Jump to content

The job of a pre amp


Recommended Posts



  • Volunteer
5 minutes ago, Happy said:

The apes dont strike me as rocknroll speakers....

But neither the doors...

The Devores were one of the high points of the show for me. Really good on everything Bill threw at them - and to be clear, his demo music is pretty eclectic, not the usual hifi show dross 

Link to comment
Share on other sites



7 minutes ago, Happy said:

Sweet spot is a funny thing with DRC indeed. 

Look at the example I posted.    The have boosted around 200Hz.   This is (very likely) the cancellation of sound reflecting off the floor. 

 

At some other listening locations... the cancellation from the floor is a at a different frequency, and a different number of dB deep ....  so the correct they have applied to get the lovely looking green curve (about 5dB boost around 200Hz) is now wrong, and causing a peak in the response, next to an uncorrected dip.    The transition from peak to nearby dip, causes a huge boost/drop in SPL through that frequency range for a listener sitting in this spot - and this sounds "wrong".

 

8 minutes ago, georgehifi said:

I do believe in dsp for the low bass

It can actually have more problems in the low bass .... because the variation with listener position is usually greater.    So a boost/cut to fix one position .... is more likely to be the wrong boost/cut in another position.

 

9 minutes ago, georgehifi said:

 the mids and highs won't be sterilized

Whether this happens or not, is about how the DSP is programmed.

 

10 minutes ago, georgehifi said:

Trouble is to have the bass done with dsp and the mids and highs done with analog, there is a huge latency problem then, the bass unit would have to be meters in front of the mids and highs.

There are two ways around this:

 

1.   Using DSP does not mean you get any delay by default.   It's the filter shapes which create the delay.    Program filters which do not contain any (or too much) delay.

 

2.    You can apply delay to the mids up .... and no other filtering.    Of course, this does mean that for analog sources, they will need to go through an A to D process.

 

 

 

  • Like 1
Link to comment
Share on other sites

23 minutes ago, davewantsmoore said:

Because the "attempt" wasn't very good....

Given the "attempt" was by implemented & controlled by one of the DEQX principles...

I am reasonably confident he would not agree with that assessment...

Link to comment
Share on other sites

27 minutes ago, davewantsmoore said:

Whether this happens or not, is about how the DSP is programmed.

Not to me, it's the quality of the dac's and surrounding semiconductors that's the problem with the amount of processing going on.

 

There was a very expensive medium stand mount speaker at the Sydney show last year that was hailed as the next best thing since sliced bread, 5 or so drivers with their own amps and full dsp done all within the speaker, it was so cold and sterile and emotionless I couldn't believe that some like it, then again I've heard nothing about it since then even here, so maybe I was right. 

 

Like I said before in my last post, yes do dsp for bass/room, but not the mids and highs, trouble is if you keep the mids and highs analog there is a massive latency problem that can't be fixed I've been there and tried it, so has Art Vandelay. We both were going to do just our bass.

 

Cheers George

Edited by georgehifi
Link to comment
Share on other sites

30 minutes ago, davewantsmoore said:

You can apply delay to the mids up .... and no other filtering.    Of course, this does mean that for analog sources, they will need to go through an A to D process.

Not acceptable to me as it will be a step backwards to what I have now, as my D to A is far more superior and it's done once.   

 

Cheers George 

Edited by georgehifi
  • Like 1
Link to comment
Share on other sites



1 hour ago, Rob181 said:

Given the "attempt" was by implemented & controlled by one of the DEQX principles...

I am reasonably confident he would not agree with that assessment...

 

It's just one possibility for what was reported.

 

The reality is that most acoustic problems cannot be resolved by EQ (DSP), and it is possible to make them worse, especially for seating positions outside a small window.

 

I have discussed this with Alan, with other DSP vendors, and obviously with many speaker (incl. room) designers, who all understand that this statement isn't particularly controversial.

 

 

There's obviously lots of other reasons why someone might not have liked it... 

Edited by davewantsmoore
Link to comment
Share on other sites

 

1 hour ago, georgehifi said:

Not acceptable to me as it will be a step backwards to what I have now, as my D to A is far more superior and it's done once. 

 

Not to me, it's the quality of the dac's and surrounding semiconductors that's the problem with the amount of processing going on.

Sure.

There are possible ways to arrange it so the delay is digital, and you continue to use your high quality DA, and there are not multiple DA AD, etc.

 

1 hour ago, georgehifi said:

massive latency problem

The latency is caused by the type of filters you programmed into the DSP.   Choose filters with appropriate (eg. approaching zero) delay.

 

1 hour ago, georgehifi said:

that can't be fixed

See above.   The delay was your choice.

 

1 hour ago, georgehifi said:

We both were going to do just our bass.

You should  :)

 

Give me a shout if you need any tips....   I won't dive too far into it here, but if you are using filters with lots of delay, there are reasons why that probably isn't a good choice   (in addition to the delay being unacceptable for your specific situation)

Link to comment
Share on other sites

1 hour ago, davewantsmoore said:

Sure.

There are possible ways to arrange it so the delay is digital, and you continue to use your high quality DA, and there are not multiple DA AD, etc.

Not when you have a Linn CD12 .

 

Cheers George

Edited by georgehifi
Link to comment
Share on other sites

  • Volunteer
3 hours ago, georgehifi said:

There was a very expensive medium stand mount speaker at the Sydney show last year that was hailed as the next best thing since sliced bread, 5 or so drivers with their own amps and full dsp done all within the speaker, it was so cold and sterile and emotionless I couldn't believe that some like it, then again I've heard nothing about it since then even here, so maybe I was right. 

If you are referring to the Kii threes, I’ve heard them in a couple of setups and imho they are astonishingly good. 

