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MiniDSP require signal boost with pro amps - Page 2

post #31 of 111
Quote:
Originally Posted by Ricci View Post

One more thing....Is there anyone with a receiver plugged directly into a pro amp who cannot calibrate their sub system to 15dB hot, 90dB with the amplifier trim all the way up and their SW channel trim at maximum? Anyone? I am genuinely curious here. I asked this a couple of times long ago and no one ever replied, which I'm assuming means something.

I've never been able to clip a pro amplifier with any consumer level signal - usually ends up about 10dB short.
post #32 of 111
Weird - I can clip my Crown XLS1000 with ease running an old H/K AVR146 receiver.
post #33 of 111
Quote:
Originally Posted by MBentz View Post

I've never been able to clip a pro amplifier with any consumer level signal - usually ends up about 10dB short.
Odd, I've personally measured sine waves in excess of 7.5Vrms on the SW output from an Onkyo TX-NR809, Pioneer Elite SC-05, and a Pioneer Elite VSX-84TXSi prior to the onset of the SW output clipping. That can drive any pro amp I'm aware of into clipping several times over.
post #34 of 111
Quote:
Originally Posted by Pain Infliction View Post

This is really good advice. I do have a question though?.......Why should one set the minisdp input voltage to .9v? Would that clip the input on the dsp? I am about to receive mine in the mail and am learnig the best possible settings for the device before integrating it into the sub chain.

I forgot to mention that the Balanced MiniDSP was setup with an unbalanced connection on the input and output with the jumper set at 0.9v. I just took an rca cable that I had lying around, cut it in half and coneccted it up.
post #35 of 111
Quote:
Originally Posted by Stereodude View Post

Odd, I've personally measured sine waves in excess of 7.5Vrms on the SW output from an Onkyo TX-NR809, Pioneer Elite SC-05, and a Pioneer Elite VSX-84TXSi prior to the onset of the SW output clipping. That can drive any pro amp I'm aware of into clipping several times over.

Agreed, you shouldn't need more than 1Vrms to drive most pro amps into clipping.

However, I run highly efficient mains and usually can't go above -20 on the main volume control without my ears bleeding. Figure +12dB on the subwoofer output and you're still 26dB away from the max output. 26dB less than 7.5Vrms is 0.38Vrms, or about 6dB shy from clipping. I don't think the Denon receivers I've played with will do 7.5Vrms anyway - although to be fair I've never measured.

Btw, do they really have +/-12V rails for the Preouts?
post #36 of 111
Quote:
Originally Posted by MBentz View Post

Agreed, you shouldn't need more than 1Vrms to drive most pro amps into clipping.
However, I run highly efficient mains and usually can't go above -20 on the main volume control without my ears bleeding. Figure +12dB on the subwoofer output and you're still 26dB away from the max output. 26dB less than 7.5Vrms is 0.38Vrms, or about 6dB shy from clipping. I don't think the Denon receivers I've played with will do 7.5Vrms anyway - although to be fair I've never measured.
Btw, do they really have +/-12V rails for the Preouts?
Your math is a little off relative to my measurements. In the case of the two Pioneer units, that voltage occurred with a DTS encoded test tone that had a -0.01dBFS 40Hz sinewave in the LFE channel with the master volume at 0dB and the SW level trim at 0dB. The Onkyo was at +3dB (or +3.5dB I don't recall exactly) on the master volume with the SW level trim at 0dB.

So, at -20dB on the MV with +10dB on the subwoofer (max channel trim) you'd be 10dB less than the ~7.5Vrms (in the Pioneer case) which would put you at ~2.3Vrms on the SW output. The Onkyo would be ~1dB less (+12dB sub -20MV) at ~2.1Vrms. This all assumes your mains have the level trims set to 0dB and not some negative value which would result in a net increase the SW signal amplitude.
post #37 of 111
Guys,

These might be dumb questions but I have my miniDSP at 0.9V and I have it split at the receiver using a y-cable one end going to the mini and another going to an external plate amp for my buttshakers. Does this half the signal voltage coming out of the receiver between the two outputs on the y-cable? Meaning if my receiver's preouts are 1.5V should I half this number since I have it split at the jack?

Also, if a pro amp is rated at max output at 6V and I get one of the newer mini's that have 8V output, will there be any issues having more voltage than required coming out of the mini into my pro amp?

