Is it Really Worth It?

[KEM]

Right now, I have a (mostly) all-analog system.

Only exception is the Oppo BDP-105 and Bryston BDA-3 for digital files and media. No streaming. I am very pleased with the sound.
My listening is divided about half and half between LPs and CD/SACD/Digital files with a bit of FM radio thrown in.
I have used REW to assist me in placing the speakers, the sub and sound traps (Real Traps products). For the final tweaks I gently used a graphic equalizer (dBx 1231).
I've managed to tame all but one room mode.
Frequency response is"flat" to about 2KHz where I let the FR drop faster than the suggested curve since I have aversion to high frequency sizzle.
Phase response is not minimum phase. There's many more 360 phase shifts than are predicted for a minimum phase system. She attached graph.



OK. Great. But now I'm wondering if the sound would be even more enjoyable than now using a DSP for room correction (keeping the traps) and for crossover. This would eliminate my trusty, great sounding ML#38s pre, dBx EQ, Sublime Acoustic K231 crossover (75Hz) and Bryston BDA-3. In place I would have the MiniDSP Flex Balanced or SHD. II guess I could just buy one and get the answer. But I'd like to hear about other journeys such as mine before I spend the money.

And is all that excess phase shift wreaking damage to my sound?

I am quite emotionally attached to all my components and need a significant amount of persuasion before I replace any component. I have tried a few other pre and power amps, but have always come running back because the sound didn't get better, got worse, or brought other unwelcome problems.

Don't be shy about being overly technical. I have an MS in Physics (Optics/Electronics) and have spent my entire career doing product development.

Thanks for your attention!

Rest of System:
1. Technics SL-1200G TT
2. Parasound phono pre
3. Bryston 2.5B^3 power amp
4. Revel f208 Floorstanding speakers
5. Hsu ULS-15 Sub.

 

[staticV3]

Replacing a bunch of noisy ASPs with a single, transparent and mathematically perfect DSP is something that audio enthusiasts in the past could only have dreamt of.

The scary part is that it's up to you to put the capabilities to good use (or up to your wallet, with Dirac).

It's totally possible that after your first go at digital room correction, you'll end up preferring your old setup. Practice makes perfect.

Though in my mind, there's no question which setup has greater potential for sound quality.

For starters, I think https://www.loudspeakers.audio/en/ offers an extremely compelling solution that's easy to use, powerful, and completely free of charge.

At the other end of the UX spectrum, there's OCA's YouTube tutorials for fully manual correction: https://youtube.com/@ocaudiophile

 

[terryforsythe]

I got miniDSP SHD about 2 years ago, and I was sold. The control over crossover frequencies, crossover topologies, crossover slopes and time delays helped me get a speaker/subwoofer crossover transition better than I could before, and using DSP for room correction was a game changer for me.

This year I went further. I pulled out my passive crossovers, sold my SHD, and got a Flex HTx (8 channel) and additional amplification. Now I am all active. My system sounds fantastic.

 

[kemmler3D]

now I'm wondering if the sound would be even more enjoyable than now using a DSP for room correction (keeping the traps) and for crossover

Short answer: Yes. You've got quite a few 5+dB swings in the bass, some approaching 10dB. This is definitely audible.

I think cleaning up the room mode region is more impactful than you would guess intuitively. If you want some subjective mumbo-jumbo about it: The timbre of instruments seems more vivid and realistic when the fundamentals and lower harmonics are all in good alignment. This gives you the impression of the whole sound improving, not just bass. This is not really possible without PEQ, so I definitely recommend you give it a try.

 

[KEM]

Short answer: Yes. You've got quite a few 5+dB swings in the bass, some approaching 10dB. This is definitely audible.

I think cleaning up the room mode region is more impactful than you would guess intuitively. If you want some subjective mumbo-jumbo about it: The timbre of instruments seems more vivid and realistic when the fundamentals and lower harmonics are all in good alignment. This gives you the impression of the whole sound improving, not just bass. This is not really possible without PEQ, so I definitely recommend you give it a try.

I've tried PEQ with RANE hardware. Really messed up the distortion and phase. Could you elaborate on what exactly makes PEQ better than GEQ or none at all?