As for expensive, I guess that’s relative. Given that you have speaker, amps and dac all in one, I think they are actually very good value. 

Link to comment
Share on other sites

1 hour ago, georgehifi said:

Not when you have a Linn CD12 .

As a semi tongue in cheek suggestion (because it's a PITA, and has limitation but) .... you could do what some of the purist crew do.

 

Copy the CD to an audio workstation.  Edit the audio so it is filtered as you require, and copy it back to a CD.

Link to comment
Share on other sites



Nah!

I still can't see doing just bass DSP room correction without ruining the purity of the mids and highs as they are now.

The only way as Arty thinks (which is hypothetical) is to move the bass forward a couple of meters in front of the ESL panel. Same with him and his B&W 800 D's

 

Cheers George

Edited by georgehifi
Link to comment
Share on other sites

23 minutes ago, georgehifi said:

I still can't see doing just bass DSP room correction without

Cool, so you didn't understand what I was suggesting?  (re: editing the CD - which admittedly is a pain in the bum).

 

 

... or, if you're not sure how to create filters which don't have any latency, then just ask  :) 

Edited by davewantsmoore
Link to comment
Share on other sites

1 hour ago, georgehifi said:

I still can't see doing just bass DSP room correction without ruining the purity of the mids and highs as they are now.

The only way as Arty thinks (which is hypothetical) is to move the bass forward a couple of meters in front of the ESL panel. Same with him and his B&W 800 D's

Unless your DAC IS the DSP and then everything is consistently at the quality of your DAC itself. That's my approach with my DSPeaker DAC. It does some room correction for midrange and treble as well but is usually minimal compared to what it does in the bass range.

Link to comment
Share on other sites



 

I thought I did a reasonable reply to the OP but i see things have gone way off topic but i can't delete my post now, sigh.

Edited by kenwstr
Discussion has gone way too far off OPs topic
Link to comment
Share on other sites

  • Volunteer
1 hour ago, davewantsmoore said:

 

 

 

For example...

The Kiis don’t have a latency problem because in general you don’t need a sub with them so there’s nothing to integrate. It’s all there in the one box. 

 

As as far other room correction goes, I guess you just need to time-delay the frequencies that aren’t being “corrected”. Of course this means everything (potentially) goes through a digital conversion. I’ve heard and owned speakers that do this, and there is absolutely no issue - you simply cannot tell that there’s an extra step in the chain.

Of course, if you are starting with a digital file then there is no extra conversion at all. 

Edited by Sir Sanders Zingmore
Link to comment
Share on other sites

1 hour ago, davewantsmoore said:

Cool, so you didn't understand what I was suggesting?  (re: editing the CD - which admittedly is a pain in the bum).

 

 

... or, if you're not sure how to create filters which don't have any latency, then just ask

Anything else you will suggest will not give the mids and highs in this untouched order Original CD > Linn CDP > pre > mid/high poweramp > esl. Anything else you suggest to me will be a compromise.

 

Cheers George

Link to comment
Share on other sites

6 minutes ago, georgehifi said:

Anything else you will suggest will not give the mids and highs in this untouched order Original CD > Linn CDP > pre > mid/high poweramp > esl.

 

Yes, what I have suggested will give you that.    Although it won't be the original CD.    The only difference between the original CD will be that the bass has a filter applied to it  (just like you are trying to do).   The mids and highs will be untouched.

 

At playback, there will be no DSP in operation, no extra/different DA happening ....  not for the bass, and not for the mid/high either.   It will be all "pure analog" from your CD player onwards.

 

If you understand that, but your only objection is to a "copied" CD, as opposed to the real original disc.....  then, well there's an impasse.    I've not found copied discs to sound inferior.

 

 

One "cool" thing about this way.... is that you can record a disc with copies of a track which has no filter, bass filter, 2nd bass filter, whatever....  and you can skip between tracks, and hear exactly the sound of filter vs no filter (or whatever filter).    It takes uncertainty out of the equation when people are unsure if they don't like the "filter", or if they don't like all the extra DA AD, noisy DSP, etc. etc. that could be responsible.

 

Link to comment
Share on other sites

25 minutes ago, Sir Sanders Zingmore said:

The Kiis don’t have a latency problem because in general you don’t need a sub with them so there’s nothing to integrate. It’s all there in the one box. 

Sure they do (I guess it depends on how you define "problem").    The default filters in the Kii Three introduce a large amount of latency ....  the reason is due to the specific filters chosen.

 

Kii offer a second filter option, which is designed with no delay  (at the expense of low frequency phase correction, which is not possible without introducing delay).

 

 

The point I was trying to illustrate, was that "DSP doesn't mean delay problem".    Filters (of all types, analogue, passive, active, DSP, whatever) make delay based on their shape.

 

25 minutes ago, Sir Sanders Zingmore said:

As as far other room correction goes, I guess you just need to time-delay the frequencies that aren’t being “corrected”.

Sure.    If you split your audio in half.... and send one half through a filter which introduces significant delay .... then you would need to delay the other half too.

 

25 minutes ago, Sir Sanders Zingmore said:

Of course this means everything (potentially) goes through a digital conversion.

You could apply the delay while the audio was still digital  (ie. before DAC) .... but if you can't do that, then a constant delay with frequency basically requires converting to digital  ('cos you have to "store" the audio somewhere while you wait for time to pass).

 

25 minutes ago, Sir Sanders Zingmore said:

I’ve heard and owned speakers that do this, and there is absolutely no issue - you simply cannot tell that there’s an extra step in the chain.

Sometimes that extra step can be audible .....   and often people believe it will be.

Link to comment
Share on other sites



  • Recently Browsing   0 members

    • No registered users viewing this page.




×
×
  • Create New...
To Top