# Can't get no Sub EQ Satisfaction!



## aj72 (Apr 14, 2013)

I've got an unbalanced 2 X 4 mini DSP 0.9V and am finding as others have reported severe loss of signal strength which in turn results in boosting the gains on my MIC2200 about 10dB. I'm as a result of gain structure issues getting a clipped input signal in the signal chain resulting in my power amps clipping lights coming on before they reach their power limits. I can't find anywhere when people have this problem what the best solution is? Is the balanced version going to fix the clipping? is there another product for sub EQ that is better and has a better voltage match? I don't mind spending money if I get something that works properly. All I want is to be able to run my power amps to close to full power with out the input signal getting clipped and have a pretty flat in room response. is this too much to ask? At the moment I'm barely getting to reference and limitations of input signal are becoming a factor. I had somebody else do the setup with the mini DSP but he didn't really know or tell me about the clipping being a limiting factor with this setup? I didn't know enough about what I was doing to do it myself but am willing to learn I just want a product that will get a fairly flat response without clipping the nut signal is this possible? I had a great result previously using my MIC2200 only but since moving house couldn't get it right using this hence the move to miniDSP. If the 2X8 works better I would get it but does it have the same issues? I have a Dayton V2 Omnimic and can use this with my laptop to measure FR but my knowledge of PEQ is basic. Please help!


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## Wayne A. Pflughaupt (Apr 13, 2006)

It’s well known that the unbalanced miniDSP clips easily. People with this problem typically switch to the balanced version. But why are you using _two_ equalizers in your signal chain? Or is the MIC just there as a signal booster?

Regards,
Wayne


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## aj72 (Apr 14, 2013)

Yes MIC2200 is just used for boosting.


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## Wayne A. Pflughaupt (Apr 13, 2006)

Thanks for the info. :T

Next issue, I can’t tell from your opening post if you’re having problems with just the subwoofer signal chain, or the full system. The reason I ask is that your thread title says “Sub EQ,” but the post itself refers repeatedly to “power [/b]amps[/b],” as in many amps, which suggests mains amps as well as sub.

Regards, 
Wayne


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## aj72 (Apr 14, 2013)

Thanks for your responses Wayne. It is only the subwoofer signal chain I'm referring to here. I will detail below the subwoofer chain sequence bearing in mind the following.

-I have to use a Samson S Convert to boost signal due to a line level mismatch between my domestic preamp and subwoofer poweramps. I have tried everything without it but signal strength was never enough even with boosting sub trim on the preamp to max. I have a Rotel RSP1570 7.1 channel preamp FWIW.

-I did use the MIC2200 as the PEQ initially and was very happy with it but moved house and it sounded nothing like it did even when generating a flat response + or -5dB using Dayton V2 Omnimic. I'm beginning to wonder if it's the MIC2200 but nothing indicates something wrong with it. The FR I can generate in the new house is pretty much the same as my old place but the sound isn't. This is why I decided to try the Mini DSP and was recommended the unbalanced by the guy who did the setup. I also use the Advanced plugin.

Signal Chain (I have dual Passive JTR 2400 Captivators wired 8Ohm hence the need for one amplifier for each Captivator running in Bridged mode)

Rotel Preamp ->Mini DSP 2X4 unbalanced ->Samson S Convert ->Behringer MIC2200 ->Crown XLS5000 or Behringer EP4000 -> Subs

The thing I noticed after the EQ was done with the Mini DSP was an immediate drop in signal strength. What I can say is how excellent it sounds but the clipping is a deal breaker for me if I can't sort it out. If I knew the Balanced option, as much as I hate the Phoenix connectors, would solve this issue I would go for it but don't want to spend more money only to find it wasn't suitable either. Unfortunately I'm not knowledgeable enough in knowing the setup and wouldn't like to pay for someone to come again. Would the EQ that I have now be directly transferrable to the Balanced 2X4 if I were to buy it? Thanks.


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## Wayne A. Pflughaupt (Apr 13, 2006)

Thanks for the info, aj . :T



aj72 said:


> I've got an unbalanced 2 X 4 mini DSP 0.9V and am finding as others have reported severe loss of signal strength which in turn results in boosting the gains on my MIC2200 about 10dB. I'm as a result of gain structure issues getting a clipped input signal in the signal chain resulting in my power amps clipping lights coming on before they reach their power limits.


Not sure I’m getting this. If the amp’s clip lights are coming on, how can the amp _not_ be putting out full power?




aj72 said:


> Rotel Preamp ->Mini DSP 2X4 unbalanced ->Samson S Convert ->Behringer MIC2200 ->Crown XLS5000 or Behringer EP4000 -> Subs


The MIC2200 has both input and output gain controls that will boost the signal, so I don’t see the need for the S-Convert. :scratch:




> The thing I noticed after the EQ was done with the Mini DSP was an immediate drop in signal strength. What I can say is how excellent it sounds but the clipping is a deal breaker for me if I can't sort it out.


Yes, the miniDSP doesn’t have much headroom. Obviously you have to drop the signal from the Rotel low enough to not clip the miniDSP inputs, then boost it up on the other side. I’m sure you know this already...




> -I did use the MIC2200 as the PEQ initially and was very happy with it but moved house and it sounded nothing like it did even when generating a flat response + or -5dB using Dayton V2 Omnimic.
> 
> The FR I can generate in the new house is pretty much the same as my old place but the sound isn't.


So if I understand, the issue really isn’t not being able to drive the amps to max, but that things don’t sound the same way in the new place as they did in the old one? Sounds like one of a few things: You might have a house curve issue, especially if you went from a large room to a small one. Or, you may have the speaker wire polarity reversed on one of the amps/sub driver. Double and triple check them both. My best guess, however, is that you have one of the Reverse Polarity switches engaged on the MICC2200. That will have the same effect as flopping speaker wire polarity.

Regards,
Wayne


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## mikmaz (Jan 9, 2014)

Hi, 

I am running a denon receiver with a crown xls2000 for my ultimax 18 sub. I used a balanced minidsp 2x4 for hpf and eq. I used the 4way advanced plugin. It was harder to get get connected because it requires bare wire inputs and outputs. Once I got that figured out I was REALLY happy. It has higher output signal than the unbalanced version and works great. Even with my ear to the driver there is no hum or noise at all!!!. My svs pb12plus has a lot more noise close up than my diy build. My sub trim is set to -6 and my crown gain dial is 2 notches back from full power. No boosters needed.


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