How much Power is to much Power

[THATpurpleKUSH 5,000+ posts]

Its up to your budget to determine the point where the value of headroom begins to diminish.

 

[JTF Vegas]

I remember a car enthusiant talking about headroom 20 years ago. He stated, "The more headroom the better!". He is now 70% deaf in both ears!!
Just something to remember. Please be mindful of your hearing, once its gone, its gone!

 

[stephgirl]

So to complete my test The impedance rise (ohms) that the amp sees will rise depending and we know that higher ohms means more resistance and then = less power out of amp. That why most run 1 or 2 ohm to subs to get as much of the power out of amp but because of the rise the amp will not put out as much power then at the 1 ohm for say. So to JTF Vegas point his 1000w so amp and his 500w sub the impedance rise to say 8-12ohm ( less power) will only see about the 412w as you said.
So a 200w rated amp say to a 100w speaker after the impedance rise that amp will only put out say the 100w at speaker rated and then after the arise the amp will not have to work as hard to keep that 100w and will run cooler. Also the proper voltage (gain adjustment) Am i correct?

So i clearly understand now. That impedance (ohm) rise do play a big factor. So you want to get a amp that is higher rated then the speaker so when the rise happens and it ends up putting out less power, you want that less power to be close to the speakers rated power as possible.

 

[stephgirl]

I remember a car enthusiant talking about headroom 20 years ago. He stated, "The more headroom the better!". He is now 70% deaf in both ears!!
Just something to remember. Please be mindful of your hearing, once its gone, its gone!

JTF vegas your correct. I'm not 20 anymore and i have had a nice sounding system in my vehicles for years and i can agree that i have had some loss of hearing. When my friends or family or coworkers talk to me and i have to say, what you say, and they not standing to far away, there is something wrong. That is why i have thought about adding a more power to my system but i have to stop myself and say, it is loud already. When you pull into the work place parking lot and your coworkers say, i can here you coming, for me I think it is loud enough. For me it is mostly about SQ these days.

good comment JTF Vegas

 

[wew lad 5,000+ posts]

Someone will correct me if I'm wrong, but midrange speakers and tweeters will have much less rise than a subwoofer unless the midrange is in an enclosure. It's almost negligible with a midrange speaker (<10%).

 

[JTF Vegas]

JTF vegas your correct. I'm not 20 anymore and i have had a nice sounding system in my vehicles for years and i can agree that i have had some loss of hearing. When my friends or family or coworkers talk to me and i have to say, what you say, and they not standing to far away, there is something wrong. That is why i have thought about adding a more power to my system but i have to stop myself and say, it is loud already. When you pull into the work place parking lot and your coworkers say, i can here you coming, for me I think it is loud enough. For me it is mostly about SQ these days.

good comment JTF Vegas

Yes hearing loss is permanent! No SQ or SPL installation is worth your hearing.

 

[stephgirl]

Someone will correct me if I'm wrong, but midrange speakers and tweeters will have much less rise than a subwoofer unless the midrange is in an enclosure. It's almost negligible with a midrange speaker (<10%).

Someone will correct me if I'm wrong, but midrange speakers and tweeters will have much less rise than a subwoofer unless the midrange is in an enclosure. It's almost negligible with a midrange speaker (<10%).

I was thinking that in my mine also. Being that low frequencies require more power to produce the waves. You would think that the high powered amp for subs and the rise we have been discussing would be less on say a tweeter or a midrange speaker amp.

THATpurpleKUSH said it " Impedance changes with frequency. But dose it change higher or lower as frequency goes up ? Once you have that info then you can make a better choice on amps. Being that things seam to double in values, i would think it would be a good rule to get an amp that is 2x the rated as the speaker. 100w speaker x2 200w amp. 500w sub x2 1000w amp

 

[THATpurpleKUSH 5,000+ posts]

I dont know a lot about midranges but in a car audio install they are considered infinite baffle.

So the question becomes do infinite baffle alignments have a flatter impedance curve, which should equate to less overall rise.

We need @keep_hope_alive to straighten this out.

 

[fithwheel]

Break out the dats.
Parts express is a good resource.
they have frequency response,phase,impedance, and spl graphs on most of the drivers they sell anyone can look at. Pretty sure they're measured ib.

 

[n2audio 5,000+ posts]

~10+ yrs ago when Richard Clark and David Navone moderated at the carsound tech forums there were endless amounts of information/debates between engineers and this was always a popular topic. JL had a rep there a lot. JBL had a rep there a lot -- among others.