 

[Jim Taylor]

OK. Great. But now I'm wondering if the sound would be even more enjoyable than now using a DSP for room correction (keeping the traps) and for crossover.

When you say, " ... even more enjoyable ...", what sort of improvement do you expect to be audible?

Jim

 

[KEM]

When you say, " ... even more enjoyable ...", what sort of improvement do you expect to be audible?

Jim

I don't have an agenda. Maybe I'll know it when I hear it. Like, is al that phase variation I have messing the quality of sound?

 

[Jim Taylor]

I don't have an agenda. Maybe I'll know it when I hear it. Like, is al that phase variation I have messing the quality of sound?

When I consider an upgrade, there are specific issues on which I focus. It seems that your methods are different from mine. I apologize, but I don't believe that I can help you.

As you mentioned earlier, you may need to purchase a DSP unit and simply see what it can do.

I wish you the best of luck!

Jim

 

[kemmler3D]

Could you elaborate on what exactly makes PEQ better than GEQ or none at all?

So yeah, basically every room has peaks and nulls in the bass response. So at a given seating position it's not uncommon to have +/- 10dB or more from 20-300hz (give or take.)

The reason PEQ is so important is you can select the frequency of each band. With GEQ the frequency is fixed. Most of the changes you'll usually need to make are between 20-200hz, on a GEQ you're lucky to have 4 bands in that range, but it can often take 10 or more bands to really flatten the bass. Also, you need to get extremely lucky to have a GEQ band line up exactly with a peak, with PEQ you simply dial it to the correct frequency.

PEQ also allows you to choose the width of the band, which is obviously critical to avoid affecting frequencies that don't need changing.

Also, GEQ and PEQ work on the same principle and assuming the same filter types are used, should give you the same phase distortion for a given adjustment.

Lastly, phase distortion is not desirable per se, but in the bass the phase is hard to hear and also usually jacked to hell by the room anyway, so it's worth the trade-off to get the frequency response right.

And if you are truly concerned about phase distortion, DSP lets you adjust that separately via FIR filters or allpass filters. So it's pretty much a win all around.

As for distortion, you mostly need to be careful to leave enough headroom for the adjustments you're making. If your speaker or amp doesn't have anything more to give when you try to boost (say) 30hz, yeah, you're going to get distortion, but that's not inherent to EQ.

 

[MaxwellsEq]

For the final tweaks I gently used a graphic equalizer (dBx 1231).

For an analogue graphic equalizer, this is probably as good as it gets. But, even the best analogue graphic equalizers cannot begin to compete with a quality equivalent using DSP in terms of measured performance depredation.

When you factor in digital Parametric EQ, which allows the frequencies to be specifically selected, along with the Q and often the processing choices, digital PEQ is simply a no brainer compared to even the best analogue graphic equalizers.

 

[Mr. Widget]

Right now, I have a (mostly) all-analog system.

Only exception is the Oppo BDP-105 and Bryston BDA-3 for digital files and media. No streaming. I am very pleased with the sound.

Then why change anything? Even though it is certainly possible to improve your system's performance objectively, there are no guarantees of you getting more pleasure from your system.

I've tried PEQ with RANE hardware. Really messed up the distortion and phase. Could you elaborate on what exactly makes PEQ better than GEQ or none at all?

As others have pointed out, a PEQ is far more useful than a graphic, but the learning curve can take some patience and they are not for everyone. That said, when I was 100% analog, I used a Meyer Sound CP-10 analog PEQ because graphics are just too limiting.

 

[KEM]

Then why change anything? Even though it is certainly possible to improve your system's performance objectively, there are no guarantees of you getting more pleasure from your system.

As others have pointed out, a PEQ is far more useful than a graphic, but the learning curve can take some patience and they are not for everyone. That said, when I was 100% analog, I used a Meyer Sound CP-10 analog PEQ because graphics are just too limiting.

That's intriguing. I've also used the Rane

When I consider an upgrade, there are specific issues on which I focus. It seems that your methods are different from mine. I apologize, but I don't believe that I can help you.

As you mentioned earlier, you may need to purchase a DSP unit and simply see what it can do.

I wish you the best of luck!

