double 18 reflex |
Post Reply | Page 12> |
Author | ||
MARTYNJONHALL
Registered User Joined: 02 January 2005 Location: Burton On Trent Status: Offline Points: 335 |
Post Options
Thanks(0)
Posted: 15 November 2007 at 10:22pm |
|
I know the pro's around here will laugh at me, but has any one got the plans for a cab like this??im no good at working oout volumes & things but great at the practical side
please help me
thanks to you all in advance
i think this cab is a citronic cab?
its got the external dimensions but its the ports and inner ones that are missing
|
||
CLsystems
Old Croc Joined: 16 March 2007 Location: Birmingham Status: Offline Points: 2736 |
Post Options
Thanks(0)
|
|
have you heard one of these cabs?
|
||
TONY.A.S.S.
Old Croc Joined: 21 February 2007 Location: United Kingdom Status: Offline Points: 6878 |
Post Options
Thanks(0)
|
|
When you realize that the sound emitted from the rear of a speaker is the same as the front, I wonder why they bothered to turn one speaker round. Answers on a postcard please.
|
||
CLsystems
Old Croc Joined: 16 March 2007 Location: Birmingham Status: Offline Points: 2736 |
Post Options
Thanks(0)
|
|
my guess is they saw a push pull cab once, and in the morning after they got over there hangover they drew the design on a fag packet.
|
||
Mark James
Old Croc Joined: 15 January 2006 Location: rig side Status: Offline Points: 5309 |
Post Options
Thanks(0)
|
|
http://www.speakerstore.nl/index.php?l=nl&pg=11&c=60
|
||
me so horny me love you long throw
horn loaded for her pleasure |
||
Mark James
Old Croc Joined: 15 January 2006 Location: rig side Status: Offline Points: 5309 |
Post Options
Thanks(0)
|
|
@tony as guess would be that because the other baffle is behind the front one [if that made sense ie one baffle is further back in the cab] the chamber may be slightly smaller [unless its a single chamber] or the magnet would not fit without hitting the back wall of the cab? just a brief guese
|
||
me so horny me love you long throw
horn loaded for her pleasure |
||
MARTYNJONHALL
Registered User Joined: 02 January 2005 Location: Burton On Trent Status: Offline Points: 335 |
Post Options
Thanks(0)
|
|
so guys, best just build a g sub then??
anybody tryed other drivers in them?
|
||
heinrich
Registered User Joined: 21 February 2007 Location: Calindagan Status: Offline Points: 280 |
Post Options
Thanks(0)
|
|
looks like Beta3 drivers in there...............
|
||
.....power is nothing without control....
|
||
HansA
Registered User Joined: 07 March 2007 Location: Norway Status: Offline Points: 595 |
Post Options
Thanks(0)
|
|
I don't have your address. Does not this setup help to cancel out some nonlinearities from the drivers. When coupled in parallel? Thats what I've been thought. Besides from that its just a narrow reflex cab. Probably for tight "stackabillity". Don't need no plans to do that. |
||
�*�o�O�o�*�*: HansA, The FUBAR sound technician :*�*�o�O�o�*�
|
||
_djk_
Old Croc Joined: 23 November 2004 Location: United States Status: Offline Points: 6002 |
Post Options
Thanks(0)
|
|
If you run them at an angle, they work better this way:
|
||
djk
|
||
_djk_
Old Croc Joined: 23 November 2004 Location: United States Status: Offline Points: 6002 |
Post Options
Thanks(0)
|
|
A quick thumbnail sketch of what I use (no photo available):
Why do push-pull slot-loaded?
In Reply to: Subwoofer configurations posted by Wayne Parham on May 16, 2003 at 02:49:27: The reductions in 2nd harmonic distortion from PP mounting on a flat baffle are well known, the non-linearities are equal and opposite and thus the 2nd harmonic is canceled. Because of the driver spacing it only happens in the bottom octaves. The cheaper the driver, the bigger the improvement. I have measured as much as a 20dB change.
In Reply to: Re: "Is the equal and oposite reaction limited to 2nd harmonics, and does it make the system less efficient" |
||
djk
|
||
_djk_
Old Croc Joined: 23 November 2004 Location: United States Status: Offline Points: 6002 |
Post Options
Thanks(0)
|
|
The cheaper the drivers, the more push-pull will help them. "Are there any (more or less) exact figures you can talk about when it comes to reducing distortion with push pull? And/or how much of a noticeable difference (to the ear) are we talking about?" Some old comments cut&pasted from elsewhere(sorry, the link is dead): Kind of like this: http://cgi.ebay.com/ws/eBayISAPI.dl...Item&item=73392 75215&category=47094&rd=1 This was a box EV came out with after I talked with one of their engineers at a trade show about 20 years ago. EV showed me the light in 1974 with the Interface A, an SBB4 alignment with a Q=2 filter ahead of the amplifier, so it became a B6. All my best vented designs were assisted B6 or C6 after that. Around 1980 a friend of mine that was a FOH engineer with dB Sound turned me on to the (then) unreleased MTL4 design. I thought it was cool, but didn't like the short x-max 18s (I don't like 18s in general), and didn't want to have to use a fork lift to move it. I built a half-height design with two 15s facing each other on a narrow slot. On one of the pair I mounted the drivers push-pull (the reversed driver hooked up out-of-phase electrically). This sounded so different I thought it sounded funny (at first). It sounded funny because it had no distortion. It made a large 40hz bass horn sound distorted in comparison. I had Eminence custom make me a large x-max 15 that had the same volume displacement as a good 18 (and went lower). Now, of course, we see push-pull boxes from EAW, TAD, etc, although I have not seen any exactly the same as the ones I made. I took an engineering type job (doing L-band RF stuff for the military) about seven years ago and haven't really made anything much since then. I've been thinking it may be time for another production run as some of my old used boxes are trading hands for more than I sold them for new. and: The EV MTL4 has a 6dB peak at 160hz that they eq out in the crossover. The djk slot loaded enclosure exibited the same peak when the woofers were mounted face to face leaving a good sized cavity. Mounting the drivers in push-pull fashion reduced the cavity to virtually zero and the peak went away. As well as the second harmonic distortion.Third harmonic distortion is reduced by the low pass action of the slot. Doppler distortion is reduced by the drivers being at a right angle to the listener. Box size is reduced by equalized sixth order techniques. I find a Qts of .312 to be optimum for this purpose. The slot for 15's limits the HF response to 200 hz. There is a peak around 800 hz. This is completely determined by the depth of the slot. There is no increase in efficency over a regular box. djk Posted by Jon Risch ( B ) on August 08, 2002 at 20:00:23 In Reply to: Push-pull woofers - how much real distortion reduction happens? posted by freddyi on August 08, 2002 at 12:21:23: A lot depends on the quality of the drivers, however, even very linear woofers will usually show a 6 dB reduction. It is also more noticable at high drive levels, where the woofers are nearing the suspension limits, and the non-linearities are greater anyway. Jon Risch (Peavey) |
||
djk
|
||
Post Reply | Page 12> |
Tweet |
Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |