Your absolutely correct , people say ‘ I put 500 watts to my midbass, tweeter blah blah but the truth is they have no scientific or rational basis of proving that x number of watts are actually going to the speaker.

 

Absolutely - as much power as you can reasonably run. The principle is called headroom. iyamwuthiam is absolutely incorrect about there being no scientific or rational basis.

The reason to run a lot of power isn't for output. Music is highly dynamic: symbol crashes, snare drum hits, and other instruments have a lot of energy released over a miniscule amount of time compared to the overall duration of the note - and way more than the RMS of the rest of the music. If you're not running with enough headroom, these transients will cause the amp to clip when it doesn't have enough power to reproduce them.

Additionally, some speakers simply require more power than RMS to reach their limits. This is common with speakers in small pods that don't have enough airspace. And that's power that's in addition to whatever headroom you run.

Some people go crazy with headroom. High end home audio guys recommend 10x recommended RMS power. I think 1.5x is reasonable. 3x is fairly easily achievable.

 

High end home audio guys recommend 10x recommended RMS power. I think 1.5x is reasonable. 3x is fairly easily achievable.

Thanks. I'll stop worrying about amp/speaker matching then. Control the gain and be careful with the volume knob

 

 

C'mon.....I know you are itching......

 

I think of power as control. The more power you have, the more precisely you can control speaker movement, which means sounds quality. I'm not talking 1000w to your mids and highs. But 200w sounds SO much better than 50w.

 

That’s a fun way to think of it, but it’s not real. More power does not give a speaker more control, it doesn’t improve the sound quality, it simply makes the speaker louder.

 

I want all the power.

 

So, no one is saying what they do though..... How much do you run over the speaker RMS recommendation?

 

I don’t run over RMS, it’s not a terrible idea, but 50 watts on midbass is plenty, so I run a small 5 channel that fits nicely under my seat.

 

I have at least rated power on everything. That doesn't mean its beeing used though. My mids and tweeters have alot of overhead (100w) that's not beeing used. Mids n tweeters don't need alot of power to get loud. My midbasses have 200w available to them and I think they are rated 150w. When tunning I made so many cuts on the bottom end to match my curve who knows what they see at full tilt. But I rarely have to go full tilt to get loud AF.

Now subs (front and rear) they all have double the rated power available to them. 🤷🏽

Mids n tweeters don't need the headroom, midbasses add a lil on top, subs let's try n blow those.. 😃

Dammit I told my self to stay out of it...

 

I have at least rated power on everything. That doesn't mean it beeing used though. My mids and tweeters have alot of overhead (100w) that's not beeing used. Mids n tweeters don't need alot of power to get loud. My midbasses have 200w available to them and I think they are rated 150w. When tunning I made so many cuts on the bottom end to match my curve who knows what they see at full tilt. But I rarely have to go full tilt to get loud AF.

Now subs (front and rear) they all have double the rated power available to them. 🤷🏽

Mids n tweeters don't need the headroom, midbasses add a lil on top, subs let's try n blow those.. 😃

Dammit I told my self to stay out of it...

View attachment 385221

What happened to that GB60 of yours that you were 'giving' 200 watts?

I can't tell the last time I looked at a speaker's RMS rating. 70 - 100 watts from a good AB amp is plenty for the front speakers and 500 to 700 watts from a class D amp is plenty for a sub.

 

I'm gonna quote @MrToadsWildRide (I think it was him apologies if it wasnt)

Speakers dont need power, ppl do. If it's not loud enough for you, YOU need more power.

I think that's how it went 🤔

 

Thanks all. I just see these Marconi amps at 120w x 4 and like, why do I need this much for fronts, but I want the A AB supply. I have some A headphone amps and stereo amps and love them to death for home.

 

The only Macaroni amps I know of that are A-AB are the Pro 4|30 and the Zero A Class and I think the Pro 4|30 is 4 x 170. Great front stage amp and probably the best in the Pro line.

Zero A Class on mids (30/100 A/AB) and Zero 4 on tweets (100) and midbass (210) is probably the best mainstream combo you can run for a 3-way front.

 

the rating the manufacturer gives on most entry level and mid to upper range gear (unless otherwise stated) is based on a full range signal sent through the supplied crossovers. You can almost always get by with sending them more power with a 60-80Hz highpass crossover as it reduces the chances of bottoming out and alleviates any thermal concerns. Good passive crossovers usually have one or more tweeter attenuation settings because you really don’t need them getting the same power as the woofer, especially when they are often mounted closer to the listener.

