Am I damaging my type R?

[SoulSoak]

Hey guys,

I'm a car audio noob so I'm sorry if I annoy you. I just want to be sure I'm not damaging my sub. Okay so I have an older rockford fosgate 700s two channel amp. And I have a new alpine type r swr12D2.

I have the sub and amp wired according to this Diagram. http://a248.e.akamai.net/pix.crutchfield.com/ca/learningcenter/car/subwoofer_wiring/1DVC_2-ohm_2ch.jpg

So my amp is giving the type R 700rms at 4ohms while bridged. The sub sounds great, hits hard and sounds clean. But here's my question.

My amp gains are turned all the way up on both channels. I've been reading that it's bad to run your amp with max gain due to "clipping". And I've read and read but still I'm failing to understand.

I never turn up my head unit volume to the extent To distortion sounds from my speakers. So doesn't that mean my subwoofer should be getting a clean signal? Also... My sub is rated like 500-1000watt rms, so the 700rms my amp pushes should be compatible just fine right?

I have no particular reason for this post other than preventative damage. My sub sounds great, no odd sounds or distortion, no farting or unhealthy sounds. My amp stays just luke warm even after continuous play, never gets hot. I just want to protect my investment. I read that having amp gain maxxed is bad, and I also hear that having it maxxed is fine. Can someone shed some light? I just don't want to trash my equipment, need some peace of mind.

Thanks , Soak

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[gckless 5,000+ posts]

The search function is an endless amount of knowledge.

 

[SoulSoak]

The search function is an endless amount of knowledge.

Granted.

I suppose when I've stated that I've "read and read" yet fail to understand... I should continue to do so and get nowhere?

Just looking for someone who feels enticed to enlighten a new guy. Thanks for your impeccable response time however.

 

[Tbsh 10+ year member]

Look up how to set your gains using a DMM if you don't have access to a O-Scope.

 

[Side Show 10+ year member]

^^ set gains correctly, are your speakers amped also?

 

[DoesDad 10+ year member]

I've always set my amps by ear and never had a problem. I don't run more than 1000 watts rms though. That being said, the gain turned all the way up on the amp doesn't sound like a good idea. I'd turn em' down somewhat just to be safe.

 

[SoulSoak]

Thanks for the replies guys. I did more digging and found what I need to do. I was scared to turn the gains down because I have two channels running one sub and I want them at the exact same level. So after more research, I've found that I do this....

My amp is 700rms x1 @4ohms bridged. According to the formula, I get 2800watts. I Get 52.91053 Volts. So I divide that by 2. I end up with Approx. 26.5 volts per channel. So I'll use my Multimeter after work today and set these gains using that formula. Hopefully that's correct. Thanks again

 

[Jepalan]

You don't get 2800watts. When bridged, the amp is running like a single channel mono amp. The specs for the 700s say that it will put 700w into a single 4-ohm load when bridged. You calculate voltage using 700W RMS and 4-ohms as the input to the equation. It does look like your voltage numbers are correct however....

Total voltage at the speaker should be V = SQRT(PxR) = SQRT(700 x 4) = 52.91053 VRMS and 26.5 V RMS per channel. Be sure to use the AC volts setting on your DMM.

 

[SoulSoak]

You don't get 2800watts. When bridged, the amp is running like a single channel mono amp. The specs for the 700s say that it will put 700w into a single 4-ohm load when bridged. You calculate voltage using 700W RMS and 4-ohms as the input to the equation. It does look like your voltage numbers are correct however....
Total voltage at the speaker should be V = SQRT(PxR) = SQRT(700 x 4) = 52.91053 VRMS and 26.5 V RMS per channel. Be sure to use the AC volts setting on your DMM.

Thanks for verifying that for me. Sorry, I had meant 2800 units for the equation. Also one more thing, all I have to do is burn a test tone disc and I'm ready to do this. Is there any difference between using a 45hz, 50hz, or 60hz tone? Or will all give me the same result?

Also one more thing, my amp uses a bass remote. And idealy, I use it as more of a "sub on, sub off" knob. So I'd assume that when I do this test, I set my head unit eq to flat, and turn my bass remote knob all the way up prior to the test. That way I have the perfect gain volt setting with the knob maxed, that way I can't over drive the system correct? Thanks

 

[basswiigee]

Thanks for verifying that for me. Sorry, I had meant 2800 units for the equation. Also one more thing, all I have to do is burn a test tone disc and I'm ready to do this. Is there any difference between using a 45hz, 50hz, or 60hz tone? Or will all give me the same result?
Also one more thing, my amp uses a bass remote. And idealy, I use it as more of a "sub on, sub off" knob. So I'd assume that when I do this test, I set my head unit eq to flat, and turn my bass remote knob all the way up prior to the test. That way I have the perfect gain volt setting with the knob maxed, that way I can't over drive the system correct? Thanks

I always use the 50hz or less testtone..... you can get them from realm of excursion...... and yes turn knob max when you set....

 

[bbeljefe]

Sounds like you've read some good information on gain setting but here are a few more things you should know...

Most modern music is bass heavy at ~40Hz, which is why that's the most common frequency used to gain set with a scope or distortion detector. Gain is a sensitivity setting, not a volume setting and it works like this: most amps have a voltage range from 200mV-6V. This means that the amp can produce 100% of its power with as little as 2mV of signal strength or as much as 6V. Most aftermarket head units output either 2, 4 or 6 volts and it's important to know what yours sends. Line out converters produce

If you're using the head unit's internal amp, your max safe volume will be about half, so if the volume readout goes from 0-62, then 30-33 will be the highest level you use and that's where you should set it when you gain set the amp. And a note about clipping... it starts at 1% THD and you don't hear it until ~10% THD so if you're hearing the distortion made by a clipped signal, it's pretty bad.

 

[SoulSoak]

Okay I'm irritated as hell right now. So I've downloaded test tones and burned 4 different cds. I've tried test tones from 4 different vendors and NONE of them work in my head unit. It's weird because, I've burned music and play those cds in my head unit just fine. But all these test tone cds don't work, and they're all mp3 format as well just like my burned music cds.

So I've tried using my multimeter to set my amp gain via volts, and the **** meter just jumps all over so badly that I can't get an accurate or stable reading to go by. It will go from 2 or 3 volts, then jump to 25 volts, then 12 volts etc. Like WTF...

Just irritated because I've wanted to set my amp gain for the passed 4 days but I've been so busy doing **** for other people, that now when I finally get a chance to do this it won't cooperate. FML

Where can I get a test tone CD or something that will play a 50hz tone or something? I have a factory head unit and I'm running my amps RCA's off an LOC. I don't have an Aux input. I'm stuck to strictly CD's. I guess I'm more or less just pissed off that my head unit will play burned mp3 cds but won't play my ******* burned test tone cd's. Sorry for the attitude, just seems nothing can go right for me lately.

 

[pickup1 5,000+ posts]

Your amp has 2 gain controls? A left and right?

 

[SoulSoak]

Your amp has 2 gain controls? A left and right?

Yes it's a two channel bridgeable amp. Rockford Fosgate 700s. Therefore I have to divide the voltage rating among the two channels. Ultimately resulting in the fact that I have to set each channel at approx. 26.5volts. My issue is the fact that I can't get a test tone to work on a cd in my car, and when I try setting the amp gain volts by playing a regular song... the volts just go crazy on the meter due to different frequency notes being played.

 

[hispls 5,000+ posts]

You kids are thinking way too much into this.

If it sounds good it is good.

If the speaker isn't smelling funny or making bad mechanical noises you're likely using it within safe operating limits.