desperate times = desperate measures

[tastychoice]

So, my ampeg ba 500 died and I'm poor. All I have at this moment is a 4x10 ampeg cab and a fender blues deluxe. I understand that bass will shred my speaker at high volumes. If I plug the 40 watter into the 4x10, is there anything other than a little dirt to worry about? I don't want to send more gear to the shop.

[Emibass]

cab would be fine, but the amp driven over its power will give up.

[tastychoice]

So you're saying go for it but don't crank it?

[Emibass]

I´m saying you COULD go for it but don´t crank it. The only thing is maybe 40W are not suficient for the gig. You could ask the sound guy to put your bass trough monitors.

I giged without amp and did fine.

[Fuzzbassian]

It'll go,that's for sure.In a pinch,I've used my 50 watt guitar head with my 4x10.Not much in the way of headroom,but atleast you can hear it.When I loaned it to my friend who drove it with drop C and some fuzz pedals,there was a distinct smell of burning,and a bit of a repair bill to deal

[christw]

Originally Posted by Emibass

cab would be fine, but the amp driven over its power will give up.

It's a 40w tube amp designed for guitar players to overdrive. I don't see a problem there. It'll be just fine as long as the cab impedance is matches the available transformer tap(s).

[Emibass]

Originally Posted by christw

It's a 40w tube amp designed for guitar players to overdrive. I don't see a problem there. It'll be just fine as long as the cab impedance is matches the available transformer tap(s).

You´re right. I skiped the part of what kind of amp we´re talking about.

[christw]

Originally Posted by Emibass

You´re right. I skiped the part of what kind of amp we´re talking about.

That's what I figured. If it was a 40w SS amp, I wouldn't be telling him to go ahead and overdrive it either.

[Muziekschuur]

Maybe the BA500 has a minor issue? If you share a photo with us we can diagnose what's wrong?

[tastychoice]

The ba500 is at the shop, at least a 4 week wait. I tested the power cable and replaced the fuse which was blown but still no life. I'm just trying to get through this month. Luckily I only have rehearsals lined up for the next few weeks due to recording. As long as I'm able to compete with drums, I'll be happy. Thanks for the input. I do use fuzz and an eh hog. Perhaps I'll omit the pedals until I get my ampeg back, just to be safe.

[James Judson]

Use any amplifier for any thing they all do the same thing. Here's the biggest differences comparing guitar amps to bass amps.

1. EQ section. Makes sense that a bass needs to BOOM and a gtr needs to TWANG (not a hard fast rule but you get the idea).

2. Power section. Bass needs like 10 times the power to keep up with a gtr.

3. Speaker section. Bass speakers need to be able to handle all them watts.

So mix and match to your hearts content. Just use your ears cuz your rig will warn you when danger lurks (you could be running out of controls, watts, speakers). It cost a lot of money to put the smoke back in once it escapes so common sense can go a long way.

[tastychoice]

Also, the ampeg died 45 min into a 3 hour gig. I had to go straight into the house and it sounded like dog feces, especially the effects. That's why I'm seeing what my options are, I'm gun shy with going through the house. I guess I should be glad I was able to make any sound that night, even if it sounded like garbage.

[Electricblue]

Something to take into consideration, but I'd need someone to verify this.

I'm pretty sure wattage/sound works on a curve. (2x the volume = 10x the watts)

So with a 300w amp turned up half way, you'd only be using 30w.

I'm not sure if that's accurate, so don't listen to it unless somebody knowledgable can confirm it

[Tuned]

Originally Posted by Electricblue

Something to take into consideration, but I'd need someone to verify this.

I'm pretty sure wattage/sound works on a curve. (2x the volume = 10x the watts)

So with a 300w amp turned up half way, you'd only be using 30w.

I'm not sure if that's accurate, so don't listen to it unless somebody knowledgable can confirm it

Volume is exponential, where double the power is 6dB more sound pressure level. 40W is 13% of 300W, so the decibel drop is calculated by 6x log 0.13 base 2, or 6x (log 0.13 / log 2), which is -17.6dB.