Thanks for the help.
post #38 of 111
No, the Y cable doesn't half anything itself. Both the MiniDSP and the amp for your "buttshakers" should get the full voltage from your receiver.

There are some rare exceptions to this, but they would be very rare cases where the input impedance of one of the devices was very low resulting in it dragging down the voltage because the receiver couldn't source enough current.
post #39 of 111
Thread Starter 
Quote:
Originally Posted by Audiophile1178 View Post


Here is my new level settings:
Mains: -8 dB
Center: -12 dB (The lowest setting possible for me)
Surrounds: -10.5 dB
Subwoofer: +3 dB
.

I'm just not comfortable running my channel trims bottomed out like that just to accomodate the irregularities of the MiniDSP. How do I then adjust the amp gains for each channel (6 of them)? I'm actively bi-amping (DSP).

Actually, it is a moot point since I ditched the MiniDSP in favor of the QSC DSP-30. Whala...no more need for all this input sensitivity mismatch BS.
Anyone want to buy a balanced MiniDSP?
post #40 of 111
Quote:
Originally Posted by Wrager View Post

Anyone want to buy a balanced MiniDSP?
Sure! Send me a PM. What plugin are you throwing in? biggrin.gif
post #41 of 111
Thread Starter 
PM sent.
post #42 of 111
Ill take it if stereo doesn't want it
post #43 of 111
Quote:
Originally Posted by brian6751 View Post

Ill take it if stereo doesn't want it
Too slow. tongue.gif
post #44 of 111
Sounds more like a speaker vs. sub sensitivity issue resulting in a lack of gain problem on the sub side of things. This isn't a consumer vs. pro level thing, it's a system gain issue. A boost box may be the only answer in this situation, unless you can find an amp with very high input sensitivity (low voltage number) or exceptionally high gain. Assuming, of course, you have no plans on changing speakers or sub(s) to get sensitivity more alike.
post #45 of 111
Quote:
Originally Posted by braveheart123 View Post

Any signal booster does jack up the nosie floor if any; but it depends on what you use it for. As long as it is only for the subwoofer; there won't be any issue. For the mains; it is a big no no.
I am using Art CleanBox Pro to bump up the sub signal from Denon for Crown XLS1000 to run diy sub. I used it on Onkyo 809 also, which had terribly low pre-out signal i.e. 0.2V. Yamahas are no different. Only the high-end avrs like NAD or Rotel have in access of 1.2V pre-out sections.
All these mass market avrs esp Yamaha, Denon, and Onkyo (I've used them all) have terrible output voltage on their pre-outs and are a bad weak signal source to pro amps without a bump box.

I had problems with my Yamaha but my Onkyo 709 has no problems with a Crown XLS1000 and 1500.
post #46 of 111
Thread Starter 
Quote:
Originally Posted by whoaru99 View Post

Sounds more like a speaker vs. sub sensitivity issue resulting in a lack of gain problem on the sub side of things. This isn't a consumer vs. pro level thing, it's a system gain issue. A boost box may be the only answer in this situation, unless you can find an amp with very high input sensitivity (low voltage number) or exceptionally high gain. Assuming, of course, you have no plans on changing speakers or sub(s) to get sensitivity more alike.

You might be on to something there. My mains have a sensitivity of 101 dB. The QSC has adjustable input sensitivity, so problem solved. I can run all of the trims and gains at about 50%.

Wait, upon second analysis, the 2242's have a sensitivity of 99dB.
post #47 of 111
I just finished tuning my sub with the miniDSP and I have it in between the Yamaha avr and the ep2000. I do not have any gain issues at all and the gain on the amp is only at 18. At 18 it is really loud! my freakin sub is rockin my house hard and vibrating everything downstairs! Love it though. I was worried about what some people were saying about the miniDSP not able to supply the amp with enough power, but it for sure does so anybody reading this dont be scared away by that.
post #48 of 111
Just out of curiosity, are the Behringer EP1500/EP2500 or EP2000/EP4000 amplifiers a good choice to power the LCR's in a theater type setting? I am getting ready to order a Minidsp to EQ my setup, including my LCR's, and I would like to power my LCR's with the Behringer EP series of amps, I am just not sure if that is a good combo due to most AVR's not have as much voltage at the output of the pre-outs for the mains?
post #49 of 111
The Behringers have similar input sensitivity to "consumer" amps.

