dayton @ $129.

The thing is I think the Audax Pr170MO need to have a relatively high high pass (around 300-350), ant the woofer that is supossed to work the best higher up ist the $171 aurasound.

Now, I guess it wont be a really a problem spending a little more, and SOLEN has even the plans for the aurasound. But what now bothers me is the price of the whole two subs if plate amps are taken in consideration.

What about one "digital" 2 channel amp / kit for the 2 Subs?

[mashaffer]

That high crossover is a problem for most plate amps I suppose. You could use a modified Sonic Impact but for very little more you could get an Audio Source power amp that would not need any modification. Another option is to get a used integrated amp or receiver (70s vintage) from a garage sale and build your own line level crossover. You could use op amps or passive for a crossover.

I am going that route with an open baffle project I am currently working on. I am using an 5.25" radio shack fostex OEM for mains and 10" goldwood high Q drivers for the woofers. I am driving the RS units with my Sony STR-V4 receiver (55W/ch). Rather than throw away the huge efficiency advantage of the RS drivers with speaker level crossovers I am biamping in a sort of kludged way with the headphone outputs going to my Peavey mixer amp (200W@4ohms in both main and monitor circuits). I use the 9 band EQ on the Peavey to "low pass" the signal for the woofers. Considering that the "crossover" is far from ideal the results are quite nice.

The next step is to build a 2nd order passive line level crossover and use that to connect the headphone output to a 70s vintage Realistic 35W/ch (8ohms) receiver I have laying around.

These speakers are quite capable down to 40Hz in my 14x14 room but given my love of organ music I am also working on a sub for them.

mike

[tinitus]

Those aurasound seems to have double spider, and in your case you dont need nor want that
I really dont think that a any sub driver would be good at 300hz, much too heavy
With 300hz xo point you cant just use any active xo and then do random passive between mid/tweeter
You are definately facing problems

[swak]

Mike,

yes, that is the problem with plate amps, and they are also not cheap. The one with the highest cut off freq has it at 200, normally 160Hz. Anf the filters are 12 or 24 dB/oct, which could be not enough if cutting the freq. off quite high (350-400Hz).

Do you mean there are amps from audiosource with integrated cut off filters? I could only find plain vanilla switching amps.

There is naturally the path you mentioned building crossovers (passive= big inductors) and attaching some amp, but as I mentioned, there is little time for that. A Behringer dig xo would be a solution, but thats another couple hundred to throw in.

Are there any gainclone (bridged) clones kits with integrated op-amp crossovers?

[mashaffer]

No the XO need not be expensive. One quad op amp, a hand full of caps and resistors plus power or go the passive line level approach with literally $2 worth of parts in it.

If you don't want to make a power supply for an active crossover get a couple of nine volt rechargeable batteries instead.

BTW why the high crossover? Are you crossing directly to a midrange driver? maybe a simpler solution is to use a full range instead so you can cross at 200 or less. You could still use a passive speaker level crossover to a tweeter with such an arrangement.

mike

[tinitus]

What do you think of this 10" AurumCantus with 21hz Fs, should fit in closed around 50-60 liter and I bet it has much nicer high FR than any sub driver, thus much better coherence with the mid/tweeter with 12db or even 6db xo (with corrections)

http://www.partsexpress.com/pe/showd...number=296-430