MTH30 Questions : Complete Noob! - Page 4 - 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 24th January 2013, 11:24 PM   #31
sebDIY is offline sebDIY  Belgium
diyAudio Member
 
Join Date: Oct 2011
Measurement (calibrated) from one of my MTH:



Click the image to open in full size.
  Reply With Quote
Old 25th January 2013, 03:01 PM   #32
tb46 is offline tb46  United States
diyAudio Member
 
Join Date: Jan 2006
Location: Texas
Hi sebDIY,

Thanks for that. It basically confirms the Hornresp simulation (real life smaller peaks, etc.). How high up do you use it?

Regards,
__________________
Oliver
  Reply With Quote
Old 25th January 2013, 08:58 PM   #33
diyAudio Member
 
Join Date: Jan 2008
Quote:
Originally Posted by sebDIY View Post
Measurement (calibrated) from one of my MTH:
Click the image to open in full size.
Thanks for posting the chart, what were the measurement conditions?
What drivers did you use in your cabinets?

Looks like a classic example of Hoffmann's iron law, low, loud, small, pick two.

In your example of the MTH, the lower octave of typical pop musical bass is sacrificed for small and loud, response is 25 dB down around the low B (31.5 Hz) on a bass guitar.

As usual, smoother than Hornresp would predict.
  Reply With Quote
Old 25th January 2013, 10:28 PM   #34
diyAudio Member
 
Join Date: Nov 2007
Quote:
Originally Posted by weltersys View Post
As usual, smoother than Hornresp would predict.
I want to see the impedance response curve. That will show how close the sim matches the actual design.
__________________
www.diysubwoofers.org
  Reply With Quote
Old 25th January 2013, 11:35 PM   #35
sebDIY is offline sebDIY  Belgium
diyAudio Member
 
Join Date: Oct 2011
Quote:
Looks like a classic example of Hoffmann's iron law, low, loud, small, pick twoClick the image to open in full size..

In your example of the MTH, the lower octave of typical pop musical bass is sacrificed for small and loud, response is 25 dB down around the low B (31.5 Hz) on a bass guitar.
For my use it's perfect. I was searching a light cabinet (mine is 23Kg with ferrite driver, this is the lightest of all cabinets I've tried), searching also clean sound, and it is, with ability to make strongest level in this size. I have compared with some 18" bass reflex. The 18 BR goes lower, but MTH-30 makes more level and is more dynamic, also lighter and smaller.

The loudspeaker is LF12G301 RCF, measurement groundplane 2 meters without any wall into18 meters perimeter

Without any any eq, you can cross at 110/120hz without hearing any ugly resonance, but I think it is usable above 120Hz with Eq cutting peaks. I know some people cross it 150Hz. I use most of the time for wedding: 2 MTH-30 and 2 ZX1 EV. I have made 200 people without any problem in this configuration and I think it can do even more.
  Reply With Quote
Old 25th January 2013, 11:48 PM   #36
diyAudio Member
 
Join Date: Jan 2008
Quote:
Originally Posted by Brian Steele View Post
I want to see the impedance response curve. That will show how close the sim matches the actual design.
Oliver's (TB46)Hornresp FR peak and dip locations matching senDIY's measured peak and dip locations indicate the sim matches the design very closely.

I find it interesting that most in the DJ and PA business are perfectly willing to trade LF extension for SPL.

Art
Attached Images
File Type: png Measured, Sim.png (157.6 KB, 44 views)
  Reply With Quote
Old 26th January 2013, 12:08 AM   #37
diyAudio Member
 
Join Date: Feb 2004
Quote:
Originally Posted by weltersys View Post
Oliver's (TB46)Hornresp FR peak and dip locations matching senDIY's measured peak and dip locations indicate the sim matches the design very closely.

I find it interesting that most in the DJ and PA business are perfectly willing to trade LF extension for SPL.

Art
Lots of small pa setups don't use subs, so in comparison this is very good.
  Reply With Quote
Old 26th January 2013, 12:23 AM   #38
diyAudio Member
 
Join Date: Jan 2008
Quote:
Originally Posted by turbodawg View Post
Lots of small pa setups don't use subs, so in comparison this is very good.
"Very good" is a relative term, like "good enough".

The Mackie HD1502, a fairly small speaker on a stick using a 15" and 1" exit HF driver drops off only 1/6th octave above the MTH30.
Attached Images
File Type: png Relative Good.png (98.1 KB, 55 views)
  Reply With Quote
Old 26th January 2013, 12:26 AM   #39
sebDIY is offline sebDIY  Belgium
diyAudio Member
 
Join Date: Oct 2011
Quote:
I find it interesting that most in the DJ and PA business are perfectly willing to trade LF extension for SPL
Most wedding rooms I work got reverberation, and can sound "whaouwhaouwhaou" in the infrabass range, espacially with very compressed music, so I prefer, from far away, a truncated and dynamic bass cabinet, more listenable, than a slow sub.
  Reply With Quote
Old 26th January 2013, 01:00 AM   #40
diyAudio Member
 
Join Date: Aug 2010
Quote:
Originally Posted by weltersys View Post
Oliver's (TB46)Hornresp FR peak and dip locations matching senDIY's measured peak and dip locations indicate the sim matches the design very closely.

I find it interesting that most in the DJ and PA business are perfectly willing to trade LF extension for SPL.

Art
Well, for me at least, I'm not "in the business", so to speak, it's a hobby. I specifically need something "one man" portable." If it's not easy to grab and go, I just won't take it. No 18" sub, and most 15" subs are not just grab and go for me.

Well, I'm still debating on what exactly that I'm going to do here, I'm fairly certain that I'm going to build at least one pair of small 12" TH subs.

I have some more pedestrian questions.

First, does anyone have any specific recommendations for the following items:

1) Connector plates, I want to use speakons.
2) Finish, I'm leaning towards some sort of paint, but I want to know what people like and use, and what's cost effective.
3) Handles and pole mounts.

Given the simulation results and measurements here, I'm not seeing a lot of difference between the low frequency extension of the MTH30 and the THAM12, which is a bit smaller. I also notice that hornresp really considers only the dimensions of the horn and the properties of the driver, and how the horn is folded, holding all else constant, doesn't come into play in the sim. I have no sense of how the quality of the horn fold impacts real results, but, given what I've read elsewhere on this forum, performance is relatively insensitive to small deviations holding all else constant.

Consequently, it appears that I can trade off some SPL for LF extension in the THAM12 by just making the cabinet about 3 to 4 inches taller. After that, it appears to be diminishing returns for additional length. I simed this using the 12PS100. Looking at the design, it seems that I could scale the height in the build plans fairly easily without dramatically affecting the taper of the horn or any other critical dimensions. Anything that I'm overlooking here?

Finally, I haven't sim-ed it yet, but, I'm leaning towards the B&C 12NDL76 for weight reasons. Any thoughts on this, are there any other good choices of driver in the 10 pound range that I should consider? In particular, is there anything less expensive that would work almost as well?

tnx,
gs
  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
Running Home audio in my car. Complete Noob. leochevalier91 Car Audio 16 18th December 2011 10:53 PM
Advice for/questions from a complete noob to amplifier DIY. jaistanley Class D 10 18th November 2010 08:32 PM
complete noob question beauistheman Chip Amps 19 10th August 2009 06:37 PM
Complete noob needs help tstarn06 Class D 5 10th March 2008 09:03 AM
Complete noob to all of this, help to my feet? jesuslovesyou Subwoofers 5 4th September 2007 01:51 PM


New To Site? Need Help?

All times are GMT. The time now is 02:48 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