Single sheet TH challenge - Page 89 - 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 5th April 2011, 11:06 AM   #881
diyAudio Member
 
Join Date: Nov 2010
Quote:
I'm congratulating you on your learning, your design efforts, and your follow through to a finished product.
Thanks Jim; I am pleased with my boxs. Andy
  Reply With Quote
Old 5th April 2011, 11:44 AM   #882
Chaps is offline Chaps  Denmark
diyAudio Member
 
Join Date: Nov 2010
Quote:
Originally Posted by 4pyros View Post
I still need to weigh it. I will get back to you.
Would it make any sense to measure my boxs at 28.3VRMS @10 Meters like Danley dose? Then may be my tests would be more concusive. Andy
I think that would be interesting!
  Reply With Quote
Old 5th April 2011, 01:29 PM   #883
diyAudio Member
 
Join Date: Jan 2011
Flip, 12 of those bad boys must sound great!
  Reply With Quote
Old 5th April 2011, 01:29 PM   #884
jbell is offline jbell  United States
diyAudio Member
 
Join Date: Apr 2003
Location: .
Quote:
Originally Posted by 4pyros View Post
I still need to weigh it. I will get back to you.
Would it make any sense to measure my boxs at 28.3VRMS @10 Meters like Danley dose? Then may be my tests would be more concusive. Andy
Absolutely, especially since you plan on running them as pairs with tops over for your intended use.

Measure a pair @20v each @10m with the cabinets side by side upright, and then again with the cabinets on their side with the mouths touching.

Then measure a single cabinet @28v@10m upright, and on it's side.

Those 4 measurements would be nice to see, and also should give you a great idea on how they will perform in real life, as you'll probably be running these 20m from the audience in pairs.
  Reply With Quote
Old 5th April 2011, 02:01 PM   #885
tb46 is offline tb46  United States
diyAudio Member
 
Join Date: Jan 2006
Location: Texas
Hi jbell,

Just stumbled across your outside testing in Post #845. Very nice indeed. You wouldn't have the numerical data from, say 20Hz to 300Hz, would you?

Regards,
__________________
Oliver
  Reply With Quote
Old 5th April 2011, 02:47 PM   #886
diyAudio Member
 
Join Date: Jan 2008
Quote:
Originally Posted by 4pyros View Post
Here are the unofficial results. I wish it was better down lower but I got a good peak at 180Hz. I am calling it good to make more. Any other thoughts? Andy
Andy,

The upper frequency "peaks" will reduce in multiples. They should be well above where you would want to cross over a "sub", anyway.

Your lesser measurements below 50 Hz could be due to several different possibilities:

1) If you are using a dB meter that has only “A “and “C” scale, the “C” scale is better for measuring LF, but is still down about 2 dB at 40 Hz.

2) Microphones have different response, your or Jim’s may have deviations in the LF.

3) You added some corner ramps, which reduce cabinet volume. They did not seem to affect the upper response compared to Jim’s, but the reduction in cabinet volume may have reduced the LF.


Overall, the SPL readings are remarkably consistent between the two builds.

I am curious as to what voltage the 3015LF in the SS15 will sustain without exceeding Xmax (19.2 mm peak to peak).
Looking at your SPL readings I’d guess about 45-48 Hz will be as low as your cabinet can go with full power, 450 watts, 60 volts.

Art Welter
Attached Images
File Type: png Resp. & Weighting.png (103.4 KB, 548 views)
  Reply With Quote
Old 5th April 2011, 05:30 PM   #887
diyAudio Member
 
Join Date: May 2001
Location: Bangalore, India
Given all the caveats posted by Art Welter, what has the 4pyros' cab gained over Jim's? At first glance, it looks like a lot more of weight and path-length for a slight loss in LF SPL levels and gain at HF at frequencies before which the subs will be crossed over anyway.

Perhaps, we will still find out that Jim has pretty much optimised the 3015LF in his SSTH15!!
__________________
Sam
  Reply With Quote
Old 5th April 2011, 09:30 PM   #888
diyAudio Member
 
Join Date: Nov 2010
Quote:
Given all the caveats posted by Art Welter, what has the 4pyros' cab gained over Jim's? At first glance, it looks like a lot more of weight and path-length for a slight loss in LF SPL levels and gain at HF at frequencies before which the subs will be crossed over anyway.
The testing was not perfect and the mesherments may not be exact. I know my pyro box should go slightly lower than Jim's SS15. I need to come up with better ways to test it and repost the results. Coming soon. Andy
  Reply With Quote
Old 5th April 2011, 09:51 PM   #889
diyAudio Member
 
Join Date: Nov 2010
Quote:
Would it make any sense to measure my boxs at 28.3VRMS @10 Meters like Danley dose? Then may be my tests would be more concusive.
My main thought here is it will be alot easier to dial in 28.3VRMS on a 1000 watt amp than it is to try and keep a 2.83VRMS setting. Andy
  Reply With Quote
Old 5th April 2011, 10:04 PM   #890
diyAudio Member
 
Join Date: Nov 2010
I also had some problums with my test waves. I downloaded the the test CD that Jim had suggested and put it on a stick. My player would not play the files so I put them on a CD.
I started testing at 10 to 20Hz and was getting some high numbers. Than when I whent to 20-30Hz the DBs dropped by 10 or so and steady rose again from there. I am not shure what that was about but I will take a look at the CD in Gold Wave and try to convert the files for the stick that can work on the player. Andy
  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
Here is a Challenge latala Solid State 41 12th May 2011 01:13 AM
Renovation Challenge ZirconiumZephyr Multi-Way 16 1st September 2009 08:38 AM
Design Challenge #1 kgillies Subwoofers 12 13th June 2007 03:20 PM
a challenge --or I need help lawrence99 Car Audio 0 9th March 2005 04:44 AM
The challenge ! thylantyr Solid State 51 24th July 2003 08:41 PM


New To Site? Need Help?

All times are GMT. The time now is 12:06 AM.


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