Ohms for a combo amp and external speaker cabinet...

[metalchurch]

I have a question to help out RFBuck with his Bugera 333 combo amp, and I just wanted to run this by you guys to get an "expert" opinion so I dont steer him wrong.

He's using a Bugera 333 combo amp that has two outputs for the combo, one for the internal speakers, and one to run to a second cab. The amp also has switchable impedance... 4, 8, or 16 ohms.
When the combo's by itself, he sets it to 16 ohms as the 2 speakers are 8 ohms each.

***I think if the combo is @8ohm, then the internal speakers should also be 8ohm, right??***

His cab is 16 ohms mono, so when he runs the two together he sets the impedance to 8 ohms and he has a 6x12 basically.

***I would tend to think he might be able to get away with setting the amp @16ohm, and using the cab @16ohms.**

He was told that the wattage of the speakers really doesn't matter except for sound quality...how it breaks up, etc. It's the ohmage he has to watch. As long as the speakers he puts in the combo are 8 each, he can continue to do it the way he has been.

**I would say this:
Combo amp - to use the internal speakers set @8ohm and rewire the cabinet @8ohm

**Or***
Disconnect the internal combo speakers and set the Amp @16ohm and use the cabinet @16ohm


I just wanted to run this by you guys to get other opinions so I dont steer him wrong and potentiall damage his amp.

Could you guys give some insight on this one?
How would you wire this to utilize all of the speakers?

Thanks alot!

[Ron]

***I think if the combo is @8ohm, then the internal speakers should also be 8ohm, right??***

No. There is no way to get an 8 ohm load out of two 8 ohm speakers, it's either 4 ohms (parallel) or 16 ohms (series).

His cab is 16 ohms mono, so when he runs the two together he sets the impedance to 8 ohms and he has a 6x12 basically.

Yes. The speakers in the 333 combo are 8 ohms each wired in series for a 16 ohm load. The output jacks are in parallel, so a 16 ohm cab in parallel with the internal 16 ohm load equals an 8 ohm load.

***I would tend to think he might be able to get away with setting the amp @16ohm, and using the cab @16ohms.**

Only if the combo's internal speakers are disconnected.

He was told that the wattage of the speakers really doesn't matter except for sound quality...how it breaks up, etc. It's the ohmage he has to watch. As long as the speakers he puts in the combo are 8 each, he can continue to do it the way he has been.

True to a certain extent... if either of the internal speakers would fail because they can't handle the power driving them, and no other cab is connected, it could leave the amp driving an infinite (open) load and the output transformer could fry. Tube amps have to have a load connected to them.

**I would say this:
Combo amp - to use the internal speakers set @8ohm and rewire the cabinet @8ohm

A 4 speaker 16 ohm cabinet can't be wired for an 8 ohm load and neither can the internal 8 ohm speakers.

**Or***
Disconnect the internal combo speakers and set the Amp @16ohm and use the cabinet @16ohm

That will work.

How would you wire this to utilize all of the speakers?

He's already doing it correctly. The internal 16 ohm load in parallel with the 16 ohm external cab, and the impedence switch set to 8 ohms.

[JackANSI]

That.

[lonewolf]

I have a question to help out RFBuck with his Bugera 333 combo amp, and I just wanted to run this by you guys to get an "expert" opinion so I dont steer him wrong.

He's using a Bugera 333 combo amp that has two outputs for the combo, one for the internal speakers, and one to run to a second cab. The amp also has switchable impedance... 4, 8, or 16 ohms.
When the combo's by itself, he sets it to 16 ohms as the 2 speakers are 8 ohms each.

***I think if the combo is @8ohm, then the internal speakers should also be 8ohm, right??***

If the combo is @8 ohms, then the internal speakers would be 16 ohms each in parallel or 4 ohms each in series.

In this case, the speakers are 8 ohms each and apparently are wired in series for a 16 ohm total. If they are wired in parallel, it is only 4 ohms total.

If the cab is 16 ohms and the combo is 16 ohms, the total load is 8 ohms in parallel. Just plug the extension cabinet into the extension speaker out and set the amp to 8 ohms output and you are set.

If you are concerned about that sound, you can always disconnect the internal speakers, then plug the extension cabinet into the internal speakers' jack and set the amp for 16 ohms.

[metalchurch]

Ok, then he's running it correctly as is?

I have another question:
Would he get a better sound by disconnectin the internal combo speakers and setting it up @ 16ohm mono with the cabinet?

Thanks for the replies!

