MLTL for Tannoy DU386? GM? - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

Multi-Way Conventional loudspeakers with crossovers

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 8th November 2012, 08:09 AM   #1
DeonC is offline DeonC  South Africa
diyAudio Member
 
DeonC's Avatar
 
Join Date: May 2002
Location: Kimberley, South-Africa
Default MLTL for Tannoy DU386? GM?

Hi GM

You are the forum MLTL guru, so I wonder, is it possible or even worth it to put the Tannoy DU386 in a MLTL? At the moment I have them in Berkley reflex cabinets, as I was wondering if a damped MLTL would not be a better option. Here are the specs:

Vas: 483 l
Fs: ˙22 Hz
Qts: ˙0.18
Qa: 2.4
Qe: 0.2
Mmd: 68g
Mma: 22g
Sd: 770c m2
BL: 18.7 N/A
Re: 5.7 Ohm

Thanks,
Deon
__________________
I don't suffer from insanity. I enjoy every minute of it.
Have a look at my favorite thread: Interesting YouTube video clips
  Reply With Quote
Old 9th November 2012, 02:07 AM   #2
Bare is offline Bare  Canada
diyAudio Member
 
Join Date: Dec 2001
Location: vancouver
Stuff them into Whatever you desire :-)
But Tannoy 15's have a MASSIVE Bass output. These have proven to sound 'better than most' even when stuck into Half Barrels.
Not a lot of real world need to try and extract the last erg of Bass energy via a convoluted Enclosure. Unless you like cutting bits of wood and cobbling up a DIY enclosure.
Many clearly thrive on this exercise.. they keep doing it, year after year, after year :-)
  Reply With Quote
Old 9th November 2012, 04:28 AM   #3
DeonC is offline DeonC  South Africa
diyAudio Member
 
DeonC's Avatar
 
Join Date: May 2002
Location: Kimberley, South-Africa
Hi Bare

The bass on these is good, but definately not massive. Due to the low Q, they have a downward slope from just above 100Hz in a sort of extended bass shelf type of response, and roll away completely below about circa mid 30Hz. It is good bass, very tight and defined, just what proponents of low Q drivers talk about, but it ain't very deep or that powerful. That is why I'm curious about the possibility of a MLTL. I can't do it myself currently, as I don't have a mathcad program. I used to have a freeware mathcad program, but a hard-drive crash ended that. But even so, I trust GM's ability and knowledge on this subject far more than my own limited ability to sim.

Enjoy,
Deon
__________________
I don't suffer from insanity. I enjoy every minute of it.
Have a look at my favorite thread: Interesting YouTube video clips
  Reply With Quote
Old 9th November 2012, 04:30 PM   #4
Bare is offline Bare  Canada
diyAudio Member
 
Join Date: Dec 2001
Location: vancouver
OK.. in fairness, the Berkley Boxes are likely the worst performing enclosures ever sold on by Tannoy. Understandable that you want better.
There are 'many' Box plans and suggestions available.. you are not the first in this desire.
Not overlooking that those Large/heavy LF cones DO work to their best with a decent amplifier of 20+ Amp current capability.. read Amp specs carefully and No, Price is Not the primary determinant in this.
Split the inputs to the Crossover IF you love your tubes and use those on the HF section.. Passive Bi Amping.
Start Here: TANNOY Monitor Gold dual concentric speakers
Follow links and even Google. G'luck
  Reply With Quote
Old 9th November 2012, 05:05 PM   #5
sreten is offline sreten  United Kingdom
diyAudio Member
 
Join Date: Nov 2003
Location: Brighton UK
Hi,

The Berkeley cabinets are probably bigger than you need to go, my sims
indicate around 35 to 50L sealed and 70 to 100L vented, they are 98L.

