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post #91 of 2439 Old 10-28-2010, 06:17 AM
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Originally Posted by coctostan View Post

Where did you see this?

9 posts earlier.

Sanjay
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post #92 of 2439 Old 11-02-2010, 02:40 PM - Thread Starter
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A possible roadblock to the MiniDSP doing subwoofer LT circuits. The input voltage is 0.9Vrms/2.6Vpp input capabilities.

This post has me concerned about getting enough voltage to amps like the Marathon MA-5050.

Quote:


Probably not. The inputs/outputs of the MiniDSP modules are limited to 900mV, and that's right in the neighborhood of where most amplifiers would be delivering their rated power. So, if your MiniDSP modules are feeding the amplifiers directly I'd say your chances of clipping the MiniDSP outputs are near zero. This is what I was referring to with the "well considered maximum levels" comment. Unlike the DCX (and other commercial units) a multi-channel post-volume control is not necessary with the MiniDSP units.

The Emotiva power-amps have 32db voltage gain (which is a bit more than usual) so your MiniDSP working voltage levels would be a bit less than they would otherwise and reduce the chances of clipping even further.

Obviously, if programming large EQ boosts in the MiniDSP you might get into trouble, so you have to be aware.

Cheers,

Dave.


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post #93 of 2439 Old 11-02-2010, 02:54 PM
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This is nothing more that standard cross standards problems.

If you have a Reva it is setup for (portable) CD player (ipod) output levels in it's inputs.

The Revb can take most AVR speaker line outs, and most sub channels could clip it.

The outputs will be able to put out comparatively higher signals than the inputs can except, but there will be a limit. You will still need a line level converter for some applications.
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post #94 of 2439 Old 11-02-2010, 03:02 PM - Thread Starter
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soho, do you have the RevA and RevB mixed up?

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This product is a RevA version with 0.9Vrms/2.6Vpp input capabilities. It is the perfect fit for PC sources, portable players or any source capable of lowering the signal to this level. If you intend to connect it to a CD player, or any other source which you don't have volume control over, you should purchase the RevB version instead.

From that it says RevB is for CD players.

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post #95 of 2439 Old 11-02-2010, 03:36 PM
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Sorry, I meant portable CD players, or ipods with volume knobs. I'm getting old.

They meant dedicated component CD/DVD players.
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post #96 of 2439 Old 02-28-2011, 05:04 AM
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nothing new on the miniDSP??? i am thinking of getting one of these to EQ my subs. I have dual ULS-15s and have a terrible in room response. can this little device work for me?
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post #97 of 2439 Old 02-28-2011, 05:27 AM
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Quote:
Originally Posted by Kimwyn View Post

nothing new on the miniDSP??? i am thinking of getting one of these to EQ my subs. I have dual ULS-15s and have a terrible in room response. can this little device work for me?

Yes it is awesome. I used it with my Danley DTS-10. It is friendly and effective.

http://www.avsforum.com/avs-vb/showthread.php?t=1311967

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post #98 of 2439 Old 02-28-2011, 07:34 AM
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thanks for your help. How long does it take to get from Hong Kong to the US?
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post #99 of 2439 Old 02-28-2011, 08:13 AM
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Quote:
Originally Posted by Kimwyn View Post

thanks for your help. How long does it take to get from Hong Kong to the US?

About a week.

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post #100 of 2439 Old 02-28-2011, 08:49 AM
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Quote:
Originally Posted by Kimwyn View Post

nothing new on the miniDSP??? i am thinking of getting one of these to EQ my subs. I have dual ULS-15s and have a terrible in room response. can this little device work for me?

Sure, it will work, but it has 2 potential limitations: delay is limited to 7.5ms and it only outputs 0.9Vrms, which may not be enough to drive some amps to full power. If these are not issues for you, it is a neat unit for the money.
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post #101 of 2439 Old 02-28-2011, 09:33 AM
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Hey guys, I am looking to buy one of these soon to use in my sub build for a High pass filter and eq.

However, I was wondering several things.

How well does this work as a digital crossover?
Would I be able to use only one for a crossover in a 2 way system for my LCR AND the sub applications such as HPF and EQ?

What is the best one to get for overal applications? BALanced? unbalanced? In a box or not?

Might be kinda cool to build my own box for it but at the same time I do not know if I would break something...

Trying to enjoy the simple things in life.

 

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post #102 of 2439 Old 02-28-2011, 09:47 AM
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Quote:
Originally Posted by A9X-308 View Post

Sure, it will work, but it has 2 potential limitations: delay is limited to 7.5ms and it only outputs 0.9Vrms, which may not be enough to drive some amps to full power. If these are not issues for you, it is a neat unit for the money.

Yep. The voltage thing is the bigger issue for me. I will have to use it in tandem with a DCX being used to boost the output. Kind of ironic there. I just need something that can apply dsp below 20hz and this is the cheapest most powerful option. If they would make a finished and assembled version capable of about 5v in and out, with greater delay capabilities and put it in one of the 1/3rd rack space cases with room for XLR and RCA in outs both, I would be all over it.

