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 19th May 2011, 10:09 AM   #311
diyAudio Member
 
Join Date: Dec 2009
Location: California
Quote:
Originally Posted by 4pyros View Post
Ya just woundering if I should put in extra bracing befor I seal up my boxs. Andy
Did you end up using 3/4" outer panels? I built 2 SS15 enclosures (w/3015LF drivers) and the panels vibrate just a bit. Next time I'll use 3/4" outside panels with the same/similar standard braces.
  Reply With Quote
Old 19th May 2011, 10:17 AM   #312
diyAudio Member
 
Join Date: Nov 2010
Quote:
Did you end up using 3/4" outer panels?
I used 3/4" throughout. The rear vibrats some. Andy
  Reply With Quote
Old 19th May 2011, 10:19 AM   #313
diyAudio Member
 
Join Date: Dec 2009
Location: California
Quote:
Originally Posted by m R g S r View Post
The 18lw2400 is on sale for 330 shipped. I'll go with two of those each in a TH18 box braced very well made with good ply and I'll use the xti4000 to power. I'll see how that works for me for the time being.

I only see the 8 ohm version listed on the site but on 18sound's site they list a 4 and 8 ohm version. I'll call them and see Whst they say.
I wonder how the 18LW2400 driver would compare to the RCF LF18N451 in the real world.



Note: Both drivers are at (xmax + 1.6mm) and are being modeled in Xoc1's TH18
Attached Images
File Type: jpg SPL (4) 18LW2400 vs LF18N451.jpg (82.5 KB, 335 views)
  Reply With Quote
Old 19th May 2011, 01:14 PM   #314
diyAudio Member
 
Join Date: Jan 2011
So the 18lw2400 is theoretically hitting xmax with only 630 watt input, yet it was mentioned before that they need at LEAST 1500 watts to get anywhere near xmax?
Either way i just grabbed the xti4000 last night so I have some power to play around with. Now I need to get the drivers and some wood! yayy!
  Reply With Quote
Old 19th May 2011, 01:19 PM   #315
diyAudio Member
 
Join Date: Jan 2011
Quote:
Originally Posted by NEO Dan View Post
40Hz horns with $700 usd drivers? If 40Hz is all you are after why not stick with more of the efficient SS15's, but use better/more cost effective drivers?

If 140dB & 30Hz extension is the goal I think you will need 4 cabinets of a different design.

Why is there no model of the 18sound driver?
Also why are the sections set to conic, that should be parabolic right?
Are you directing this towards me dan? I am doing it because I do want that extra 10hz that the ss15 doesn't have. I'm currently building another ss15 for a friend, i can test that with some power but i doubt it will have the output i'm looking for!
Also, are you saying 4 of xo1c's cabs won't hit the 140db @ 30hz?

and yes can someone please model those 18 sound drivers. the 2400 and the 9600c.
  Reply With Quote
Old 19th May 2011, 01:24 PM   #316
epa is offline epa  Netherlands
diyAudio Member
 
Join Date: Apr 2010
Location: amsterdam
Quote:
Originally Posted by m R g S r View Post
So the 18lw2400 is theoretically hitting xmax with only 630 watt input, yet it was mentioned before that they need at LEAST 1500 watts to get anywhere near xmax?
Either way i just grabbed the xti4000 last night so I have some power to play around with. Now I need to get the drivers and some wood! yayy!
i didn't do the math(djim is better @ it)
but first you got powercompression.
second hr only shows sine waves excursion,so in real live use excursion wil be much less.
so you might need that 1500 watts to get to x-max in real live use.

Last edited by epa; 19th May 2011 at 01:27 PM.
  Reply With Quote
Old 19th May 2011, 01:27 PM   #317
diyAudio Member
 
Join Date: Jan 2011
Quote:
Originally Posted by epa View Post
i didn't do the math(djim is better @ it)
but first you got powercompression.
second hr only shows sine waves,so in rael live use excursion wil be much less.
so you might need that 1500 watts to get to x-max in real live use.
Okay so the modeling is just showing xmax using sin waves not program power..got it!
  Reply With Quote
Old 19th May 2011, 03:16 PM   #318
Djim is offline Djim  Netherlands
diyAudio Member
 
Join Date: Dec 2009
Location: 'Ollanda
Quote:
Originally Posted by NEO Dan View Post
40Hz horns with $700 usd drivers? If 40Hz is all you are after why not stick with more of the efficient SS15's, but use better/more cost effective drivers? If 140dB & 30Hz extension is the goal I think you will need 4 cabinets of a different design.
Why is there no model of the 18sound driver? Also why are the sections set to conic, that should be parabolic right?
Dan, Xoc1’s design is based on Jbell’s SS15 which is the best price versus efficiency. The goal was to keep the efficiency but extend its range to be able to play all types of music (including dance and D&B). The -3dB point at 38Hz (1/3WL) is therefore a very good balance between efficiency and frequency extension. Maybe not your cup of thee but that’s personal.

