4 RSS315HF-4 12" + 1 HPSA1000 Amp Project

[damcard]

This is my first post on Home Theater Guide. Hello. I have a 11.5' x 14.5' room that I am turning into a theater. Currently I am using a Yamaha RX-V1500 receiver, 3 Phase Tech PC 3.1s for my front left, center, and right. I have 2 Phase Tech 6.1s for my rears. I have the 5 for my 5.1 system. I just ordered the parts to build my subwoofer. I already purchased them, so I do not need alternative part suggestions.

I ordered 4 Dayton RSS315HF-4 12" high fidelity subwoofers and a Dayton HPSA1000 plate amp plus other little items like floor spikes etc. I believe I would like to make two separate subwoofer enclosures for my left and right mains to sit on. I believe I would like the subs to face the front, one speaker above the other so that the sub is taller than it is wide. The plate amp can go in one speaker and each enclose will have two banana plugs to connect them.

The drivers can be found here:http://www.partsexpress.com/pe/pshow...95-464&scqty=4

The amp can be found here: http://www.partsexpress.com/pe/showd...number=300-808

Lastly, I would like to build a sealed enclosure for each pair and use a Linkwitz Transform Circuit if my amp will have enough power. I have ample space for them, but would like to keep them a small as I can without compromising the sound.

To get started on this project, my first question is what free software can I use to start designing these enclosures and has anyone here used the Linkwitz circuit with more than one driver?

[JonMarsh]

WINISD and Unibox are two possibilities for free software- some find WINISD easier to use, but in my experience Unibox, which runs in Excel, is more flexible and accurate. Google is your friend to find these on the net.

For a Linkwitz transform, you're better off in most cases with the HO version of the RS315, which will better tolerate the extra power needed for a small box with a transform equalizer.

Here's a good description of the LR transform concept to be sure you're up to speed (and why you need the higher power handling driver)

http://sound.westhost.com/linkwitz-transform.htm

Here's a spreadsheet for calculation.

http://www.trueaudio.com/downloads/linkxfrm.xls

There are dedicated units like the Marchand Bassis which will implement this, but it can usually be done just fine with a "standard" lower cost equalizer like a Behringer BFD.

Some Adire plate amps have an LT circuit built in- check their site, or their dealers like CSS in Canada.

Have fun! You should have a nice setup when you're done.

~Jon

[damcard]

Thanks Jon,

WINISD and Unibox are two possibilities for free software- some find WINISD easier to use, but in my experience Unibox, which runs in Excel, is more flexible and accurate. Google is your friend to find these on the net.

I will try both of the programs you listed tonight.

For a Linkwitz transform, you're better off in most cases with the HO version of the RS315, which will better tolerate the extra power needed for a small box with a transform equalizer.

I am already getting the HF drivers. They were shipped today. So, I will have to make due. I thought having 4 of the HF drivers would be better than one of the HO drivers which were what I was going to get originally. So, do you think the HF drivers at 400 watts RMS/700 watts max will not cut it in a 11.5’ x 14.5’ room? If so, then I will probably just try doing a very large sealed enclosure or a smaller ported enclosure.

Here's a good description of the LR transform concept to be sure you're up to speed (and why you need the higher power handling driver)

http://sound.westhost.com/linkwitz-transform.htm

Here's a spreadsheet for calculation.


http://www.trueaudio.com/downloads/linkxfrm.xls

I have looked at these before, I will read up again now that I have specs.

There are dedicated units like the Marchand Bassis which will implement this, but it can usually be done just fine with a "standard" lower cost equalizer like a Behringer BFD.

I will look into this as an alternative.

Some Adire plate amps have an LT circuit built in- check their site, or their dealers like CSS in Canada.

I have the 1000 watt plate amp. That is the one I will be using. It was also shipped today. If it is not powerful enough for the Linkwitz transform, then I will have to go with the large sealed or smaller ported enclosure.

Have fun! You should have a nice setup when you're done. ~Jon

Thanks, I am looking forward to getting it all together. -David

[JonMarsh]

The 1000 watt plate amp should be fine- the RS woofers are not that power hungry, compared to some of the really long throw long Xmax drivers.

WINISD or Unibox should be able to give you a good idea of how small a box you can get away with. The bigger the box, the less EQ you need and the less worries about power handling. The HF series work best in moderate size boxes. Xmax limited power handling is the same as the HO series, but the HO series can dissipate more power in the voice coil.

Remember that depending on placement, you'll get some room gain below 50 Hz, so you probably won't want to think in terms of flat anechoic response to the frequencies below 30 Hz, but a slight net taper and roll off (anehoic), with a gradual down slope from 60 Hz to 20 Hz, tapered about 4-5 dB.

~Jon

[damcard]

I recieved my drivers and amp.

I recieved my drivers and amp plus some other stuff. I used Unibox, atleast tried to. The attached jpegs are pieces of the screen shot. The single image was too large so I broke it up. Could one of you that are experienced with Unibox see if I did it right? It gave me a F3 of 40.55 Hz. I thought that was too high. I am not sure what vB to use. It is at 39 (1.377 cubic feet) liters in this screen shot. It seemed that going higher did not change the response much. Still, 39 liters seems too small, right? Also, I did not know the Sd of this driver. How do I correctly measure it? I used the Sd from the Titanic MKII 12" driver. As you can see, I need help.

[KeithM]

since you have entered 2 drivers in parallel, you'll need double that box size. it still seems really small. WinISD is recommending 134-7 liter box.

[Bent]

Your last capture of the box sizes/F3/Fb, etc shows the graph not having been updated...

also, when entering the T/S param. (I don't know for sure here), should you double the driver's Vas for two drivers, or will Unibox do that for you when you say two drivers in parallel?

[Bent]

AHA! it would seem you didn't convert the Vas to liters prior to using unibox...
3 cubic feet is not 3 Liters... it's closer to 84 liters.
Try simulating with 84 liters as the Vas of the driver.