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Yet again!!! Fishy/Jonathan/Glasswolf

 

Bronze Member
Username: Deathshadow

Post Number: 26
Registered: Oct-04
Just doesn't get any better for me right now guys -_-. The amp either completely crapped out or something else is wrong. To make a long story short and minus my adult temper tantrum with a side of choice words I was driving along today and the subs stopped bumping as usual, this time they have not started to bump again. I checked EVERYTHING over and so far I have concluded the following:

*I am 100% positive the wiring is all correct
*I am 100% positive it isn't the subs
*I am 100% positive the amp is getting enough power (14.2+ volts with the car on).
*I am 99.9% positive Power Acoustik is a P.O.S company.

So this pretty much leaves the amp or a ground yet again... Although today while participating in my new found hobby of fumbling around inside my trunk compartment something did strike me as a valid possibility. The former area of paint that I had grinded away to make a suitable ground now has a coat of RUST on it... While I do not consider myself to be anywhere near worthy of an audio install professional I do know rust m0lests the ability to properly ground a lead. Plus being in a car environment with the applied voltage from the ground and the tendency of moisture provides an adequate breading ground for this orange/brown terrorist. Today I will re-grind these areas over and see if this is the problem. What do you guys think about all of this?

Thanks.

[Note] This is in reference to my previous answered post located here:

https://www.ecoustics.com/electronics/forum/car-audio/105614.html
 

Silver Member
Username: Fishy

Tamarac, FL USA

Post Number: 558
Registered: Sep-04
WD-40?

Although if that amp is getting hot I'd think it might be doing the thermal protection thing.

I dunno, I got some pretty crappy grounds in my vehicle and my system still works. I always just scratched up the paint a bit with a pocket knife and DeWALT'd that thing on in there.

But I'm not what one would consider a professional.

:-)

-Fishy
 

Gold Member
Username: Glasswolf

NorthWest, Michigan USA

Post Number: 4709
Registered: Dec-03
you can run a longer ground if you need to reach an area of solid metal without rust.
that could cause a bad ground, yes.


and I agree power craptastik (as I'm fond of calling them) is a poorly made product.
much better stuff out there without spending too much more.
 

Bronze Member
Username: Deathshadow

Post Number: 27
Registered: Oct-04
I might break out the mig welder and show that lead whats up. How about amps guys, are kicker/hifonics amps any good? Any better ones?
 

Gold Member
Username: Glasswolf

NorthWest, Michigan USA

Post Number: 4718
Registered: Dec-03
Hifonics.. some folks like em.
I'm not that fond on them.
Kicker, RF, and MTX are all about on par.. good amps, affordable, well made, durable, not bad looking.
If you want high end, look at Sinfoni, McIntosh, Zapco, or similar.. really depends on the budget mostly.
 

Bronze Member
Username: Deathshadow

Post Number: 28
Registered: Oct-04
I have two Alpine Type R 12" 4 ohm DVC subs 300RMS and 1,000 peak, would this amp be suitable?

http://www.etronics.com/product.asp?stk_code=kic04kx6001

I have the subs coils wired in series then I wired both subs in parallel to achieve a 2 ohm load, so im assuming since this puts out a mono 600 RMS load each sub would get 300 watts? What about peak power it doesnt say anything, or do you not worry about that? Also does this have a low pass filter on it, sorry im still n00b.

 

Gold Member
Username: Glasswolf

NorthWest, Michigan USA

Post Number: 4734
Registered: Dec-03
yes 300w each. peak is meaningless.
the kx600.1 is a very good amp.
 

Silver Member
Username: Fishy

Tamarac, FL USA

Post Number: 567
Registered: Sep-04
I never thought about usin an arc welder in that manner.

That would definitely assure an adequate ground in my book.

Ummm.... did you say you were bridging that thing into a 2 ohm load? or is that a monoblock "power craptastik" as Glass puts it. A 2 channel, 2 ohm bridge might explain your power problems.

Now if your Alpines have DUAL 4 ohm vc's then your wiring them together as a 4 ohm load which should be cool.

Why is dual voice coil nomenclature so darn confusing?

:-)

-Fishy
 

New member
Username: W_c_rontgen

Middle of Nowhere, Central WI USA

Post Number: 6
Registered: Oct-04
Make sure that ground wire is NOT attached to your amp when you weld it! :P
 

Gold Member
Username: Glasswolf

NorthWest, Michigan USA

Post Number: 4759
Registered: Dec-03
hahaha

Fishy I thought about that, but he did mention that it'd worked fine for a long time, so I figured load was within spec.
 

ThatGuyYouKnow
Unregistered guest
I was thinking of Geting (2) 04KX600.1, 1 per RE SE12 sub I have, and planning on an Amp Rack.
I really dont like how 1 amp powers 2 Sub's, maybe my amp but I'd like to KNOW that each amp would be working at 2ohms.
Everytime I have both subs hooked up its sounds like I would need to turn up the volume OR gain but i keep gain less than half, Now if I just have 1 hooked up its like 3 to 5 times of the old Volume. Each Sub is wired @ 2Ohm's and I have each sub on its own channel(mono amp that has 2 channels)I think when I have 2 X 2Ohm hooked up the amp see's 4ohm, cuz the 4ohm load it can handle is way low
If im wrong pls tell me
Im not a Master Electrition, maybe I should be...
 

Bronze Member
Username: Deathshadow

Post Number: 30
Registered: Oct-04
I had my subs coils wired in series and then wired them together in parallel to the amp to one channel.
The load presented to the amp is 2 ohms, so 600 watt amp and 2 subs each coil gets 150 watts (300 a sub). Some amps can not handle that 2 ohm mono load and will shut down, unlike my "Power Craptastic" 720 Watt Mono amp that just blew up and hasn't worked since :-)

My voltage barely ever dipped on an extreme level, the amp always got 14.2 volts + and I had a 2.4 Farad capacitor in the mix. The Type Rs are under rated and can handle 500 RMS so I hear but im still going to run 300 fsck it.
 

Bronze Member
Username: Deathshadow

Post Number: 31
Registered: Oct-04
when I say one channel I mean bridged onto where the amp indicated - and + for a mono 720 load
 

Gold Member
Username: Glasswolf

NorthWest, Michigan USA

Post Number: 4789
Registered: Dec-03
is it possible you had one sub out of phase?
 

Bronze Member
Username: Deathshadow

Post Number: 33
Registered: Oct-04
meaning....
 

Bronze Member
Username: Deathshadow

Post Number: 34
Registered: Oct-04
Just noticed something, the amp is putting out SOME power lol and SOME is an over statement. The subs to rumble a tiny tiny tiny bit if you put your hand on them but nothing more. Did the amp take a crap or what's going on?
 

sorrykid
Unregistered guest
the amp is finished... its not 1 ohm stable, if your running two alpines its taking it down to 1 ohm. The amp probably kept getting hot and finally over time took a crap on yea. Sorry

p.s. power acoustik sucks... i know from experience.
 

Silver Member
Username: Fishy

Tamarac, FL USA

Post Number: 579
Registered: Sep-04
I think Glass was referiing to thatguyyouknow's "problem" of one sub sounding louder than two. Normally 2 subs run in parallel will sound much louder than just the one of the same sub assuming of course the amp can handle the reduced impedance.

With two subs wired this way you have twice the cone area and in many cases nearly twice the total power as well so it should take LESS gain to have the same output. If your subs are wired "out of phase" its a different story. If you have the polarity reversed on one sub it moves "out" when the other moves "in" effectively cancelling each other out.

You can check for correct polarity for a set of subs a couple ways. If you attach the pos and neg leads off a small flashlight battery to the "correct" pos and neg terminals of your box you induce a DC offset to the subs. If wired correctly BOTH subs will move "out" together. If wired out of phase one will move in and the other out.

Another quick way to check for in phase operation of a couple of parallel wired subs is to gently push on one cone(w/ sytem off of course). The movement of the voice coil(s) of one sub in its motor's magnetic field will induce a bit of current in the wiring which will cause the other sub to move as well. If both subs move together in the same direction then they are wired correctly "in phase".

-Fishy
 

Bronze Member
Username: Deathshadow

Post Number: 39
Registered: Oct-04
LOL what ohm load is it? The way I do the math if I have two DVC 4 ohm subs and the coils are wired in series then the remaining coils wired together in parallel from each sub I have a total 2 ohm load... People have told me I have a 1 ohm load, and a 4 ohm load, and a 2 ohm load... lol please clear this up someone?
 

Bronze Member
Username: Deathshadow

Post Number: 43
Registered: Oct-04
anyone o_O?
 

Silver Member
Username: Fishy

Tamarac, FL USA

Post Number: 583
Registered: Sep-04
lol, its confusing huh.

When people say that they have DVC 4 ohm subs it usually means that they have subs which have two 4 ohm voice coils that can be wired either to give a 2 ohm or an 8 ohm speaker, neither of which is a "4 ohm sub".

Which model do you have? the 1241D or the 1221D?

The 1221D has two 2 ohm voice coils(1 or 4 ohm sub).

The 1241D has two 4 ohm voice coils(2 or 8 ohm sub).

A pair of 1221D's with voice coils in series, wired in parallel will give you a 2 ohm mono load.

A pair of 1241D's wired the same way will give you a 4 ohm load.

that help? :-)

-Fishy

 

Bronze Member
Username: Deathshadow

Post Number: 46
Registered: Oct-04
Wow... Is there anyway I can get these 2 subs wired up as 2 ohms? I have 1241Ds...-_- Or any amp that will give me 600 watts. Someone told me itd be a 2 ohm load and I went with it, this changes everything -_-! I need to push 300 a pc to these.
 

Silver Member
Username: Fishy

Tamarac, FL USA

Post Number: 587
Registered: Sep-04
I dunno, the guys at Adire talk about utilizing only one voice coil and shorting(or adding a variable resistor) to the other one on the Shiva, but this changes the the Qts of the driver and cuts the power handling in half. I've seen other companies specifically prohibit this practice on their subs.

It may be time to give the "power craptastik" a decent burial and find yourself a good 1 ohm stable monoblock or 2 ohm stable(4 ohm bridged) 2 channel amplifier.

You sure you have the voice coils in series and not parallel? Any monoblock should be able to handle a 4 ohm load with ease. 1 ohm might be a different story.

-Fishy
 

Bronze Member
Username: Deathshadow

Post Number: 50
Registered: Oct-04
Im gonna sell the 4 ohm DVC subs for 190 bucks and just buy the 1221Ds. If I then wired the coils together in series on each sub then wired both subs together in parallel I would have a 2 ohm load and could use my MRD-M501 Class D mono amp correct!? :-)
 

Silver Member
Username: Fishy

Tamarac, FL USA

Post Number: 593
Registered: Sep-04
Yep, those would give you a 2 ohm load, but, err..... you might want to check out the T/S parameters or the recommended enclosure for the 1221D's. They might sound a lil different than the 1241D's in that same enclosure. You may not notice the difference however.

Yeah if your stuck on goin with an Alpine amp thats what you need to do otherwise I'd just get a different amp. Into a 2 ohm load you're gonna get 550 watts with that 501 at 14.4 volts, but only 425 watts at 12.

I dunno, if you can get $190 for those things I guess I'd say go for it.

-Fishy
 

Damien Roberts - other PC
Unregistered guest
First off I would like to thank you & glass enormously for your time helping me out with my efforts to learn more; I greatly appreciate it. My alternator puts out 14.1 - 14.4 volts all the time while the car is on and the battery holds 13.x with it off. The MRD-M501 was also under rated, it actually puts out 630 RMS @ 14 volts. So really that works out to be perfect. Its not that I am stuck with the Alpine amp, I just really like the features, looks, and digital controls. Two Alpine Type Rs retail for 210 each retail around here, the speakers are brand new and I still have the boxes and paper work for them. Im going to post a ad in the paper for $190.00 (for the pair) hopefully I will get it :-(! As for box parameters for both 1241s and 1221s .7 - 1.0 cu. ft. is reccomended. I dont know if this is what you meant by T/S or not. Let me know what you think, take it easy fish.
 

Silver Member
Username: Fishy

Tamarac, FL USA

Post Number: 594
Registered: Sep-04
I was just pointing out that the 1221's and 1241's are two different woofers which MIGHT sound a bit different in the same enclsoure.

If you look at the specs of these 3 10w3v2 models

http://www.jlaudio.com/subwoofers/pdfs/10W3v2_MAN.pdf

you'll see that they have slightly different parameters and which result in different recommended enclosure sizes. Although the same suspension, motor, and cone are used different voice coils have different electrical characteristics(dif Qes, Qts) as well as different geometry(dif length in motor gap => dif Xmax).

If you have a sealed box you'll probably never notice the difference however.

-Fishy
 

Bronze Member
Username: Deathshadow

Post Number: 60
Registered: Oct-04
Hmmm I see check this out, I really know nothing about the specifics.

<------------------------------------------------>
General common data:

* Diaphragm Material : Kevlar Reinforced Pulp
* Magnetic Weight : 89.4oz.
* Mounting Depth (top mount) : 178mm (7")
* Mounting Diameter (top mount) : 275mm (10-7/8")
* Recommended Box Types : Sealed/Vented/Bandpass
* Recommended Sealed Box Volume : 0.7 -- 1.0 cu. ft.
* Spider Material : Nomex
* Voice Coil Diameter : 50mm
<------------------------------------------------>

<------------------------------------------------>
Alpine Type R 1221D:

Thiel Small Parameters

* Coil Height (Hvc) : 36.7mm
* Cone Area (Sd) : 467.59 sq. cm
* D.C.Coil Resistance (Re) : 1.8 ohm + 1.8 ohm
* Electrical Q (Qes) : 0.40
* Equivalent Suspension Stiffness (Vas) : 58 liters(2.04cu.ft.)
* Free Air Resonance (Fs) : 27Hz
* Frequency Response : 24Hz - 1kHz
* Gap Height (Hag) : 10mm
* Impedance (Nominal) : 2 ohm + 2 ohm
* Inductance (Le) : 2.41mH at 1kHz (0.84mH at 20kHz)
* Linear Excursion (X linear) : 13.35mm
* Maximum Excursion (X peak) : 26.7mm
* Mechanical Excursion (Peak-to-Peak) : 55mm
* Mechanical Q (Qms) : 8.68
* Sensitivity : 87 dB/W/M
* Total Loudspeaker Q (Qts) : 0.38
<------------------------------------------------>

<------------------------------------------------>
Alpine Type R 1241D:

Thiel Small Parameters

* Coil Height (Hvc) : 37.74mm
* Cone Area (Sd) : 467.59 sq. cm
* D.C.Coil Resistance (Re) : 3.6 ohm + 3.6 ohm
* Electrical Q (Qes) : 0.45
* Equivalent Suspension Stiffness (Vas) : 58 liters(2.04cu.ft.)
* Free Air Resonance (Fs) : 28Hz
* Frequency Response : 24Hz - 1kHz
* Gap Height (Hag) : 10mm
* Impedance (Nominal) : 4 ohm + 4 ohm
* Inductance (Le) : 3.85mH at 1kHz (1.34mH at 20kHz)
* Linear Excursion (X linear) : 13.87mm
* Maximum Excursion (X peak) : 27.7mm
* Mechanical Excursion (Peak-to-Peak) : 55mm
* Mechanical Q (Qms) : 8.31
* Sensitivity : 87 dB/W/M
* Total Loudspeaker Q (Qts) : 0.43
<------------------------------------------------>

Does the 2 ohm sub pose a significant difference?
 

Bronze Member
Username: Deathshadow

Post Number: 62
Registered: Oct-04
Dont mean to rush it guys or be a pest but I need an answer, they might be sold tomorrow!! :-)! Thanks again!
 

Gold Member
Username: Glasswolf

NorthWest, Michigan USA

Post Number: 4953
Registered: Dec-03
personally I wouldn't put both in the same box.. if that's what you're after.
 

Bronze Member
Username: Deathshadow

Post Number: 69
Registered: Oct-04
What box would you recommend for 1221s? I got a 140$ box for free from a friend who works at a retail store, it ehh fell off a truck you could say... :-)
 

Bronze Member
Username: Deathshadow

Post Number: 77
Registered: Oct-04
glass?
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 2421
Registered: May-04
Go ahead and get the dual 2 ohm subs. I highly doubt you'd notice a difference between those and the dual 4 ohms, even if you did it wouldn't be for the worse. Main difference is inductance, etc because of electrical differences as Fishy stated above, there is a little difference in excursion, but again not noticeable. I'd stick to Alpines recommendations for the box, and choose your preference of sealed vs. ported.
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