2 Ohm Capable Lightweight Heads

[agedhorse]

Lightweight Class G Amp? I didn't know they existed. I will say my GK 1001rbii and Mesa Carbine M6 seem quite a bit louder and hit harder than my Mesa Subway amps despite being lower Wattage RMS.

Note that the gain and volume knob taper is much different on both of those amps compared with the Subway. Gain and volume come up faster but do not increase much in volume past 12:00 compared with the Subway's gain/volume that continue to increase smoothly all the way to the end.

Also, the voicing of both amps are quite different too, the brighter, more aggressive voicing sounds louder earlier on because of how the ear's sensitivity changes with both frequency and level.

 

[crazyBassClown]

An ohm is an ohm and there should not be a Genzler or TC ohm.There must be a reason why.

A DC ohm is not the same as an AC ohm and an AC ohm depends on frequency.
For instance where does this nominally 8 ohm speaker actually have an 8 ohm impedance?

 

[Old Garage-Bander]

I really do not get this. I think TC says that also about one of their amps that only works with TC cabs. An ohm is an ohm and there should not be a Genzler or TC ohm.There must be a reason why.

They (Genzler) do make good products and staying in their ecosystem is not a bad idea.

You bought our amp! You MUST buy our cabinet! Otherwise I'll get you and your little dog too!

But yeah, what @agedhorse says. It's not always as cut and dry as it seems.

Don't push everything to the max. Leave yourself some margin for error.

 

[Rip Van Dan]

Other than the Mesa Subway line, are there any other lightweight/high power heads that are 2 ohm capable? I’ve owned a D-800 and WD-800 and may go back that but just wanted to know if there are other options out there. I have a bunch of 4 ohm cabinets so a head that can support a 2 ohm load is ideal for me.

There are a couple of DNA class D heads that will do so. The first one they came out with was the [Invalid or Expired Link Removed], which puts out 1350-watts rms at either 4Ω or 2Ω. Their newer [Invalid or Expired Link Removed], which I have, will also go down to 2Ω. It puts out 800-watts into 4Ω and, to quote the manual, "it will put out near full power into a 2 Ω load".

The manuals of both go on to say that they don't recommend running it at 2Ω as your normal configuration because it was designed to be most efficient and sound best going into either 4Ω or 8Ω. But it you need to use it in 2Ω they can both do it. David used to say the same thing about his Eden amps. He said he only made them 2Ω capable because competitors were doing it. Said those Eden amps sounded best at either 4Ω or 8Ω. And yet his Eden amps got run at 2Ω by a lot of folks for a lot of years. So, I'm guessing if you need something to run at 2Ω all the time you might want to look for a different amp. On the other hand if you need to run it at 2Ω to run the cabs you need at a particular gig, these will do it.

I personally have the DNA-800 and I run it into my 8Ω DNS-210 for my indoor gigs. I could stack my DNS-210 on top of my 8Ω DNS-410, but that would just take it down to 4Ω. I do have two 4Ω Eden EX-112's and I could hook those together I suppose, but my DNS-210 sounds better so I don't. I might have to do that one time just to see how it sounds.

 

[agedhorse]

A DC ohm is not the same as an AC ohm and an AC ohm depends on frequency.
For instance where does this nominally 8 ohm speaker actually have an 8 ohm impedance?

View attachment 4779161

>2 octaves between 200Hz and 1kHz in the mid 5's qualifies this as a 4 ohm nominal speaker with any transducer or amplifier engineer that I know (including me).

 

[logdrum]

Thanks for the explanation Andy. And yeah I know that the speaker impedance changes as sound comes out of it. I reread the Magellan 800 manual and I do not see the 2 ohm compatibility. If that is indeed possible only with their cabs, why not explain it, put what Andy just wrote in their website. Some musicians, full time ones can comprehend this.

The simple answer is just don't ever get to a 2 ohm situation. Buy 8 ohm cabs to begin with. I know this

Maybe it does not matter to them, but it is not uncommon to use difference amplifiers and cabs all the time in pro audio. I do not think that making true 4 ohms cabs that will not behave badly in a 2 ohm configuration is only known by a select few. How about a compatibility list, to avoid the DIY folks. There are folks that want a la carte or off menu.

For so long Randy Smith has this white paper on why Mesa Boogie tube amps do not have biasing controls and why using Mesa branded tubes is the way to go explaining how they tube match etc. As an addendum on their manuals. Of course people ignored this and would put KT88s on their 6L6 amps or bias them hot. The amps were robust enough to not blow up but they did NOT sound any better. I just bought stock Mesa tubes and maybe would be out extra 10 - 20 bucks more for a set. They never failed on me.

I do not expect it from TC (specially that they are now Behringer) but something that Genzler can do. Again, I did not see the 2 ohm statement in the manual and if I am buying their amps, I will not risk it. I will stick to 2.67 ohms as my minimum load. Please note I am not anti Genzler.

 

[agedhorse]

There are things that when put into manuals get taken out of context.

