Titan 48 for 12v build// No Labs in the UK

[Seth]

I wouldn't go down the 2 ohm road.

Is this because...

I can't answer for Bill. But, I would guess that he was unaware that your current amplifier is rated for a 1Ω load when he made the comment. Personally, I can't think of a reason to not "go down the 2 ohm road" given your individual set of circumstances... unless the cab could be part of a larger system at some point.

[Grant Bunter]

I can't answer for Bill. But, I would guess that he was unaware that your current amplifier is rated for a 1Ω load when he made the comment. Personally, I can't think of a reason to not "go down the 2 ohm road" given your individual set of circumstances... unless the cab could be part of a larger system at some point.

Just because you can never means you should.
1 ohm is very near to the value of a short circuit, ie 0 ohm. Running an amp at 1 ohm will chew way more current than 2 or 4 or 8 ohms. Step up to a 2 ohm load, and the stress on the amp is still there, just not quite as severe.

Since one goal of the OP is to cart a system and run it off battery, anything that can be done to reduce current consumption is good.
When we're using a mains powered amp and trying to maximise cab count, we can start doing impedance manipulation.
We don't want to series wire in the case of cart sound, as it's more difficult to find amps with sufficient voltage swing to make it work.

So, that brings us to 2 x 8ohms cabs (which may be 2 x 16ohm paralleled drivers per cab, or 1 x 8 ohm driver a cab), paralleled with another cab that's the same, for a 4 ohm load preferably or, 2 ohms if it has to be.

Since there's a lot less 2 ohm capable mains powered amps out there, it would be smarter to stay away from 2 ohm cabs...

[Seth]

I respectfully disagree

[Mishkin]

I had written and thought I had sent a a message a few posts back thanking everyone whose thrown out suggestions, cautionary advice, even modeled possibilities in their simulators for this 12"s for 12 Volt-Titan hunt. Somehow that message didn't send.

So, I want to say that now ...

It's a good community to learn in and I appreciate all your efforts. I feel this thread is interesting!

[Mishkin]

On the issue of em-phaser amps :

I'm actually not sure about that. Is EM-PHASER a relatively well known and well respected brand over there? I've never heard of it before. In my experience, not-so-well-known amp companies, well known budget amp companies, and sometimes even well known and respected amp companies only advertise their "peak" output and are bold enough to even claim it's RMS. Almost none state an honest and true RMS without also stating a max output. If their "rated power output" IS truly continuous RMS figures, then you're right, it is double. I'm doubtful that's the case. But, I've been wrong many times before and will wrong again.

The Pioneer specs indicate both, continuous and maximum output figures, and I find it believable.



But, like Bruce said, the numbers are only helpful if you're fairly certain it's a true and honest RMS figure.

Yes, I was taking Emphaser as honest at their stated RMS values. And that was why your suggestion it was the same baffled me..... and Bruce's calculator answer seemed to miss my point.


They are a small German company. That only seem to supply the German speaking world. There's nothing on them in English on the Internet (which is a little disconcerting) . The amp in question isn't there but there are other older em-phaser amps on a independent German amp testing website where They more or less match their stated RMS specs.

Like u said, it is strange they don't give peak values. But I have the feeling that maybe the 12v car audio world over ther may just be a little less hype mongering than we are used to.

I'm gonna try track down the guy who advised me about them. See if he's got more chat to back them, Because it'd be a way to get 600watts at 4ohms for alot lot cheaper than doing so through alpine or Pioneer or another well known American brand.

[Mishkin]

Additionally, in my Hornresp model of the T48 (admittedly, probably not exactly right) that driver is at it's 10mm Xmax right at 35Hz and 35 volts, so it's a good match to the amp's capabilities and a 40Hz highpass engaged.

Seems to make a lot of sense. No?

But a question on this Xmax/voltage situation - if I go for the two fourteks at 2ohm . Would the Emphaser (assuming it does put out the the stated RMS) actually be uneescesary / overkill or would it still help get the most out of those two as long as its highpasswd at 40 and voltage controlled?

[Mishkin]

Just because you can never means you should.
1 ohm is very near to the value of a short circuit, ie 0 ohm. Running an amp at 1 ohm will chew way more current than 2 or 4 or 8 ohms. Step up to a 2 ohm load, and the stress on the amp is still there, just not quite as severe.

Since one goal of the OP is to cart a system and run it off battery, anything that can be done to reduce current consumption is good.
When we're using a mains powered amp and trying to maximise cab count, we can start doing impedance manipulation.
We don't want to series wire in the case of cart sound, as it's more difficult to find amps with sufficient voltage swing to make it work.

So, that brings us to 2 x 8ohms cabs (which may be 2 x 16ohm paralleled drivers per cab, or 1 x 8 ohm driver a cab), paralleled with another cab that's the same, for a 4 ohm load preferably or, 2 ohms if it has to be.

Since there's a lot less 2 ohm capable mains powered amps out there, it would be smarter to stay away from 2 ohm cabs...

I can see the point that it's gonna chew through battery in bike cart mode... But I think maybe I'm here for a good time not for a long time

In van mode I can always run the engine (like inbuilt generator) and re direct the exhaust awY from the crowd with a pipe. Done it before. Used the outlet pipe from my dryer at home . Afterwards when I reinstalled it at home The flat smelt like diesel exhaust anytime we dried clothes for about two weeks I'll find something else next time...

