Still confused with those watts!

[taught]

Hey there!

While reading and searching amp subject a friend of mine came to me that he has a head and cab for sale:

Head: Ashdown MAG300H Evo II
Cab: Ashdown MAG 410T Deep 450W

Everything is clear about ohms, my question is that how much volume I get through a 300 watt head if I connect this 450 watts cab to it? Does the cab get enough power to provide nice sound? Doesnt it get 'lost'? The head only 4 ohms while cab is 8, here I lost' power' already then here comes the watt difference.

And what happens later if I decide to hook another - lets say - cab like this? Is a 300 watt head able to energise two 450 watt cab? In this case the ohm will match perfectly (4 head, and 2*8 at the cabs).

I currently own an Ashdown electric blue 180 combo, and this humble fellow sadly cannot provide the sound I want at the level of volume I need. Our band plays bluesy rock and roll, so I dont need crazy high volume to fight to get heard. Whats more, I even get the volume level I need, its just that the sound get distorted and cranky that high.

 

[ChefKen]

Your rig will be pretty powerful with 300 watts driving 4x10 compared to your combo. Yes, the head could drive 2 4x10 cabs and probably get you arrested at rehearsal!

 

[Omega Monkey]

Think of a 300w lightbulb (or 2 150s, 3 100s, 4 75s, etc...). Puts out a lot of light and heat right? Do you really not think that could move a paper speaker cone (or a few them) a few millimeters back and forth?

Also, if the average speaker cabinet has a sensitivity of about 95db at 1w (about as loud as a diesel truck passing by), and you gain 3db every time you double the power, by 256w, you would be putting out 119 db (just under the threshold of pain which is 120).

I don't know how people somehow still get the idea that speaker wattage ratings are what the cab "needs" rather than it's limits. If everybody thought like that, there would be a lot more blown speakers out there. In fact, the normal rule of thumb is that you should only put about half as many watts of low frequencies through a speaker as it's rated for. So for a 450w cab, you should be able to put 225 into it all day long for the most part. But most people also don't realize if you crank up the bass knob all the way and add 10-12 db of low end, you're going to be pushing about 10 times more power into the speaker.

So yeah, if you keep the EQ relatively flat, a 300w amp should be fine with a 450w cab, and even better with 2 of them.

 

[JimmyM]

I regularly use a 25w head into a cab rated for 400w. Sounds awesome, if not the loudest rig in the world. You will be fine...just use common sense and don't turn up so loud that it strains your cab.

 

[sharkbait130]

Your head doesn't really care much how many watts your cab is rated for. The head is more concerned with the ohms that the cab or cabs are rated for. Your 300 watt head will put out 300 watts to a 4 ohm load whether it is from 1 cab with a 4 ohm rating or 2 cabs both with 8 ohm ratings. (Two 8 ohm cabs will leave you with a 4 ohm total load.) With your single 8 ohm cab , your head will be putting out around 175 watts. With another 8 ohm cab hooked up your head will be putting out it's full 300 watts @ 150 watts to each cab. If you ran a single 4 ohm cab , your head would be putting out it's full 300 watts to it.
Don't worry about under powering your cab. See Jimmy's post above. Also , I regularly run a 100 watt head into an 800 watt cab at practice. It sounds fine and plenty loud. Where you can get in trouble with an under powered cab is if you try to get it too loud for the excursion limit of your speakers but that's another thread. Like Jimmy said , use your ears..... if it sounds farty and like it's hurting the speakers , it probably is. This rule applies to under powering as well as over powering.
The stuff I described above applies to solid state amps. Tube amps are a bit different. Your amp is SS so the above stuff applies. Hope this helps.

 

[Raf Seibert]

Your head doesn't really care much how many watts your cab is rated for.

This is a great statement. Cabinet ratings for the watts they will tolerate lead to more confusion than almost anything. This whole post certainly clarified the issue nicely. I sometimes wonder if not mentioning cabinet watts might not be better than struggling to explain this to neophytes. I know that this will not happen, but the whole issue of cabinet watts just seems to add more confusion than clarity.