For example, we do not promote operating our Subway amps in the 2 ohm position while running 4 and 8 ohm cabinets to reduce the rated output, because it brings out the "creatives" that assume that this means the opposite is ok too, even if you tell them not to. This happens to be a TalkBass exclusive feature.

 

[willddd]

Bergantino Forte's
GK Legacy's

And Bergantino BAmp

 

[jnewmark]

While not 2 ohm rated, the Genz Benz ShuttleMax 12 has two 600 watt power amps so you get the same end result of being able to run a pair of 4 ohm cabs with a bonus of 1200 watts of beautiful, beautiful power.

This is what I do, and love it. I use two, Schroder, 15PL cabs, but most of the time, I only need one. The Shuttlemax12.2 is the most versatile bass head I've ever played.

 

[Andrea Lo]

Yeah, just giving the little guys a shout out. I couldn't find a way to view the manual, so maybe not a contender for this thread, but it does appear to be a nice unit. I beat up the ad copy a bit in the thread, but there is a good reputation behind the builder, and they have a member here. Says 1000 watts at 2 ohm. I'm curious as to the caveats.

Hi, both the CODA and the SISMA work at 2ohm. At very high volume you can go into thermic protection but will not do any damage to the head. I usually suggest a higher impedance if you play really loud stages, I mean so loud you must use ear protection devices. BTW we are always working to make our power amp section more and more capable of handling 2ohms load. If thats a must for you hit me up in DM.

 

[BlueTalon]

I usually suggest a higher impedance if you play really loud stages, I mean so loud you must use ear protection devices.

For anything louder than a coffee shop gig, we all should wear hearing protection. Always.

I never leave home without it.

 

[agedhorse]

Hi, both the CODA and the SISMA work at 2ohm. At very high volume you can go into thermic protection but will not do any damage to the head. I usually suggest a higher impedance if you play really loud stages, I mean so loud you must use ear protection devices. BTW we are always working to make our power amp section more and more capable of handling 2ohms load. If thats a must for you hit me up in DM.

As a general note, if an amp shuts down when being driven at high volume, is it really 2 ohm stable?

 

[Andrea Lo]

Well, I've pushed into thermic protection well know amps at 4ohms. Or I have blown cabs under declared wattage. When you are pushing 1.2k watts at 125dB/1m what is really safe?

 

[agedhorse]

Well, I've pushed into thermic protection well know amps at 4ohms. Or I have blown cabs under declared wattage. When you are pushing 1.2k watts at 125dB/1m what is really safe?

Ok, then in this case are those amps really 4 ohms stable?

Ok, are the cabinets accurately rated or perhaps not?

 

[Andrea Lo]

Ok, then in this case are those amps really 4 ohms stable?

Ok, are the cabinets accurately rated or perhaps not?

All gear can be taken to a break point. 2ohm loading is a stressful operation, "stable" is getting through a gig but maybe a not-ventilating flight case and two 810s pushed hard can bring an head to its limits. Sounds fair? Let me know whats your rig so I can get your point better. Let me say more: wanna try a Sisma? Let me send you one for your feedback, you could then send it to another fellow TB player who wants to get a fair opinion.

 

[agedhorse]

2 ohms is not stressful if the amp is properly designed to drive 2 ohm loads with adequate margins.

I have a long history of amplifier products that drive 2 ohm loads without issues, going back almost 30 years. Same thing regarding driving 4 ohm loads.

 

[Andrea Lo]

2 ohms is not stressful if the amp is properly designed to drive 2 ohm loads with adequate margins.

I have a long history of amplifier products that drive 2 ohm loads without issues, going back almost 30 years. Same thing regarding driving 4 ohm loads.

I totally agree, surely both CODA and SISMA drive 2 Ohms loads with adequate margins.

 

[joel406]

The Epifani UL901 says on the back 4 ohm minimum load.

I spoke to Nick Epifani directly on the phone. I said (quote) the 2nd gen UL901 will do 2 ohms stable.

Personally I won’t chance it.

I have the UL 901 3rd gen. Due out next year. Stamped 2 ohm minimum load on the back I have been running it at 2 ohms regularly with great results.

But since Nick says the 2nd gen will do 2 ohms I suppose the guy who designed it should know.

You may want to check it out.

 

[agedhorse]

In your post #50, you stated that those two amps will go into “thermatic protection”, at 2 ohms and you suggest using a higher impedance cabinet for loud stages. In post #57 you then state that both amps drive 2 ohm loads with adequate margins.

I’m saying that an amp that has adequate margin can drive a 2 ohm load without thermal thermatic) protection issues at high volumes or any conditions that a player is likely to encounter in the real world.

There’s quite a difference between an amp just surviving 2 ohm loads and an amp driving 2 ohm loads without thermal shutdown. The amps I have designed to operate at 2 ohms will do so without thermal shutdown. There are plenty of players here doing exactly this without any issues, it’s not an idle, unsubstantiated claim.

 

[Andrea Lo]

The amps I have designed to operate at 2 ohms will do so without thermal shutdown. There are plenty of players here doing exactly this without any issues, it’s not an idle, unsubstantiated claim.

Just to clarify, what amps are you talking about? I'd love to do an AB test here. My margins could not be your margins.