# [Math help needed]Wattage vs Speaker cone area decision

Discussion in 'Amps and Cabs [BG]' started by Blankmann44, Sep 25, 2008.

1. ### Blankmann44

Sep 23, 2007
Greetings,

I have an Eden D118XL that with my current amp is only getting about 235 watts. The cab is rated at 500 watts (8 ohms). If I can get more watts to the cab (i.e. buy another power amp) will the extra ~265 watts make a big difference? I know it will make some kind of difference, however I feel that the speaker is not loud enough and I'm not sure if that's because I need another 18 inch or because I need to give the one 18 i have now its full wattage.

So what would you do to get louder, while keeping \$ cost at a minimum.

a. Give the cab the full 500 watts

or

b. Get another 18 inch speaker, and not necessarily max out either cab's power rating.

Basically this boils down to wattage vs combined speaker cone area. I know there's some math that someone can apply here and help me out.

Thanks!

2. ### MatticusManiaLANA! HE REMEMBERS ME!

Sep 10, 2008
Pomona, SoCal
Whats the max wattage of your amp? Im assuming you run it at 8ohms? Can it give you more wattage if you run it at 4ohms? If so, I'd reccomend andding another cab.

3. ### bongomaniaCommercial User

Oct 17, 2005
PDX, OR
owner, OVNIFX and OVNILabs
Doubling your wattage results in only a small increase in audible "loudness". Unfortunately, while there is math involved in this, the number of different factors -each with their own equations, and including nearly infinite variables- means you can spend all day doing mathematical equations and still not get the results you want. As one example, speaker driver efficiency and cabinet tuning are just as important mathematically (and factually) as wattage and speaker diameter.

Edit: the short answer is that you will generally get more "loudness" by adding a second speaker cab, as long as your amp can handle the resulting total impedance load. You can also improve loudness by careful use of EQ and/or compression.

4. ### slyjoe

Jun 28, 2008
Valley of the Sun (AZ)
Add the cab. More speaker area, plus lower ohms = more power, should be louder. And what Bongo said - damn, I'm always agreeing with him.

5. ### Blankmann44

Sep 23, 2007
My eden wt800a has two power amps in it, each has 400 watts at 4 ohms. One power amp I run my 210(4) pretty much maxing that cabs power rating, the other side i'm running my 118(8) at 235 watts, if i could get the 118 down to 4 i could give it 400.

6. ### JTESupporting Member

Mar 12, 2008
Central Illinois, USA
More speaker area will trump more power in most cases. I know from bitter experience. When I got my Eden D410XLT I opted for the 4 ohm one in order to get the maximum power from my amp (WT-400). And that rig was fine for most gigs. But for those few gigs where I needed more sound I had few options. A buddy had WT-400 and a pair of D410XLT at 8 ohms. We did some A/B comparisons, and no matter which amp we used, we found no audible difference between my 4-ohm cabinet and his 8-ohm cabinet. The extra power available with the 4-ohm load was negligible as far as we could hear.

But, boy, when we plugged in his other cabinet... We got the same power mine had (both amps at 4 ohms now) but his was noticably louder and fuller sounding. Add speaker surface instead of watts.

jte

7. ### Blankmann44

Sep 23, 2007
Great response. Really convincing. Thanks a lot, now I have things to consider. Which cab to add to a 210xst/118xl combination. 410xlt maybe?