Need an extra cab for my 200w trace head

[Soloshchenko]

Hi guys, as stated, I'm fairly new to bass from guitar and my understanding of amp power is awful.

I currently play through a 200w RMS trace head into a 1x15inch speaker. Recently also plugged into a 400w warwick cab (running two cabs from one head) and the sound was awesome.

Unfortunately the 4x10 Warwick is too big for gigging needs, do I still need to get something that is 400watts RMS?

Can anyone recommend a small 400watt cab which won't break the bank?

Cheers.

[Musky]

Was the tone you found awesome or the volume?

If it's volume you're looking for there's a number of reasons the Warwick would have been louder beyond just the rated wattage. For a start the Warwick was running into two cabs, and the 4x10 alone will shift more air than your 1x15 even before you take the second cab into account. The two cabs will probably be running at 4 ohms which will get the full rated power out of the amp - at 8 ohms it will only produce about two thirds of the rated power. Assuming your Trace is running into an 8 ohm cab you'll be getting about 130W out of it.

Unfortunately plugging your Trace into a cab rated at 400W, or even 4000W, won't necessarily make it any louder - it'll still knock out about 130W into 8 ohm load. There's more to volume than wattage, but your best bet to get an increase in volume is to add an additional cab to your rig

The wiki might be of some use (though it could probably do with some updating) [url="http://wiki.basschat.co.uk/info:amps:impedance_and_wattage"]http://wiki.basschat.co.uk/info:amps:impedance_and_wattage[/url]

Edited August 28, 2009 by Musky

[Soloshchenko]

[quote name='Musky' post='583595' date='Aug 28 2009, 02:44 PM']Was the tone you found awesome or the volume?

If it's volume you're looking for there's a number of reasons the Warwick would have been louder beyond just the rated wattage. For a start the Warwick was running into two cabs, and the 4x10 alone will shift more air than your 1x15 even before you take the second cab into account. The two cabs will probably be running at 4 ohms which will get the full rated power out of the amp - at 8 ohms it will only produce about two thirds of the rated power. Assuming your Trace is running into an 8 ohm cab you'll be getting about 130W out of it.

Unfortunately plugging your Trace into a cab rated at 400W, or even 4000W, won't necessarily make it any louder - it'll still knock out about 130W into 8 ohm load. There's more to volume than wattage, but your best bet to get an increase in volume is to add an additional cab to your rig

The wiki might be of some use (though it could probably do with some updating) [url="http://wiki.basschat.co.uk/info:amps:impedance_and_wattage"]http://wiki.basschat.co.uk/info:amps:impedance_and_wattage[/url][/quote]

Cheers, that is a really big help. Yes, it is increased volume I am looking for but also I found the actual sound was significantly improved. The warwick was over the other side of the room so naturally I just got a fuller, more detailed kind of sound. That's what I'm looking for.

So really what you are saying is as long as head and original cab (1x15) are running at 8ohms, a big 400 watt cab (this Warwick is currently borrowed) is kind of pointless isn't it?

Ie. I could be getting anything above 130 watts (say another 200 watt cab) and I'm sorted in what I'm trying to achieve?

[Musky]

[quote name='Soloshchenko' post='583611' date='Aug 28 2009, 02:59 PM']Cheers, that is a really big help. Yes, it is increased volume I am looking for but also I found the actual sound was significantly improved. The warwick was over the other side of the room so naturally I just got a fuller, more detailed kind of sound. That's what I'm looking for.

So really what you are saying is as long as head and original cab (1x15) are running at 8ohms, a big 400 watt cab (this Warwick is currently borrowed) is kind of pointless isn't it?

Ie. I could be getting anything above 130 watts (say another 200 watt cab) and I'm sorted in what I'm trying to achieve?[/quote]

If you got another matching 1x15 8 ohm cab you'd get a small but noticeable increase in volume. Doubling the number of woofers will give you a 3db increase in volume (assuming the cabs have the same sensitivity) - that's the same increase you'd get by doubling the power of your amp. Add to that you'd be upping your available power by roughly 50% (going from 130W into 8 ohm to 200W into 4 ohms). That will also give you a small - though barely noticeable - increase in volume.

If you are looking at replacing your 8 ohm 1x15 with an 8 ohm 4x10 with similar sensitivity drivers you would get more volume, simply because the 4x10 is capable of physically moving more air (think about the surface area of the speakers to start with). The wattage of the cab doesn't actually come into the equation - that just tells you the thermal power handling of the cab before you can expect the voice coils to melt.

Wattage is a pretty poor way of trying to work out the volume. The efficiency of the cab is far more important - a cab with a sensitivity of 99db driven by 200W will sound as loud as a cab with only 96bd driven by 400w.

[alexclaber]

[quote name='Musky' post='583632' date='Aug 28 2009, 03:23 PM']If you got another matching 1x15 8 ohm cab you'd get a small but noticeable increase in volume. Doubling the number of woofers will give you a 3db increase in volume (assuming the cabs have the same sensitivity) - that's the same increase you'd get by doubling the power of your amp. Add to that you'd be upping your available power by roughly 50% (going from 130W into 8 ohm to 200W into 4 ohms). That will also give you a small - though barely noticeable - increase in volume.[/quote]

Adding a second matching cab will give you more like a 6dB increase in SPL, which will perceived as even more due to the way our ears work. It's a big difference!

