Amp Adjust & Install

 

Bronze Member
Username: Chrisinoregon

Post Number: 11
Registered: Oct-11
I just purchased a RF T1500-1BDCP amp to push my 1 JBL W12GTI MKII sub that I have in a Obcon Slot-ported box. I'm running 4 gauge power wire from my battery to a Shuriken SK-BT20 batt then out to the amp for obvious power sucking reasons. What gauge speaker wire should I run to my sub? Also, are there any other suggestions as to how to adjust my amp? I'm running the sub parellel which should get me to a 3ohm load. With the birth sheet from RF it says that I'm looking at 1468 rms at 3 ohms. My sub is rated at 700watts rms, but I've been told that I can push 1000-1200 watts rms to this sub in this box. Any suggestions? Thank You
 

Silver Member
Username: Joe1234

Post Number: 881
Registered: May-09
1) Use 12AWG for your sub
2) Below is the manual of your amp check page 8:

http://www.rockfordfosgate.com/rftech/library/2010/3_Amplifiers/1230-56132-01_RF PowerMonobd-MAN.pdf

The sub will be helped a lot if you engage the infrasonic filter VERY important.

Also set the gain of the amp as instructed there.

3) How do you know that's the proper enclosure for your sub?? the wrong enclosure will have the sub blow.
 

Bronze Member
Username: Chrisinoregon

Post Number: 12
Registered: Oct-11
I believe it is a 2.5 or 3 cubic foot box. I think this sub will operate best in this box, so I'm told. What are your thoughts?
 

Silver Member
Username: Joe1234

Post Number: 894
Registered: May-09
JBL recommends a 2.25 cuft gross enclosure volume, taking away displacements for their port and the driver the net internal volume (Vb) comes to 2.0 cuft they recommend a port tuning of Fb = 30Hz.

Obviously their recommendation is for use within their rated power of 700W.

SPL alignments usually go for smaller boxes tuned higher, these changes allow the sub to take more power.

You can use the sub in whatever enlosure you have just watch the power.

Here's an enclosure building thread that show how much work can go into enclosure design as is being done right now on the subwoofers forum:

https://www.ecoustics.com/electronics/forum/car-audio/697680.html
 

Bronze Member
Username: Chrisinoregon

Post Number: 13
Registered: Oct-11
Ok, this is a lot of great info Joe. I guess what I want to do is run my amp at about 1000 watts RMS without blowing my sub. I listen to rock, country, hip-hop/rap. What enclosure setup do you recommend I go with? I looked at the link that you recommended and that is a lot more in depth than I'm ready to jump in to right now. That is some serious optimizing and all I'm looking to do is get some power without blowing my sub. Please help suggesting a box. Thank You
 

Silver Member
Username: Joe1234

Post Number: 904
Registered: May-09
Ok Chris first I would need to know the model of the Obcon enclosure you have or better yet the specifications, I will take a look at it, most likely the JBL specs are the way to go, you should have received a SPL competition aligment paper in the box according to them if you find it that would help. If your enclosure is no good and want to build a custom one then just create a build thread in the subwoofers forum.
 

Bronze Member
Username: Chrisinoregon

Post Number: 14
Registered: Oct-11
Hey Joe, I have the inside dimensions for my enclosure 13"x13"x18" = 3.0 cubic feet. 13"x13"x15" = 2.5 cubic feet if I measure to the partition for the slot port. I couldn't find any JBL spec sheet anywhere. This is all I got and I couldn't find the Obcon model #. Hope this helps. I also have another amp (RF T400-2) that I got just to run my 6x9's 2 Focal 690 cvx. They are rated at 80 watts rms, so I know I will have to run my gain at half power at 4 ohms. My question is 1) should I run it at HP on the crossover? 2) What frequency? the variable is 50hz-500hz 3) Should I get a Punch EQ controller for this amp? Any other advice as to how to tune this amp for these 2 speakers would be greatly appreciated! Thanks and have a good thanksgiving. Chris
 

Silver Member
Username: Joe1234

Post Number: 924
Registered: May-09
Ok Chris let me know if you can find it here:

www.obcon.com

The dims you give are about 3000 cubic inches which happily are not 3 cubic feet. google "3042 cubic inches to cubic feet"

1) Yes, when your sub is up and running.
2) 60Hz
3) I usually don't recommend amp EQs since it's easy to blow speakers by accident with them, it's better to use soft equalization from your HU or a signal processor.

Well this are SQ speakers and not overly difficult to damage so better keep the gain low, some people Dynamat the rear deck or custom install on a very solid non resonant surface, all speakers will sound better installled that way. Also a high end HU can improve you whole system SQ.

Thanks! happy thanksgiving to you!
 

Bronze Member
Username: Chrisinoregon

Post Number: 15
Registered: Oct-11
Ok, The website helped a bunch. The Obcon box I have looks just like the GZ Series Hatchback Slot Vent Speaker Boxes 12" (318-12). The outside dimensions of my enclosure are 15.0"H x 15.25"W x 20"D. If this is a tight box, tighter than a 2.25 which JBL recommends, then I should be in good shape running my amp at 1000 watts right? Also, what hz should I adjust my T1500-bdcp amp at with this box? Thanks again...
 

Silver Member
Username: Joe1234

Post Number: 925
Registered: May-09
I think yes, the gross internal volume of the box for those external dimensions you gave and assuming 0.75 inch wood thickness will come to 2.2 cubic feet, so about the same as JBL suggests, the difference is the slot port for which I have no dimensions (the window of the port must be on the back or on the side) so I cannot determine the tuning frequency but it's safe to say that it's displacement will be bigger than the aero JBL uses on their box. I would need a full diagram with dims of the box to predict performance.

You should set to 60Hz also and engage the infrasonic filter switch to protect the sub. Set the gain as indicated in the manual in page 8 of the amp. Also set the PUNCH EQ knob to MIN at first.
 

Bronze Member
Username: Chrisinoregon

Post Number: 16
Registered: Oct-11
Hey Joe, this is a new question. I'm using a Phoenix Gold Ryval series 4 channel amp (v754) to run my 4 Infinity Kappa 6x8's. My first question is 1) On the aux out rca slot, is that the rear or front channel? Because I will be running it out to a 2 channel RF T400-2 for my Focal 6x9's and I want to make sure that I can fade both the rear infinities and the rear 6x9's that I'll be running in the rear deck. 2) I've been told that this amp isn't the best quality amp as far as clean power goes. I want to power the Kappa's which are rated at 100w rms. PLEASE recommend at least 4 or more other good quality 4 channel amplifiers that I can run. My budget for the amp is $200.00 - $400.00...As always - Thank You
 

Bronze Member
Username: Chrisinoregon

Post Number: 17
Registered: Oct-11
P.S. My budget for an amp is now $300.00 - $800.00
 

Silver Member
Username: Joe1234

Post Number: 961
Registered: May-09
Ok Chris as for your first question, the manual does not say but I guess that will be extremely easy to check.

And yes it does not have figures of a SQ amp, neither the RFs are SQ amps as such. I would say that infinity kappas as good as they are they are not the best either.

If I remember right the those Kappas are 90W, your current amp is 120W/channel, a 100Wx4 will suffice or a 120W is what you want.


 

Bronze Member
Username: Chrisinoregon

Post Number: 18
Registered: Oct-11
I'm on your time buddy. No hurry here...
 

Silver Member
Username: Joe1234

Post Number: 963
Registered: May-09
So I edited my previous post, let me know your thoughts.
 

Bronze Member
Username: Chrisinoregon

Post Number: 19
Registered: Oct-11
Yeah, I do want a 120w - 150w Sq amp. If you could give me at least 4 good Sq amps that you recommend, I would greatly appreciate it. I got a great deal on the Kappas and I'm gonna be putting them in my other car. If you could recommend some good Sq 6x8's to go in the doors, that would be great as well. I'm sure you're gonna recommend some component grade 6 1/2's along with the proper sound deadening as well. I've already got that in mind. I just would rather stay with good quality 6x8's, but I'm not opposed to 6 1/2's either. Please give me your advice on 4 good amps and some speakers for my doors. My budget for the speakers is $200.00 - $800.00. Thanks again!
 

