10" cabinet transformation? - 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 8th January 2013, 04:25 PM   #11
diyAudio Member
 
Rullknufs's Avatar
 
Join Date: Mar 2010
Location: Sweden
Send a message via Skype™ to Rullknufs
Quote:
Originally Posted by Moonfly View Post
Chances are you modelled incorrectly for the addition of the circuit. If you add in a LTC, then you need to reduce the signal power used. Look at the amplifier apparent load graphs, and reduce the main signal input until the maximum power simulated in the apparent power graph matches you original max input signal. So, if you used 500 watts input power, then added in a LTC, you then need to modify the input signal so your apparent power graph maxes out at 500 watts. Reducing input power to 10% is usaully a good place to start.

What you will notice is that your original response shape changes, but if your target frequency was say 15hz, you get pretty much the same spl at that frequency (because thats the limits of the system), but everything above it is flattened out.

Something else you will then notice is how cone excursion and group delay are reduced in the upper range (thus improving the upper bass character of the sub), and all the high excursion and increased GD will have been pushed lower down the FR. If your using a large driver (15" or more, or multiples of smaller drivers), then a 10hz target with a .707 or less target system Q will give the best result. With a 10hz target, all the cone excursion and GD above 20hz is reduced dramatically. These properties below 20hz will increase above and beyond what the maximums were in the un-eq'd response, but this isnt very important because its all pushed below the 20hz threshold where your ears simply wont pick up on them due the frequency being too low.
I don't really understand how you mean. Yes, the amplifier apparent load is different betwen linkwitz transform and without. But I still don't see how I can hit 105+dB @30Hz in a 45l sealed box with ~9mm excursion and ~180w power handling.
Could you do some simulations for me and post some pictures to better explain what you mean?


Quote:
Originally Posted by Inductor View Post
Hi, and thanks for explaining, I now understand. Not a easy way out. Take your time.
Edit: I like your main speakers. Your problem must be just new subs.
What enclosure for those subs?
Some car guy will buy that (subs) from you. Just embark in a new project. Post with question for the best suitable sub for you with set-up you already have and cost you want to achieve. Components and amps are also expensive I have to agree. (More) In this case simple is better. Be appreciative of others spent time with your thread and they will help.
I might be wrong but it seems you are doing it fine... "12dB boost at ~25-30Hz to extend the bass a little further" (you said and seem pretty happy) so what's exactly that you need?
Yes, the main speakers are fine but no matter how good the woofers may be they are limited by their size. Can't break the laws of physics, especially not in a ported/aperiodic cabinet. I wouldn't get much money for these subs really, about $40 each if I'm lucky. Remember I bought them for ~$45 on sale (ordinary price was ~$120).

Just ignore my previous threads/posts about these subwoofers. They were fine when I had my Mar-Kel speakers and SPL was limited. But now that I've gotten some more money and bought better main speakers I want some more action down low too. I mean, what's the point being able to play 110dB @30Hz when your mains can only handle like 90-95dB (thinking of the Mar-Kel). But now my mains can handle 110dB without problems and so I need some subs to keep up with them. Okay, the subs can play fairly loud at ~50Hz and above but so does my mains. The subs have almost zero output at ~30Hz but my mains still have a bit of power there (still too little for my taste though).

Do you understand my thoughts or should I explain further? When I have drivers that can hit high SPL at somewhat low frequencies in the right cabinet, why not use them? Why get rid of them and pay lots of extra money for something that about as good as the ones I have?
__________________
My audio and DIY blog: http://phimusic.blogspot.se/
  Reply With Quote
Old 8th January 2013, 04:53 PM   #12
diyAudio Member
 
Rullknufs's Avatar
 
Join Date: Mar 2010
Location: Sweden
Send a message via Skype™ to Rullknufs
If it matters I will try to measure my current response in room. The only mic I have available at the moment is a Audyssey mic that came with my dad's Onkyo receiver. I could borrow another mic but it's more for singing/instruments than for accurate measuring.

But I plan to construct a gainphile measuring mic using the Panasonic WM-61A, but that's a project I plan to start with within a month or two.
__________________
My audio and DIY blog: http://phimusic.blogspot.se/
  Reply With Quote
Old 8th January 2013, 05:00 PM   #13
Moonfly is offline Moonfly  Spain
diyAudio Member
 
Join Date: Oct 2012
Quote:
Originally Posted by Rullknufs View Post
I don't really understand how you mean. Yes, the amplifier apparent load is different betwen linkwitz transform and without. But I still don't see how I can hit 105+dB @30Hz in a 45l sealed box with ~9mm excursion and ~180w power handling.
Could you do some simulations for me and post some pictures to better explain what you mean?

That amount of output is the absolute maximum this driver could achieve, and its pushing it past 9mm excursion (12mm). Two drivers would do it and remain within xmax though. The driver wants more cabinet, is that possible or set in stone.

I'll try get some images up and explain what I mean better. What eq do you have at your disposal?
  Reply With Quote
Old 8th January 2013, 05:42 PM   #14
diyAudio Member
 
Rullknufs's Avatar
 
Join Date: Mar 2010
Location: Sweden
Send a message via Skype™ to Rullknufs
Quote:
Originally Posted by Moonfly View Post
That amount of output is the absolute maximum this driver could achieve, and its pushing it past 9mm excursion (12mm). Two drivers would do it and remain within xmax though. The driver wants more cabinet, is that possible or set in stone.

I'll try get some images up and explain what I mean better. What eq do you have at your disposal?
Yes, I know it's the absolute maximum the driver can take and I plan to use both my drivers and not just one. It will also be the maximum level I will ever play, I think. Usually when I play "loud" I hit about 100dB, measured with my digital radioshack SPL meter at listening position.

