How to set up a shoot out

ctviggen · « **on:** 9 Aug 2004, 12:50 pm »

Last night I decided to compare the DAC in my Pioneer Elite DVD/CD player with the DAC in my Proceed AVP. I'm using the Pioneer Elite as a "transport." (Naturally, I'm also "comparing" analog and digital interconnects.) I have to say that I had a very hard time determining which was better. For one thing, the Proceed AVP as DAC yields a higher volume for some reason. For another, I don't have my remote programmed to switch sources, so I had to get up and switch sources. I listened to one song several times, switching between the two, yet I'm still not sure which is better. My questions:

Do people typically level match when performing these tests?
Do you pick out particular instruments or voices for comparison?
What else is good to do for a test like this?

I ask because I have an Ack Dack coming for review and would like to be able to determine whether to spend the money for it or not. Thanks for any help!

ABEX · « **Reply #1 on:** 9 Aug 2004, 01:53 pm »

You might want to consider an SPL meter which Radio Shack sells. A disc or you can Download Freq. test tones which you then can set the vol. to match levels when changing cables.

If I had known awhile back I could have sent you a copy of one of S-Philes test CD's. Maybe someone out where you live has one.

There is a great article about testing that Robert Harley wrote while back in S-Phle which I have been trying to take notes and post it.

Good luck!

ctviggen · « **Reply #2 on:** 9 Aug 2004, 06:27 pm »

Thanks! I do have a RS meter and several test disks (Avia for 5.1 and Stereo Review for a bunch of two-channel stuff). I guess I'm just wondering how you go about this. I assume you test at a certain tone, then figure out what the dB reading is at that tone for the softer of the two, then set the level for the louder to be the same as the softer. Then, you'd have to always set the loudness per the preamp based on the input. Does that sound correct?

nathanm · « **Reply #3 on:** 9 Aug 2004, 06:58 pm »

Just pick a desired level, let's say 70db. Play the pink noise CD track and adjust the volume knob so that both DACs are generating 70db at the listening position on ye olde SPL meter.

nathanm · « **Reply #4 on:** 9 Aug 2004, 06:59 pm »

Just pick a desired level, let's say 70db. Play the pink noise CD track and adjust the volume knob so that both DACs are generating 70db at the listening position on ye olde SPL meter.

John Casler · « **Reply #5 on:** 10 Aug 2004, 01:25 am »

In all the comparisons and shoot outs I have done I found it best to do the following:

1) Play a cd at the volume you would be testing or comparing at.
2) Place the white/pink noise track in the player and without touching the volume, measure and write down what the level was.

This will tell you what level to set it to be congruent with all changes.

If the white/pink noise was 75 db, then you can always check the level matching by playing the white/pink noise, no matter how many changes are made in the system.

I was not good enough at listening to white/pink noise and knowing how 75 or 80 db translated into music, so I did it the other way around, to find my true listening level.

Hope that makes sense

eico1 · « **Reply #6 on:** 10 Aug 2004, 01:52 am »

I don't think a "sound meter" is a reliable way to match levels. A DVM at the speaker terminals (one or the other) will have far fewer problems and will be much easier than a tripod mounted meter.

If you are just holding the meter up in your hand, you are creating way more trouble than you think. Interconnects do not need matching and probably not speaker cables either.

I don't know if you should expect to hear differences in your dacs once level matched, but try different music selections.

steve

ctviggen · « **Reply #7 on:** 10 Aug 2004, 07:48 pm »

Thanks for all the replies. I do hope to hear differences in DACs, as I'm thinking of purchasing the Ack Dack, but I won't purchase it if I can't hear a difference using it. I have heard dramatic differences when performing other modifications, like cables. However, the two DACs I have now are very close in sound, although I do believe the Proceed is better (a bit more realistic). However, the Proceed also was louder, so I'm trying to determine the best way to retest using stricter guidelines so that I can determine which DAC is better. This will be preparation for my test of the Ack Dack. I'm getting it on a loaner program -- you pay $50 and he sends you a DAC. If you like it, you finish payment; if you don't, you send it back.

nathanm · « **Reply #8 on:** 10 Aug 2004, 09:21 pm »

The Ack! Thhppt! DAC demo program is a very good idea. I demoed it myself against the analog outs of my CD player and switching between the two via the input selector switch on the amp. Luckily the levels were very similar and I did not notice any volume jump. It's a dandy little piece of equipment. The large diameter perforated sheet is definitely the cat's pajamas. Now, if there were a stainless mesh screen underneath that...whoah!

