ICEpower + miniDSP

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GerhardW

Member
2007-01-03 1:33 pm
I need advice on implementing the following:

Source -> miniDSP 2 x 4 Kit (unbalanced) -> ICEpower 1000ASP -> Dayton Audio UM15-22.

The source would be a Marantz AVR with sub pre-out.

The miniDSP has 0.9V output which means I'd need a buffer.

First question: would it be worth while implementing a buffer that would convert the unbalanced miniDSP output to a balanced input for the 1000ASP or is this overkill (which I suspect) since the units would sit right next to each other in the amp enclosure.

The amp's datasheet includes this statement: "The output stage is a full bridge topology with a 2nd order filter meaning the power output on the terminals Vo+ and Vo- is balanced." and "The balanced speaker outputs are both “ hot ”. It has 2 sets of these. The UM15-22 is the dual 2 Ohm VC model which I would probably have to wire in series to present a 4 ohm load to the 1000ASP. Second question: with this being a mono amp, how are these two outputs to be connected to the "single" voice coil sub?

Thanks in advance for the help!
 

mga2009

Member
2015-11-20 10:34 pm
Hi,

I am almost in the same boat as you...

I have a 3E Audio DSP (ADAU1701 same as miniDSP 2x4) with the difference that this DSP takes single ended input and it outputs balanced signal @ 3v. After that, I feed an ICEpower 500ASP and then a Dayton Ultimax UM15.

For what I have read, the amp's input it's not sensitive enough to accept 0.9volts from the 2x4. It will work, it will sound loud, but you will not get all the loudness and power the 1000ASP can give with only 0.9volts. For that, you need a stronger signal level, so you should look the MiniDSP balanced 2x4 or the 2x4HD.

Regarding the balanced or unbalanced signal, I think the 500ASP and the 1000ASP can take single ended input (as long as it is strong enough) and if the distance is short it should not add too much noise.

Oh, and yes... you should wire your VC in series to get 4ohm. The 1000ASP's P4 connector has 2 hot and 2 cold, you should use one of each to power your speaker. I don't know the reason for a 2+2 pin arrangement.

Regarding the Warning: "The balanced speaker outputs are both “ hot ” with a common-mode DC level equal to Vp/2. Balanced probes should always be used for monitoring and measurements." I cant help you there, as I am not an expert, so let's wait for one to chime in.
 
Get an active DI-Box from a pro audio shop. It will drive your weak sub signal to a balanced level, use able by the 1000ASP. These boxes can be had in all kind of flavors. Just avoid the passive version, as they are not suited for the miniDSP and will degrade bass. You can build a single ended/ balanced buffer too.

Take care 1.
Always switch on the ICE amp last and switch it off first. Otherwise even a sub chassis might suffer from the huge "Thump" the miniDSP produces (not very best piece of equipment, if you ask)

Take care 2.
The ICE amp is a module to be fitted by professionals, in most cases to active loudspeakers. It has all kind of protections for this case, but is not short cut resistant.
If you connect + and - out with each other or ground, you amp will be irreparable damaged, even if there is no signal.
Today anyone expects amps to be idiot proof. They ARE NOT! Think about it, even if you know, others may not. So take care.

If you do it all right, this combination should shake your house and garden...
Build a strong housing for the Dayton, with many reinforcements or a matrix, not only thick walls, as this is essential for the sub´s sound, independent of vented or closed design.
 

mga2009

Member
2015-11-20 10:34 pm
Get an active DI-Box from a pro audio shop. It will drive your weak sub signal to a balanced level, use able by the 1000ASP. These boxes can be had in all kind of flavors. Just avoid the passive version, as they are not suited for the miniDSP and will degrade bass. You can build a single ended/ balanced buffer too.

Take care 1.
Always switch on the ICE amp last and switch it off first. Otherwise even a sub chassis might suffer from the huge "Thump" the miniDSP produces (not very best piece of equipment, if you ask)

Take care 2.
The ICE amp is a module to be fitted by professionals, in most cases to active loudspeakers. It has all kind of protections for this case, but is not short cut resistant.
If you connect + and - out with each other or ground, you amp will be irreparable damaged, even if there is no signal.
Today anyone expects amps to be idiot proof. They ARE NOT! Think about it, even if you know, others may not. So take care.

If you do it all right, this combination should shake your house and garden...
Build a strong housing for the Dayton, with many reinforcements or a matrix, not only thick walls, as this is essential for the sub´s sound, independent of vented or closed design.

Very good recommendation!

I've got the ART CleanBOX Pro: CLEANBox Pro – Dual Channel Level Converter – ART Pro Audio

It's good, but it's price does not make it a good buy. It's around USD$70, so if you get the MiniDSP 2x4 and this Direct Box, you are very close to the 2x4HD price (and way over the 2x4 balanced). I bought it to use with my Behringer NU3000DSP and it worked flawlessly.


If you can get it for a good price, I would recommend it, or maybe there are other active direct boxes that are cheaper/better.
 

GerhardW

Member
2007-01-03 1:33 pm
Thank you all for your comments. I will experiment first a bit to see what the audible difference is between a miniDSP 2x4 HD and the non-HD version. I have an HD version which I use in my PC audio setup. It would not be too much of a problem for me to throw together a buffer - I have all the parts.

I am hoping that the total delay from when power is applied to full signal amplification which is tacd + tsd = 1.65s would be enough to eliminate the miniDSP's thump. If not I will implement the external Standby/Protect control circuit but with a delay.
 
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