Hi
I'm playing around with an active speaker using JBL 2226h and B&C DC250.
I'm using a MiniDSP 2x4 for crossover and DSP.
The problem is there is a hissing noice which I can't live with.
I tried a lot of different things but I can't get rid of it.
I have googled this and there seems to be a with the Minidsp regarding this maybe because the drivers are very efficient?
So, what to do?
I would have upgraded to the 2x4HD but if this also has the hiss, then that would just be waste of money.
I tried to find an alternative to Minidsp but nothing really came up - is it true that there isn't any other products like Minidsp on the marked?
I don't want to go for a PC based DSP.
I have also taken a look at Hypex FA123.
But how good is the DSP here compared with the MiniDSP?
And, what about sound quality do they sound good?
So what are my options?
I'm playing around with an active speaker using JBL 2226h and B&C DC250.
I'm using a MiniDSP 2x4 for crossover and DSP.
The problem is there is a hissing noice which I can't live with.
I tried a lot of different things but I can't get rid of it.
I have googled this and there seems to be a with the Minidsp regarding this maybe because the drivers are very efficient?
So, what to do?
I would have upgraded to the 2x4HD but if this also has the hiss, then that would just be waste of money.
I tried to find an alternative to Minidsp but nothing really came up - is it true that there isn't any other products like Minidsp on the marked?
I don't want to go for a PC based DSP.
I have also taken a look at Hypex FA123.
But how good is the DSP here compared with the MiniDSP?
And, what about sound quality do they sound good?
So what are my options?
I'm using a 2x4hd on a 2220/emilar ea175 setup. No hiss at all and I'm not attenuating the compression driver downstream. Now the odd thing is I had a 2x4hd two years ago and that one hissed like crazy. Maybe newest revision corrects something, I don't know. But this is working great for me now. The behringer 204hd I used previously hissed too but not as much as the first hd did.
So maybe buy a new 2x4hd I really like mine although the drc8a looks like a great solution too as pointed out above.
So maybe buy a new 2x4hd I really like mine although the drc8a looks like a great solution too as pointed out above.
How is your gain structure? Where do you control volume and where do you pad the compression drivers?
The MiniDSP 2x4 has a limited dynamic range of >98 dB. It is best to control the volume after the DSP and to avoid using the output attenuators for more than a few dB. Driver padding should be done after the MiniDSP, for example with an L-pad between amplifier and compression driver, like in the JBL M2. Assuming your compression drivers can play 120 dB and 20 dB of hiss is acceptable, directly connecting a MiniDSP to the compression driver amplifier results in too much hiss. This can be fixed by adding a volume control after the DSP. At low volumes it attenuates hiss, at high volumes the hiss will be masked by music. Assuming 60 dB of SNR is sufficient, the MiniDSP should be driven at at least -38 dB FS.
The MiniDSP 2x4 has a limited dynamic range of >98 dB. It is best to control the volume after the DSP and to avoid using the output attenuators for more than a few dB. Driver padding should be done after the MiniDSP, for example with an L-pad between amplifier and compression driver, like in the JBL M2. Assuming your compression drivers can play 120 dB and 20 dB of hiss is acceptable, directly connecting a MiniDSP to the compression driver amplifier results in too much hiss. This can be fixed by adding a volume control after the DSP. At low volumes it attenuates hiss, at high volumes the hiss will be masked by music. Assuming 60 dB of SNR is sufficient, the MiniDSP should be driven at at least -38 dB FS.
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That is if indeed it is the miniDSP that causes the hiss. Have you made absolutely certain that is the case? For instance, when you remove the miniDSP from your (pre) amp and short the (pre)amp input, is the hiss gone?
When you short the input to the miniDSP, is the hiss still there?
It's probably wise to do a couple of tests before shelling out a bunch of money and finding that the issue is elsewhere.
Or look at a solution like TBL gives above.
Jan
When you short the input to the miniDSP, is the hiss still there?
It's probably wise to do a couple of tests before shelling out a bunch of money and finding that the issue is elsewhere.
Or look at a solution like TBL gives above.
Jan
Given your high sensitivity speaker components it is a 100% clear that the hiss is coming from the ADAU1701. Same thing with my miniDSP when I use any compression driver and the same thing with my RCF ART701MK2 (which has, guess, only a ADAU1701 in it). You'd better upgrade to something that has a decent DAC/analog output.