ctviggen · « **Reply #9 on:** 10 Aug 2004, 09:49 pm »

My original plan was to compare my current two "DACs" (they're not really separate DACs) to see which was better and then compare the better one with the Ack Dack. Previously, I had done a shootout like this by playing very short pieces of music over and over and switching between the two. I thought that the Proceed sounded more natural during that test. What I did then was listen to certain instruments/voices. But I went to a NY Rave (a meeting between audiophiles) and they switched DACs. There, the improvement was immediate. But with my case, I was having a hard time discerning the improvement between my DACs. Maybe I won't have that hard of time with the Ack (and I hope I don't -- I hope I say, "Wow! That sounds so much better"). However, I'd like to develop a better, more "scientific" testing process before I commit to spending another $500 on a system that keeps sucking money out of my wallet (with good effect, but still).

jgubman · « **Reply #10 on:** 10 Aug 2004, 10:07 pm »

Are you listening to the Elite via your proceed's "analog bypass" path (if it has one)? Are you sure you are bypassing the AVP's DAC when you test the Elite's DAC?

Otherwise, I hate to even suggest this, and based on the proceed's reputation, I doubt this is the case, but maybe the preamp isn't up to the task? The preamp could be "coloring" the outcoming signal...

ctviggen · « **Reply #11 on:** 11 Aug 2004, 03:55 pm »

What I'm doing is taking the digital out of the Pioneer Elite DVD player into a digital input of the Proceed AVP (Audio-Video Processor). That's one signal path, and the AVP should act as a DAC and a preamp. The other signal path is from the PE DVD player's RCA outputs to analog inputs of the Proceed AVP. The Proceed shouldn't do anything but act like a preamp for this second signal path.

The Pioneer DVD player was $2,000 retail, so it was Pioneer's top of the line player at the time. The Proceed was $5,500 retail. (These aren't the prices I paid.) However, the AVP has a lot to do -- all the different DD, DTS, DAC, preamp, switching, etc.

I'll see if I can discern a difference again between the two. Perhaps my hearing isn't up to par? That could save me some money!

jgubman · « **Reply #12 on:** 11 Aug 2004, 04:35 pm »

I may be wrong, but some receivers require you to push a button (usually called "analog bypass" or "analog direct" or something like that), otherwise, they convert all incoming analog signals to digital so that they can then apply things like Dolby Prologic processing, bass management, etc. Usually, and I don't know if this applies to the proceed or not, if you just put an analog signal into a surround sound processor and set the output format to "stereo", the processor will do the A->D some processing and then D->A conversion.

That situation would certainly explain why you don't hear a difference.

And, I think your hearing is definately up to par, since you could easily discern the differences at the NY Audio Rave shootout.

jgubman · « **Reply #13 on:** 11 Aug 2004, 04:45 pm »

Just found a copy of the AVP's manual. It says this about analog-only output:

analog-only operation:

If you have an analog source such as the output of a phono preamplifier that you prefer to keep entirely in the analog domain, simply set up its input for 2-ch/surround off and no subwoofer. (The subwoofer crossover is implemented digitally.) When the AVP receives an analog signal under these conditions (which do not require any digital processing functions), the signal is kept in analog form and travels only through a high quality analog preamplifier, bypassing analog to digital and digital to analog conversion.

This can be done by selecting 2-ch/surround off as the default surround mode for the input in question, and by choosing force off as the subwoofer mode default for that same surround mode (see mode defaults, later in this section).

Do those sound like the settings you're using?

ctviggen · « **Reply #14 on:** 11 Aug 2004, 05:02 pm »

I believe so. However, I'll have to check, as I set up these inputs a long time ago. I definitely do not hear the sub, as I don't like the sub in stereo.

ctviggen · « **Reply #15 on:** 14 Aug 2004, 12:50 am »

Ok, I tried this again. This time, I programmed my Pronto remote to be able to switch between the two inputs (one was the Pioneer Elite CD/DVD player RCA outputs, and the other was using the PE DVD player as a transport and the Proceed as a DAC). The Proceed beats the PE. The Proceed sounds "right" -- any instrument you pick out in one song sounds better than the same instrument when using the PE. Additionally, there's more separation between instruments and the sound is more lively. The sound from the PE is more "dead" and it's more like a wall of sound rather than being able to pick out specific instruments.

So, I guess you have to be able to switch inputs quickly to make some of these determinations.