Jim

I am an experimenter. Sometimes I make a change in order to find out something. For example::

1. Is having excess phase a problem?
2. Does the SHD fix excess phase?
3. Will I like the sound if my system has both A/D and D/A for every input? I.e. no pure analog path.
4. Is the SHD an upgrade or a different approach?
5. Will I ever be able to grasp the silly computer geek acronyms? Should I even try?
6. I have about half the room covered in traps, mainly corner and wall. How will the SHD work in is circumstance?

There's something wrong (in my mind) with hooking a computer up to music. As soon as one does that, the music can be made to sound like whatever the user wants it to sound like, which is often not what what the musicians or the mastering folks intended. In this sense one could call digital "artificial". Please note that I do listen to digital. There's no computer in my system.

These are a few of the questions I'd like answered. Of course, it's best if I just bought the SHD and played around with it. But I could spend the $1K on something else. I don't want to make another expensive mistake.

I don't have an agenda. I do have enough time to give the SHD a try.

The reason for the original post was to listen to what others' experiences were before I jump in headfirst. That's because when I do jump in headfirst, I am all in. I need to assess if the added confusion is worth the considerable effort.

It seems that I didn't word the original post to obtain replies I wanted..
I am interested in what others experienced during the change from all analog to all digital.

Is it worth it?

 

[KEM]

Short answer: Yes. You've got quite a few 5+dB swings in the bass, some approaching 10dB. This is definitely audible.

I think cleaning up the room mode region is more impactful than you would guess intuitively. If you want some subjective mumbo-jumbo about it: The timbre of instruments seems more vivid and realistic when the fundamentals and lower harmonics are all in good alignment. This gives you the impression of the whole sound improving, not just bass. This is not really possible without PEQ, so I definitely recommend you give it a try.

Could you provide some insight on how I can smooth out the "semi-periodic" FR variations from 20-200Hz using a PEQ? It only has 5 bands. A low Q filter would not smooth the bumps out. I could use all five of the PEQ modules on just this region. Is this desirable?
Thanks!

 

[kemmler3D]

1. Is having excess phase a problem?
2. Does the SHD fix excess phase?
3. Will I like the sound if my system has both A/D and D/A for every input? I.e. no pure analog path.
4. Is the SHD an upgrade or a different approach?
5. Will I ever be able to grasp the silly computer geek acronyms? Should I even try?
6. I have about half the room covered in traps, mainly corner and wall. How will the SHD work in is circumstance?

1. Only if it's a huge swing in phase and/or group delay. Normally phase distortion is difficult to hear.

2. I think it can, although it's somewhat a separate process.

3. Let me put it this way. If elves snuck into your room at night and added the A/D D/A converters, you probably wouldn't notice any change in sound. But if you don't like knowing that there is digital stuff in your signal path, it may sound worse to you because your mind expects it to sound worse. Only you can really decide on that point.

4. There are many ways to skin the DSP cat. The SHD is a good way to do room correction, it is far from the only way. You could try it out (on a limited basis) with a $80 WiiM Mini, by doing measurements with a $100 UMIK and manually inputting the filters, to see if you like it.

5. Sure you can, whether it's worth the effort is a matter of taste.

6. Honestly it will probably work better than if you didn't have traps. The traps should help keep the decay time down, once you knock down the peaks in response with EQ it should sound pretty great.

There's something wrong (in my mind) with hooking a computer up to music. As soon as one does that, the music can be made to sound like whatever the user wants it to sound like, which is often not what what the musicians or the mastering folks intended.

I definitely understand this point of view and somewhat share it myself. I look at it like this. The nice thing about digital is the bits are virtually guaranteed to go out the same way they came in - as the artist intended. As for EQ, I use it to correct the flaws my room introduces. This is also getting closer to what the artist intended, not further away.

Can you introduce all sort of special effects and nonsense with a computer? Absolutely. But just don't do that, problem solved.

 

[kemmler3D]

Could you provide some insight on how I can smooth out the "semi-periodic" FR variations from 20-200Hz using a PEQ? It only has 5 bands. A low Q filter would not smooth the bumps out. I could use all five of the PEQ modules on just this region. Is this desirable?
Thanks!

