"Houston we have a problem" Isobarik Sub - Page 2 - 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 December 2005, 10:50 AM   #11
diyAudio Member
 
Join Date: Nov 2005
Location: Portland TN
Default simon5

I don’t need to have box smaller then Vb 1.5 it would really be better then the VB .64 because @ a Vb of 1.5 I would end up with a bottom box as a base of 16.5 X 14.25 X 21.25 which should be pretty close to work with to make a stuffed pipe transmission line with a 7” or 8” driver on top as my next stage. As a said before I am working on a bi-amped flool standing Loudspeaker and have to keep my box sizes with in reason so I don't end up with a 10' high tower in my livingroom. My wife is pretty cool about this stuff but I think that would get me on the couch!!*LOL*
  Reply With Quote
Old 12th December 2005, 07:14 PM   #12
simon5 is offline simon5  Canada
diyAudio Member
 
Join Date: Nov 2004
Location: Québec, Québec
If you can make it 1.5 cu.ft with a base of 16.5 X 14.25 X 21.25, to get a flatter frequency response, you could port the isobaric enclosure.

You could port it with a single FP3 vent (18 inches long), which would sit parallel with the 21.25 inches side.

You wouldn't have noise problems under 300W imput to the isobaric pair.

What amplifiers are you planning to use?

Please use woofer to woofer if you go isobaric. The other configurations aren't very good. Magnet out isn't that pretty but it's the way it should be done.

Here's the FR curve at 300W ported vs. sealed for your 1.5 cu.ft enclosure.
I optimized the tuning of the ported enclosure to give flat response down to a in-room F3 of about 22-23 Hz.
Attached Images
File Type: jpg blahfuck.jpg (89.5 KB, 103 views)
__________________
DIYaudio for President !
  Reply With Quote
Old 12th December 2005, 07:17 PM   #13
simon5 is offline simon5  Canada
diyAudio Member
 
Join Date: Nov 2004
Location: Québec, Québec
BTW, if you got some money left, the proper way to do it to be able to use more than 300W without noise would be to use passive radiators.

Acoustic Elegance got some on sale at 45$ each.
__________________
DIYaudio for President !
  Reply With Quote
Old 13th December 2005, 06:27 AM   #14
diyAudio Member
 
Join Date: Nov 2005
Location: Portland TN
Default simon5

I am trying to take in all you have suggested but it just a bit much, as I have had my head set on a close box with both speakers facing the same direction. The mag to mag push-pull again made the box to large because the isobaric chamber Vb, but was my first choice. The thought of a clam shell was never on my mind, but then you may have a very good point. The one thing about that idea that sets me back is, I would not have any idea how to make it look good with the sub hanging out the back of my towers. I have never been a fan of any other type of box beside a close type for the last 20 years every car I owned had sealed box 10” drivers so I was just trying to put a bit of a spin and something I know works by using the sealed isobaric sub. I seen lots of ported boxes at the sound competitions for that SPL but never heard nothing I liked, they just get sloppy when you put to much power to them but not to put them down they do give up some really great SPL with much less power and I just assumed that good bass comes at a cost with no compromise. I also realize I have not heard everything and don’t know everything. I will just say this, my best hope for this project is to have tight bass with a very flat response and I will be willing to learn what ever the great people in the group are willing to teach Me.! I am going to try to look more at your ideas. I may need a bit more time to digest it as I know nothing about ported or passive type design and have not studied them to any extent. I have been studying about transmission line design, as for my decision to use that for my next step woofer.

Now as for the Amps I will be using I am currently looking to purchase 2 Adcom GFA-565 Mono Blocks to drive the subs I am currently using an Adcom GFA-585, also I may decide to go tri-amped and add a GFA-545 to drive my tweeters. I am a big fan of Adcom amps!!!!!! I am also looking for a good active crossover to put this whole thing together.
  Reply With Quote
Old 13th December 2005, 06:33 AM   #15
diyAudio Member
 
Join Date: Nov 2005
Location: Portland TN
Default simon5

Quote:
Originally posted by simon5
BTW, if you got some money left, the proper way to do it to be able to use more than 300W without noise would be to use passive radiators.

Acoustic Elegance got some on sale at 45$ each.

Now you have really got me curious


What the the thing with noise with a sealed box over 300 watts I have 1000 watts driving 2 10" subs in my car and they sound tight and clean. I have seen somthing about this in other threads hear too
  Reply With Quote
Old 13th December 2005, 06:43 AM   #16
diyAudio Member
 
Join Date: Nov 2005
Location: Portland TN
Quote:
Originally posted by Volenti



I would suggest a real world test would indeed help you a great deal in deciding on what configuration would be most suitable for you.

I am thought that it would help,plus it may help me learn a bit more too. All the formulas and program simulations are fine but lack a fun factor! I think I will just set up my first box using the single Vc’s because that box could also work for some of the ideas (simon5) has presented to me with.

Thanks again for your help with all the data verification
  Reply With Quote
Old 13th December 2005, 10:18 PM   #17
simon5 is offline simon5  Canada
diyAudio Member
 
Join Date: Nov 2004
Location: Québec, Québec
You would have a noise problems if you go ported with my suggestion and you use more than 300W. You'll have vent noise. Air is going too fast in the vent.

With passive radiators, the box is closed, so no vent noises.
Clamshell isobaric with passive radiator, that would be interesting hehe!
__________________
DIYaudio for President !
  Reply With Quote
Old 14th December 2005, 10:05 AM   #18
diyAudio Member
 
Join Date: Nov 2005
Location: Portland TN
Default The test

I have completed some tests regarding sealed, ported and passive radiator and I am thinking know at this point I have come down to using one of 2 and I was able to make one box size to real world test both. I can make one internal size box @ 12.5 X 12.5 X 17.8 box to do my testing as this should be a good base size the loudspeakers I intend to build them into. It would seem that the seal individual VC box will be my first choice and the then PR. I just need a bit more help as to how to place my drivers, down firing front, side or whatever also the best placement for the PR’s ? I would like any input that you all may have on which the PR or the SB would be most effective to make good tight bass. These will be used mostly for Rock type music and secondly for the subs for my home theater. Home theater would be least important. Here are my last simulations.
Thanks
Attached Images
File Type: jpg comparison (dayton 295-185).jpg (100.0 KB, 67 views)
  Reply With Quote
Old 14th December 2005, 07:57 PM   #19
simon5 is offline simon5  Canada
diyAudio Member
 
Join Date: Nov 2004
Location: Québec, Québec
You want the PRs to be front firing or side firing.

Also test both coils in parallel after you tested with a single coil when you do your sealed box. You might like it even if it doesn't look nice in BassBox.
__________________
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
What makes an amplifier "bright", "warm", or "neutral"? JohnS Solid State 51 13th December 2009 07:42 PM
FS: Seas Excel TL Home Towers "Thors" Houston/Austin pickup only kappa546 Swap Meet 15 1st September 2008 04:12 PM
Cheapie Dai-1chi 8" FR driver in an isobarik box? Brisso57 Full Range 9 13th April 2007 12:43 PM
"lift off " or "Houston we have a problem" tenderland Tubes / Valves 16 1st May 2005 06:08 PM
Need help with IC Based Amplifier "pop" problem (Integrated Component) Monolith Solid State 7 13th March 2003 04:01 PM


New To Site? Need Help?

All times are GMT. The time now is 01:47 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