He would often reference his experience testing speakers in the lab. They had a giant commercial amp on a cart they wheeled around for all these tests. Its power output was insane. Like 10kw x 2 or something like that. He said they commonly used it to test 50w coaxials. They never damaged a speaker unless they made a mistake on the power handling test.
IMO having an amp that matches the speaker's RMS rating is the bare minimum if optimal speaker performance is the goal. Generally, I think 150-200% is the sweet spot.

RMS ratings are supposed to be what the speaker can handle continuously for an indefinite amount of time. Music is nowhere near that type of signal, as you clearly understand. You would need to exceed the rms rating for several seconds, if not minutes for it to even be a concern. So unless your plan is blast 0dB sine waves all the time there's not much point in concerning yourself with power ratings unless you're doing something completely ridiculous.

 

[THATpurpleKUSH 5,000+ posts]

I do know that IB and sealed enclosure impedance curves are close to the same shape, I'm just not sure if the curve is flatter with IB alignment. I know the volume and port tune affect the shape of the curve so those variables alone might make it hard to compare the two.

 

[fithwheel]

Idk.
As far a 2 much power etc. I just worry mostly about mechanical limits. Thermal is easily controlled between gain and input signal. I don't see anything wrong with 150 or 200% provided crossover points are set right.
Set up and some common sense go a long way when it comes to not damaging speakers.

 

[THATpurpleKUSH 5,000+ posts]

Bass Box Pro will show acoustic and electric power graphs which plot thermal and displacement limits across the frequency spectrum. You know the limits before you even wire up the driver.

 

[stephgirl]

~10+ yrs ago when Richard Clark and David Navone moderated at the carsound tech forums there were endless amounts of information/debates between engineers and this was always a popular topic. JL had a rep there a lot. JBL had a rep there a lot -- among others.

He would often reference his experience testing speakers in the lab. They had a giant commercial amp on a cart they wheeled around for all these tests. Its power output was insane. Like 10kw x 2 or something like that. He said they commonly used it to test 50w coaxials. They never damaged a speaker unless they made a mistake on the power handling test.
IMO having an amp that matches the speaker's RMS rating is the bare minimum if optimal speaker performance is the goal. Generally, I think 150-200% is the sweet spot.

RMS ratings are supposed to be what the speaker can handle continuously for an indefinite amount of time. Music is nowhere near that type of signal, as you clearly understand. You would need to exceed the rms rating for several seconds, if not minutes for it to even be a concern. So unless your plan is blast 0dB sine waves all the time there's not much point in concerning yourself with power ratings unless you're doing something completely ridiculous.

WOW n2audio that name Richart Clark sound familiar. I can remember back in 90's when i worked at the GM car dealership here in So Cal and a few of us service technicians that were into car audio used to read Car Audio Magazine. What i remember was this guy who was a expert car audio person and sound tech guy and had articles or where written about him articles on system setups from amps specs to speakers and speaker placement and so on. I think he was affiliated with or worked out of a shop called Speaker Works in Orange California. To this day the one thing that stands out in my mind was this guy said in an article that, if you had to install an equalizer unit in your car to adjust the sound for sound shaping or volume your system was not set up correct and the amp power and speaker placement was not right. On the amps I think he was refering to amps also not having enough power to the speakers. That now i understand what he means and what we have been disusing. At the time i think it was a Buick Regal car he was showing. We all remember the EQ units many used to install in the cars back then for more volume and sound. This guy had no equalization in the car and it rocked. I wonder if this is the same guy? wow dating myself.

 

[stephgirl]

~10+ yrs ago when Richard Clark and David Navone moderated at the carsound tech forums there were endless amounts of information/debates between engineers and this was always a popular topic. JL had a rep there a lot. JBL had a rep there a lot -- among others.

He would often reference his experience testing speakers in the lab. They had a giant commercial amp on a cart they wheeled around for all these tests. Its power output was insane. Like 10kw x 2 or something like that. He said they commonly used it to test 50w coaxials. They never damaged a speaker unless they made a mistake on the power handling test.
IMO having an amp that matches the speaker's RMS rating is the bare minimum if optimal speaker performance is the goal. Generally, I think 150-200% is the sweet spot.

RMS ratings are supposed to be what the speaker can handle continuously for an indefinite amount of time. Music is nowhere near that type of signal, as you clearly understand. You would need to exceed the rms rating for several seconds, if not minutes for it to even be a concern. So unless your plan is blast 0dB sine waves all the time there's not much point in concerning yourself with power ratings unless you're doing something completely ridiculous.

Update On Richard Clark. Did a Google search and yes same guy. That guy was great. Just have not heard that name in very long time.

Also comment on n2audio post. After the much in dept discussion and deeper meaning and understanding. I have to say that in your point that the amp performance goal that in general an amp having 150 - 200% is a sweet spot makes sense.