since new topics here in Geek Central seem to be few and far between.......I was wondering what ideas some people may have relative to quantifying small changes in sound quality, or, less subjectively, system response. Since the topic is complex (and controversial) enough already, let's avoid speaker/room interactions and just discuss measuring electrical signals (the signal may be measured at different places in the signal chain depending on the goal of the measurement), and let's only measure unamplified signals for now to make it even easier.
I'm not interested in discussing DBTs or other testing methods using humans as the detection device. In this thread I'd like people to stay focused on using devices to measure differences in system response. The goal isn't to figure out if 'Component A' sounds better than 'Component B'. The goal is merely to determine that there is or is not a difference between A and B, and hopefully some indication of how large the difference is.
To give everyone a starting point, I'll propose a method that is likely very flawed (please forgive my ignorance if this has been proposed before). With any luck, the process of pointing out the flaws in my proposal will lead to some better ideas, and maybe even a method that eventually becomes reliable and accepted. Keep in mind that I'll be assuming any tests will be conducted scientifically, using the best methods possible to reduce potential errors or inconsistencies - in other words, I'll be omitting some of the details that are necessary to achieve precision and accuracy in the spirit of simplicity.
Start with a high quality digital recorder. Given that this exercise has no budget, we'll use either a DSD recorder or a 24/192 PCM recorder. Hook the recorder up as far upstream in the system as possible so that the recorder is connected to the output of the device in question. Now start recording samples of your reference material - you'll obviously want a digital source of the same format as your recorder, and it should be a complex music signal - no pure sine waves or square waves. Record lots of samples, because I'm sure no two samples of the same clip will be recorded exactly the same due to vibration and a slough of other factors.
Once you have enough samples, you can compare the samples to one another, and also to the source. If there's too much variation, you can stop testing and start thinking of a better way to do this. If you find a fair amount of consistency among your samples, then average the samples together. The difference between the average of your samples and the source is a rough gauge for your system's baseline distortion, including the recording device, of course.
Now, switch out the component and record the same number of samples you did in part 1. Now compare the averages of the two sets of samples. Are the averages different? If so, there's likely a difference in system response. How big is the difference compared to the baseline distortion?
Once again, this has probably been explored before and probably won't work, but why won't this work?
-Pete
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Topic - Objective Measurements to Compare Components Within a System - pburant 10:37:07 08/15/03 (138)
- Look what you started! nt - clarkjohnsen 07:27:44 08/23/03 (1)
- Started?...or continued? <nt> - pburant 07:52:28 08/26/03 (0)
- Re: Objective Measurements to Compare Components Within a System - john curl 13:28:59 08/21/03 (131)
- I think you're missing my point a bit..... - pburant 19:35:47 08/21/03 (130)
- Re: I think you're missing my point a bit..... - jon_banquer@yahoo.com 20:00:14 08/24/03 (5)
- Much as your point is to say, "You're wrong,"...... - pburant 08:09:55 08/26/03 (4)
- Re: Much as your point is to say, "You're wrong,"...... - jon_banquer@yahoo.com 12:46:45 08/26/03 (3)
- Re: Much as your point is to say, "You're wrong,"...... - pburant 05:23:57 08/27/03 (1)
- Re: Much as your point is to say, "You're wrong,"...... - jon_banquer@yahoo.com 22:05:49 08/29/03 (0)
- Re: Much as your point is to say, "You're wrong,"...... - jon_banquer@yahoo.com 15:55:05 08/26/03 (0)
- You may have missed it... - Charles Hansen 19:45:04 08/21/03 (123)
- And now I've seen them as well.... - Commuteman 09:47:10 08/22/03 (45)
- Re: And now I've seen them as well.... - jneutron 09:58:50 08/22/03 (44)
- Hey, we're agreeing! - Commuteman 10:12:15 08/22/03 (43)
- Hee hee..we're jumpin thread to thread.. - jneutron 10:28:00 08/22/03 (42)