Vent tuning I reckon is best around 28Hz and low bass boost would be good, passive
line level (6dB/octave) or active peaking 2nd order high pass, Q=1.5, f= 28Hz (+4dB).

rgds, sreten.
__________________
There is nothing so practical as a really good theory - Ludwig Boltzmann
When your only tool is a hammer, every problem looks like a nail - Abraham Maslow

Last edited by sreten; 9th November 2012 at 05:10 PM.
  Reply With Quote
Old 10th November 2012, 05:37 AM   #6
GM is offline GM  United States
diyAudio Member
 
GM's Avatar
 
Join Date: Jun 2003
Location: Chamblee, Ga.
Quote:
Originally Posted by DeonC View Post
Hi GM

You are the forum MLTL guru, so I wonder, is it possible or even worth it to put the Tannoy DU386 in a MLTL?
Greets!

Just one of many around here these days. MJK’s and others contributions have generated a plethora of [ML] TL and horn design gurus, some with far more comprehensive experience [at least measurement wise] than me.

Anyway, unless you plan to EQ them or just want to go lower, either of which requires a large net Vb, there’s no advantage to using a MLTL to damp such an already over-damped [low Qts] driver, though some folks will [critically] damp the vent as required to ensure there’s no audible/perceived vent pipe harmonic ‘ringing’.

You can still get the MC 8 demo at MJK's site.

So, what’s the game plan?

GM
__________________
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
  Reply With Quote
Old 10th November 2012, 06:21 AM   #7
DeonC is offline DeonC  South Africa
diyAudio Member
 
DeonC's Avatar
 
Join Date: May 2002
Location: Kimberley, South-Africa
Hi guys

Quote:
Originally Posted by Bare View Post
There are 'many' Box plans and suggestions available.. you are not the first in this desire.
I have many different box plans from Tannoy, including the corner and rectangular GRFs and Westminster horns (all of which are beyond my skills and available tools/workshop), various vented boxes, etc, but as Sreten stated, the Berkleys are the biggest reasonable vented boxes for these units. The DU386 is the lesser version of the HPD units, and the specs show it. Where the HPDs like a box as big as you can make it, these as not so good.

Quote:
Originally Posted by Bare View Post
Thanks. I actually know this site well, but all the boxes are for the better versions of the 15“ DC. That is why I was hoping GM could help me with a MLTL. I was (vainly, maybe) hoping a MLTL would give me more than a standard vented.

Quote:
Originally Posted by sreten View Post
The Berkeley cabinets are probably bigger than you need to go, my sims indicate around 35 to 50L sealed and 70 to 100L vented, they are 98L.
That is what my sims also indicated, going bigger brings no real benefits.

Quote:
Originally Posted by sreten View Post
low bass boost would be good, passive line level (6dB/octave) or active peaking 2nd order high pass, Q=1.5, f= 28Hz (+4dB).
Thanks for the suggestion, but I think I'll pass. I am worried that I'll hurt them when I turn the wick up for some serious rocking.

Quote:
Originally Posted by GM View Post
Just one of many around here these days. MJK’s and others contributions have generated a plethora of [ML] TL and horn design gurus, some with far more comprehensive experience [at least measurement wise] than me.
My friend, you're being way too modest.

Quote:
Originally Posted by GM View Post
though some folks will [critically] damp the vent as required to ensure there’s no audible/perceived vent pipe harmonic ‘ringing’.
I was thinking experimenting with putting some foam or carpet underfelt in the port to see the effect. Less bass, but I would like to see what the effect will be.

Quote:
Originally Posted by GM View Post
You can still get the MC 8 demo at MJK's site.
Thanks, I will look into that.

Quote:
Originally Posted by GM View Post
Anyway, unless you plan to EQ them or just want to go lower, either of which requires a large net Vb, there’s no advantage to using a MLTL to damp such an already over-damped [low Qts] driver.
I actually was just hoping for a more extended and stronger bass than I am getting with the reflex. This has set me wondering, if a MLTL is not really going to give me what I want, how about a TQWP. Here is my idea:

I thought (and I know I'm crazy) of a 20Hz TQWP. Now that is one LONG pipe. I works out to 4.3m long by my calcs. But if I fold it into three parts, then the total height of the unit will be only about 1.6m (, only he says). Then to put the driver in the middle of the pipe, I just put it in the middle of the central fold, and listening height will be at about 0.8m, which is perfect for me. Then add a Karlson style cut to the end of the line (an idea stolen from the WBAL Betsy TQWP elsewhere on this forum- I have a pic that I'll try to upload), and the response could be more what I'm looking for. What do you think?

