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 September 2011, 10:11 AM   #1
ODougbo is offline ODougbo  United States
diyAudio Member
 
Join Date: Aug 2011
Location: Maryland USA
Default MCM 8" 55-2421 Isobaric

Pics of my 3rd front to back 55-2421 Isobaric box. A friend gave me a sheet of ½” MDF and I had one more pair of 55-2421, so couldn’t leave that combination sitting around.

½” is too light, so decided to build the box complete and then go back and “wrap” it with a second layer, lapping the joints and thickening the walls up to 1”.

The second ½” layer will be added today also I did use ¾” scrap for the tunnel.

As far as isobaric design, I’ve tried side by side speaker boxes - two speakers in one huge sealed cabinet - two speakers in ported box, on and on. I’ve gone back and isobaric mounted them, it does work better as far as low bass, rumble, and that sensation of power.

For another example, I took an old pair of 10” NTH woofers, (pretty old but in good shape,) again with a small tunnel and a box one half the size, the best bass ever. I wish I built them years ago

Attached Images
File Type: jpg Profile.JPG (645.3 KB, 984 views)
File Type: jpg Clamps.JPG (721.4 KB, 895 views)
  Reply With Quote
Old 14th September 2011, 07:54 PM   #2
ODougbo is offline ODougbo  United States
diyAudio Member
 
Join Date: Aug 2011
Location: Maryland USA
To follow up on this thread, attaching pic of finished box/design. The ½ over ½ MDF worked out well, a little more time/energy than I had planned, but glad I did it.


I have two of these in the back of the HT room, the bass is fantastic and loving it. The bass response is low, powerful and defined; I did find some 2" black foam “floor stands” to get them up off the floor a bit.

I connected them to two channels on a 5X200watt amp. and moved the rear speakers (shown left) to an older 100watt stereo amp. The 4ohm, MCM woofers are wired in series.


During the signal generator testing, there is noticeable bass enhancement down at 25hz, it rolls off pretty quickly after that (down to 20hz).

I like this project, somewhat easy to build, it works well and the costs are low. I also like that they sound great at low volumes; no need for "loud", bass enhancement, etc.


The 2 MCM woofers are $60 (sale price); I don’t think there is a single woofer out there for that amount that can do what this combination can achieve, if so, I would be curious what is out there that compares.
Attached Images
File Type: jpg halfoverhalf2.JPG (704.2 KB, 816 views)
  Reply With Quote
Old 14th September 2011, 08:41 PM   #3
epa is offline epa  Netherlands
diyAudio Member
 
Join Date: Apr 2010
Location: amsterdam
nice finish ,
to bad they don't sell in europe.
__________________
one good thing about music ,when it hit you feel no pain.
so hit me with music
.
  Reply With Quote
Old 14th September 2011, 08:58 PM   #4
diyAudio Member
 
Join Date: Apr 2010
I have two in a bassreflex and they sound great. Next build for the same driver bass horn
  Reply With Quote
Old 14th September 2011, 09:05 PM   #5
ODougbo is offline ODougbo  United States
diyAudio Member
 
Join Date: Aug 2011
Location: Maryland USA
I’ve been watching your thread; and yes I may come over to the dark side. Any speaker project sounds good to me and I have 1 driver left on the bench. I was going to ask if you can take some shots during fabrication. I think I understand it, but pics would be great.



Quote:
Originally Posted by kornnylike View Post
I have two in a bassreflex and they sound great. Next build for the same driver bass horn
  Reply With Quote
Old 14th September 2011, 09:07 PM   #6
ODougbo is offline ODougbo  United States
diyAudio Member
 
Join Date: Aug 2011
Location: Maryland USA
Truth be known, that was a three coats before lunch project. That’s a flat, water based paint by Valspar, but when sprayed it has a bit of sheen. Since it was MDF there’s another easy trick to fill the flat surfaces (most will shout no-way). I skim coated it with regular green lid drywall compound; probably the fastest way to fill everything at once. The “mud” was applied very, very “tight”; on a gray primer (1st) coat and then sanded lightly.
Quote:
Originally Posted by epa View Post
nice finish ,
to bad they don't sell in europe.
  Reply With Quote
Old 14th September 2011, 09:17 PM   #7
diyAudio Member
 
Join Date: Apr 2010
Quote:
Originally Posted by ODougbo View Post
I’ve been watching your thread; and yes I may come over to the dark side. Any speaker project sounds good to me and I have 1 driver left on the bench. I was going to ask if you can take some shots during fabrication. I think I understand it, but pics would be great.
Sure I wil. I have few Things to finalize before building start, if every thing goes well I will start next week.
  Reply With Quote
Old 14th September 2011, 09:34 PM   #8
Djim is offline Djim  Netherlands
diyAudio Member
 
Join Date: Dec 2009
Location: 'Ollanda
Quote:
Originally Posted by epa View Post
nice finish , to bad they don't sell in europe.
Epa, these are relabelled TangBand's loudspeakers which are available in Europe. But it's complete "stierenstront" we have to pay around 80Euro's for the same driver...

Last edited by Djim; 14th September 2011 at 09:37 PM.
  Reply With Quote
Old 14th September 2011, 11:32 PM   #9
diyAudio Member
 
revboden's Avatar
 
Join Date: Feb 2011
wait... Djim can say that in Dutch but i can't say ******** in english. that's Bull Smeg...



Last edited by revboden; 14th September 2011 at 11:36 PM.
  Reply With Quote
Old 15th September 2011, 02:04 PM   #10
epa is offline epa  Netherlands
diyAudio Member
 
Join Date: Apr 2010
Location: amsterdam
Quote:
Originally Posted by Djim View Post
Epa, these are relabelled TangBand's loudspeakers which are available in Europe. But it's complete "stierenstront" we have to pay around 80Euro's for the same driver...
well some relatives asked me to bild a ht subje(dus ik dacht lekker goedkoop)
but on the other hand i have plenty of other commitments right now,so ill put it in the fridge for now.
__________________
one good thing about music ,when it hit you feel no pain.
so hit me with music
.
  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
MCM 55-2421 T/S Parameters and thoughts greg_mcquaid Subwoofers 9 11th March 2012 04:36 PM
Mcm 8" 55-2421 Ts parameter kornnylike Subwoofers 223 28th November 2011 08:04 PM
Silly's 1st Sub -- 8" MCM 55-2421 Sillyboy Subwoofers 18 6th July 2006 08:26 AM
Question regarding the MCM 8" Woofer (Part #55-2421) Phlim Subwoofers 2 2nd February 2006 10:46 PM
Looking for MCM 55-2421 Woofer lancer Parts 0 5th December 2004 05:03 PM


New To Site? Need Help?

All times are GMT. The time now is 03:26 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