help figuring out a huge quad 18 bass horn

Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic

   well, i know this is going to sound crazy and i know its going to be fun.

New venue, new dj booth, full construction..got me thinking, what can i do with the space under the dj booth?  i was going to put four ported subs across the front and leave the back 2/3 for storage but..

in a space seven feet deep, eight feet wide, and 22 inches high, what could be done?  i'd like to use four drivers, lower budget as i dont think high power/super high excursion would be needed in a bass horn this size.  flat to 35 should be no problem?  30 would be even better.

My thought is this, one fold per side with two drivers loaded on it, giving me a horn length of aprox 10 feet, exiting one huge horn mouth along the eight ft by 22 inch side.

anyone up to designing this?  i have an idea of it, but little experience to back it up.

thanks for any input,
mike

Author	Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic
lycantheleopard Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 01 April 2012 Location: san jose ca usa Status: Offline Points: 428	Post Options Post Reply Quote lycantheleopard Report Post Thanks(0) Quote Reply Topic: help figuring out a huge quad 18 bass horn Posted: 30 November 2013 at 1:44am
	well, i know this is going to sound crazy and i know its going to be fun. New venue, new dj booth, full construction..got me thinking, what can i do with the space under the dj booth? i was going to put four ported subs across the front and leave the back 2/3 for storage but.. in a space seven feet deep, eight feet wide, and 22 inches high, what could be done? i'd like to use four drivers, lower budget as i dont think high power/super high excursion would be needed in a bass horn this size. flat to 35 should be no problem? 30 would be even better. My thought is this, one fold per side with two drivers loaded on it, giving me a horn length of aprox 10 feet, exiting one huge horn mouth along the eight ft by 22 inch side. anyone up to designing this? i have an idea of it, but little experience to back it up. thanks for any input, mike

all bass Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 11 October 2012 Location: the Netherlands Status: Offline Points: 1855	Post Options Post Reply Quote all bass Report Post Thanks(0) Quote Reply Posted: 30 November 2013 at 2:42am
	Normally i wouldn't recommend these because of their awkward shape but... 3x 20" wide Lab 12 loaded BFM Tuba 60's would fit in there. Will have a good low end extension to 28hz (not flat though) and with cheap drivers. Edited by all bass - 30 November 2013 at 2:50am

Centauri Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 29 November 2004 Location: Newcastle Aus Status: Offline Points: 1792	Post Options Post Reply Quote Centauri Report Post Thanks(0) Quote Reply Posted: 30 November 2013 at 8:16am
	Ravehorn? http://s128.photobucket.com/user/rave-roborg/library/ravehorn?sort=3&start=all&page=1

Dub Specialist Sound Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 15 November 2013 Location: Smethwick Status: Offline Points: 4873	Post Options Post Reply Quote Dub Specialist Sound Report Post Thanks(0) Quote Reply Posted: 30 November 2013 at 4:07pm
	Wow propa Bass Horns , none of the 1850 bizness.....
	Musical Roots Reggae Vibration is Life! for music is sound...sound is vibration...vibration is energy... and energy begets life. Therein lies my passion!...MUSIC IS LIFE...

studio45 Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 16 October 2007 Location: United Kingdom Status: Offline Points: 3864	Post Options Post Reply Quote studio45 Report Post Thanks(0) Quote Reply Posted: 30 November 2013 at 4:32pm
	If you only have 22 inches of height you can't load two 18 inch drivers stacked vertically and so they will end up entering the horn at slightly different points, this is probably a bad thing. You could do a manifold-loaded straight horn a la the Opus 6x15 super-sub, ie have four drivers in their own rear chambers with separate throat chambers firing into one horn throat, with the horn dimensions then being most of the available depth, full height and full width at the front. You would of course need trap-doors in the booth floor for access and this would not be a removable solution but part of the structure of the booth. Some quick Hornresp-ing with the PD1851 driver indicates you should be able to hit about 140-145dB from 34 to 180Hz with 4000 watts input (across the four drivers)
	Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA

lycantheleopard Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 01 April 2012 Location: san jose ca usa Status: Offline Points: 428	Post Options Post Reply Quote lycantheleopard Report Post Thanks(0) Quote Reply Posted: 30 November 2013 at 7:46pm
	i like the idea of the four drivers across the back with there own throats, i agree that side by side loading would not be as good, i didnt think of that. would you mind simming with the eminence 4018lf? i'll find the specs for you in a sec..the pd1851 is quite pricy in the states, so a lower budget option would be preferable.