Silver Member
Username: Joe1234

Post Number: 968
Registered: May-09
Ok Chris I will comment on some SQ brands for you to check out:

Well known SQ speakers are from: Rainbow, Focal, Morel, CDT, DLS, DynAudio. some lesser known are HAT, Hertz.

Well known SQ amps are from: Zapco, Steg, Arc Audio, TRU, McIntosh, Brax, DLS, Audison, Sinfoni, LP, Genesis.

Just to name a few.

But I am going to aim low since 1) you are looking for extremely powerful speakers, SQ speakers and amps are not usually that powerful. 2) you have SPL components on your system. 3) I think you just want some better amp and speakers that are loud:

For amps 4 channel amplifiers above 100W per channel:

http://www.sonicelectronix.com/item_15358_JL-Audio-HD600-4.html

http://www.sonicelectronix.com/item_26219_Alpine-PDX-F6.html

http://www.sonicelectronix.com/item_29975_MB-Quart-Q4.150.html

http://www.sonicelectronix.com/item_27474_MB-Quart-ONX4.125.html

For 6.5 components above 100W per channel:

http://www.sonicelectronix.com/item_13416_DLS-Ultimate-UP6i.html

http://www.sonicelectronix.com/item_7610_JL-Audio-ZR650-CSi.html

http://www.sonicelectronix.com/item_22325_Image-Dynamics-CXS64-v.2-4-ohm.html

Notice here that is harder to get SQ component speakers and amplifiers that do 100+ watts per channel.

I think that the 6x9s you have on the back should suffice for rear fill no need for 6x8s on the back doors so I would recommend just using the back channels for the 6x9s and the front channels for the components.

You should throughly research all brands mentioned at the start if you still want top SQ.

And yes you are right I would recommend deadening at least in the doors.
 

Bronze Member
Username: Chrisinoregon

Post Number: 22
Registered: Oct-11
Hey Joe, I posted a new thread over on the eq's and crossover's link.
 

Bronze Member
Username: Chrisinoregon

Post Number: 23
Registered: Oct-11
This is for Joe if possible. I posted on here some time back under ampifiers and you were very helpful. I am finally done with my system and now I need some advice on how to properly adjust my head unit, amps etc. I don't know where to start, so I will list all my equiptment first. Head unit is a Pioneer DEH 8400BH, I'm running an Arc Audio 5150 xxk 5 channel amp for my front speakers (Focal Access 6.5, 4" and tweeter component set with an additional set of RF Punch tweeters) all up front. The 6.5's and RF tweeters are in Q logic kick panels while the 4" mids along with the Focal tweeters are in the place of the original 6x8's in the front doors. They are all connected to the Focal crossover's. I have, in the rear doors, running off the rear channel, RF power series 6x8's. I'm running a T400-2 amp to my Focal 6x9's in the rear deck. The rear channel rca goes to my rear amp and then to the input of the real channel of the arc amp for the rear doors so I can fade the rear together. Finally, I'm running the fifth channel on the arc to a rf punch 10" sub in a slot ported box along with a T2D212 in a slot ported box seperate from the other box ran from a third amp, a RF T1500BD-CP. I dynamatted all my doors and trunk and have bass control knobs for the two amps running the subs. Now that you know what my system consists of maybe you can assist me in adjusting it for the cleanest sound quality I can get. I need help in adjusting the hpf, lpf, and eq and all other adjustments on the head unit. Also the gains and frequncies on all three amps. Please give me a detailed step by step explanation on how to properly adjust all these. I don't have a oscilloscope and I don't have access to one either. As always, thanks for all of your help and advice... Chris Oh yeah, my car is a 06 Ford Focus 4 door
 

Bronze Member
Username: Cadillac

Post Number: 72
Registered: Feb-12
YOU GOT ALLOTE OF HELP FROM THIS FORUM
 

Bronze Member
Username: Chrisinoregon

Post Number: 37
Registered: Oct-11
Yes, I have recieved a wealth of help, direction and advice on this forum. I am extremely grateful and appreciative for all the help that I've got from this forum. Thank you!
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