Speakerplans.com Homepage
Forum Home Forum Home > Plans > Other plans
  New Posts New Posts RSS Feed - New reflex cab 2x18" RCF
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

New reflex cab 2x18" RCF

 Post Reply Post Reply
Author
Message
Albert44 View Drop Down
Registered User
Registered User


Joined: 30 May 2007
Status: Offline
Points: 10
Post Options Post Options   Thanks (0) Thanks(0)   Quote Albert44 Quote  Post ReplyReply Direct Link To This Post Topic: New reflex cab 2x18" RCF
    Posted: 24 July 2008 at 4:24pm
Hi!
I'm going to build this box (but I'm really in doubt with the vent air velocity...)

It's a rectangular prism box
Vb:235 litres
Fb:54,5 Hz
N°6 round vents (no flare end) long 53 mm each,diameter 95 mm.
Drivers:N°2 rcf LF18X400 run in parallel
Powered with 2000 watt.
Below the evaluation performance:



as You can see in the air velocity graph the top arrives to 33,2 m/sec,just below the maximum acceptable.Could You please give me some suggestion? I'm doing something wrong?



Edited by Albert44 - 24 July 2008 at 4:30pm
Back to Top
MarjanM View Drop Down
Old Croc
Old Croc
Avatar

Joined: 10 February 2005
Location: Macedonia
Status: Offline
Points: 7810
Post Options Post Options   Thanks (0) Thanks(0)   Quote MarjanM Quote  Post ReplyReply Direct Link To This Post Posted: 24 July 2008 at 5:23pm
Why did you tuned the box so high?
I would have made it to go at least down to 40Hz. That driver has resonance freq of 28Hz
235 liters is very small box for 2x18" drivers.
Try to make it at least 400 liter and tune it to 35-40Hz
What is the application?

You can reduce the air velocity by enlarging the port diameter.


Marjan Milosevic
MM-Acoustics
www.mm-acoustics.com
https://www.facebook.com/pages/MM-Acoustics/608901282527713
Back to Top
Albert44 View Drop Down
Registered User
Registered User


Joined: 30 May 2007
Status: Offline
Points: 10
Post Options Post Options   Thanks (0) Thanks(0)   Quote Albert44 Quote  Post ReplyReply Direct Link To This Post Posted: 24 July 2008 at 7:33pm
Hi marjan!
I've tuned it high to obtain a higer SPL.If I tune it to 40 I'll lose the kick.You're right whatever the box is tuned high but I don't need deep low frequency...I'm looking for a good kick in the stomach.I use it for independent hardtechno and hardcore music (it will be coupled with other 2 double reflex cabs)
 
http://www.myspace.com/struttura44

Back to Top
Albert44 View Drop Down
Registered User
Registered User


Joined: 30 May 2007
Status: Offline
Points: 10
Post Options Post Options   Thanks (0) Thanks(0)   Quote Albert44 Quote  Post ReplyReply Direct Link To This Post Posted: 24 July 2008 at 7:37pm
I know that enlarging the diameter is the simplest solution but the frontal panel is no t so big to host 6 bigger pipes...probably I can try to flare them,but I don't know the right radius & calcolous to keep this tuning!!!
Back to Top
 Post Reply Post Reply

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.06
Copyright ©2001-2023 Web Wiz Ltd.

This page was generated in 0.109 seconds.