I'd say the Hypex FA123 is the best solution, something that I consider for my RCFs as well.
I'd say the Hypex FA123 is the best solution, something that I consider for my RCFs as well.
... I've been looking at the DB Mark XCA series a bit.
Blue Aran - The UK's no.1 Loudspeaker Component Stockist > dBMark > System Controllers > Digital Lms
Seems like decent value for the money?
Blue Aran - The UK's no.1 Loudspeaker Component Stockist > dBMark > System Controllers > Digital Lms
Seems like decent value for the money?
So did you explore this further? Has anyone found other minidsp alternatives for active speakers?
I too like the functionality of minidsp products but yearn for hardware with better performance. My 4x10 HD is very flexible but the residual noise is sometimes audible through highly sensitive drivers, ditto my opendrc-da8. Makes me wonder whether distortion from these units is a factor in the performance I hear in my systems. Hypex doesn't offer standalone DSP any more, and no one else seems to offer any other alternatives.
There is always using a PC to consider, lots of processing power if truly needed.
IMHO, the worst part of most audio DSP boxes are the data converters. Best to avoid them as much as possible. Best to go in digitally so as to avoid an unnecessary ADC conversion, again, if possible.
For the DSP chips, one might want to check the specs for any internal ASRCs. Typically they are not spec'ed as well as the better external ASRC products from TI and AKM, say, SRC4392 and AK4137.
It's true that at the listening position it's not usually an issue, tho my rooms are extremely quiet. With reduced gain, I can't get quite enough volume when desired.
For the record, the ASP I bought from Linkwitz for Orions had almost zero audible hiss from the tweeter even just a few inches away. I guess that's my perhaps unrealistic expectation -- the gear should be silent when it's not singing. But that goes back even to phono/LP days; my gear mostly was silent when idle.
Research what it takes to make a JBL M2 work. Go with the stand alone processor. Used is not too expensive.
It wouldn't hurt to take a look at the 3e Audio DSP unit (LINK). I have one and have been very impressed. It doesn't have a GUI and is programmed using SigmaStudio which might be a problem for some people. I see it as a plus since SigmaStudio has more capability than any pre-packaged GUI (I also have a miniDSP with the advanced 2.1 plug in). Plus 3e Audio provides the source code for their SigmaStudio project.
The DE250 has 19dB more sensitivity than the Seas in the Orion. That ASP would also sound noisy with anything but a perfect gain structure if it were driving a DE250.
Back in the Phono/LP days your system likely couldn't do 120dB at the LP and it would not have had a 100dB SNR. These are not fair comparisons.
Improving on the 103dB SNR that the MiniDSP has won't be the magic solution either because it is not currently defining your SNR.
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Not having heard from the OP yet, it does seem to be a gain matching problem as others have pointed out.
I use the Pass ACA's directly on my JBL 2453h-SL compression drivers as it has only 12 dB of gain and there is only the faintest of hiss when pressing the ear right up to the CD. I have a large protection cap in series to protect against the ACA turn off thumps.
Like jan.didden says, did you short out the input on your tweeter amp to see if the hiss went away? Like cowanaudio says as well, you may need to attenuate your tweeter, either the amp itself or using a passive resistive pad to gain match to the woofer. Or maybe it is the ASP... and tweeter amp combo... Won't know until the OP starts eliminating variables.
I use a i3 miniPC for digital XO, driver time alignment, driver linearization, room correction all in the digital domain. Works great for music server and convolution.
Good luck!
I use the Pass ACA's directly on my JBL 2453h-SL compression drivers as it has only 12 dB of gain and there is only the faintest of hiss when pressing the ear right up to the CD. I have a large protection cap in series to protect against the ACA turn off thumps.
Like jan.didden says, did you short out the input on your tweeter amp to see if the hiss went away? Like cowanaudio says as well, you may need to attenuate your tweeter, either the amp itself or using a passive resistive pad to gain match to the woofer. Or maybe it is the ASP... and tweeter amp combo... Won't know until the OP starts eliminating variables.
I use a i3 miniPC for digital XO, driver time alignment, driver linearization, room correction all in the digital domain. Works great for music server and convolution.
Good luck!
You're right, I'm looking back with rose tints.
I admit the level of noise is very low in my setup. The max gain in the amp is 1.0V for full 40W (x8) and the tweeter hiss is inaudible at 3' most of the time. As soon as the music starts, it's completely moot. I'm just gonna shut up about this now.
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