DIY 1st timer: Please help the noob.

zhopudey · 26th July 2008, 12:04 PM

Hi everyone,

I've decided to take the plunge into diy

I have bought a pair of Peerless India 3" fullrange drivers and a pair of 8" woofers ( S20NISH-08) http://www.peerlessaudio.com/product...3.asp?pname=17

Now I'm stuck at the designing stage

I used WinISD Pro, and entered the parameters for the 8" as given in the help, but I keep getting a "Divide by zero" error. I also tried speaker workshop, but couldn't quite figure it out. Is there any other software I could try?

Have any members from India used this woofer? I think I need Sd, Hc and Pe values for WinISD to work.

Also, I can't decide whether to go for 2 sealed boxes or one isobaric box. What are the comparative pros and cons? My room size is 9.5x12.5x8.75 (WLH)

TIA

Ron E · 26th July 2008, 01:29 PM

Sd = S = 230.58 cm^2 or .023058 m^2
Pe = Pi - not specified - you can guess, maybe 50-100Watts
Hc = height of coil, not specified
( Hc(oil)-Hg(ap) )/2 = xmax, for a nonspecific 8" woofer you might guess that Xmax is 3-5mm - so Hc is 11-15mm (probably at low end of this range)

Try entering only the following parameters into the parameter sheet (watch out for units)
Fs
Qes
Qms
Cms
Sd
Re
Pe
Xmax

Then let the program calculate the rest and don't be too concerned if the calculated values are a little different than your spec sheet. It is fine to put in a guess value on the last two in my list, it does not affect box volume calculation, it only affects port design and max output.

[edit .. if you try this and still have problems entering parameters , post a screen shot of what you are entering]

zhopudey · 26th July 2008, 02:10 PM

Thanks for the fast reply

I'll try this out and report back.

zhopudey · 27th July 2008, 02:31 PM

Ok that worked

I'd mixed up some of the units earlier.

Any suggestions regarding 2 sealed boxes vs a single isobaric box?

Ron E · 27th July 2008, 05:47 PM

Well, the decision is between space or performance.

You will get more SPL out of 2 separate woofers - you might save a little space with an isobaric, but you will get less output. It's your decision.

26th July 2008, 12:04 PM	#1
zhopudey diyAudio Member Join Date: Sep 2007	DIY 1st timer: Please help the noob. Hi everyone, I've decided to take the plunge into diy I have bought a pair of Peerless India 3" fullrange drivers and a pair of 8" woofers ( S20NISH-08) http://www.peerlessaudio.com/product...3.asp?pname=17 Now I'm stuck at the designing stage I used WinISD Pro, and entered the parameters for the 8" as given in the help, but I keep getting a "Divide by zero" error. I also tried speaker workshop, but couldn't quite figure it out. Is there any other software I could try? Have any members from India used this woofer? I think I need Sd, Hc and Pe values for WinISD to work. Also, I can't decide whether to go for 2 sealed boxes or one isobaric box. What are the comparative pros and cons? My room size is 9.5x12.5x8.75 (WLH) TIA

26th July 2008, 01:29 PM	#2
Ron E diyAudio Member Join Date: Jun 2002 Location: USA, MN	Sd = S = 230.58 cm^2 or .023058 m^2 Pe = Pi - not specified - you can guess, maybe 50-100Watts Hc = height of coil, not specified ( Hc(oil)-Hg(ap) )/2 = xmax, for a nonspecific 8" woofer you might guess that Xmax is 3-5mm - so Hc is 11-15mm (probably at low end of this range) Try entering only the following parameters into the parameter sheet (watch out for units) Fs Qes Qms Cms Sd Re Pe Xmax Then let the program calculate the rest and don't be too concerned if the calculated values are a little different than your spec sheet. It is fine to put in a guess value on the last two in my list, it does not affect box volume calculation, it only affects port design and max output. [edit .. if you try this and still have problems entering parameters , post a screen shot of what you are entering] __________________ Our species needs, and deserves, a citizenry with minds wide awake and a basic understanding of how the world works. --Carl Sagan Science is a way of thinking much more than it is a body of knowledge. --Carl Sagan

27th July 2008, 05:47 PM	#5
Ron E diyAudio Member Join Date: Jun 2002 Location: USA, MN	Well, the decision is between space or performance. You will get more SPL out of 2 separate woofers - you might save a little space with an isobaric, but you will get less output. It's your decision. __________________ Our species needs, and deserves, a citizenry with minds wide awake and a basic understanding of how the world works. --Carl Sagan Science is a way of thinking much more than it is a body of knowledge. --Carl Sagan

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Timer for airconditioning?	thuur	Everything Else	5	7th June 2009 07:13 AM
First Timer needs help	mgalvez	Tubes / Valves	24	17th October 2007 10:34 PM
Need help with PIC timer.	Tolik	Parts	9	9th May 2007 10:02 PM
Help a first timer to select...	CJ900RR	Tubes / Valves	12	31st January 2006 04:46 AM
stupid first-timer	Lico	Tubes / Valves	9	20th November 2003 09:54 PM


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

26th July 2008, 02:10 PM	#3
zhopudey diyAudio Member Join Date: Sep 2007	Thanks for the fast reply I'll try this out and report back.

27th July 2008, 02:31 PM	#4
zhopudey diyAudio Member Join Date: Sep 2007	Ok that worked I'd mixed up some of the units earlier. Any suggestions regarding 2 sealed boxes vs a single isobaric box?

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read