I just ordered the balanced kit and it looks like about 3 weeks for shipping on that one.
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post #103 of 2439 Old 02-28-2011, 10:13 AM
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Quote:
Originally Posted by A9X-308 View Post

Sure, it will work, but it has 2 potential limitations: delay is limited to 7.5ms and it only outputs 0.9Vrms, which may not be enough to drive some amps to full power. If these are not issues for you, it is a neat unit for the money.

Related to what Penn said earlier, how does this affect the Bi-Quad add-on?

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post #104 of 2439 Old 02-28-2011, 10:16 AM
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Quote:
Originally Posted by Kimwyn View Post

thanks for your help. How long does it take to get from Hong Kong to the US?

Kimwyn - before adding any boosts to your ULS's you may want to discuss with HSU in advance. I recall someone mentioning there is a large amount of boost already inherent in the amp of the ULS (I think it was Caci who mentioned the amount of boost), so you don't want to over do it ...

 

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post #105 of 2439 Old 02-28-2011, 11:46 AM
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Quote:
Originally Posted by A9X-308 View Post

Sure, it will work, but it has 2 potential limitations: delay is limited to 7.5ms and it only outputs 0.9Vrms, which may not be enough to drive some amps to full power. If these are not issues for you, it is a neat unit for the money.

Quote:
Originally Posted by Ricci View Post

Yep. The voltage thing is the bigger issue for me. I will have to use it in tandem with a DCX being used to boost the output. Kind of ironic there. I just need something that can apply dsp below 20hz and this is the cheapest most powerful option. If they would make a finished and assembled version capable of about 5v in and out, with greater delay capabilities and put it in one of the 1/3rd rack space cases with room for XLR and RCA in outs both, I would be all over it.

I just ordered the balanced kit and it looks like about 3 weeks for shipping on that one.

Quote:
Originally Posted by bossobass View Post

Related to what Penn said earlier, how does this affect the Bi-Quad add-on?

Bosso

It appears the balanced version can produce 2V rms assuming you are using a balanced connection. The only question is if this can drive the amplifier to full output. EQ applied won't change the required output Voltage, just as the LT doesn't change the amount of available maximum output of a sealed box at a single frequency.

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post #106 of 2439 Old 02-28-2011, 12:25 PM
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Quote:
Originally Posted by t6902wf View Post

yes it is awesome. I used it with my danley dts-10. It is friendly and effective.

+1

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post #107 of 2439 Old 02-28-2011, 12:27 PM
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The RevB version outputs 2 V; revA can be changed to B w/jumper

http://www.minidsp.com/onlinestore/d...nidsp-2x4-revb

Quote:
Originally Posted by A9X-308 View Post

Sure, it will work, but it has 2 potential limitations: delay is limited to 7.5ms and it only outputs 0.9Vrms, which may not be enough to drive some amps to full power. If these are not issues for you, it is a neat unit for the money.


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post #108 of 2439 Old 02-28-2011, 06:56 PM
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Looks like I'm mistaken; revB can accept up to 2V *input*.

And looks like I've got a problem; my Peavy CS4080HZ needs 2.25 V input for full output.

Noah
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post #109 of 2439 Old 02-28-2011, 07:01 PM
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The designer of REW recommends Rev B for our purposes. That's the one I bought. Need to go pick it up from USPS tomorrow. Took a week and a day to get here.

"The boom is dead, long live the bass"
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post #110 of 2439 Old 03-01-2011, 03:35 AM
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Quote:
Originally Posted by A9X-308 View Post

Sure, it will work, but it has 2 potential limitations: delay is limited to 7.5ms and it only outputs 0.9Vrms, which may not be enough to drive some amps to full power. If these are not issues for you, it is a neat unit for the money.

There is a 2 volt version too. I wish I had that one as I would like to drive a pro amp for my subs. Any one with a cheap ready built circuit to boost the signal from my miniDSPs? I don't want to have to buy them both again.
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post #111 of 2439 Old 03-01-2011, 05:44 AM
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Quote:
Originally Posted by Theresa View Post

There is a 2 volt version too. I wish I had that one as I would like to drive a pro amp for my subs. Any one with a cheap ready built circuit to boost the signal from my miniDSPs? I don't want to have to buy them both again.

http://www.samsontech.com/products/p...fm?prodID=1699
I use a Sampson s convert but it looks like it is no longer available.

An ART cleanbox does the same thing for $65.

http://www.bhphotovideo.com/c/produc..._Matching.html

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post #112 of 2439 Old 03-01-2011, 05:55 AM
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Quote:
Originally Posted by Mark Seaton View Post

It appears the balanced version can produce 2V rms assuming you are using a balanced connection. The only question is if this can drive the amplifier to full output. EQ applied won't change the required output Voltage, just as the LT doesn't change the amount of available maximum output of a sealed box at a single frequency.

I guess my question wasn't worded properly.

Yes, the L/T can't increase maximum output, but it can easily send a signal that exceeds maximum output capability.

So, it's impossible to clip the minidsp (actually, what is the power supply?) and the boost is unlimited?