The idea of using the expensive 9600c was just to show the max potential of the design. For the price of one 9600c you can buy two 2400’s which I would choose. Also this design is very easy on drivers and you can fill it with many different types of 18"s and even 15"s if you like.

Quote:
Originally Posted by CRESCENDO View Post
I wonder how the 18LW2400 driver would compare to the RCF LF18N451 in the real world. Note: Both drivers are at (xmax + 1.6mm) and are being modeled in Xoc1's TH18
For both drivers there is something to say so it really depends on what is more important to you.

Quote:
Originally Posted by epa View Post
i didn't do the math(djim is better @ it but first you got powercompression. second hr only shows sine waves excursion,so in real live use excursion wil be much less. so you might need that 1500 watts to get to x-max in real live use.
Still a little uncomfortable with the idea, I can see. It is actually quiet simple. TH’s have about 5dB more efficiency over basreflex. So if basreflex has 128dB max the TH would end at 133dB, right? Well, how would that be possible if the excursion isn’t similar to basreflex? If excursion was higher in TH’s you would never reach the +5dB at max power and it would make no sense using TH’s in the first place. Like basreflex if you drop the system Fb below the Fs of the driver you will see the excursion rapidly increases.

Quote:
Originally Posted by m R g S r View Post
Okay so the modeling is just showing xmax using sin waves not program power..got it!
Clean single sine waves always show higher excursion and do radiate better to air. That’s why bass sounds often have strong sine waves in them. If the Fb of an TH design is set higher than the Fs of the driver you can use AES power ratings as given in the Thiele-Small parameters of the driver.

Last edited by Djim; 19th May 2011 at 03:21 PM.
  Reply With Quote
Old 19th May 2011, 08:32 PM   #319
Xoc1 is offline Xoc1  United Kingdom
diyAudio Member
 
Xoc1's Avatar
 
Join Date: Nov 2008
Location: Devon UK
Quote:
are you saying 4 of xo1c's cabs won't hit the 140db @ 30hz
The reason why I posted up my design in the first place was Crescendos request for a cabinet that would sim to 4 cabs @ 140db @ 35hz (and was more compact than the 30Hz monsters that we were discussing) I showed this sim with the PD 1850 in post 215
The PD 1850 might not be as efficient as most, but it plays a bit lower than most drivers. In theory it needs more power, but it also has low thermal compression levels

Quote:
40Hz horns with $700 usd drivers? If 40Hz is all you are after why not stick with more of the efficient SS15's, but use better/more cost effective drivers?
Look at the comparison using a 3015lf in post 218
The ss15 can not use an 18" driver. A decent 18" driver will shift more air than a 15". The bigger cab sims about 10hz lower - take your choice - there is always a compromise somewhere.
Quote:
why are the sections set to conic, that should be parabolic right?
If your are refering to what I simmed with akabak then I had to set hornresp to Con to export the data. If there is a better setting I could use, then please tell!
  Reply With Quote
Old 19th May 2011, 09:08 PM   #320
diyAudio Member
 
Join Date: Dec 2009
Location: California
Anyone up to compare the compression levels of the LF18N451 http://www.parts-express.com/pe/show...umber=294-894# vs 18LW2400 http://www.loudspeakersplus.com/pdfs/18LW2400.pdf? As they seem to be the best options (bang for buck) on this side of the sea. I guess we would just need the comp levels of the RCF driver since the 18Sound levels have been calculated earlier in this post.

And if a driver could take more power than the sim displays to reach xmax, then will it play louder or is the thermal/mechanical compression making it more difficult for the driver to reach xmax, therefore taking more real-world power to reach it's sim'd output at the hornresp xmax?

Last edited by CRESCENDO; 19th May 2011 at 09:15 PM. Reason: Addt'l question
  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
Nakamichi PA-5 and PA-7 Design Help Requested Apogee Pass Labs 20 30th May 2013 03:54 PM
Nakamichi PA-7 & PA-5 Bias Setting? sourceoneaudio Solid State 6 8th March 2012 12:37 PM
Vintage Peavey PA-120 Transistor PA amp ElectricMan Swap Meet 2 26th May 2010 05:22 PM
Nakamichi PA-7 and PA-5 amps Redwingnine Pass Labs 11 30th April 2010 09:27 PM
5.1 DIY kit with on PA speakers (or good & small DIY kit with PA speakers) ? jm_kzo Multi-Way 54 22nd April 2009 07:54 PM


New To Site? Need Help?

All times are GMT. The time now is 05:55 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