When running active though, do you need 200w for your tweeters if you have 200w for your mids? Nope. You have removed the resistors and shelf filters in the passive box so sending them 200w just means you’re going to use amp gains to lower them or the eq. This has been argued to death in other threads but in my experience, the higher frequencies don’t need the power to produce the same volume for the same reason your mids don’t need the same power as your subs.

I have an old school setup, the processor outputs 2v to an active crossover which can boost the signal up to 4v. The amps can only accept a max of 2.5v and as such are set to the minimum gain and I use the crossover to eek out that extra .5v before the amp clips. With 400w for 0-50Hz, 200x2 for 60-500Hz, 50x2 500-2.5KHz, and 50x2 for 2.5KHz+, the system naturally produces a decent Harman curve except I needed to lower the upper midbass slightly (300-500Hz) and tweeters are lowered a little as well. The rest just falls in line.

I will never go back to 50w for midbass after hearing what 200w sounds like…and my midbasses aren’t anything fancy, just 25 year old MB Quart QWD160 6.5”s.

 

the rating the manufacturer gives on most entry level and mid to upper range gear (unless otherwise stated) is based on a full range signal sent through the supplied crossovers. You can almost always get by with sending them more power with a 60-80Hz highpass crossover as it reduces the chances of bottoming out and alleviates any thermal concerns. Good passive crossovers usually have one or more tweeter attenuation settings because you really don’t need them getting the same power as the woofer, especially when they are often mounted closer to the listener.

When running active though, do you need 200w for your tweeters if you have 200w for your mids? Nope. You have removed the resistors and shelf filters in the passive box so sending them 200w just means you’re going to use amp gains to lower them or the eq. This has been argued to death in other threads but in my experience, the higher frequencies don’t need the power to produce the same volume for the same reason your mids don’t need the same power as your subs.

I have an old school setup, the processor outputs 2v to an active crossover which can boost the signal up to 4v. The amps can only accept a max of 2.5v and as such are set to the minimum gain and I use the crossover to eek out that extra .5v before the amp clips. With 400w for 0-50Hz, 200x2 for 60-500Hz, 50x2 500-2.5KHz, and 50x2 for 2.5KHz+, the system naturally produces a decent Harman curve except I needed to lower the upper midbass slightly (300-500Hz) and tweeters are lowered a little as well. The rest just falls in line.

I will never go back to 50w for midbass after hearing what 200w sounds like…and my midbasses aren’t anything fancy, just 25 year old MB Quart QWD160 6.5”s.

This is super helpful and a really good explanation. Thank you. And, side note, slightly jealous of those old MB Quart's.

 

Your welcome.

I’ve also been going through a lot of old school install features lately to see how they used to do it back in the day. Here’s a great example:

Brian Silvester - 2000 Ford Mustang GT - 2001 AS&S

Kelly, Tim "Setting the Benchmark" Auto Sound & Security July 2001: 54-63. https://live.staticflickr.com/65535/52839882742_362093f780_h.jpg https://live.staticflickr.com/65535/52840863190_d99c1166dd_h.jpg https://live.staticflickr.com/65535/52840453221_1ac1ae6e33_h.jpg...

www.caraudiojunkies.com

Two amps wired for just 3 channels, a zx500 for the subs that made 600+ watts, and a zx350 rated 100w at 4ohms and 200w at 2ohms. But look carefully at the install and you’ll spot a pair of midbasses on each side and the article mentioning some secrets in the crossover. Guaranteed they had the amp putting out 200w from 80-200Hz to the pair of 6”s on each side (wired parallel), and 100w to the 5.25” component set, with maybe some tweeter attenuation.

 

Your welcome.

I’ve also been going through a lot of old school install features lately to see how they used to do it back in the day. Here’s a great example:

Brian Silvester - 2000 Ford Mustang GT - 2001 AS&S

Kelly, Tim "Setting the Benchmark" Auto Sound & Security July 2001: 54-63. https://live.staticflickr.com/65535/52839882742_362093f780_h.jpg https://live.staticflickr.com/65535/52840863190_d99c1166dd_h.jpg https://live.staticflickr.com/65535/52840453221_1ac1ae6e33_h.jpg...

www.caraudiojunkies.com

Two amps wired for just 3 channels, a zx500 for the subs that made 600+ watts, and a zx350 rated 100w at 4ohms and 200w at 2ohms. But look carefully at the install and you’ll spot a pair of midbasses on each side and the article mentioning some secrets in the crossover. Guaranteed they had the amp putting out 200w from 80-200Hz to the pair of 6”s on each side (wired parallel), and 100w to the 5.25” component set, with maybe some tweeter attenuation.