Thanks,
Deon
Attached Images
File Type: png TQWP%20for%20BetsyK.png (31.4 KB, 170 views)
__________________
I don't suffer from insanity. I enjoy every minute of it.
Have a look at my favorite thread: Interesting YouTube video clips
  Reply With Quote
Old 10th November 2012, 08:35 AM   #8
DeonC is offline DeonC  South Africa
diyAudio Member
 
DeonC's Avatar
 
Join Date: May 2002
Location: Kimberley, South-Africa
Ok, guys, here is something I've been wondering about for a while. What will be the effect of cutting a Karlson-like slot into a port? Take a driver like the Tannoy DU386 mentioned above, and the Berkeley enclosure. The Berkeley has a large rectangular port, tuned lowish. So what would the effect be if I made the port longer, but cut a Karlson-style slot in it? As I understand it, the Karlson slot widens the range of frequencies that the port/pipe resonates at (see 1st pic below). I suspect the range of frequencies at which the port will resonate will have an upper limit set by the opening size of the port and the internal box volume. What do you think? So, to my thinking, the Karlson slot will either have one of two main effects:

1. The spread of frequencies which will be reinforced will be much wider than for the standard port, but the energy will be less. IOW, a greater spread, but weaker bass, or

2. The spread of frequencies which will be reinforced will be much wider, and with more power, but the load on the driver will be much more, therefore requiring more power. So in this scenario there will be more bass throughout the spectrum, at the expense of power handling (no free lunches).

So what do you think? I am personally hoping that option 2 is the correct one. What do you think?

Deon

PS. I added a pic to show what I meant with the double-folded 20Hz TQWP (NOT to scale, just a concept drawing).
Attached Images
File Type: png karlfreq.png (6.9 KB, 159 views)
File Type: jpg Tannoy%2020Hz%20TQWP%20with%20Karlson%20port%20idea.jpg (6.5 KB, 158 views)
__________________
I don't suffer from insanity. I enjoy every minute of it.
Have a look at my favorite thread: Interesting YouTube video clips
  Reply With Quote
Old 11th November 2012, 07:08 AM   #9
DeonC is offline DeonC  South Africa
diyAudio Member
 
DeonC's Avatar
 
Join Date: May 2002
Location: Kimberley, South-Africa
Here is a question for the horn guys- I've been looking at the plans for the rectangular GRF horns. They don't seem to difficult to build (unlike the corner GRF or the Autograph, etc). Only problem is that the GRF horns where developed for the Monitor Gold drivers, and they have different specs to my units. Will the DU386 work in these horns?

Thanks,
Deon
__________________
I don't suffer from insanity. I enjoy every minute of it.
Have a look at my favorite thread: Interesting YouTube video clips
  Reply With Quote
Old 11th November 2012, 03:18 PM   #10
ark is offline ark  United States
diyAudio Member
 
Join Date: Dec 2003
Location: Arcata, CA
i'm contemplating something similar with a 12" full range field coil driver.
i thought this was an interesting design by planet10 that could be scaled up.

http://p10hifi.net/tlinespeakers/FAL...metri3D800.gif
  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
Altec 416b MLTL, design by GM westend Multi-Way 10 23rd April 2011 01:56 AM
Has anyone rear ported the GM MLTL 48 ? batdan Full Range 3 15th December 2009 06:00 PM
GM MLTL fine tuning loninappleton Full Range 35 17th April 2008 07:31 PM
Veneering the JX92S GM MLTL LizardBrain Full Range 10 5th April 2006 09:31 PM
Pictures of GM MLTL-48? PrimaLuna Full Range 28 2nd February 2006 10:01 AM


New To Site? Need Help?

All times are GMT. The time now is 12:03 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