LB audio

Wishes you Merry X-Max and Happy New Year 2006!

HU:ALPINE, Pioneer, Nakamichi X-overs/EQ's: Audiocontrol EQX, DQT, EQT, 6XS, Alpine PXA-H 701, F1 status, Orion, PhoenixGold AMPS: McIntosh, PPI, Lanzar, Genesis, Milbert, TRU-Tech - A, AB class, DD, GroundZero, SPL DYNAMICS D -class Speakers/subs: JBL GTI series, TREO SSX series (made 2 WR this year with model SSX12.22), DigitalDesigns 95xx and 99xx, JL series 6 and 7 v2, RE

It is still under construction Head unit: ALPINE CDA 7939 R + CHA-S 604 CHANGER Processor: ALPINE ERA-G320/probably I will switch to ALPINE PXA-H701 X-over: AUDIOCONTROL 6XS Amps: LANZAR OPTI 500.2 - 2X (for subbass) LANZAR OPTI 200.2 - 2X (for bass and mid) LANZAR OPTI 100.2 - 1X (for tweeters) Speakers: JBL 08 GTI - TWEETERS JBL 500 GTI - MIDS KEF B200G JBL W 15 GTI - 2X Interconects and signal cables: DLS ULTIMATE LOCKOUT, ULTIMATE BALANCED CABLE, ALPINE AI-NET BATTERY: 2 X VESNA EXTREME 90 Ah/2750A Power cables: DLS, CALIBER Speaker cables: DIETZ, BASIC, STREETWIRES Damping material: DYNAMAT EXTREME 2 layers, DYNAMAT ORIGINAL 2 layers, BRAX ExVibrations 3kg

Round edges or 45 deg helps eliminate standing waves and it is good for SQ but SPL is other thing. If SPL box is made correct then you should make standing waves inside box and all 45 deg or smooth corners destroy them. All boxes from 1st, 2nd...places I saw arround the European 3x competitions were made in this maner. When you create standing wave in box at right freq. than you gain your SPL quite a bit. It also help if you make your box and port inside as smooth as you can!!!! difference can be up to 0.5 dB. Be wery careful when you do bracing!!! braces MUST have smooth edges!!! But at first try without it!!!!

I like dB Drag Racing competition because there is no other judge but comp & TL to tell who is loudest! For SQ we have in Europe EMMA and IASCA - but in my country judges judge the car in many cases with eyes and not with ears - unfortunately

Yellyfish 420 YGPM

Hi again and thank you all for gretings! This is the link you wanted: http://www.ground-zero-audio.com/ I used to compete with model GZPA 1.5000 (4 pcs strapped togather), but they relesed new model - even more powerfull - 1.6000 - 6kW/16V and 4.6kW/12V Thw car is European make FIAT PANDA - the car is crap but it is very good for SPL competition and it works from 68-72 Hz-depends of production year - the older it is - on higher freq it works (Italian crap) Box is clasic ported with 190 mm port - my own production. If anybody needs help - let me know. Pictures of dBDrag car will send you on e-mail. - give me your adresses! Bye!

The closed boxes have roll off 12db/oct, ported box have roll-off 24 dB/oct - output from port shifts 180 deg. below tuning freq. - that' why closed box plays lower than Ported box. Driver in ported box have same thermal limit, but X-max at tuning freq is much smaller then in closed box - that's why it takes more power and it is louder at tuning freq and higher. Due phase shift driver below tuning freq becomes unloaded - you have to use subsonic filter to avoid mechanical demage on driver.

With smaller box your impendance will be lower and so you will get more power from your amp/s. Try to make bigger port. Rise tuning freq. a little bit higher. Dont forget on battery. Don't put any damping material in box and make inside of your box as smooth as you can (paint it with color or Top coat or Gel coat)

Hello! I'm coming from Slovenia/EU. I found your forum to be very educational and informative! I compete in dB Drag Racing in Europe and this year we allready set two World Records in Street B. My top result is 156.7dB. This result was set with Alpine HU 9835, 4 x GZ GZPA 5000 D amps and two TREO SSX 12.22 subs in ported enclosure. My sistem for everiday listening pleasure consist from a little older HU Alpine 7939R + processor ERA-G 320, AC 6XS xover, Five Lanzar OPTI amps (200.2 2X, 500.2 2X, 100.2 1X), speakers are from JBL (W1500 GTI, 508 GTI) and KEF (B200G) C-ya!