Advice for users of analog inputs (only) of the DSPeaker AntiMode Dual Core

[Guidof]

As a result of a recent exchange of emails with DSPeaker support in regard to the internal resolution of the device, I became aware that if one uses only the analog input (in my case connected to the analog output of my Benchmark DAC2 -- see sig), it is then possible to decrease the automatically calculated headroom. I experimented with this, and decreased the headroom from 6dB to 3dB.

 

This produced a startling overall improvement in the already excellent sound quality of my setup. What I hear as a result is greater clarity, even more accurate timbres, a more precise soundstage, and more realistic musical presentation.

 

If you are a DSPeaker user and have only the analog input connected, it may be worthwhile to try reducing the calculated headroom. I think you would be pleasantly surprised with the results.

 

Regards,

 

Guido F.

[gnobber]

how do you make the adjustment, Guido?

[Guidof]

how do you make the adjustment, Guido?

 

Settings Menu>Audio Settings>Headroom

 

Guido F.

[Regnad]

So, wow, thanks for that! Even though I did RTFM I glossed over this setting. It also seems to me like an improvement but there is also a volume increase so will listen more. Mine was set at 10 or more and I have it at 3 now. For fun, have a listen to the highest setting.

 

I would like to understand exactly what this is doing. I will contact DSPeaker but have you any info?

[Guidof]

I have not inquired with DSPeaker, but I assume that it frees up a few bits and thus affects the resolution with which the signal is processed internally. Do let me know if you find out anything from them.

 

Guido F.

[Guidof]

BTW, I also noticed an increase in volume with the decrease in headroom. I have no idea why this should be . . .

 

Guido F.

[Regnad]

Here is the response to my question:

 

"Usually more volume means better sound, as our auditory system is hearing "more". So in order to have a fair comparison you'd need to lower the master analog volume controller of the AM2DC to compensate the amount of dB's.

 

However, in technically you are right. Smaller headroom means wider average wordlength for the signal, and with analog in&out it is usually recommended to lower the headrooom even all the way to 0dB (or as low as possible as long as there is no signal clipping).

 

The headroom is more necessary for the digital input/output as they are always max scale by definition, unlike the analog signal that depends on the source output voltage. Hence the analog signal inherently already contains some "headroom" and doesn't require as much more as the maxed up digital signal.

 

Note that you must set the headroom manually to lower setting after you touch any filter, as the automatic will override the manual setting whenever you design a filter, including changing the Quick-Tone. This is something we have considered to change in the future firmware as most people would prefer manual override being permanent."

[Guidof]

Thanks, Regnad. Have not tried the 0 dB headroom yet! But I will tonight.

 

Guido F.

[Regnad]

I will add my vote for a firmware change as it is a nuisance to bump the bass and then have to go to the menu. Also, I lowered the master volume from 0 to -6 to compensate and the level is the same now.

[Guidof]

OK, I tried the 0dB headroom, with no mishaps. I hear a more three-dimensional sound stage and enhanced clarity. Going from 3dB to zero there does not seem to be the increase in volume as when going from 6dB to 3dB. Anyway, my AM2DC volume control is always set for no attenuation; I use the volume control in my Benchmark DAC2 for selecting gain; it works very well.

 

Guido F.

[islandman]

I have an opportunity to buy a McCormack MAP-1 (multi-channel analog pre-amp). Will the duo core work being placed between a DAC and analog pre-amp like this?

 

The signal path would be DAC (RCA outs) > Duo Core (RCA ins) > Duo Core (RCA outs) > MAP-1 (RCA ins) > MAP-1 (multiple RCA outs to power amps and sub). In this configuration would the duo core work on all the bass frequencies going to all the speakers and sub below the upper cut off frequency? Is there any reason this will not work?

[Guidof]

The Dual Core is a stereo unit that works in pure stereo (2.0) or stereo plus subwoofer (2.1). Thus it would work with the MAP-1 only if you used the latter in a 2.0 or 2.1 system. It would not work to correct a 5.1 system, for example.

 

Regards,

 

Guido F.

[islandman]

ok Guido, thanks for the response.

[islandman]

Ok, another question. Let's forget the MAP-1 for the moment. In, another system I run

 

computer (USB) to

DAC ( L/R - RCA outs) to

AVR (L/R - RCA ins).

 

Triinov that is in this processor can divide this incoming stereo signal into 5.2 in a number of ways so that from just a stereo incoming signal I can have sound coming from all 5 speakers, and the subs. What if I inserted the duo core between the DAC and the AVR using just stereo RCA's? Would this work?

[Guidof]

I'm not sure, but I suspect it won't work. The correction feature of the Dual Core depends on measuring a 2.0, 2.1, or 2.2 'system', where by system it is meant the interaction of a 2.x speaker array AND the room they are in. With a multichannel system, regardless if the multichannel was the result of processing an original stereo signal, the interaction of speaker output and room would be totally different from a 2.x system and thus unlikely to generate the desired correction. In other words, the algorithm that generates the desired correction depends on measurement of a stereo setup.

 

But you may want to email DSPeaker and ask them.

 

Regards,

 

Guido F.

[islandman]

Thanks again. What you said makes sense. I will email Dspeaker as you suggest, and see what they say, and post it here.