I fuggin suck at this shit!!

[lonewolf]

Ok, then he's running it correctly as is?

I have another question:
Would he get a better sound by disconnectin the internal combo speakers and setting it up @ 16ohm mono with the cabinet?

Thanks for the replies!

I fuggin suck at this shit!!

That depends whether or not the external cabinet sounds a lot better than the internal speakers.

Just try them and choose the best sounding combination. You may find that you are better off using the extension cabinet as a stage prop.

[orangekick]

Ok, then he's running it correctly as is?

I have another question:
Would he get a better sound by disconnectin the internal combo speakers and setting it up @ 16ohm mono with the cabinet?

Thanks for the replies!

I fuggin suck at this shit!!

It's all personal taste at that point. I used to run a Mesa DC10 2x12 combo on top of an Orange 4x12. The combination of the open back Mesa combo with the gigantic sound of the Orange cab was really great for the band that I was in at the time.

[metalchurch]

Well, yeah I knew it is personal preference at this point.


The problem that he's having is that he has his combo @ face/ear level and he's having a hard time matching the EQ to have the combo + the cabinet sounding good.

The combo @ ear level is too bright.
I dont think he's gonna be able to find a happy medium, unless he puts the combo on the floor, or faces it away from him.

That's mainly why I suggested that he goes with the cabinet only @16ohms, and disconnect the combo speakers.
Problem solved there in my opinion.


Any ideas on what to do?

[orangekick]

He could stand 10 feet away from it all and see what it would sound like from the audience's perspective.

[metalchurch]

He could stand 10 feet away from it all and see what it would sound like from the audience's perspective.

Yeah that's a good point for sure.
I know that alot of the members on here, and other gigging musician's EQ their amps while they stand back away from it.
Because what sounds good to you (close up) will not sound good to the audience.
You want to sound good to the audience, not yourself.

I'm sure that Buck probably tried that one because he seems to know what he's doing and he gigs out alot.

Maybe he could throw a blanket over the combo to take the high end off of his face?

[orangekick]

He could put these in his combo.

http://www.webervst.com/blocker.html

[metalchurch]

I've never seen that before, but that looks like it would be exactly what he needs.
Thats a genius product aint it? One of those "I wish I thought of that" things.
Have you tried that before?

[orangekick]

I have never used them, but I tend to be a guitar player who uses a lot less treble than most. I do know some guys online who swear by them. They're really great for helping to tame the treble that a lot of combo amps put out.

[Ron]

Those blockers look like a really easy DIY project.

[RFBuck]

I finally get a chance to log in and reply!!

Thanks to you all for the input. Lonewolf, I've met at Magoo's. I'm from the band that opened for Lies, Inc. You liked my Bugera...we discussed the Vintage 30's.

The situation concerning speakers is this:
I use the two in the combo and the 4x12 cab together for a 6x12 config. My ohmage is all set correctly. The combo speakers are 70 watters and the cab's are 100 watters. Naturally, the speakers will behave differently due to their handling power...how they sound, break up, etc. I like having the combo speakers at head level to hear, but I know that dialing the amp in for those speakers will NOT sound the same as what's coming out the cab's speakers. This is why I considered 100 watt speakers for the combo, too... to have an equal sound at all levels....head and feet.

[lonewolf]

Higher power handling implies a higher break-up level, but aside from that, has nothng to do with the tone of a speaker--especially in 4x12 cabinets.

In your case, if you crank your amp to the full 120 watts, the internal speakers are getting 1/2 the power (60 watts) and the cabinet is getting 1/2 the power (the other 60 watts). When you distribute that to the speakers, each internal speaker is getting 30 watts and each cabinet speaker is only getting 15 watts...not nearly enough to break up 100 watt speakers. Even if you use only the cabinet each speaker is only getting 30 watts at maximum output.

This is one of the reasons Marshall put 25 watt speakers in their 4x12 cabinets....the speakers could more easily break up using 100 watt amps. Now, you can get Marshall 4x12' stock loaded with 60 watt Celestion Vintage 30s. These are some of the best sounding guitar speakers ever made, but combine a V30 4x12 cab with a 100 watt head, and the speakers will NEVER break up.

I hope this puts some perspective on the situation.

[orangekick]

Those blockers look like a really easy DIY project.

Very true. I know some people who have rigged up their own versions very easily.

[metalchurch]

Those blockers look like a really easy DIY project.

Very true. I know some people who have rigged up their own versions very easily.

I was thinking the same thing.