Your thoughts on DSP units, I have my own conclusions

[zinda]

Recently there's been lots of talk involving DSPs to put the cherry on top of a system so to speak. Using it mostly as I saw for subwoofers and room correction. I had an opportunity to get full use out if one of these so I figured why not?

My system uses a pre amp, dual 25 band eq (with spectrum display, pink noise and pure tone generator with single or sweep plus a microphone input to do testing - so I have something to check back to see where things are going), a 3 way active crossover, 3 separate 500w RMS 2 channel amps feeding 2 - 3 way DIY speakers. I figured I could take full control over the entire system and replace 2 components right away in the process opening up a large space too.

Fully understanding what they do and what the terms that they use to work with these things I saw it to not be an issue with setting it up quickly to get a starting point. Setting crossover points and assigning them to outputs, even putting a bit of eq in place mimicking what I had already found to work for me. Of course this all needs to be done using your computer so that means long rca cables, converting rca to mini headphone and back blah blah blah. After rounding cables and changing my stereo around I had a mess of rca cables that needed to be changed to 1/4" or XLR! So after another 6 hours of making cables I was ready to get started. At first I hear nothing, then check through the huge pile of wires and recheck which amps went to each output and tried again only to hear what sounded like it was bring sent through a tin can before the amps. Back to the computer. What a pain in the ass!

So if everything is set right what do I change to make it sound like I did a few hours ago? Well I couldn't get it to sound anything like it did so I figured I'd turn off everything and just let it run full range with no eq. Connected it and it still didn't sound right. Everything flat ran into my 3 way crossover and it was altering the sound beyond comprehension? Back to the computer checked every for defeat. Yup! Ok try something different using a mic to see if my changes are actually affecting what they show they should be. Nope.

2 more days of struggling to figure out why it's ruining my sound and I download a freeware program with rta fir the comp. Well the first thing they want me to do is test my computer to make sure it can even be used for this purpose. Funny but I wasn't told to do that with the DSP but it made full sense to do this in my mind. After a few tests I find out that my top of the line Realtech sound chip on my gaming motherboard has a high level of distortion on 1 channel as it passes sound through the mapper and back into the card. Next was to find out if it is on the output or input. At this point I didn't even care. I tried to see if it could be masked and no, my computer was unable to work properly with audio? Funny how the DSP had no concern to tell me that I should be running tests first, but that still didn't explain why the sound was bad even running it by itself?

So after 3 days with nothing to show but a pile of cords that I wasted time making it went back. S few months later I see ==er DSP that I can use all features and this one could be set without a computer since it has a read out onboard and Bluetooth with an app for the phone. This time I was able to use regular cables running to a strip connection which made it way easier to set up since I was already using that input I was ready to go quickly. Once again the set up was straight forward and I did a quick crossover set up or do I thought it would be. The 3rd channel would not accept the new setting at the low end. I tried 10 times and finally skipped it and did the 4th 5th and 6th. Than returned to 3 and after 8 more tried it moved closer but still not where I put it. I turned it off and on then tried a few more times and I was able to set it but then had difficulty changing the slope. Eventually it changed and I was ready to plug the amps I to it.all volumes and input levels are zero and turned on the pre and started music. My outboard eq that was disengaged from the I put showed sound.

I turn up the input on the high amp and it sounded weird but I figured it's just playing the tweeters and very low volume . I turn on the mid amp with inputs down at zero I start to turn both dials and I hear this ripping noise coming through the mids on one side or both I turned everything off by pulling the power on the DSP.

Checked all settings and connections same thing. Set everything flat, connected another amp I wasn't using and a set of full range speakers up to channel 1 and 2, it worked but it sounded like it was playing through another tin can!

At that moment I decided that I wasted enough time with these worthless items and promptly packed it up to send back the first was a miniDSP the 2nd was an Expert connect p2. Without even considering anything else but the AD-DA working at only 24 bit I can't see these things being worth the time to even consider. The expert also gave a loud pop when I adjusted the low crossover point that send sound though every driver at full power. If I was using any other type of tweeter than electrostats they would have been killed.