Other than that I don't really follow the rest of the argument. The whole 12v world is geared toward lowering the impedance and getting more out the lower volts. But I also do admit I'm not that knowledgeable so might have missed somethings.

Isn't it like Seth said earlier that if the titan was coming in doors in some future scenario I could just take the access plate off the front and rewire the 12s to a mains friendly 8ohms? Ten mins and ready to go?


Another question, out of interest : I've been taught that mixing subs is a big never, no no,... What about same cabs but mix of drivers? If all the extension tuning etc is from the cab? Why not?
Would it be a big no no To couple a twin 12 4ohm (as Seth is proposing) (rewired in series) - wth a 2nd titan loaded with a 3015LF? In some lovely, hypothetical, titan filled future

[Seth]

...if I go for the two fourteks at 2ohm . Would the Emphaser... ...be uneescesary...

Completely unnecessary. The amp you have is a very good match for the Fourteks.

...I could just take the access plate off the front and rewire the 12s to a mains friendly 8ohms?

Personally, I would run wire from each driver to a jack plate on the back of the cab and do wiring changes there. That way you don't have to pull the access panel and drivers.

...Would it be a big no no to couple a twin 12 4ohm with a 2nd titan loaded with a 3015LF?

You could do that. Not a big deal.

[Grant Bunter]

I respectfully disagree

Seth, with what mate?

[Seth]

I agree, "anything that can be done to reduce current consumption is good." The rest of it, not so much.

[Grant Bunter]

Other than that I don't really follow the rest of the argument. The whole 12v world is geared toward lowering the impedance and getting more out the lower volts. But I also do admit I'm not that knowledgeable so might have missed somethings.

The whole 12V world has been brought about by necessity, but has changed over time based on what people expect from 12V systems.
You can't alter the laws of physics, so, in the absence of mains power, you need to utilise what's available.
ie, 12V power amps.
What's the features of many 12V power amps? Modest output with high current draw. And you're right, lower impedance load handling. But that comes at a cost.
The only reason you get more out of auto sound systems is cabin gain, not because you lowered impedance.
Cabin gain is the free lunch.
Take away cabin gain (eg your cart), and you have to compromise a system that was compromised in the first place even moreso.

So, here's some numbers just as examples (assumes a perfectly linear power amp output);

8 ohm load and 60V required from the output = 450W and 7.5 amperes.
4 ohm load and 60V required from the output = 900W and 15 amperes.
2 ohm load and 60V required from the output = 1800W and 30 amperes.

Obviously, the higher the impedance load, the less the draw (battery +/- alternator), less stress on the 12V power amp power supply, lighter cabling.

[Seth]

Now run the numbers for the two specific driver/impedance/voltage scenarios that we're actually discussing.

[Grant Bunter]

Now run the numbers for the two specific driver/impedance/voltage scenarios that we're actually discussing.

I take it that was also aimed at me.
If you have something to say, then say it.

My post wasn't even directed to you. So if you want the numbers run, then off you go with it.

Other than that, a 3015LF in a T48 is to be voltage displacement limited to 60V, so that's done.
The other hasn't had a voltage limit provided by Bill in this thread, so it's a crap shoot.
So could the driver be, considering the last one modelled didn't model well...

[Seth]

Relax Grant. I'm sorry if it feels like I'm attacking you. I'd rather avoid us getting into it like we do from time to time. I should have just said nothing. It's my fault and I'm sorry.

...if you want the numbers run, then off you go with it.

8Ω @ 60V = 450W
2Ω @ 30V = 450W

Obviously, the higher the impedance load, the less the draw (battery +/- alternator), less stress on the 12V power amp power supply, lighter cabling.

In the two options we're currently discussing, the above does not hold true. Same battery/alternator draw (probably in the neighborhood of 50A after taking the amps efficiency into account), same cabling required, and neither option is inherently more or less efficient than the other. The 8Ω option does not consume less amperage. The 4Ω drivers, wired in series, would be just fine with 60V of voltage swing and it's not difficult to find mains powered amps with sufficient voltage swing to make that work.

The #1 goal of his project is to have a mobile battery powered system. Powering with a mains power amp is a "what if" afterthought. He already has in his possession an amplifier and it's specs are only sufficient if run at 2Ω and the amp is designed to be used continuously at 1Ω. There's zero issue or concern about a 2Ω load on this amp. Side benefit is it's super easy to rewire for an 8Ω load if he ever gets around to purchasing pro gear.

If he chooses the 2 parallel driver option, he would save money on the drivers and save money by not having to buy another amplifier. It should give him a cab that's comparable in performance to one loaded with 3015LF on 60V and keep expenditures minimal, which he's also expressed as a focus/goal.

I can't think of a good reason he shouldn't go with the two driver option. It just makes sense, given what he has and what he wants to achieve.

Just because you can, doesn't necessarily mean you should. But, in this case he can and absolutely should go with a 2Ω cab. The only downside is using unvetted drivers.

[Grant Bunter]

^ Errr how can you just ignore physics, and the associated equation?
V=IR

It doesn't matter how the load occurs, but the amperes in an overall 8 ohm cab load requiring 60V (7.5A) are half that of a 2 ohm load requiring 30V (15A).
That's amperes on the output side of the amp, and since energy can't be created nor destroyed, if the requirement on the output stage goes up, so does the requirement from the input power supply.
Sure, the output if the system is run with an alternator would be fine, but not as much so if running on battery alone.
If you see it another way, well *shrugs*...