Odd noise from BL's

[Chevybwoi2007 0]

My BL's are omitting a 'popping' and 'crackling' noise on low Hz. Anyone know what it could be?

It sounds like a voice coil problem, but sometimes it makes the noise and sometimes it doesn't which leads me to think it MAY be an amp problem.

They're dual 2's wired at .5 ohms. My electrical system is PLENTY capable.

I REALLY hope it's not the subs but I doubt it, especially since BOTH subs do it at the same time.

[Fi Car Audio 64]

Either both subs have problems, its a power/amp issue, or a tuning/settings issue. What are you tuned to and where is your subsonic set to? Seems like it might be playing below tuning. What amp?

[Chevybwoi2007 0]

Either both subs have problems, its a power/amp issue, or a tuning/settings issue. What are you tuned to and where is your subsonic set to? Seems like it might be playing below tuning. What amp?

Tuned to 40 Hz.

Subsonic: on. LoL (no option besides on/off on amp)

I'm running a RF Power T5002.

It's worked fine for about 4 months, it just started the other day. Nothing has been changed prior/post problem.

[NDMstang65 403]

I'd venture to say that the power supply is going out on you...

You do know that is not the proper amp to be running a pair of those subs with right?

2-Channel Amp Specifications

* Amplifier Type: 2-channel

* RMS Power @ 4 Ohms: 75W x 2

* THD at 4-Ohm RMS Power: 0.08%

* Bridged RMS Power @ 4 Ohms: 300W x 1

* Speaker Level Inputs: no

* Preamp Outputs: yes

* Built-In Crossovers: HP/LP

* Bass Boost: 0 - 18 dB

* Frequency Response: 20-20,000 Hz

* Signal to Noise Ratio: >80 dB

* Fuse Rating: 100 amps

Shipping: 20.5 lbs

It's made to run at 4ohms mono, not .5ohm.

[Fi Car Audio 64]

Found the issue... it has taken several months of playing below tuning to break them in... the filter is 27 Hz at 12 dB per octave fixed. This allows for full power to go to the subs below tuning which is equivalent to free air. Need to either get a filter in line to get rid of those frequencies, change the amp, or change the enclosure and tune lower.

Or what Nick said ^^^^^

[Fi Car Audio 64]

Oh... didnt know it was only 300W to them??? Might side a little more with Nicks idea then.

[Chevybwoi2007 0]

The amp was only made to be 'temporary' anyways.. :'(

The birth sheet claims 500 x 2 at 2 ohms.

My electrical system is PLENTY capable of handling a measly 1000 watt amp, I'm assuming it's not the power supply.

I've got an autotek mm 1400.1D laying around, it's not the BEST amp, but could I use that temporarily?

I'd like to eventually run an autotek mm 4000.1d and give them 1400 a piece a 2 ohms, but ehh.....money no there right now.

Edited July 19, 2007 by Chevybwoi2007

[NDMstang65 403]

You definitely do not want to run that amp that low...it's supposed to be seeing close to a 4ohm load mono, not .5ohm...

I honestly don't see how its still running to be honest with you. Rockford makes a tough amp, especially the T series...

[Chevybwoi2007 0]

LoL. Out with the old I guess...

Thanks though. I'll see if another amp helps, hopefully.

[theabunai 3]

chit kudos on that amp lasting at 1/2 ohm for 4 months man.... Rockford FTW.....

If the box is tuned to 40hz scott what would you suggest the SS filter be set to (if it was adjustable) ??

Edited July 19, 2007 by theabunai

[Chevybwoi2007 0]

chit kudos on that amp lasting at 1/2 ohm for 4 months man.... Rockford FTW.....

If the box is tuned to 40hz scott what would you suggest the SS filter be set to (if it was adjustable) ??

I've ran that amp at .5 since February 2006!

I don't know either!

[Fi Car Audio 64]

Found from some old lit that it is set to 27Hz at 12dB/Octave. 13 Hz and that shallow of a slope is WAY too low. Normally set 2-5 Hz below tuning depending on filter slope.

Old RF was tough stuff. I melted plastic with my old Punch 45... thing got so hot for so long that the black anodize started to turn brown and gold. Took way more abuse than any other amp Ive ever owned until the day I sold it.