Raf

 

[Schmorgy]

It's always ok to under power the cab, you just don't want to do the opposite. Think of the head's wattage as what it can put out, and the cab's wattage as what it can take. As mentioned above, keep in mind that cranking the bass knob on the EQ is going to result in a lot more juice into the speaker.

 

[zortation]

Any amplifier can run a single 8 ohm cab, it's just that most amp companies don't show wattage figures for both, which is dumb. Personally, 300 watts into 8 ohms will not quite make it in a full band setting at a club, especially if you are concerned with headroom...but adding a second 8 ohm box will be perfect.

 

[JimmyM]

Any amplifier can run a single 8 ohm cab, it's just that most amp companies don't show wattage figures for both, which is dumb. Personally, 300 watts into 8 ohms will not quite make it in a full band setting at a club, especially if you are concerned with headroom...but adding a second 8 ohm box will be perfect.

That all depends on the band. I play in one where that rig is gross overkill.

 

[taught]

Well the thing is that the current 180W 1*12 4 ohm combo is not enough and my budget doesnt allow me to buy a head and TWO cabs right away. So I have to stick with 300w watt head plus single 8 ohm cab. I know that this way that cab will only have approx. 180 watt which is the same that i currently have, but I hope that 410 will get me more volume than 112. Hell the volume is even enough with the current combo the problem is that I currently have to crank up the gain and output which causes bad sound.

Ohh yea, and nice infos you threw in here, appreciate that!

 

[Kirk Bryant]

Why can't we get a Sticky for this stuff.

. People please use the search function.

And yes you can run WAY More watts into a cab that is rated a fraction of what a head gives out IF you use your ears and LISTEN to the cab for audio complaints so as not to vaporize it.

 

[Macho McHorse]

I have an Ashdown MAG300 15" combo connected MAG 410T Deep 450W and trust me its plenty loud and has a nice sound. I've had it for years (maybe 12?) with no problems what so ever. They're a great amp for the price.

 

[danosix]

Any amplifier can run a single 8 ohm cab, it's just that most amp companies don't show wattage figures for both, which is dumb. Personally, 300 watts into 8 ohms will not quite make it in a full band setting at a club, especially if you are concerned with headroom...but adding a second 8 ohm box will be perfect.

Firstly, who are you playing with, Meshugga? 300 watts into a 410 is LOUD. Even the 175 Watts that the 300 watt amp into 8 ohms will be bloody loud. The difference in volume between the two (175 and 300) is nominal. The same difference in volume when adding the second cab will be the second cab, not the added wattage - of course both together will be a noticeable difference - but that's because it's TWICE the thhe difference either on their own.
But honestly, unless you're playing metal in a band that doesn't use FOH, 300 (or even 150-175) into a 410 will be more than enough for MOST bands us mortals - in particular newbies - will ever play with.

 

[BruceBass3901]

Well the thing is that the current 180W 1*12 4 ohm combo is not enough and my budget doesnt allow me to buy a head and TWO cabs right away. So I have to stick with 300w watt head plus single 8 ohm cab. I know that this way that cab will only have approx. 180 watt which is the same that i currently have, but I hope that 410 will get me more volume than 112. Hell the volume is even enough with the current combo the problem is that I currently have to crank up the gain and output which causes bad sound.

Ohh yea, and nice infos you threw in here, appreciate that!