This is bringing back to my HS days, reading Car Audio magazine. Thanks for this.

 

Idk about y’all but when I powered my mids and tweets with my biketronics amps, the gain was hard to set - I had to drop it all the way down and just barely turn it up a notch or else it would clip them or overpower them. Maybe I should have put the dsp.3 on them - I just didn’t want to mess with dsp’ing. 180 watts going to speakers that need only 10 to 50 watts is overkill and truthfully not worth it.

 

But isn’t headroom already accounted for between RMS power and peak (Max) power?

A respectable Helix Class D will provide 100w RMS, and 130w Max per channel.

 

RMS is the same as PEAK power. They are just different measurement units, sort of like 1L is RMS and 33.814oz is PEAK. They are basically the same thing but manufactures rather use the 33.814 unit number because it’s BIGGER and that’s what bass heads want. Peak is just twice the RMS.

If the amp is capable of doing 100watts RMS then can do 130watts dynamically, there is really no audible difference, 1.1db of headroom is inaudible to many.

 

30W isn't nearly enough headroom on 100W. 2x RMS value is good headroom. Matching max to max is better than matching rms to rms, but as stated, a lot of other factors involved.

On my PS8-50, the tweeters are turned way, way down with just 50W available, the mids are right around neutral w/ 50W and the the midbasses on 200w are boosted just a little bit, for now... I have the same midbasses in the rear doors with 500w available to each, and while I can bottom them out if I turn the gain up too high, they sound great otherwise...

 

Food for thought…

20hz. 1000watts
40hz. 500
80hz. 250
160hz 125
320hz 62.5
640hz 31.25
1280 15
2.5khz 7.5w
5khz 3.75w
10khz 1.875w
20khz 0.9w

this is for average energy distribution in music

normally we raise the low end by 10+db

so assuming 1kw on bass it makes everything a 1/4 or less of those figures above 300hz to balance the sound/tune to a house curve

now tell me you need 100+watts if your sub has 1kw on a set of mids or tweeters… you will have stupid amounts of headroom with 120x4 👍🏼

 

Great info. It seems like the critical point is having the right power to your midbass where they pick up from the subs. And that list seems to confirm my distribution of power is fine: 1300w-sub, 240w-midbass, 75w-mids, highs and rear fill.

 

Personally, I use amps that are higher rated than the speaker's RMS. And simply hedge my gain settings. My rationale is like a sports car that has more horsepower than necessary but simply take it easy on the pedal. I'd rather have the power I need, and know that I do VS not having enough when I want it.

 

I’m pretty much the opposite, I have more fun driving a slow car fast but they sell just as many Corvettes as Miatas so to each their own.

I guess I apply that to car audio as well, but more that I stick to within maybe 10% of rated power and make sure I get close to max volume on typical listening sessions.

 

AC isn't necessarily sinusoidal. You're taking a simplification of the math and applying it incorrectly...

 

20hz. 4000w
40hz. 2000w
80hz. 1000w
160hz 500w
320hz 250w
640hz 125w
1280 60w
2.5khz 30w
5khz 15w
10khz 7.5w
20khz 3.6w

Fixed!!!! 😃 🤟

 

Only 4k? My old db drag machine had 20k off a single grp31 size battery 🤯 it was definitely male… good for only 30 seconds lol 😂😂

 

70w amp into 60w speakers

The volume knob requires judicial maturity

And yes, the amp caused some interesting speaker smoke and smells.

And then I used the 70w amp with 75w speakers.... which lasted longer but still suffered greatly

Learn the importance of not abusing the volume setting.

 

Do many of you all run overpowered amps compared to RMS speaker recommendations?

I mean, buy an amp rated for 120w rms at 4ohms, but speaker only recommends 80w rms.

I can see the benefit of not running an amp full tilt, cleaner signal, but then also running the risk of an accidental max volume incident.

If you all do run this way, how much over (% wise) do you normally go? Asking as 4 channel amps like the 4|10 are 120x4. 6.5" can eat that up, but 1"....I guess you control that with gain?

Sorry for being so basic.

I usually run 1.8-2 times the rms rating, except on tweeters. They hardly ever actually get that much, just on peaks, or sine waves. As for your concern about max volume "accidents", set the gains correctly and that won't be an issue, just watch out for sine waves in EDM, rap, and other bass heavy music.

 

Rule of thumbs: 1.5x RMS wattage rating is considered reasonable margin for home theater amps with very wide dynamics range for all kinds of film. However for in car audio, I could not imagine if I EVER want to play music at RMS at all. Edge cases of serious bass heads of course exist, but are they relevant? Only you can answer that question.