[quote name='Musky' post='583632' date='Aug 28 2009, 03:23 PM']If you are looking at replacing your 8 ohm 1x15 with an 8 ohm 4x10 with similar sensitivity drivers you would get more volume, simply because the 4x10 is capable of physically moving more air (think about the surface area of the speakers to start with). The wattage of the cab doesn't actually come into the equation - that just tells you the thermal power handling of the cab before you can expect the voice coils to melt.[/quote]

If you replace your 1x15" with an equal sensitivity 4x10" then you'll get no increase in SPL unless the 1x15" is incapable of handling all the power of your amp (which with so little power is unlikely to be much of a problem).

[quote name='Musky' post='583632' date='Aug 28 2009, 03:23 PM']Wattage is a pretty poor way of trying to work out the volume. The efficiency of the cab is far more important - a cab with a sensitivity of 99db driven by 200W will sound as loud as a cab with only 96bd driven by 400w.[/quote]

Exactly! But unless everyone rates sensitivity the same way then that doesn't help much, unfortunately.

Alex

[Musky]

[quote name='alexclaber' post='583712' date='Aug 28 2009, 04:22 PM']Adding a second matching cab will give you more like a 6dB increase in SPL, which will perceived as even more due to the way our ears work. It's a big difference![/quote]

Hah, I knew I ought to be leaving this to the experts!

[quote]If you replace your 1x15" with an equal sensitivity 4x10" then you'll get no increase in SPL unless the 1x15" is incapable of handling all the power of your amp (which with so little power is unlikely to be much of a problem).[/quote]

If cab sensitivity was the same yes, but if [i]driver[/i] sensitivity was the same wouldn't you get more volume from the greater overall displacement capability? Please tell me I've at least got that bit right.

Edit: Aha! I knew I'd got that 3db figure from somewhere on here! Or am I just being thick again?

[url="http://basschat.co.uk/index.php?s=&showtopic=10740&view=findpost&p=113399"]http://basschat.co.uk/index.php?s=&sho...st&p=113399[/url]

Edited August 28, 2009 by Musky

[alexclaber]

[quote name='Musky' post='583730' date='Aug 28 2009, 04:41 PM']Hah, I knew I ought to be leaving this to the experts! [/quote]

No no, let the expertise proliferate!

[quote name='Musky' post='583730' date='Aug 28 2009, 04:41 PM']If cab sensitivity was the same yes, but if [i]driver[/i] sensitivity was the same wouldn't you get more volume from the greater overall displacement capability? Please tell me I've at least got that bit right.

Edit: Aha! I knew I'd got that 3db figure from somewhere on here! Or am I just being thick again?

[url="http://basschat.co.uk/index.php?s=&showtopic=10740&view=findpost&p=113399"]http://basschat.co.uk/index.php?s=&sho...st&p=113399[/url][/quote]

You're right about the 3dB sensitivity increase. But you also need to figure in either the increased power output of the amp due to the lower impedance (~2dB) or the increased power handling (particularly the displacement limited power handling) - doubled power handling equals 3dB gain. So you get either 3+2 or 3+3 ish, depending on whether the amp runs out of power first or whether the speakers run out of excursion first.

If the sensitivity of the 15" and 4x10" was the same then whichever handle the most power in the lows will go loudest - assuming that at least one of the cabs reaches its limits before the amp does. That ability to handle power in the lows is a key part of displacement capability. Bear in mind that displacement depends on cone area AND cone excursion - you need both to move air.

Alex

[Musky]

Oh well. I'm getting there - slowly.

Alex, does that mean that if you had say a 2x10 and a 4x10 loaded with the same drivers and similar cab designs the 4x10 wouldn't be louder for a given wattage? Obviously the 4x10 would have a higher max SPL, but I thought it would be louder at any given power level. I'm getting confused now!

[alexclaber]

[quote name='Musky' post='584405' date='Aug 29 2009, 12:12 PM']Oh well. I'm getting there - slowly. [/quote]



[quote name='Musky' post='584405' date='Aug 29 2009, 12:12 PM']Alex, does that mean that if you had say a 2x10 and a 4x10 loaded with the same drivers and similar cab designs the 4x10 wouldn't be louder for a given wattage? Obviously the 4x10 would have a higher max SPL, but I thought it would be louder at any given power level. I'm getting confused now![/quote]

Yes, you are! If you have a premium 10" bass guitar driver, like a DeltaLite 2510-II, which has a LF sensitivity of 94dB, then a 1x10" will have a sensitivity of 94dB, a 2x10" 97dB and a 4x10" 100dB. Furthermore the displacement limited power handling will be about 75W, 150W and 300W respectively, so the max clean SPL in the lows will be about 112dB, 118dB and 124dB respectively. Sensitivity and max output in the mids is higher but it gets more complicated when you increase the number of drivers because of how they couple so it's not quite so straightforward to predict.

Alex

[Musky]

Cheers Alex.

I bet Soloshchenko wishes I'd just said 'run two cabs' now!