For a similar thread some years back I took an average of the input sensitivity of all my "consumer" amps and of all my pro audio amps. Guess what? The average of the pro audio amps was slightly less (higher input sensitivity/lower voltage number) than the consumer amps.

Certainly that may not hold true in all cases but the urban legend of some big difference between input sensitivity of consumer vs. pro amps needs to die. By and by it's just not there if you actually look at the numbers.
post #50 of 111
Quote:
Originally Posted by Martycool007 View Post

Just out of curiosity, are the Behringer EP1500/EP2500 or EP2000/EP4000 amplifiers a good choice to power the LCR's in a theater type setting? I am getting ready to order a Minidsp to EQ my setup, including my LCR's, and I would like to power my LCR's with the Behringer EP series of amps, I am just not sure if that is a good combo due to most AVR's not have as much voltage at the output of the pre-outs for the mains?

What LCR's will you be using? Those amps put out some serious power!
post #51 of 111
Quote:
Originally Posted by Pain Infliction View Post

What LCR's will you be using? Those amps put out some serious power!

I am going to be building a trio of both Seos12/DNA360/JBL2226 and also another trio of Corn-Scalas or possibly a trio of Statements. Haven't fully decided yet, but I plan to do sort of a theater speaker shootout and sell the ones that I like the least. I do believe that either of these speaker would be great if powered by an EP1500 or possibly even an EP2500/4000. Right now I have a Definitive Technology BP-30 setup that I power with only a Denon AVR-3312, and I doubt my BP-30's could handle one of those EP amps.
post #52 of 111
I think you would be surprised what the SEOS and Cornscalas will do powered only by your avr.

That's a lot of work to do just to try them out. Can't you find someone local who has them and ask if you can demo them?

Here's how I suspect your shoot out would result

Movies - SEOS
Movies/music - Cornscalas
Music - Statements
post #53 of 111
That is a lot of work indeed but I will def subscribe to your thread if you make one. By the way....I think the ep1500= ep2000 and the ep2500= ep4000. You probably already know that though.


I really want some l/c/r's that can keep up with my sub. I just dont know what to use yet. The l/c/r's will be powered by an Emotiva XPA3 amp that I am already using. Any suggestions? This is in a dedicated theater.
post #54 of 111
Quote:
Originally Posted by Martycool007 View Post

I doubt my BP-30's could handle one of those EP amps.

I have a pair of BP-30s. Connected them to a Crown K2 several years back. They couldn't handle WFO when running full range, but they did OK. If you're running a sub and have ~ 80Hz HPF on the BP-30s I don't think it would be a problem.
post #55 of 111
Sorry to dig up a dying thread but am currently using a pair of CHT 18.2's each driven by a bridged QSC 2450 with an antimode in the middle. I also have an unbalanced minidsp 2x4 currently not installed. I was thinking of tossing the 2x4 in the mix to add a house curve. All the research is telling me this unbalanced unit does not put out adequate voltage for pro equipment. Is this correct? Any way to integrate it or should I just sell it and get a balanced unit?

Thanks.
post #56 of 111
You can still use the unbalanced but set the jumper to 2V.
post #57 of 111
Quote:
Originally Posted by Pain Infliction View Post

You can still use the unbalanced but set the jumper to 2V.
I'm pretty sure that would have the opposite effect. The output of the unbalanced unit is always "0.9Vrms". By setting the jumper to 2.0Vrms he needs more input signal to get the same output signal.
post #58 of 111
Quote:
Originally Posted by Pain Infliction View Post

You can still use the unbalanced but set the jumper to 2V.

I thought the jumper only affected the input? Regardless of the jumper setting, the output is .9v on the unbalanced kit. Maybe I'm wrong?

Check out the chart: Click here.
post #59 of 111
You are right. I don't know what i was thinking??
post #60 of 111
I just read this entire thread and I still have no idea what is going on. I'm still not sure if the DSP will clip before my amp or what voltage is correct for my setup. Can someone just tell me if the configuration below will work and what sensitivity to set the MiniDSP to?

PS3 > Denon 4311 > unbalanced RCA cable (x2) > MiniDSP Balanced 2x4 > unbalanced XLR cable (x2) > EP2500/4000 (x2) > LMS 5400 (x2)

Just FYI, the purpose of this is to do some slight EQ and setup a high pass filter for my amps sake then rerun Audyssey on the Denon.
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