New cabinets is not a problem. I understand that I can't get that very far with my current 45l cabinets (which look like **** anyways so new cabinets would be nice).

At the moment I have a Reckhorn S-1 but I have plans getting a MiniDSP instead to get access to some fancier stuff.
__________________
My audio and DIY blog: http://phimusic.blogspot.se/
  Reply With Quote
Old 8th January 2013, 06:01 PM   #15
Moonfly is offline Moonfly  Spain
diyAudio Member
 
Join Date: Oct 2012
Then I think your choices would be to either create a LTC with the mini DSP in the current sized cabs, or put them in 90 litres to make them more efficient and need less power and less eq.

Model them in WinISD in the current cabs (45l), add a LTC filter setting fp=30hz and Q=.7. Then look at the cone excursion graph and alter the input signal so cone excursion hits xmax at 30hz. It shouldnt take much signal, set to maybe 50 watts. When you look at the apparently load graph now, it will show you how much power the sub will now draw at 30hz. This would be you max input power required from your amplifier.

If your target is 30hz, then you will likely need a HPF, but as the model seems to indicate the excursion will only ever hit 12mm right down to 10hz you may find your ok without one.
  Reply With Quote
Old 8th January 2013, 06:22 PM   #16
diyAudio Member
 
Rullknufs's Avatar
 
Join Date: Mar 2010
Location: Sweden
Send a message via Skype™ to Rullknufs
Quote:
Originally Posted by Moonfly View Post
Then I think your choices would be to either create a LTC with the mini DSP in the current sized cabs, or put them in 90 litres to make them more efficient and need less power and less eq.

Model them in WinISD in the current cabs (45l), add a LTC filter setting fp=30hz and Q=.7. Then look at the cone excursion graph and alter the input signal so cone excursion hits xmax at 30hz. It shouldnt take much signal, set to maybe 50 watts. When you look at the apparently load graph now, it will show you how much power the sub will now draw at 30hz. This would be you max input power required from your amplifier.

If your target is 30hz, then you will likely need a HPF, but as the model seems to indicate the excursion will only ever hit 12mm right down to 10hz you may find your ok without one.
Well, EQ wont make me play any louder, really. Yes, I need less power to reach 30Hz at a certain SPL but it wont increase max SPL. I'm still limited to ~97dB at 30Hz while a 70l tuned to 30Hz ported cabinet would give me about 12dB more max SPL at 30Hz.
__________________
My audio and DIY blog: http://phimusic.blogspot.se/
  Reply With Quote
Old 8th January 2013, 06:31 PM   #17
Moonfly is offline Moonfly  Spain
diyAudio Member
 
Join Date: Oct 2012
Well if the output increase is priority then the decision is made and you will want to go ported. Like you say, the max output in sealed is max an there is no way around it.
  Reply With Quote
Old 8th January 2013, 07:03 PM   #18
diyAudio Member
 
Rullknufs's Avatar
 
Join Date: Mar 2010
Location: Sweden
Send a message via Skype™ to Rullknufs
Quote:
Originally Posted by Moonfly View Post
Well if the output increase is priority then the decision is made and you will want to go ported. Like you say, the max output in sealed is max an there is no way around it.
Yes, I want to increase maximum output.
__________________
My audio and DIY blog: http://phimusic.blogspot.se/
  Reply With Quote
Old 8th January 2013, 07:31 PM   #19
Moonfly is offline Moonfly  Spain
diyAudio Member
 
Join Date: Oct 2012
Then 135 litre cabinet tuned to 20 hz will give you about 105db flat to about 20hz with 100 watts. 45 litres is too small. Is 135 litres to big (I suspect so), what sort of cab size do you want.
  Reply With Quote
Old 8th January 2013, 07:45 PM   #20
GM is offline GM  United States
diyAudio Member
 
GM's Avatar
 
Join Date: Jun 2003
Location: Chamblee, Ga.
Quote:
Originally Posted by Rullknufs View Post
What do I need? A way to achieve good SPL down to ~30Hz while still keeping it as cheap as possible. You adults who have jobs may think that $1000 isn't very much, if you want you could get that much spare money in a month without problems. For me it would take almost a year, see the difference? Yes, If I could I would just go buy a pair of Scan-Speak 32W/4878T00 and be happy but that would require me to save money for one and a half year and not buy anything else during that period.

But if you guys are so pessmistic I'll just go with what WinISD says and see what happens. Might not be the best but it should get me closer to my goals.

Understood and no, I didn't remember you were a juvenile, though this posting otherwise strongly implies it, but what does either of these have to do with mine and others postings that were specific to your driver on your old thread?

WRT being pessimistic, I tend to make do with what’s available if for no other reason than I enjoy the challenge, so here’s my take on a similar ‘one note wonder’ woofer and how to theoretically squeeze a fair amount of performance out of it using a MLTL: pioneer ts-w5102spl

GM
__________________
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
  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
Cabinet for bass with 10" Audio Nirvana Wardsweb Full Range 16 17th March 2012 04:12 AM
kinda ot... 10" x 10" x 10" aluminum block/bar, does such thing exist? Mickey Pass Labs 9 15th November 2011 08:22 PM
RCF 13360051 Phase Plug 10" cabinet ideas? col Multi-Way 0 8th February 2011 03:32 AM
8" or 10" sub driver to go with computer speakers, music only, sealed cabinet. doors666 Subwoofers 9 25th November 2010 03:17 PM
HT: scale 10" sub cabinet for 12" driver? bbaker6212 Multi-Way 9 8th May 2003 06:54 PM


New To Site? Need Help?

All times are GMT. The time now is 04:20 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