First post and DIY subwoofer questions... - diyAudio
Go Back   Home > Forums > Loudspeakers > Subwoofers

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
Reply
 
Thread Tools Search this Thread
Old 12th January 2005, 07:09 AM   #1
diyAudio Member
 
Join Date: Jan 2005
Location: CANADA
Default First post and DIY subwoofer questions...

Hello everyone, looks like a good board here! I just bought my first peices to my first home system last month. I have a Yamaha RX-V1500 receiver and a pair of Pro-Linear Euro Series PTX50T towers. I just ordered a 1000W plate sub amp from partsexpress:

http://www.partsexpress.com/pe/pshow...08&ctab=4#Tabs

And I have two Image Dynamics IDQ v.2 DVC 2 ohm subs here that aren't being used so I am going to be using them for my home subs. Going to wire them into a 8 ohm load on the amp giving them about 250 watts each sub. The subs are going to each be in their own enclosure, with one sub in each corner of the room. So the amp will have its own enclosure built and it will go at my entertainment stand somewhere.

My questions concern my woofer enclosures... I downloaded WinISD, is this a fairly accurate program for finding out what size to build the best box size? I am going to be using sealed enclosures just for simplicity. Or should I just kind of go with what the specs that were given with the sub, even though it is a car audio sub. Next question is do I need acoustic foam inside my box or would polyfill work or could I do without? The feet I was going to get for the sub enclosures were these spikes:

http://www.partsexpress.com/pe/pshow...40-725&scqty=4

or should I get the larger ones that are 1/2" instead of 3/8"?

Any help or suggestions appreciated! Thanks
  Reply With Quote
Old 12th January 2005, 10:49 PM   #2
simon5 is offline simon5  Canada
diyAudio Member
 
Join Date: Nov 2004
Location: Québec, Québec
WinISD is very accurate, but the volume they will tell you is internal total volume, you need to substract anything that's in the box, like the volume of the driver, the bracing, the plate amplifier, so don't just build a box with external volume calculations. If it's sealed, the impact won't be big, but in a ported box, the total internal volume is very important.

Since it's a subwoofer for a car, it's probably a good idea to not use the same enclosure that the manufacturer want you to do.

Also, a good thing to note is that WinISD measure the performance of your subwoofer in a anechoic space. So, under a certain frequency, you need to consider room gain that will lift the lower frequencies in SPL, especially in a small room.
__________________
DIYaudio for President !
  Reply With Quote
Old 13th January 2005, 06:56 AM   #3
diyAudio Member
 
Join Date: Jan 2005
Location: CANADA
Hi I am trying to use the WinISD program here and got a couple questions. In the area where you fill out all the driver data, my spec sheet has everything except Sd and Z. And I'm not to sure what to put in the Re spot. On my spec sheet it says: Re - .975/3.9. Should I use .975 or 3.9? The sub is DVC 2 ohm so what should I put in the Z blank 2 or 4? The subs will be wired in series. And should I just use the Sd that they use with the IDQ they have in their list?

Thanks!
  Reply With Quote
Old 13th January 2005, 10:25 AM   #4
KEFMAN is offline KEFMAN  Australia
diyAudio Member
 
Join Date: Dec 2004
Location: Cranebrook NSW
Default subs

The enviroment for car audio enclosures is so far away from the home situation as is the difference between headfones and real life. I can't advice you on the way to go except to say, ignore the car thing!!
  Reply With Quote
Old 13th January 2005, 04:18 PM   #5
diyAudio Member
 
Join Date: Jan 2005
Location: CANADA
Somebody correct me if I'm wrong but isn't there no difference between a sub made for car audio and a sub made for home audio other then the spec sheet for box building they give? There isn't actually a difference in the sub is there? There is no problem using Image Dynamics subs for a home application even though they are sold as 'car audio' subs? I am somewhat confused with your reply KEFMAN, please explain. Also, question still stand from my last reply... about WinISD.

Thanks
  Reply With Quote
Old 13th January 2005, 07:41 PM   #6
simon5 is offline simon5  Canada
diyAudio Member
 
Join Date: Nov 2004
Location: Québec, Québec
Since you will use it in series, write 3.9 in the Re spot. Z is not important and WinISD will estimate it alone.

Check if the measurements on your specsheet were taken with voicecoils in series or in parallel. That will change BL, Re and Le.

By the way, you don't need to enter a parameter in each blank. WinISD will calculate the missing ones. Enter each parameter one by one and let it calculate parameters.

If it's the same diameter driver, there's a good chance that's the same Sd.
__________________
DIYaudio for President !
  Reply With Quote
Old 13th January 2005, 10:25 PM   #7
diyAudio Member
 
Join Date: Jan 2005
Location: CANADA
Ok this is strange, according to WinISD my enclosure should be only 22.4 litres (or .79 cuft) for each sub. This is a little smaller then the 'normal' specs for using the sub in a car sealed. Does this sound right?
Thanks
  Reply With Quote
Old 14th January 2005, 12:05 AM   #8
simon5 is offline simon5  Canada
diyAudio Member
 
Join Date: Nov 2004
Location: Québec, Québec
I think it's a bit too small, but maybe you're not aiming as low as me.

I used 70 liters tuned to 18 Hz and it looks very well but you would need a passive radiator hehe!

This subwoofer likes a small box it seems.

Did you used the suggested enclosures or you tuned it yourself?
__________________
DIYaudio for President !
  Reply With Quote
Old 14th January 2005, 01:38 AM   #9
Collo is offline Collo  Australia
diyAudio Member
 
Collo's Avatar
 
Join Date: Nov 2004
Location: Newcastle, Australia
Send a message via MSN to Collo
I've been using WinISD (0.50a7) for about a year now and I just love it.

When entering parameters into the database, make sure the "autocalculate unknowns" is unchecked when entering a new speaker otherwise you get compaints.

Sd is the effective cone area - if you don't lnow it, copy the figure from a similar sized driver in the database.

The authors run a forum at the website which is very useful
http://linearteam.proboards12.com/in...i?board=winisd

good luck with your sub....
  Reply With Quote
Old 14th January 2005, 02:01 AM   #10
simon5 is offline simon5  Canada
diyAudio Member
 
Join Date: Nov 2004
Location: Québec, Québec
It is better to have "autocalculate unknown" checked IMHO and to enter only some parameters in a certain order, then WinISD calculate the rest. WinISD complaints because the manufacturer parameters are not correct.
__________________
DIYaudio for President !
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Various Subwoofer Questions - Thanks topher_m Subwoofers 1 1st March 2008 04:44 PM
genaric questions post. branboom Planars & Exotics 6 28th December 2007 03:43 AM
AR9 Subwoofer Questions dc270 Subwoofers 0 7th May 2006 12:17 AM
subwoofer questions Jacobus Subwoofers 9 15th December 2005 12:05 PM


New To Site? Need Help?

All times are GMT. The time now is 12:31 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2