Just so you know, the Ashdown EB combos are rated at 180 watts into a 4 ohm load, as you stated in the first line of your post above. However, with the combo on its own, i.e. no additional speaker cab connected, you are only feeding an 8 ohm load, so you are therefore not getting the 180 watts your amp is rated for. You are actually getting about half of that, into a single speaker. If you get an additional speaker cabinet, such as the MAG 410 cab your friend is selling, you will be able to get the full 180 watts from you current combo

 

[bassliner50]

Your head doesn't really care much how many watts your cab is rated for. The head is more concerned with the ohms that the cab or cabs are rated for. Your 300 watt head will put out 300 watts to a 4 ohm load whether it is from 1 cab with a 4 ohm rating or 2 cabs both with 8 ohm ratings. (Two 8 ohm cabs will leave you with a 4 ohm total load.) With your single 8 ohm cab , your head will be putting out around 175 watts. With another 8 ohm cab hooked up your head will be putting out it's full 300 watts @ 150 watts to each cab. If you ran a single 4 ohm cab , your head would be putting out it's full 300 watts to it.
Don't worry about under powering your cab. See Jimmy's post above. Also , I regularly run a 100 watt head into an 800 watt cab at practice. It sounds fine and plenty loud. Where you can get in trouble with an under powered cab is if you try to get it too loud for the excursion limit of your speakers but that's another thread. Like Jimmy said , use your ears..... if it sounds farty and like it's hurting the speakers , it probably is. This rule applies to under powering as well as over powering.
The stuff I described above applies to solid state amps. Tube amps are a bit different. Your amp is SS so the above stuff applies. Hope this helps.

Yeah, this guy nailed it!

 

[wmhill]

If you use a P with flats and tort P/G, you'll never run out of power or damage a speaker. Anything else, will probably self destruct from shame......

 

[Coolhandjjl]

Watts is a rating of electrical energy that's coming out of the head, not how loud you will be. The cab determines how loud it will sound. A well engineered and highly efficient 8 ohm 410 cab will sound louder than a poorly engineered and inefficient 8 ohm 410 cab. How loud you are perceived in the audience is also dependent on cab placement and the physical attributes of the room itself.

SPL (sound pressure level) is the rating of how loud something is. To measure that, you need an SPL meter, or a calibration mic and RTA software. Some here get into that stuff, most do not, so don't worry about it.

You can certainly use generalities you read here to get started, but in the end, YMMV (your mileage may vary).

 

[Waltsdog]

Well the thing is that the current 180W 1*12 4 ohm combo is not enough and my budget doesnt allow me to buy a head and TWO cabs right away. So I have to stick with 300w watt head plus single 8 ohm cab. I know that this way that cab will only have approx. 180 watt which is the same that i currently have, but I hope that 410 will get me more volume than 112. Hell the volume is even enough with the current combo the problem is that I currently have to crank up the gain and output which causes bad sound.

Ohh yea, and nice infos you threw in here, appreciate that!

To answer the loudness question without getting bogged down by the technical stuff (which I think is what you are really looking for?): The Ashdown MAG300H + MAG 410T will be much louder than your Ashdown EB 12 180.

 

[zortation]

Firstly, who are you playing with, Meshugga? 300 watts into a 410 is LOUD. Even the 175 Watts that the 300 watt amp into 8 ohms will be bloody loud. The difference in volume between the two (175 and 300) is nominal. The same difference in volume when adding the second cab will be the second cab, not the added wattage - of course both together will be a noticeable difference - but that's because it's TWICE the thhe difference either on their own.
But honestly, unless you're playing metal in a band that doesn't use FOH, 300 (or even 150-175) into a 410 will be more than enough for MOST bands us mortals - in particular newbies - will ever play with.

I should clarify that I meant those 300 watts (rated at 4 ohms) would be reduced at 8 ohms, that we agree on. And 175 w into a 410 may be loud but it will sound like cack because the amp will be pushed too hard just to be heard and it still won't be enough. You'll have no headroom. For bass, watts aren't all for volume, you need them for a good clean sound too.

 

[samson3382]

To answer the loudness question without getting bogged down by the technical stuff (which I think is what you are really looking for?): The Ashdown MAG300H + MAG 410T will be much louder than your Ashdown EB 12 180.

This. Simply put.
Then the second cab down the road will be even better.