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Correctly measuring bookshelf speakers nearfield

Kadn

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Hello everyone

Recently, I ventured down the rabbit whole of measuring stuff. Got a cheap measurement mic (which is really quite accurate) and some cables/adapters for use accordingly.

My question is however, how to roughly measure speakers while bypassing the room variable. I used to measure at listening position, but found that the measurements would vary drastically deepening on what room I am in or how the speakers are positioned. Therefor, I looked into nearfield measurements. Measurements that are done within say 2-3 inches from the cone of the driver. This actually worked, and I was surprised, however, I have no idea on how to do it correctly.

I measured a pair of sony bookshelf speakers I had laying around and I took 4 different measurements. 1. At the woofer 2. at the tweeter 3. between the woofer and tweeter 4. at the port.

I'm just unsure of where to measure/and or how to combine these in a way. Any discussion with this is much appreciated!!

I can share the measurements if pleased
Kaden
 

daftcombo

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I'd get a second hand Klippel spinorama.
 

napilopez

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Hello everyone

Recently, I ventured down the rabbit whole of measuring stuff. Got a cheap measurement mic (which is really quite accurate) and some cables/adapters for use accordingly.

My question is however, how to roughly measure speakers while bypassing the room variable. I used to measure at listening position, but found that the measurements would vary drastically deepening on what room I am in or how the speakers are positioned. Therefor, I looked into nearfield measurements. Measurements that are done within say 2-3 inches from the cone of the driver. This actually worked, and I was surprised, however, I have no idea on how to do it correctly.

I measured a pair of sony bookshelf speakers I had laying around and I took 4 different measurements. 1. At the woofer 2. at the tweeter 3. between the woofer and tweeter 4. at the port.

I'm just unsure of where to measure/and or how to combine these in a way. Any discussion with this is much appreciated!!

I can share the measurements if pleased
Kaden

You're going to have trouble if you try to just sum the response of the woofer tweeter and port willynilly =]

If you go through my guide linked above, you don't need to do the whole thing. There's a lot pre-amble but it will show you how to eliminate the effects of the room to high accuracy! The most important bit is simply getting the speaker as far away from walls (including floor and ceiling) as possible. If you can get 5 feet of distance from each wall, you're in real good shape.

Good luck, and I'm more than happy to help with any questions along the way.
 

Shives

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I’m working on this 5 foot rule right now.
So, if the speaker has acoustic treatment around it, will this help or hurt the 5 foot rule? At least the closest walls having it covered? Thanks. Seeing if it can be done in spot where it is, or pull the wires up and run one out.
 

napilopez

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I’m working on this 5 foot rule right now.
So, if the speaker has acoustic treatment around it, will this help or hurt the 5 foot rule? At least the closest walls having it covered? Thanks. Seeing if it can be done in spot where it is, or pull the wires up and run one out.

Acoustic treatment won't hurt, I assume, but how much it helps depends on how effective the absorption is. Really 5 feet is just a guideline because it's what I've usually used. You just want to get the speaker as far from major surfaces as possible, and then use the widest gate on the impulse response possible. The good thing is you should be able to see where the reflection happens right in the impulse response. So you can try keeping the speaker where it is and see how wide of a time gate you can get.
 

Shives

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Yes!!! I like you already! Ha ha. With the way I see it above, if I’m getting this right and as you say, you’ll see the area (think you said around 7ms in the example) of where the reflection is seen or starts to show its ripples. So, I should in fact see this. I don’t see a reference to point of measure in the manual or online specs. So, I’m going to aim between tweeter and driver.
Thanks again I’ll be back soon. Hoping I get a working optical tomorrow from Amazon to test.
 

napilopez

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Yes!!! I like you already! Ha ha. With the way I see it above, if I’m getting this right and as you say, you’ll see the area (think you said around 7ms in the example) of where the reflection is seen or starts to show its ripples. So, I should in fact see this. I don’t see a reference to point of measure in the manual or online specs. So, I’m going to aim between tweeter and driver.
Thanks again I’ll be back soon. Hoping I get a working optical tomorrow from Amazon to test.

What speaker is it, if I may know? If it's a two-way without a waveguide, the reference is usually the tweeter.
 

DChenery

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For a more "home brewed" approach to measurements, check out the how to article using the KEF LS50 as an example. Note that Archimago uses the miniDSP UMIK-1 microphone with a combo of REW and VituixCAD for measurement and processing. I am currently playing with a similar setup. One caution is that you need an isolated test area as the "test signals" can very rapidly annoy other household members.

https://archimago.blogspot.com/2020/10/pspinorama-measurements-kef-ls50.html
 

Shives

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What speaker is it, if I may know? If it's a two-way without a waveguide, the reference is usually the tweeter.
Hello!! Thanks man... It’s a RP-600m that’s been modded. There is a post up and we are trying to figure if things are better or worse.... in measurement terms. If you say tweeter, then I’ll aim direct at the tweet, and how far away?
Thanks buddy!
For a more "home brewed" approach to measurements, check out the how to article using the KEF LS50 as an example. Note that Archimago uses the miniDSP UMIK-1 microphone with a combo of REW and VituixCAD for measurement and processing. I am currently playing with a similar setup. One caution is that you need an isolated test area as the "test signals" can very rapidly annoy other household members.

https://archimago.blogspot.com/2020/10/pspinorama-measurements-kef-ls50.html
Thank you! I’m going to try an accomplish one walk through at a time! The kind person who made the post has been giving me clues.. so, I will continue. Then I’ll take a look into that link. Thanks man!
 
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