- So maybe I can help the communication - Commuteman 11:20:15 08/22/03 (41)
- Re: So maybe I can help the communication - john curl 15:30:28 08/22/03 (40)
- Seebeck/peltier... - jneutron 19:24:11 08/22/03 (36)
- Re: Seebeck/peltier... - john curl 23:21:43 08/22/03 (35)
- Re: Seebeck/peltier... - jneutron 04:53:47 08/23/03 (34)
- Re: Seebeck/peltier... - john curl 08:22:30 08/23/03 (33)
- Re: Seebeck/peltier... - jneutron 09:01:31 08/23/03 (32)
- Re: Seebeck/peltier... - john curl 09:54:43 08/23/03 (31)
- Ah...deflection of any technical conversation..typical, John - jneutron 10:22:54 08/23/03 (30)
- Re: Ah...deflection of any technical conversation..typical, John - john curl 13:06:57 08/23/03 (29)
- Re: Ah...deflection of any technical conversation..typical, John - jneutron 16:29:53 08/23/03 (28)
- Ok, so can you explain how these thermal effects might manifest themselves? - Commuteman 17:29:51 08/23/03 (27)
- Re: Ok, so can you explain how these thermal effects might manifest themselves? - jneutron 12:54:34 08/24/03 (26)
- Re: Ok, so can you explain how these thermal effects might manifest themselves? - john curl 15:37:42 08/24/03 (25)
- Re: Ok, so can you explain how these thermal effects might manifest themselves? - jneutron 07:59:53 08/25/03 (24)
- Can you stop arguing with JC and describe what you think might be happening? - Commuteman 09:09:25 08/25/03 (8)
- Who's arguing? I'm being bashed for trying to explain. - jneutron 11:21:13 08/25/03 (7)
- Are you sure you can use this Seebeck/Peltier cause and effect model? - Commuteman 12:18:56 08/25/03 (6)
- I forgot to add.. - jneutron 17:20:41 08/25/03 (0)
- I'll stick to this thread. - jneutron 12:31:19 08/25/03 (4)
- Can we get to some ballpark numbers to see if it's significant? - Commuteman 13:41:47 08/25/03 (3)
- You're killin me... - jneutron 15:56:18 08/25/03 (2)
- I think we're using the same numbers.. - Commuteman 17:28:12 08/25/03 (1)
- AHA!!!!! So that's where the error is... - jneutron 17:46:53 08/25/03 (0)
- Re: Ok, so can you explain how these thermal effects might manifest themselves? - john curl 08:50:17 08/25/03 (14)
- JC..you really have to read the posts.... - jneutron 10:29:16 08/25/03 (13)
- Re: JC..you really have to read the posts.... - john curl 13:36:44 08/25/03 (10)
- Hi John - jneutron 15:21:15 08/25/03 (9)
- Re: Hi John - john curl 16:47:15 08/25/03 (8)
- Re: Hi John - jneutron 17:04:43 08/25/03 (7)
- Re: Hi John - john curl 20:16:24 08/25/03 (6)
- Re: Hi John - jneutron 21:34:29 08/25/03 (5)
- And BTW..You never did say who Dr. Van den Hul was.. - jneutron 21:48:10 08/25/03 (4)
- Everyone is entitled to their opinion.... - Charles Hansen 22:03:03 08/25/03 (3)
- Hmmm. - jneutron 05:41:31 08/26/03 (0)
- Hellllooo Charles... - jneutron 03:45:13 08/26/03 (1)
- OH, and Charles..... - jneutron 04:55:27 08/26/03 (0)
- Peltier effects are reversible with current direction - Commuteman 11:43:41 08/25/03 (1)
- AHA..gotcha - jneutron 11:58:44 08/25/03 (0)
- Yep, my oscillator is now the problem - Commuteman 16:31:13 08/22/03 (2)
- Re: Yep, my oscillator is now the problem - Dan Banquer 05:29:28 08/23/03 (1)
- Thanks - Commuteman 09:59:43 08/23/03 (0)
- Re: You may have missed it... - Dan Banquer 05:19:58 08/22/03 (2)
- Speaking of "undefensible"... - Charles Hansen 11:08:19 08/22/03 (1)
- Re: Speaking of "undefensible"... - Dan Banquer 11:44:44 08/22/03 (0)
- You are correct... - pburant 04:41:26 08/22/03 (7)
- Re: You are correct... - john curl 09:08:00 08/22/03 (6)
- Hmmmm - jneutron 09:41:21 08/22/03 (5)
- Have you ever measured a piece of audio equipment? - Commuteman 09:56:15 08/22/03 (4)
- Sure...my RMX 1450 is 45 pounds in it's case.. - jneutron 10:21:06 08/22/03 (3)
- And BTW.. - jneutron 10:39:56 08/22/03 (2)
- Now that might help... - Commuteman 11:04:24 08/22/03 (1)
- Thanks. - jneutron 14:00:15 08/22/03 (0)
- Fuck you, Hansen nt - Steve Eddy 21:06:58 08/21/03 (65)
- Releasing the rage of one too many "Ummm Bop's" ?? - slope 16:44:53 08/22/03 (0)
- Re: Fuck you, Hansen nt - middleground 06:33:30 08/22/03 (62)
- "significant advancements such as CD" There's your answer. - clarkjohnsen 08:24:19 08/22/03 (60)
- Why are the comparisons always between CD & Vinyl? - pburant 12:22:29 08/22/03 (1)
- You're right about the convenience - Commuteman 13:44:32 08/22/03 (0)
- Re: "significant advancements such as CD" There's your answer. - Dan Banquer 09:41:23 08/22/03 (57)