I read these stories of these huge improvements using these but I have to wonder how terrible did their system sound prior to that? I changed mine back and was able to get it within reason in 15 minutes using 40 year old equipment that is dead silent and 100 percent analog! Simple turn of a dial or slider while watching the display and that was it! Has anyone ever really used these with any real success?

 

[JoeESP9]

I use a DSP. It was adjusted and set using results derived from REW. It handily does what I tried to make analog linear equalizers do for quite a few years.

I've always used an equalizer to try to correct for room acoustics using measurements. My current DSP is used in the same way. I measure, set and forget. Using an equalizer as an elaborate tone control is not my style

 

[gvl]

I haven't tried running a full DSP crossover yet, but a simple convolution filter based on EQ in REW has elevated my listening experience without a doubt. All you need is a measurement microphone and a software player that has PEQ or can load a wav file with correction impulse response, for computer source anyway.

 

[stoutblock]

Once you get your room and system as good as possible, a high quality DSP combined with RTA and something like REW or Dirac Live will take it over the top. DSP will make it sound better but will not fix a bad system.

 

[JoeESP9]

Once you get your room and system as good as possible, a high quality DSP combined with RTA and something like REW or Dirac Live will take it over the top. DSP will make it sound better but will not fix a bad system.

It's the icing on the cake!

 

[Poultrygeist]

I try to avoid any device in the signal path that imparts its own sonic signature.

 

[JoeESP9]

I try to avoid any device in the signal path that imparts its own sonic signature.

By it's very nature a DSP is supposed to impart a sonic signature. If it didn't there would be no reason to have one.

IME, a properly implemented DSP used for room correction always improves the sound.

 

[RobRoy]

By it's very nature a DSP is supposed to impart a sonic signature. If it didn't there would be no reason to have one.

Yep. This is why, as an audio purist, I only listen to music on wax cylinders or acoustically recorded 78's on a wind up Victrola.

I get pure sound with no electronic sonic signature.

 

[RobRoy]

Apparently DSP is big in car stereo.

 

[JoeESP9]

Yep. This is why, as an audio purist, I only listen to music on wax cylinders or acoustically recorded 78's on a wind up Victrola.

I get pure sound with no electronic sonic signature.

I get it. No Watts is the new distortion free way to listen.

 

[whoaru99]

One can cerebrate all they want about bits, sample rates, DSP, ADC, DAC, eqs, tone controls, passive, active, blah... blah... blah.

At the end of of the day none of that matters f@#k all to me. What matters is if it sounds better to me with or without it, whatever it is.

 

[gvl]

I try to avoid any device in the signal path that imparts its own sonic signature.

Thing is, your speakers and the room have their own signature and chances are it's very far from ideal. DSP can be used to actually improve all that by counteracting those issues by injecting negative signature, if you will, that when summed with your speakers signature overall produces better characteristics.

 

[Poultrygeist]

Thing is, your speakers and the room have their own signature and chances are it's very far from ideal. DSP can be used to actually improve all that by counteracting those issues by injecting negative signature, if you will, that when summed with your speakers signature overall produces better characteristics.

Have you tried a miniDSP with a single ended triode amp powering highly resolving speakers? Any additional device you add to that signal path is audible and in the case of the miniDSP can literally kill the magic of a SET amp. It's effect is not as noticeable with SS amps. The crossover function of DSP wouldn't be needed in a couple of my FR speakers which run straight off the amp without filters or crossovers that mar the sound. Open baffles and near field box speakers can also be effective in reducing room effects.

