Tech Talk 30: Speaker Measurements

[@MDFGamingVideo]

Thanks for this tip about time gating my measurements. It just helped me identify a lot of reflections, which I KNEW I had because I am currently working on room treatments, but it explained some lumpiness and phase issues in my measurements. I learn something new each time I watch!

[@tee-jaythestereo-bargainph2120]

Great job Danny !!! Really appreciate your hard work and dedication we audiophiles really needed someone like you . 😆

[@ulamss5]

When you took the individual driver responses, does the microphone stay at tweeter level 1m away? Or does it move closer or down to the woofers for the woofer measurements etc?

[@robvermeulen]

Thanks for the insights. I was really wondering about how you measure those speakers people send in. Using the time gate in the impulse response, never thought of that myself. It looks like you are using Clio for taking those measurements. Can you perhaps shed some light on how you set up the system to take a "one watt one meter" measurement? Do you have an amp that you can configure to only output one watt? And are you using the microphone that comes with the Clio package? Many questions :D Best regards!

[@vxss346]

Love your videos, I'm doing some DIY stuff myself, I'm doing all this too through REW with success. However, I have a question about the waterfall (decay time) graphs. Measuring decay times seems much harder as I find those decay times can be up to 180ms because its within my room. (5.7m x 4.5m x 2.4m) On your videos however, when your measuring speakers people send in, your decay times seem to hover around 4-5ms, which to me is a speaker only decay time measurement. My question is, how are you achieving this without room reflections getting in the way? Are the still measured at 1m like the frequency response measurements are? Any help appreciated.

[@Herman-f9m]

@vxss346 Danny gets the decay plots out of the impulse response, which is the data he gathered in this video. A fairly typical room is going to require the gating he demonstrated to exclude echoes, with the gate set at around 4.5 milliseconds. Any decay plots you are getting over around 4.5ms is either room reflection or an indication that you have really, really bad speakers with huge amounts of stored energy.

[@vxss346]

@@Herman-f9m Cheers for the reply. Yeah, I use 3-5 ms gating for frequency response and that works great, but I think the issue is when I go to the waterfall, the gating can't be added, maybe that's an REW thing, or I'm missing something?

[@dieguerrero]

Thanks Danny for the awesome video! I fully understand the concept of gated measuring to get the room out of the response. However in the end we do listen inside a room. Will gated measurements help find and fix the room issues? Meaning the final room response should look like/match the best possible gated response that doesn't include the room?

[@disienna]

Diego Guerrero , there are a number of articles written about this subject on the web. This one may help: dtmblabber.blogspot.com/2011/03/hearing-beyond-haas.html In fact there are many on that blog that will get you thoroughly covered.

[@FND1337]

Is it even possible to measure Bass Response under 200 hz with a gated meassurment in a Room ? And if not, how do I measure it ? Thanks

[@Herman-f9m]

You use a nearfield measurement, with the microphone nearly touching the cone. What Danny illustrated in this video was a gated farfield measurement, with the microphone at one meter, or some other known distance, from the tweeter. If you measure the nearfield up to say 400Hz, and the farfield down to say 250Hz, you can move the plot of the nearfield measurement down to align with the nearfield measurement. The two should overlap pretty closely in the 250Hz to 400Hz range, so the combined nearfield and farfield measurements should be a good representation of the full range response of the speaker.

[@pabloosvaldopenizzotto1098]

Wonderful explanation!! I have experienced with Audyseey room acústicas Eq method that is being used in some AVR, a Denon in my case. In order to avoid high frequency room reflection the solution that this system offers is to roll down the high frequency response and you are loosing so much information in your listening area! It took me long time to realize about what the device were doing and then started to unse bypass L+R Eq. Mode. Thanks!!

[@darrenlomax1283]

So you leave the front mains out of the room correction DSP? Is it better?

[@pabloosvaldopenizzotto1098]

@@darrenlomax1283 yes, you are right. In my case the result was better.

[@parapobabam]

How does the speaker response look like after you worked your magic on it?

[@USA068]

oh. I just identified the mic. It's for anechoic chamber, in a lab environment. Fancy, an Audiomatica.

[@disienna]

I’m curious to see if you’ve tried measuring the vertical polar response of this speaker. It’s not always dead on the center of the tweeter. Looks like you are measuring off of the optimal listening axis even if the speaker’s manual says otherwise. Particularly with a horn tweeter, the directivity can be quite narrow and cause a very small vertical lobe. Pi speakers has some tips for this if you are unfamiliar. There are a few other sites as well. It’s a fairly straight forward process.

[@jacksound5471]

Hi sir 😎 As alway’s clean explanations ! Question: Can it be a good idea to do our tests ´outside ´ i a quiet day or night without wind for sure 😏 ? Thank you

[@dannyrichie9743]

If you can't do a gated time window type measurement then going outside on a day there is no wind is your best bet. And you have to get the speaker up and away from everything.

[@jacksound5471]

Danny Richie Thankyou sir ! Yeap i was thinking to put around at least 8 feet from the ground in an openfield 🤓

[@thomjmoore]

what software measurement package are you using?

[@dannyrichie9743]

Clio Measuring system.

[@Mickparrysstepdad]

I've lost count of the amount of times I've seen someone diy a pair of speakers, and then post a room measurement, before and after DSP. They don't move the speakers away from boundaries and gate the measurements, they just take them with the speaker in-situ, and then play with the crossover / EQ. There have got to be a lot of bad diy speakers out there. Try telling people and they ignore you!.

[@JasonLeaman]

what ? you mean i can't buy a minidsp and run the room eq wizard and it will make it sound perfect ? WHAT ? lol.. DSP = lame !

[@martingarrish4082]

Back in the day I used Liberty Audiosuite to measure speakers. For gated measurements the recommendation was to use the Hamming window to avoid harmonics in the measurement. I notice you use a rectangular weighting function in CLIO. Is there a reason for this or do you not trust Hamming or similar signal weighting? en.wikipedia.org/wiki/Window_function#Comparison_of_windows

[@scottlowell493]

When a costly speaker measures badly: Measurements are dismissed by fanboys of the product. Audiophiles in general only accept measurements if it agrees with the opinion they already have.

[@carlosoliveira-rc2xt]

Nonsense!