[ironglen]

Hi All, after all my contemplating on what to do about my anemic low end in my HT, I decided on an SVS PC-12 cylinder (thanks members for the advice), however, I now want to replace my former sub (see my 'bad box...' thread for more). So, I have plenty of speakers around that will handle 75 hz and up, but need your help in selecting a 10" driver for a cylinder sub. Why cylinder? Small footprint:bigsmile:

I read somewhere that the driver for this purpose should have a Qts < 0.40,
Fs < 45 hz, and either Vas < 4 ft3 (113L) OR Fs/Qes > 83. Is this info correct?

I have two options, a driver used from LFE out for inside only, or a flexible sub that I could use inside and in my garage. I would use it inside with an old receiver, either 70w/2xch or 100w/2ch. I could either use the low-level sub out with the 100w/2ch, which I'd send to another old receiver for power, or perhaps I could use a passive xover and use it in both places with a couple stereo speakers.

I found this svc speaker http://www.madisound.com/catalog/product_info.php?products_id=79, which looks like a good driver at a great price, but perhaps a member can help with my decision?

Cost of the driver needs to stay low, around $100, if possible.

Thanks in advance!

 

[Mike P.]

You'll be getting a SVS PC-12 for your HT. What is the 10 inch for?

 

[ironglen]

It's for my office and/or garage. (probably garage-for music only, no HT) I only have small speakers with 4.5-5.25 drivers in them

I figured I have the wood and hardware, and the tube, if I use a 12" x 48", is inexpensive at ~$12. So a driver, if a reasonable price, is all I need to hear it (the wife won't care what it looks like until I can finish it with more $

 

[ironglen]

ok, I admit it- I also want to see those awesome graphs you produce, Mike:bigsmile: That software must be purchased, correct? And is it difficult or extensive to use? I looked at the sonotube calculator and it looks like I could use the 12x48 tube with a 4" port ~12" long to tune to ~30hz, I think:scratchhead:

 

[Mike P.]

WinISD is a free download. There is a tutorial and a download link here:

http://www.hometheatershack.com/forums/diy-subwoofers/6330-winisd-pro-tutorial-download-detailed-guide-how-use-winisd-pro.html

I'll model the Aurasound and we'll see what it looks like for a music application.

 

[Mike P.]

The Aurasound looks good in 2 cu.ft tuned to 28.3 hz. The tuning reflects a full length 4 inch flared port which is 18 inches.


Xmax is reached with 200 watts input. The sub exceeds Xmax at about 25 hz which shouldn't be a problem for a music only sub.


Dimensions for a 12 inch diameter sonotube.

 

[ironglen]

Thank you Mike, I hope it didn't take too much of your time. I've been out this evening but will look the info that you posted over.

Do you (or anyone else) know if it is a good driver/manufacturer? I haven't been able to find any feedback on the quality of their drivers and I've never dealt with madisound, although I believe I heard of them many years ago.

 

[mayhem13]

http://home.comcast.net/~jhidley/

Scroll to the bottom and check out the 11-116 surplus NHT sub drivers. These were originally used in the high end XD systems. It is an exceptionally well built driver and untouchable at the price. Works very nice in 2cuft and tuned to 25hz with a 3" port at 12.5" with an F3 of 30hz. Pretty efficient driver as well.

 

[ironglen]

Thanks for the info- wow, they're clearing out alot of goods. The speaker looks like it may be a good fit as well however, there is a hold on most products during an inventory, but I may go ahead and order a plate amp as it's currently available, will suit my use, and is cheap!

 

[Mike P.]

I may go ahead and order a plate amp as it's currently available, will suit my use, and is cheap!

You should find out at what frequency the high pass filter is first.

 

[ironglen]

You should find out at what ferquency the high pass filter is first.

Thanks for the reminder; he had a link with schematics and resistors to change to modify the cutoff freqs. Say, Mike, I looked at the winisd and could use some help to determine if the driver mayhem suggested would work well, along with calculated dimensions for the tube. The specs looked somewhat similar to the Aura to me, enough that it would work well on a budget.

 

[Mike P.]

I can't get to the site for some reason. Post the parameters for the sub and I'll do a comparison.

 

[ironglen]

Thanks Mike, here are the specs when you get the chance:

npt-11-116-1
XdW woofer

Re 2.65 (this measurement often appears lower than the value stated by the manu., no?)
Fs 29.8
Qms 7.046
Qes 0.403
Qts 0.381
Vas 37.34
SPL 90.65 (signi. higher than the Aura's)
Zmax 49.0
Sd 0.03464
Xmax 12.0 (+ only, I believe)

13.2 lbs

In winisd, one of the first inputs is which type of port to use, which one would I select for a cylinder?

 

[Mike P.]

In winisd, one of the first inputs is which type of port to use, which one would I select for a cylinder?

You mean the shape of the port (round or square) in the "Vents" tab?

 

[ironglen]

It was under 'vents' but it says to use the default and select 'next'...

I got...raying: 28.26L 31.34 hz tuning...with 4" dual flared port for 31.68" !:scratchhead:

 

[ironglen]

ok, got it to output some parameters, but nothing shows up on the cone excursion graph and some others, but I now have a 60L tuned to 26.0hz with a 4" port of 20" length, with a low pass at 120hz and high pass at 20 hz. Port air is on the high end, but acceptable I think at nearly 17.5

 

[Mike P.]

It was under 'vents' but it says to use the default and select 'next'...

You must mean the "Box Type" screen when you first start. The program is suggesting a "Vented" box.

60 liters tuned to 25 hz looks good. 200 watts input with a HPF at 20 hz keeps the sub within Xmax. A 4 inch flared port 23.5" keeps the air speed under 26 m/s.

 

[Mike P.]

A couple of issues. The Aurasound and the NHT subs are 4 ohms. If you're going to power the sub with a receiver, it'll have to be 4 ohm stable.

I remember reading that the website that sells the NHT sub has a minimum order price of $80 or $90 dollars. You should check into that should you decide on the NHT sub.

 

[ironglen]

I went ahead and ordered the Aura 10" as well as a flared 4" port, and grill from Madisound. I also picked up an amp from the NHT surplus: he'll allow you to buy those without the minimum as it will be shipped in the carton without additional packaging, so ~$45 to my door for 115 W into 4 ohms. I picked up a 4' tube, ~13" dia at the store, which I'll measure and try to use the winisd to calculate it accurately with 3/4" endcap thickness.

Now, I just have to figure how to mount the plate amp to the box...I saw another member's side mount configuration, where it butts up against it. I'd rather mount it to the baseplate somehow, perhaps facing up toward the driver- I guess a top mount to another plate above the port would affect sound and make it top-heavy: any ideas appreciated!

 

[ironglen]

Thanks Mike for your help with the winisd and planning. :T Still figuring the baseplate/amp configuration, but I'll be using a 2.2 ft3 volume with a 28 hz tune (the cylinder is ~12.4" ID and my port is 17" long max, so I added a little bit), and it looked good with the stock 25 hz high pass on the foster plate amp; the amp has a 6db boost at 35hz but I wasn't able to model with it activated, so I may have to change some resistors to flatten that- or maybe not.

Turns out my old box has sides large enough for the 4 endcap pieces, and I'll add a piece of 1" plywood for the base. Just have to figure the connection to the baseplate:scratchhead: