My amp is wierd.

Juice0723 · Post by **Juice0723** » Sat Dec 15, 2007 6:35 pm

Hello, I have a phoenix gold m44 amp. And the first sub I had on this amp. The sub just was playing all good then it stopped playing the bass. So I figured it was the sub. So I put in a different sub. And today it did the same thing. The first sub lasted a long time though. And the second sub lasted about 2 weeks. Then it did the same thing. So I am thinking the amp is doing something to my subs when I hook them up to it. I have my gain on a little under 3/4. So I think thats all good. I don't know what is going on here. Could you guys help me please. Thanks

Post by **Wakeup** » Sat Dec 15, 2007 6:41 pm

What kind of subs? Voice coils? What ohms?

Juice0723 · Post by **Juice0723** » Sat Dec 15, 2007 6:53 pm

the first sub was a rockford fosgate xlc 10" single 4ohm. And the second was a massive audio dual 4ohm. I ran this one at 2ohms.

Zomb1fied · Post by **Zomb1fied** » Sat Dec 15, 2007 11:10 pm

clipping. You're frying coils because your amps signal is clipping.

Turn the gains down and stop pushing so hard.

If you look around you will find numerous threads on setting gains

Juice0723 · Post by **Juice0723** » Sat Dec 15, 2007 11:26 pm

yeah thats what I thought too. That the amp was clipping. But the sub didn't sound distorted or anything. I didn't have my head unit on max either. I put it half way and it did this. So I should set the gain lower because its a little under 3/4 right now.

Post by **Bfowler** » Sun Dec 16, 2007 12:32 am

what deck are you running?

if its a newer deck....you should likely have the gains way down...that amp was made when 2volt outs were damn near the top of the line.

most new decks put out minimum that...so by turning up the gains even a little.....you are sendind more input voltage to that thing then it ever imagined.

are you running all channels to the sub, or jus the rears?

Juice0723 · Post by **Juice0723** » Sun Dec 16, 2007 12:58 am

I am running a kenwood deck with 2volt preouts. Its like a year old. And I am using the rear channels bridged. Works down to 2ohms. And using the front channels for 2 full range speakers at 4ohms each.

HoseHead · Post by **HoseHead** » Sun Dec 16, 2007 2:32 am

Do you have the M44 manual?

M44 Manual here...

Tells you all aboot setting gains 'n stuff........

Zomb1fied · Post by **Zomb1fied** » Sun Dec 16, 2007 11:06 am

Juice0723 wrote:yeah thats what I thought too. That the amp was clipping. But the sub didn't sound distorted or anything. I didn't have my head unit on max either. I put it half way and it did this. So I should set the gain lower because its a little under 3/4 right now.

It's actually non audible distortion that does the damage because nothing seems wrong.

If you cut open the sub and take a look at the coil you can get a better idea of what happened on an amplification level to make the failure happen

Zomb1fied · Post by **Zomb1fied** » Sun Dec 16, 2007 11:06 am

Juice0723 wrote:yeah thats what I thought too. That the amp was clipping. But the sub didn't sound distorted or anything. I didn't have my head unit on max either. I put it half way and it did this. So I should set the gain lower because its a little under 3/4 right now.

It's actually non audible distortion that does the damage because nothing seems wrong.

If you cut open the sub and take a look at the coil you can get a better idea of what happened on an amplification level to make the failure happen

Juice0723 · Post by **Juice0723** » Sun Dec 16, 2007 12:36 pm

With both of the subs I had on here. I smelt both of them and I could smell nothing, aint you suppose to smell the voice coils burnt or something. And when I pushed the cone in, it didnt sound like anything unusual and went in and out perfectly. How would you get the sub opened up to see whats wrong. And should I have the gain on the lowest because it starts at 2volts. And my head unit is 2volts.

Zomb1fied · Post by **Zomb1fied** » Sun Dec 16, 2007 3:47 pm

A quick clip will not cause the coil to burn, it will simply break it clean and leave the woofer dead.

To remove the cone simply slice around the top surround, flex it inward and slice the spider.

Then cut the braid leads and it should come right out

If there was no scraping or anything then theyre not burnt, that would create debris in the coil gap between the pole piece and the magnet jamming the cone from moving freely. It definitely sounds like a broken coil failure, which is 99% caused by a very instant clip that has seen clear to breaking the coil wire cleanly.

Post by **fuzzysnuggleduck** » Sun Dec 16, 2007 9:35 pm

If your head unit is rated at "2 volts" output, it's almost certainly only going to be hitting 2 volts when it's turned up really high, I know that's how my Alpine deck works.

I can't really help with your problem but I'd be very surprised to learn that you're clipping the amp hard enough to fry subs off a 2 volt input, even with the gains set at 3/4.

Check everything with a DMM if you have one, it never hurts to see what your devices are really outputting (deck and amps).

1moreamp · Post by **1moreamp** » Mon Dec 17, 2007 10:03 am

Hummmm... A M-44 being used to drive a sub.... 4 X 40 watts...Hummm

And your gain is 3/4's ??? is that 3/4's with respect to 2 volts or 200 milli-volts < I.E. the high or low settings>??

Take a volt meter and pull the RCAs and turn on the amp with no speakers hooked up and read the DC output voltage on all 4 channels and send me those numbers please... It should be in the milli-volt range, but you can have a bad transistors and it could be in the 35 volt range also, please denote where the decimal point is in all the readings and what range your meter was on.

A 2 volt deck can over drive a 2 volt amp if the gain on the amp is set incorrectly high.

Are you bridging 2 channels to a sub ? and what ohm load is tnat sub, and who made it and what model number ???

How about your old sub that last so long ??? Who made it etc...

Were both subs new ???

Please let me know all the answers to these questions and I am sure we can figure out whats worng with your stereo. But untill all of this info is checked were all gonna be pretty much guessing at a possible cause to you issues.

Thanks ...C

Juice0723 · Post by **Juice0723** » Tue Dec 18, 2007 1:30 am

i am just bridging the rear channel to the sub. Because the rear has the low pass built in. And using the front channels not bridged for two speakers. And the sub I used first was a rockford fosgate 10"xlc rfp2410 single 4ohm. The second sub was a massive audio dual 4ohm and i ran that at 2ohms. The massive audio can take 400 or 500watts max. And half od that is the rms. Don't know the model of the massive. doesn't have anything on the sub, but I think its a pw or cw, its a old one. The subs were new when my cousin got it then I got them from him. And it says in the phoenix gold m44 amp manual that its 160watts rms bridged @4ohms. Single channel 110watts rms at 2ohms. So at 2ohms bridged was I like putting out 220watts rms or around there. It sounded like way more wattage to me. I had 2 rockford xlc's on it before at 2ohms. Same sub as I used what i first mentioned. And another rockford xlc same exact sub. I don't have a multimeter sorry if thats a volt meter.

1moreamp · Post by **1moreamp** » Tue Dec 18, 2007 9:58 am

When you run a amp bridged into a two ohm load, each channel will see 1 ohm of the load. This is NOT a number that PG ever said this amp was rated for.

I would not be surprised if your amp has a blown channel, and this is causing your speaker burn out while being bridged. Thats why I asked you to test for DC output to the speaker, sorry for not being more open as to why I asked you to check that sort of stuff.

The M series of PG amps were 4 ohm 2 ohm rated stereo and 4 ohm mono rated only. These were not meant to run competition rated loads. Now if you had used a MS or MPS series amp your amp would have had a much better survivability rate at the 2 ohm mono load you chose to use it at.

The big differences are internal rail supply voltage and heatsink mass for these two distinctly manufactured products. Essentially the channels are the same between these two series, just DC power and sink mass differences.

Another issue could be the fact the you may be pushing the amp deeply into clipping driving these speakers, clipped music can build up tons of heat on Voice coils and cause them to melt.

I used to blow tweeters till I got the correct sized amp that was not clipping into the load, then my blown tweeters issue went away. Its a pretty common problem of people under power there speakers and then burning them out with clipped music. Happens all the time. Speaker can't reall used clipped info and reproducs sound from the energy, so its absorbed as pure heat till the voice coil she is no more

Plus your using "Used" subs from someone else's setups, "USED is USED" and its doubtful if you can really tell what condition those used subs were in when you got them. They could have been baked before you hooked them up.. Just my 2 cents worth on your issues.

The M-44 was rated at 160 watts at 4 ohms per channel, and close to 80 watts per at 2 ohms for a total power of like 320 watts out of the amp. The power supply limits this. As for 1 ohm ratings they don't really exist in print anywhere I have ever seen so I would be guessing at what you getting at 2 ohm mono across two channels bridged.

On another note most folks I know using a M series amp for subs gets the venerable M-100 to run their subs, That amp has a huge advantage on a single M-44. And the M-100 has between 400 and 500 watts at the loads your working with.

If you test your amp like I described in my earlier post you can at least rule out a blown channel, And then you can move on to other possible culprits of your malady...Best of luck , and LMK what your amp tests like....C

Post by **stipud** » Tue Dec 18, 2007 10:14 am

http://bcae1.com/2ltlpwr.htm

Juice0723 · Post by **Juice0723** » Tue Dec 18, 2007 11:13 am

why one of my subs hooked up to 4ohms do this also then. Just wondering. And when I tried doing a lower ohm then 2ohm bridged like say 1ohm bridged the amp went into protect and wouldn't play anything. Shouldn't it do it at 2ohm if the amp didn't like it. and do i just use a multimeter to check the voltage. thanks for the help so far.

Juice0723 · Post by **Juice0723** » Tue Dec 18, 2007 11:17 am

and the rear channel worked well with regular speakers not bridged.

1moreamp · Post by **1moreamp** » Tue Dec 18, 2007 4:52 pm

Juice0723 wrote:and the rear channel worked well with regular speakers not bridged.

Working well and passing the tests I asked you to do are two different things. Your ears cannot hear large DC offsets, for the most part, and these along with many other lessor things can add up to the issue your having.

I see you have tried a 1 ohm mono load and found that the amps engineering defeated you at your purpose.
Please reread the post I made before this. It list most all the rated public spec's for a M-44, and NO WHERE does it say 1 ohm capable. And 2 ohms mono is the same as 1 ohm stereo so here again PG never said it would do this.
And without some real tech numbers no one here will be able to tell you whats wrong with your amp. It needs to be benched after the "hook any load to it" its been through.
I can comfortably say this because I have been repairing M-44 since they came to the market, back in the early 90's. Back when PG was but a new kid on the block....Ahhh I miss those days

You could have something as simple as over heated solder joints and such to bad caps, and DC offsets, and a whole bunch of other issues all together causing your troubles.
I sincerely suggest that you get your amp to a qualified PG tech and have the amp benched and tested to spec.
This takes some pricey tools so I would recommend you stay away from the guy that does this in his garage, and get a real professional, evaluation of your amp, on a real test bench.

Perhaps you just need more that 160 watts of bass power, perhaps the two different subs had two different specs, and therefore needed two different sets of power needs.
There are dozens of possibilities and you need to try and supply us with answers to our questions if your really in need of answers. I mean we are only as good as your info to us here, consider us a big bank account of experience but without reference info we are very limited in being able to help you.....Best of luck, and please have your amp benched at a pro's and test its spec's and do a visual inside the amp.....Cheers C

Post by **fuzzysnuggleduck** » Wed Dec 19, 2007 12:31 am

My M-100 had a leaky transistor among other things that manifested itself as a crackling, ultra low output channel.

Cecil fixed me right up.

I was able to take the basic readings he is talking about in this thread and based upon those results he was able to tell me enough for me to know that I needed pro service.

Juice0723 · Post by **Juice0723** » Wed Dec 19, 2007 1:10 am

I also forgot to tell you before my cousin sent me the amp, he had the amp tested by a official phoenix gold tech. And the tech said everything was fine. He also told me that he tested all the channels and rca's and everything else on the amp.
I will buy a mutlimeter soon and get you the voltages also. Thanks for the help so far.

Juice0723 · Post by **Juice0723** » Wed Dec 19, 2007 10:33 pm

alright I just bought a multimeter. I did every channel with the rcas and speaker wires disconnected. The rear left channel was 0.0030.
Rear right was -0.004. Front left was 0.019. Front right was -0.013.
Are there suppose to be negative on the right channel and positive on the other. Hope you can tell me if this is good or not.

Juice0723 · Post by **Juice0723** » Wed Dec 19, 2007 10:37 pm

I also had the mulimeter on DCV at 2V

1moreamp · Post by **1moreamp** » Wed Dec 19, 2007 11:01 pm

Cool Beans , the numbers look OK except for those last two, They seem a bit high compared to the others. No worries about the + - stuff its the raw numbers that are important..
The 3 or 4 milli-volt readings are what I like to see, these are like new readings. The other readings 19 and 13 milli-volts seem high to me. I would be looking at the input diff pairs for these channels. A simple test is heat or cold applied to check for thermal drift, and the next stage are the TO-128 stage just after the input pair.

Sorry I forget this is not something you work with all the time. I do so I see it in my head as I am typing,

Its funny your front channels read off spec, but you bass channels are in spec. I expect to see the opposite of this, like always ???

The M amp was never made to run low ohms, My friend here on this forum had a Route 66 I think it was and it would not run his 2 ohm subs no matter what. So your issue of protect mode at low ohms is not new.

It would be nice to swap the channels around by using a out board crossover to allow you to swap signals around and run bass on the two other channels to see if the issue persists.

If it does persist I would say the amp is just not up to the task. At least a AB of both hook ups would relieve you of any questions about the separate channels being a issue.
Can you locate a 2 way crossover and try the setup with the channels reversed so as to compare the two sets with the same musical content???

LMK, and I will stick with you till we get some acceptable answer for your questions....C