lycantheleopard Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 01 April 2012 Location: san jose ca usa Status: Offline Points: 428	Post Options Post Reply Quote lycantheleopard Report Post Thanks(0) Quote Reply Posted: 30 November 2013 at 7:50pm
	eminence definomax 4018 lf Nominal Diameter18" Power Handling (RMS)800 Watts Power Handling (max)1600 Watts Impedance8 ohms Frequency Response36 to 200 Hz Sensitivity95 dB 1W/1m Voice Coil Diameter4" Magnet Weight109 oz. Thiele-Small Parameters Resonant Frequency (Fs)32 Hz DC Resistance (Re)6.19 ohms Voice Coil Inductance (Le)4.78 mH Mechanical Q (Qms)10.38 Electromagnetic Q (Qes)0.36 Total Q (Qts)0.35 Compliance Equivalent Volume (Vas)8.4 ft.³ Mechanical Compliance of Suspension (Cms)0.12 mm/N BL Product (BL)27 Tm Diaphragm Mass Inc. Airload (Mms)211g Maximum Linear Excursion (Xmax)7.9 mm Surface Area of Cone (Sd)1188 cm² Materials of Construction Cone MaterialCoated Paper Surround MaterialCloth Voice Coil Wire MaterialCopper Voice Coil FormerKapton® / Polyimide Basket / Frame MaterialCast Aluminum Magnet MaterialFerrite Mounting Information Overall Outside Diameter18" Baffle Cutout Diameter16.57" Depth8.13" # Mounting Holes8

_djk_ Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 23 November 2004 Location: United States Status: Offline Points: 6002	Post Options Post Reply Quote _djk_ Report Post Thanks(0) Quote Reply Posted: 01 December 2013 at 6:59am
	Sigma Pro 18A2 (you specified lower budget). Two 4Ω loads, or one 8Ω load in bridge mode. The 140V drive assumes something like a bridged Crest CA9 (or equivalent). The Sigma 18's are a great inexpensive woofer, and 140V is not overpowering four of them. ±2dB 30hz~250hz, 143dB at 2.4KW (109dB/1W/1M), hi-pass at 30hz. Edited by _djk_ - 01 December 2013 at 7:04am
	djk

lycantheleopard Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 01 April 2012 Location: san jose ca usa Status: Offline Points: 428	Post Options Post Reply Quote lycantheleopard Report Post Thanks(0) Quote Reply Posted: 01 December 2013 at 10:24pm
	pretty awesome! would i gain much using the definimax 4018? they are just under double the price of the sigma, but still in the lower budget end of things.

_djk_ Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 23 November 2004 Location: United States Status: Offline Points: 6002	Post Options Post Reply Quote _djk_ Report Post Thanks(0) Quote Reply Posted: 02 December 2013 at 4:22am
	For the 1dB or so difference in extra output I wouldn't spend the extra money.
	djk

lycantheleopard Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 01 April 2012 Location: san jose ca usa Status: Offline Points: 428	Post Options Post Reply Quote lycantheleopard Report Post Thanks(0) Quote Reply Posted: 02 December 2013 at 5:15am
	dj k, any chance you might be willing to draw up a plan or share how you came to that response graph? unfortunately i dont really know where to go from here as i've never designed a horn loaded cabinet unless you count sort of copying the ev short horn loading technique in the sh1502..and i dont think that counts. i dont know if this is allowed, but i'd happily sendyou a few bucks on paypal for your time spent, but that gets into a rocky area especially on this site.. either way, thanks, its given me a lot to think about, just now i gotta carry it further.

_djk_ Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 23 November 2004 Location: United States Status: Offline Points: 6002	Post Options Post Reply Quote _djk_ Report Post Thanks(0) Quote Reply Posted: 02 December 2013 at 5:21am
	PM me your snail mail address, I'll sketch something out on paper (CAD is too time consuming).
	djk