Connecting DVC driver

[e-side]

Hello,

I can't find a way to connect a dual voice coil driver, 2*6 ohms, to my amplifier, because it's only suited to 8 ohms impedances and above.
Wiring the VCs in parallel will result in a 3 ohm load, so that the amplifier will heaten up too soon. Wiring in series will result in a 12 ohm load, resulting in a less efficient system.

I think the ideal load in my situation will be 6 ohms, but is it obtainable with 2 voice coils, both 6 ohms?

best regards

e-side

[Cal Weldon]

Is this a plate amp or a regular two channel? If it's a plate I'd wire them in series and not worry about the efficiency. If it's a regular amp then you wire one coil to each channel for 6 ohm load.

[sreten]

Hi,

you can connect the amplifier to one voice coil only.

This will change the TS parameters somewhat
(Qe thus Qt) but I'm not exactly sure how much.

The power handling of the single coil will be similar
to having both connected as the thermal capacity
of the voice coil is the same in both cases.

/Sreten.

[e-side]

Is this a plate amp or a regular two channel?

it's just a regular two channel amp, but this loudspeaker has to be connected to only one channel, because it will be used for a stereo system.

you can connect the amplifier to one voice coil only.

This will change the TS parameters somewhat
(Qe thus Qt) but I'm not exactly sure how much.

The power handling of the single coil will be similar
to having both connected as the thermal capacity
of the voice coil is the same in both cases.

I always thought that the power handling would be the half of when both coils are connected, but if it isn't my problem is solved.

I already had an idea to connect both coils while still having a 6 ohm load. This loudspeaker will be crossed over to work together with a tweeter. In stead of seeing the 2 voice coils together as 'one' unit, i thought of using both voice coils individually: 2 lowpass filters (same x-over frequency), 1 for each coil. This will result in a 6 ohm load, but it's not the easiest way of course...

best regards

e-side

[jahonen]

Actually, the power handling is just about the same, since amount of generated heat is just about the same. Maybe a 25% is reasonable derating for this kind of application (Adire's suggestion).

But I'd suggest that you short the unconnected coil, then the Qes will not change. Theoretically, leaving the other coil unconnected results doubling of Qes, which will considerably change the box alignment.

Regards,
Janne

[Cal Weldon]

Originally posted by e-side
it's just a regular two channel amp, but this loudspeaker has to be connected to only one channel, because it will be used for a stereo system.

I must be misunderstanding you.

I read:

You are hooking the woofer (and tweeter) up to one channel and some other speaker to the other?

I'll wait for your answer because this will take a while.

[bobhayes]

I personally, would wire the coils in series and calculate the crossover values to suit.
The system will be no less efficient, but will require more voltage (volume) to get the same SPL output. The current requirement from your amp will be reduced, producing less heat in the amp output.
Most amps will distort well before full volume throw anyway.

The only drawback to this arrangement is in balancing the tweeter output, but this is a problem I would be prepared to work around.

[sreten]

Originally posted by e-side

it's just a regular two channel amp, but this loudspeaker has to be connected to only one channel, because it will be used for a stereo system.
Ie-side

normally both channels are low pass filtered and then
after the filter each channel is connected to one of the
dual voice coils.
I can't see why this case would be any different.

Originally posted by jahonen
But I'd suggest that you short the unconnected coil, then the Qes will not change.
Regards,
Janne

UNDER NO CIRCUMSTANCES DO THIS !

Shorting the unconnected coil gives you a transformer
with the secondary shorted, its a very bad idea.
I don't see that Qe will not change, quite the opposite.

/sreten.

[jahonen]

Well, shorting the unused coil corresponds the situation that it is connected to mute amplifier channel, which, I believe, is legitimate way to connect it (short looks like an amplifier with zero output voltage and nearly zero output impedance).

BTW, the unused coil can be used to vary the Qts over range (1..~2), just by connecting a variable resistor across the unused coil. Adire RDO application note

Regards,
Janne

[sreten]

Hi Janne,

having thought about it further the secondary current will be limited
by the DC resistance of the coil so perhaps I was being overzealous.

And as you say a muted channel is equivalent to a short,
so I believe I stand corrected on this point.

Apologies for implying "its a very bad idea".

/sreten.