However, empirical testing has shown that people perceive 10dB to be double or half power. So even though 40W is roughly 1/8th of 300W, it will seem like 1/4 the power.

This is what I love about class D amps. Often you're using a lot less power than you think, and class D sounds just as good at 5% output as it does at 100%. Can't say that of tube or class AB.

[Tuned]

Also, guitar tube amps have an input bias circuit which limits their frequency response with a 6dB/oct roll off at about 100Hz, so you'll lose bottom end, but with the limited power output it's required to have a chance to hear what you're playing. You'll have to DI to the PA for sure, so you'll have to get the bottom end from there. If there's no subs you're pretty screwed, but worse things have happened. The Traynor Bassmaster YBA-1 is a 40W bass head, people got by with it for decades.

[hdracer]

That 40 watt blues deluxe run through a 410 should be plenty loud for you just play with the setting and it will sound great. I can get through band practice with my Bassman 100T set on 25 watts and a pair of 15's

[ThisBass]

Originally Posted by Tuned

Volume is exponential,

Most of the times that is right,
But there are exceptions out there like:
70s SVT and Mesa Boogie M6 have got Linear Pots.

Originally Posted by Tuned

where double the power is 6dB more sound pressure level.

that is +3dB.
Doubling the power increases cone excursion by 41%.

Doubling the cone excursion results in +6dB.
That is 4 times the "electrical" power.

Originally Posted by Tuned

40W is 13% of 300W, so the decibel drop is calculated by 6x log 0.13 base 2, or 6x (log 0.13 / log 2), which is -17.6dB.

A = 10*log(40 Watt / 300 Watt)
A = -8.75 dB

Originally Posted by Tuned

However, empirical testing has shown that people perceive 10dB to be double

That's right

Originally Posted by Tuned

or half power.

1/10 Power

Originally Posted by Tuned

So even though 40W is roughly 1/8th of 300W, it will seem like 1/4 the power.

Cracy math....
1/8 = 1/4

Originally Posted by Tuned

This is what I love about class D amps.

What do you love?
1/8 = 1/4 ?

Originally Posted by Tuned

Often you're using a lot less power than you think,

That's right for the RMS

Originally Posted by Tuned

and class D sounds just as good at 5% output as it does at 100%.

All kind of Amps sound best with some headroom

Originally Posted by Tuned

Can't say that of tube or class AB.

[/quote]

...some folks prefer the "edge" sounding of tube amps.

[Jeff Scott]

Originally Posted by Tuned

Also, guitar tube amps have an input bias circuit which limits their frequency response with a 6dB/oct roll off at about 100Hz, so you'll lose bottom end...

Not any tube guitar amp I have ever used for bass.

[Jeff Scott]

Originally Posted by hdracer

That 40 watt blues deluxe run through a 410 should be plenty loud for you just play with the setting and it will sound great.

+ ∞ My old 1971 Fender Princeton Reverb Amp (15 watts) with it's internal speaker (early '70s Celestion G12M-70) disconnected sounded great through my LDS 2126 cabinet (2-3012LFs and 6ND410), my 1962 Fender Concert Amp (40 watts) sounds even better and louder (it even sounds quite nice at lower volume levels into it's own 4-10 speaker complement). Even a friend's Mesa F-50 sounded excellent using the clean channel, the lead channel would be great for Lemmy. I have also had a couple of early '70s Traynor amps (YBA-3 and YSR-1), and a Mesa/Boogie DC-2 combo amp that I put the chassis into a head cabinet and used that for some gigs, too. Not a single one had this "input bias circuit which limits their frequency response with a 6dB/oct roll off at about 100Hz".

[tastychoice]

You are all awesome btw. I may try to record my eub through this thing. Sounds awesome. Grimey in the best way. I'm going to try it through a Sunn 2x15 as well.