 

Devlon

[islandman]

Guidof, I contacted Dspeaker and askeh them this:

 

"

I have an opportunity to buy a McCormack MAP-1 (multi-channel analog pre-amp). Will the duo core work being placed between a DAC and analog pre-amp like this? The MAP-1 can split the incoming stereo signal into 6 channels (5.1)

 

The signal path would be: DAC (RCA outs) to

Duo Core (RCA ins) to

Duo Core (RCA outs) to

MAP-1 (RCA ins) to

MAP-1 (multiple RCA outs to power amps and sub).

In this configuration would the duo core work on all the bass frequencies going to all the speakers and sub below the upper cut off frequency since all channels are just duplicates of the incoming stereo signal? Is there any reason this will not work?

Thanks,

Devlon

 

-----Answer from Dspeaker:

 

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[TD=class: gH, align: right]4:56 AM (5 hours ago)

 

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Hello Devlon,

 

 

Yes, it should work exactly like that, since the whole signal is passing through the AM2 Dual Core. So it will correct both speakers and subwoofers, regardless of their cutoff frequencies.

 

BR,

Toni Liitola"

 

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So if Toni understood my question correctly he says this will work If so, this opens up whole new possibilites.

 

[Kal Rubinson]

While it will do this, you should know that it will be applying the same EQ to all the speakers on a given channel and I question how effective this will be.

[Guidof]

Hmm, I think Kal is right. The Dual Core will apply the same correction to all speakers (including subwoofers) connected to each of TWO channels. That correction would not be the appropriate one for a MULTI-channel setup, most probably.

 

Guido F.

[islandman]

Yes I see. It hears as a sum, and corrects as a sum. I really don't know if good, bad, or ugly, lol

[islandman]

The Dual Core is a stereo unit that works in pure stereo (2.0) or stereo plus subwoofer (2.1). Thus it would work with the MAP-1 only if you used the latter in a 2.0 or 2.1 system. It would not work to correct a 5.1 system, for example.

 

Regards,

 

Guido F.

 

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Although, Toni at Dspeaker answered this question below, I emailed him (or her?) again to give me security about this EQ possibility before I bought this "non-refundable" multi-channel analog preamp. There were opinions from some posters that because the speakers really need to be EQ'd individually, this EQing scenario would have no beneficial effect, and could even possibly be detrimental to the overall sound. Anyway, reiterating that concern to Toni here is his response to that:

 

 

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[TD=class: gH, align: right]4:49 AM (7 hours ago)

 

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Hello Devlon,

 

Equalizing every speaker is important when you equalize them for the entire range. In the lower frequency range it is their sum behaviour that dominates, and hence we can get very close to the individually EQd results by simply correcting for their "summed" response. The only thing that really would benefit of per speaker EQ is their delay, as this affects to how they are summed up (=avoid cancellation). Even then, it would be more important to match the individually EQd speakers to ensure good summation rather than leacing them all with the independent EQ without knowing how they interact.

 

Everything else can be EQd per summed response and it will essentially decompose to the per-speaker-correction as the net result is most important.

 

BR,

Toni Liitola

[Guidof]

Toni's reply refers to the correction in the lower frequencies only. Which suggests that the Dual Core's correction is equally effective in a 2.0, 2.1, or 2.2 system. NOT thai it is effective in a multichannel system such as 5.1 or 7.1, since the side and back channels would presumably involve frequencies other than the lower ones.

 

Regards,

 

Guido F.

[islandman]

Toni's reply refers to the correction in the lower frequencies only. Which suggests that the Dual Core's correction is equally effective in a 2.0, 2.1, or 2.2 system. NOT thai it is effective in a multichannel system such as 5.1 or 7.1, since the side and back channels would presumably involve frequencies other than the lower ones.

 

Regards,

 

Guido F.

 

Yes, but I was very specific in asking Toni only about EQing 5.0, 5.1 below <500hz. I am not sure how Toni would have confused my angle and confused it with 2.0>2.2? Here is a copy of that email to him:

 

"Hey Toni,

Devlon again. I know that in a previous email you stated affirmatively that the Duo Core would work in the 5.0, 5.1 scenario that I had described, but on one of the forum sites, I am getting opinions to the contrary that basically state that the Duo Core will most likely "not" work this way even if the processor can turn a stereo signal into 5.0, 5.1. Again, if you would, affirm again to me (before I spend 1350.00 on a non-refundable MAP) that if the processor is cable of dividing 2.0 into 5.0 that all 5 speakers will benefit from the Duo Core as it will be "hearing" or correcting <500hz signals in all the speakers as a sum. Is that right? Can it do that? Again, I'm only asking about the Duo Core working in a 5.0, 5.1 system by way of a unique processor that can divide 2.0 in up to 5.1 from just a stereo signal.

Regards,

Devlon Bignault"

[islandman]

His response to the above email is in post #21 above. I am going to talk to the owner of the MAP and see if I can talk him into a demo with a return option based on how the DC 2.0 works with it.

[Guidof]

Devon: I think you are wise in requesting a demo with the MAP. Your email to Toni is very clear, and so is his answer. Still, notice that of all the connection types listed on the DSPeaker web site, not one is for any multichannel setup. This suggests, at the very least, that one should be careful in assuming it would work.

 

Best luck with the experiment, if you can swing it, and let us know if it works.

 

Regards,

 

Guido.