Bosso
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post #113 of 2439 Old 03-01-2011, 06:58 AM
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Quote:
Originally Posted by bossobass View Post

I guess my question wasn't worded properly.

Yes, the L/T can't increase maximum output, but it can easily send a signal that exceeds maximum output capability.

So, it's impossible to clip the minidsp (actually, what is the power supply?) and the boost is unlimited?

Bosso

I can see how with an input voltage near 2v, applying boost to frequencies that you can easily exceed/clip the 2v output stage. Don't most L/T circuits apply (approximately) a 12db/oct shelf filter? If so, it seems you'd to look at the maximum boost provided and provide an "allcut" filter to that same degree.

Say, the max boost was 15db, then you apply a 15db allcut filter to bring everything down to a doable output voltage - that should keep everything in check, right? I appreciate the concept of a true L/T circuit in that you're not really boosting anything, you're in effect cutting the higher frequencies to match the capability of the driver/amplifier limited excursion down low to smooth the frequency response.

BUT, what are we doing with an "L/T filter" with this device? I think it's applying boost down low, which will need some form of cut to keep the voltage in check, or am I just way off base here?

Seems like a little careful gain structure massaging is in need to make sure you're not clipping any part of the chain and maximizing the output capability of the amp.

And this reply was not aimed at you in particular Bosso, as you understand this stuff MUCH better than I do, but as someone who's trying to get his head around these devices for a future purchase, I want to make sure I'm understanding it's possibilities and limitations.

Best,
C.
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post #114 of 2439 Old 03-01-2011, 08:26 AM
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Quote:
Originally Posted by bossobass View Post

I guess my question wasn't worded properly.

Yes, the L/T can't increase maximum output, but it can easily send a signal that exceeds maximum output capability.

So, it's impossible to clip the minidsp (actually, what is the power supply?) and the boost is unlimited?

Bosso

I'm sure there are limits and you can certainly clip any device. My point was that the LT is not the detail in question, but rather the input sensitivity of the amplifier. If the amplifier reaches maximum output with 1.9Vrms input, you will never need more Voltage output than 2Vrms, regardless of the EQ or signal shaping applied.

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post #115 of 2439 Old 03-01-2011, 09:50 AM
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2 volts is just not enough for some of the pro amps unfortunately. It might be for amps with selectable input gain...Thankfully all of my amps have this now except for an old Mackie. Don't they have a suggestions board? Looks like we all need to whine about the whimpy voltage.
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post #116 of 2439 Old 03-01-2011, 09:54 AM - Thread Starter
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Ricci, they have an active forum

http://www.minidsp.com/support/forum

They also have a sub-forum on DIYaudio.com
http://www.diyaudio.com/forums/minidsp/

Both forums are active.

And Noah Katz has posted on the MiniDSP site wanting > 2V output voltage.

http://www.minidsp.com/support/forum...imit=6&start=6

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post #117 of 2439 Old 03-01-2011, 10:24 AM
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Quote:
Originally Posted by Theresa View Post

There is a 2 volt version too.

I'm not seeing that in any of the literature I have from them. Input sensitivity is adjustable via selector, but I see nothing about output.

Referring to the datasheet of the processor used in the MiniDSP, it specs max O/P as 0.9Vrms, so it appears to me they are using it's outputs direct.
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post #118 of 2439 Old 03-01-2011, 03:08 PM
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Quote:
Originally Posted by penngray View Post

And Noah Katz has posted on the MiniDSP site wanting > 2V output voltage.

http://www.minidsp.com/support/forum...imit=6&start=6

As I posted later in that thread, I was confusing output with input.

As to MiniDSP gain structure, there are input and output blocks with "VU meters" that are to be adjusted to keep the signal out of the red, presumably to keep from clipping the A/d on the inputs and D/A on the outputs.

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post #119 of 2439 Old 03-01-2011, 05:22 PM
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Quote:
Originally Posted by A9X-308 View Post

I'm not seeing that in any of the literature I have from them. Input sensitivity is adjustable via selector, but I see nothing about output.

Referring to the datasheet of the processor used in the MiniDSP, it specs max O/P as 0.9Vrms, so it appears to me they are using it's outputs direct.

I can't speak to the datasheet itself, but I've run a RevB 2V MiniDSP with around 1.5v in and 1.5v out. I measured it with a multimeter.

To those wanting a higher voltage version, do you have a receiver or preamp that exceeds 2v output? My experience is that most are 2v and below. The MiniDSP isn't going to bump your voltage just like the DCX won't.
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post #120 of 2439 Old 03-02-2011, 02:21 AM
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Quote:
Originally Posted by coctostan View Post
I can't speak to the datasheet itself, but I've run a RevB 2V MiniDSP with around 1.5v in and 1.5v out. I measured it with a multimeter.
When I looked at mine before it went out on loan, I don't recall seeing anything after the processor that would increase gain, so I'm dubious.

As the chip I/P sensitivity for 0dBFS is also 0.9Vrms, all the Rev B does is add attenuation to bring the 2V down to 0.9. I'll measure mine when it comes back.

Attachment is from the processor chip datasheet.
LL
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