- But is recording technique getting better? - Commuteman 10:39:49 08/22/03 (56)
- Re: But is recording technique getting better? - Dan Banquer 11:42:17 08/22/03 (1)
- Yep, there are some great recordings coming out - Commuteman 13:37:16 08/22/03 (0)
- You are correct, sir, and to the point. nt - clarkjohnsen 11:27:38 08/22/03 (0)
- Re: But is recording technique getting better? - jneutron 10:46:40 08/22/03 (52)
- Re: But is recording technique getting better? - eico1 12:46:32 08/22/03 (29)
- Re: But is recording technique getting better? - jneutron 13:49:58 08/22/03 (28)
- Re: But is recording technique getting better? - Ted Smith 14:16:41 08/22/03 (27)
- Hi Ted - jneutron 19:30:28 08/22/03 (1)
- Re: Hi Ted - Ted Smith 20:48:26 08/22/03 (0)
- Did we just go around in a cricle? - Commuteman 15:58:07 08/22/03 (24)
- Re: Did we just go around in a cricle? - Ted Smith 20:59:05 08/22/03 (2)
- Yep, I'm with ya - Commuteman 21:41:43 08/22/03 (1)
- Re: Yep, I'm with ya - Ted Smith 22:01:13 08/22/03 (0)
- Re: Did we just go around in a cricle? - jneutron 19:35:34 08/22/03 (20)
- Re: Did we just go around in a cricle? - Ted Smith 20:52:47 08/22/03 (19)
- Re: Did we just go around in a cricle? - jneutron 04:45:33 08/23/03 (18)
- Re: Did we just go around in a cricle? - Ted Smith 04:48:34 08/23/03 (17)
- Hi Ted. - jneutron 05:03:30 08/23/03 (16)
- Re: Hi Ted. - Ted Smith 05:58:49 08/23/03 (0)
- Re: Hi Ted. - Ted Smith 05:30:36 08/23/03 (0)
- Re: Hi Ted. - Ted Smith 05:16:51 08/23/03 (13)
- Re: Hi Ted. - jneutron 07:02:30 08/23/03 (12)
- Re: Hi Ted. - Ted Smith 07:24:03 08/23/03 (11)
- Code correction - Ted Smith 19:22:23 08/23/03 (0)
- Re: Hi Ted. what you do??edit a typo? - jneutron 07:44:47 08/23/03 (9)
- Re: Hi Ted. what you do??edit a typo? - Ted Smith 08:09:33 08/23/03 (8)
- Re: Hi Ted. what you do??edit a typo? - jneutron 09:13:54 08/23/03 (7)
- Re: Hi Ted. what you do??edit a typo? - Ted Smith 09:41:40 08/23/03 (6)
- Re: Hi Ted. what you do??edit a typo? - jneutron 10:28:39 08/23/03 (5)
- Re: Hi Ted. what you do??edit a typo? - Ted Smith 11:25:20 08/23/03 (4)
- What's confusing to most people about this - Commuteman 17:37:13 08/23/03 (2)
- Re: What's confusing to most people about this - Ted Smith 19:13:42 08/23/03 (1)
- Re: What's confusing to most people about this - jneutron 07:47:01 08/25/03 (0)
- Re: Hi Ted. what you do??edit a typo? - john curl 13:20:02 08/23/03 (0)
- Re: But is recording technique getting better? - Dan Banquer 11:37:43 08/22/03 (5)
- Re: But is recording technique getting better? - jneutron 11:55:59 08/22/03 (4)
- Re: But is recording technique getting better? - Dan Banquer 12:01:35 08/22/03 (3)
- Re: But is recording technique getting better? - jneutron 12:08:45 08/22/03 (2)
- Re: But is recording technique getting better? - Dan Banquer 12:27:04 08/22/03 (1)
- Re: But is recording technique getting better? - jneutron 12:33:45 08/22/03 (0)
- you do know I was joking, right.....? - Commuteman 11:26:28 08/22/03 (1)
- Yep..nt - jneutron 11:51:30 08/22/03 (0)
- Re: But is recording technique getting better? - mfc 11:05:58 08/22/03 (13)
- Re: But is recording technique getting better? - jneutron 11:13:26 08/22/03 (12)
- This I do not understand.... - jensw 11:09:30 08/25/03 (6)
- Re: This I do not understand.... - jneutron 13:23:36 08/25/03 (5)
- Re: This I do not understand.... - jensw 14:29:23 08/25/03 (4)
- The interesting connection - Commuteman 17:38:21 08/25/03 (1)
- Re: The interesting connection - jneutron 18:38:17 08/25/03 (0)
- Re: This I do not understand.... - jneutron 16:41:29 08/25/03 (1)
- Let's leave it like this, here, way in and down. NT. - jensw 19:19:18 08/25/03 (0)
- I like this explanation - Commuteman 14:19:04 08/22/03 (2)
- Re: I like this explanation - john curl 16:00:27 08/22/03 (1)
- Re: I like this explanation - jneutron 08:07:22 08/25/03 (0)
- Re: But is recording technique getting better? - mfc 11:26:46 08/22/03 (1)
- Now there's an interesting question.... - Commuteman 11:28:55 08/22/03 (0)
- We're a small and difficult segment of the market - pburant 07:20:40 08/22/03 (0)
- Wow! No foreplay - right down to business! <nt> - pburant 04:26:23 08/22/03 (0)
- Flawed or not, this is frikkin' *complicated*. And to what end? - clarkjohnsen 07:50:19 08/20/03 (3)
- Complicated? This is trivial compared to..... - pburant 07:12:08 08/21/03 (2)
- Re: Complicated? This is trivial compared to..... - eico1 15:44:04 08/21/03 (1)
- I like it! - pburant 08:37:54 08/22/03 (0)