[SKEEMASK 3]

Sup, Chevybwoi. This is Cut Buddy from ECR. If u are talking about those BL15s in ur Monte then ur problem is not with the subs, settings, or electrical system.....its ur ohm load. No RF amp is capable of running @ 0.5ohm unless u are burping which u are not or u've sent it to Rockford to be modded for 0.5ohm load....then that would be the only way u could series a pair of dual 2ohm bubs to a RF amp for daily usage and not frying the amp. Ur best bet is to get another amp that does its power at 2ohm like the MM4000.1D u mentioned and parallel ur subs or get 2-1ohm amps and series 1 amp per sub. That T5002 is something Id run a few comp sets off of, defenitely not 2 BLs. We've had this conversation on the other site before but I had no idea that ur subs were dual 2ohm, if I had of known that then I would have let u know that then it wasnt a safe load for daily usage. I remember u saying how loud it was and how u couldnt breathe in ur Monte. Trust me those BLs are only laughing at u with both subs sharing 1-T5002. Id do at the least 1400rms....Ideally 1800rms would really be what u need. note:thats per sub

[SKEEMASK 3]

oh and about the filter. Ur port is tuned to 40Hz. RF PowerT amps have a subsonic filter set @28Hz automatically......so all together since ur box is tuned so high ....RF wouldnt be a good amp for u period in my opinion unless u build another box and tune it in the low30Hz range. U need a amp(s) with a filter that will go up to around 35Hz or somewhere in that ballpark. It may not seem like a big difference but when u are running below ur tuninf freq u are asking for trouble. I wouldnt set it no more than 5-6 Hz lower than ur tuning freq. It would work though I was jkust pointing out the big gap in between ur 28z set point and ur 40hz tuning freq. Steve Meade runs T amps and his SPL port (interchangable) is tuned pretty high but at the same time u have to realize he does ride around pumping his SPL port though he uses high lower tuned port for daily.

Edited July 19, 2007 by SKEEMASK

[Chevybwoi2007 0]

'Sup Cut?

Yeah, you were right....I just had to much going on to focus on a new amp.

I'm bidding on that autotek MM 4000.1D that Ricoshay has for sale on eBay. I think it'll be perfect for it with 1400 x 2 at 2 ohm. I wanna' give them the full 1800 watts but I REALLY don't have room for another battery in my trunk if I needed it (doubt I would but you never know...).

Thanks though, I'll feed that RF to my dog later since it's useless. LoL

Edited July 19, 2007 by Chevybwoi2007

[Chevybwoi2007 0]

oh and about the filter. Ur port is tuned to 40Hz. RF PowerT amps have a subsonic filter set @28Hz automatically......so all together since ur box is tuned so high ....RF wouldnt be a good amp for u period in my opinion unless u build another box and tune it in the low30Hz range. U need a amp(s) with a filter that will go up to around 35Hz or somewhere in that ballpark. It may not seem like a big difference but when u are running below ur tuninf freq u are asking for trouble. I wouldnt set it no more than 5-6 Hz lower than ur tuning freq. It would work though I was jkust pointing out the big gap in between ur 28z set point and ur 40hz tuning freq. Steve Meade runs T amps and his SPL port (interchangable) is tuned pretty high but at the same time u have to realize he does ride around pumping his SPL port though he uses high lower tuned port for daily.

Yeah, I understand. I was 16 and an idiot when I built the box.

[lee 2]

Just for reference guys,that RF T5002 amp confuses alot of people. I know cuz I have one.

My T5002 Birthsheet reads:

234 rms x2 @ 4ohm

343 rms x2 @ 2ohm

520 rms x2 @ 1ohm

1040 rms bridged @ 2ohm

As you can see this is a very strong amp capable matching well with any one SSD or Q.Two woofers might be underpowered but will still pound.Remember this is how we did it back in the day.As far as bl's go,I would go with a different amp due to the suspension and power capability of this sub.

[SKEEMASK 3]

Chevy, If u went with the MM4000.1D u would be better to run both channels @1ohm or bridge it @2ohm. Just keep ur gains at a moderate level and they will be fine. Just throwing somemore options at u since u say money is an issue. U do know u can find 2-MM1400.1Ds on ebay for around $275 each shipped. Just get a Y splitter for ur RCAs which aint no more than a few bucks. That is a solid amp, Ive seen a bench test sheet performed by Carstereo magazine and they got 1750watts rms out of that lil ass amp....it wasnt the cleanest but it was fairly decent and for the price u cant beat it. Id get some high dollar comps and run em off that T5002. Id take it off ur hands for u but I dont know if I wanna run RF amps just yet. But trust me u can sell it, somebody will take it off ur hands. So far as juice, u do have a upgraded alt right? What size batteries are u running now? Id do a yellow top under the hood and 1 HC2400 in the trunk.

Edited July 20, 2007 by SKEEMASK

[Chevybwoi2007 0]

Skee, I'd love to go ahead and run 2 m1400.1D's, but I've had no luck finding another one. :'( It's like they're discontinued or something...

Even if I run the 4000.1D, I'd still only have them at 1400 a piece, BUT, I got a good deal on one for about $350!!

I think I'll keep the RF, I plan to run some Boston Pro 60 comps off of it. If I decide to sell if, I'll be sure to inform you.

Right now I've got a 220/150 amp Iraggi alt, yellow top under the hood, and an hc1400 in the back....I'll add more if/when needed.