From what I can see the SHD has 10 bands of PEQ per channel.

Using the graph you posted for example, you have peaks at 42, 55, and 98hz. I would set a filter at each of those frequencies with a gain of -3dB (give or take) and a Q of about 1.2, again just for starters. You can use higher-Q filters in the bass.

And yes I would say it's more desirable than you'd expect!

However, I think the Dirac software on the SHD does all of this for you. This is what you can do with pretty much any PEQ, I don't use Dirac but I think it's a little more sophisticated than that.

Also, I am not sure if you have subs or not. Those really help by moving the sources of bass frequencies around and creating the possibility of filling in nulls. They say you can't EQ out a null (true as far as it goes) but you can use subs to pump up the bass high enough that you EQ everything down including the nulls.

 

[MaxwellsEq]

It seems that I didn't word the original post to obtain replies I wanted..
I am interested in what others experienced during the change from all analog to all digital.

I was working in recording studios when they went from highest quality analogue recording on tape to recording using ADCs and computer based storage. There was a significant improvement in measured performance and it sounded more accurate when comparing the artists to the recordings.

I'm not sure if that helps you. You may , for instance, prefer the poorer quality analogue sound. After all, enjoyment is the point of this exercise, and preference plays a part.

 

[KEM]

From what I can see the SHD has 10 bands of PEQ per channel.

Using the graph you posted for example, you have peaks at 42, 55, and 98hz. I would set a filter at each of those frequencies with a gain of -3dB (give or take) and a Q of about 1.2, again just for starters. You can use higher-Q filters in the bass.

And yes I would say it's more desirable than you'd expect!

However, I think the Dirac software on the SHD does all of this for you. This is what you can do with pretty much any PEQ, I don't use Dirac but I think it's a little more sophisticated than that.

Also, I am not sure if you have subs or not. Those really help by moving the sources of bass frequencies around and creating the possibility of filling in nulls. They say you can't EQ out a null (true as far as it goes) but you can use subs to pump up the bass high enough that you EQ everything down including the nulls.

I was thinking about analog PEQs which have a max of 5 bands. I have two Rane mono PE-17 units. I should drag them out and play around. They do not have phase adjustment separate from the filter action.
I have an HSU ULS-15 sub with built in amp. You've got a good idea there on the sub placement.

A good way to to this is to play a pink noise file and capture the sound with a mic and display on a RTA, (such as the one REW has) while adjusting the PEQ. I can focus on the sub 200Hz area first.

 

[kemmler3D]

I was thinking about analog PEQs which have a max of 5 bands. I have two Rane mono PE-17 units. I should drag them out and play around. They do not have phase adjustment separate from the filter action.
I have an HSU ULS-15 sub with built in amp. You've got a good idea there on the sub placement.

A good way to to this is to play a pink noise file and capture the sound with a mic and display on a RTA, (such as the one REW has) while adjusting the PEQ. I can focus on the sub 200Hz area first.

Oh, makes sense. Yeah, if you have an analog PEQ then it's worth a shot! I would love to see the before/after from REW, you don't see analog PEQs everyday. I think 5 bands is enough to make a good dent in things.

 

[terryforsythe]

From what I can see the SHD has 10 bands of PEQ per channel.

Plus it has Dirac Live for room correction. Dirac Live can be used, PEQ can be used, or both can be used.

Assuming that for each of the left and right stereo channels you use one output channel for the subwoofer and one output channel for the speaker amplifier, you end up having 20 bands of PEQ for the left stereo channel and 20 bands of PEQ for the right stereo channel. I found that to be more than adequate, especially being used in conjunction with Dirac live.

Also, I think biquads can be added to the crossovers for additional PEQ bands. (My Flex HTx has that functionality - but I never tried it with my SHD). To do so, though, the crossovers also need to be specified as biquads, so it is a little more complicated.

 

[KEM]

OP here.

I used the EQ inside REW to equalize the data I showed in the first post. I did find an approach that would flatten the FR, but the time domain was untouched.
Also, I had REW create a minimum phase version of the same data. It did a great job on all time factors, but didn't change the FR.

Is this the way audio DSP works? I can never correct both the frequency and the time domain responses? If this is the case, then audio DSP is not for me.