 

[Roc Doc]

I have a buddy that was rebuilding a small house, but he wanted a big flat screen TV and in-wall speakers, tile floors, granite countertops, lots of windows, etc... He bought the then top of the line Integra with the latest Audyssey suite, 4 Crown XTI amps, and the big Def Tech in-wall L-R-C and two of the in-wall subs. I ran the room correction a couple times and the system still sounded like in-walls, so I ran SMAART and with a second laptop logged in to the DSP of the amplifiers, it took a bunch of EQ and delay (even though all the speakers were mounted in the same wall)., to get it to even out. Now it's stupid loud, but sounds great at lower volume as well.

DSP has it's place. It's no substitute for proper room acoustics, or system design, but for him it was a good solution.

 

[charles 1973]

If your using a dsp to compensate for room acoustics and speaker response and it's done properly that is a good thing. Hopefully without getting in the way of transpency. Both my Yamaha AVRs sound much better with them on. This at least provides a baseline from where we can make some changes to suit our taste or compensate for hearing loss as we age.

If you're using one to change the fundamental sound, Like the many matrix surround sound modes on most AVR's then good luck. Of all the ones on my 2 recent AVR's none are very satisfying for normal listening. The folks at Onkyo had the wisdom to keep their matrix surround modes to just small changes 20 years ago so some of them where actually pleasant using their 575x AVR if I choose to. Mostly though I listened in stereo.

 

[invalidbuffa]

I've tried several DSP devices in my A7 system over the years ranging in price from the $100 miniDSP to a $1500 rack/studio model I can't remember the name of. They provided an easy way to balance the low frequencies in a room, however they all exhibited to different degrees the side effect of depleting music of presence and realism. DSP is a good idea for subwoofers but I haven't found one that I like for full-range application.

 

[JoeESP9]

My DSP is in the feed to my subwoofers only. It's used for bass equalization only.

 

[whell]

It's the icing on the cake!

I try to avoid any device in the signal path that imparts its own sonic signature.

Nothing like a diversity of opinion on a topic.

I'd tend to side more with the crowd that would rather follow best practices to adjust room acoustics than try to use someone else's algorithmic solution, where sonic samples taken with a microphone are then subjected to equalization that I may or may not ultimately like.

Kind of like making a stew: I'll add or subtract from a recipe based on my tastes. If I buy someone else's stew, I might like the way it tastes at their house, but if I bring some home and reheat it, it might taste different at my house. I might not like how it tastes at my house, but by then I'm stuck with it.

 

[JoeESP9]

Nothing like a diversity of opinion on a topic.

I'd tend to side more with the crowd that would rather follow best practices to adjust room acoustics than try to use someone else's algorithmic solution, where sonic samples taken with a microphone are then subjected to equalization that I may or may not ultimately like.

Kind of like making a stew: I'll add or subtract from a recipe based on my tastes. If I buy someone else's stew, I might like the way it tastes at their house, but if I bring some home and reheat it, it might taste different at my house. I might not like how it tastes at my house, but by then I'm stuck with it.

Do and use whatever makes you happy.

What I'm sure of is, adding a properly adjusted DSP to a dedicated and treated room got me closer to my reference. That being live orchestral acoustic music performed in a concert hall.

The settings I use on my DSP were measured using REW, a calibrated mic and a laptop. Then set. Once set no tweaking is done. What's interesting is, my measurements and what the auto eq on my pre/pro sets are within 1dB of each other.

Since the late 70's any linear equalizer or DSP that I've had was set using measurements. Doing so has always resulted in an improvement to the sound. For me all eq's and DSP's are used in a measure, set and forget mode. Also, I haven't had tone controls since I sold my ARC SP-3 in the early 1980's

I suppose I'd feel different if my primary musical interests were pop/rock/blues. So much of it is poorly recorded. Such is usually not the case with Opera, Classical or Jazz.

The better my system does orchestral music the better it does everything else. Flat to 18Hz is the same for movies and music.

I have only one question. Why would you not want a system that's as neutral (transparent) as possible to start with?

 

[whell]

I have only one question. Why would you not want a system that's as neutral (transparent) as possible to start with?

What leads you to believe I don't?