Frequency response

[The Massive]

In an actual recorded mix they kik and bass do NOT compete !! no mud bud

I respectfully disagree. Recording, there are definitely frequencies you want to EQ around for each instrument as to not muddy each other up...lots of sub bass and kick tend to step on each other.

That said, I was referring to a live situation where I think most people can attest that a bass pushing massive amounts of low end can swallow up a kick pretty easily. Kind of like when you play in a detuned band, in say, C standard, or B standard. You have to completely re-EQ your bass to not muddy the sounds of the guitars.

All good tho sweatpea, if it works for you and you're happy, then I'm happy.

 

[AlexanderB]

That’s the entire point though, room conditions don’t affect both samples equally, the interference pattern from the reflections can make large differences by moving either the source or measurement mic by a very small amount, and this varies by frequency.

Yes, obviously, as we all know how sound changes as we walk around in a room. However:
1. The problem of different radiating patterns from different speaker designs remain, even if you do this in a sound lab. (So where to put the microphone in relation to the transducer positions on the baffle?)
Multiple microphones (or "measuring points", actually) will solve this, if you want data not only from directly in front of the baffle. Sure enough, this will also apply to the setup at home, with room resonances....
2. By setting, and adhering to, solid points of reference, you can get the same precision doing measurements at home. With sticky tape, fixed mike stands, rulers and good notes, you can get very high accuracy.
3. The irregularities and variations in "in room" response are basically inversely proportional to the frequency of the sound. So in a moderate size living room, the range that is most impactful to bass cabinet design, like below 2-300 Hz is not much affected by this. Higher up, in the "voicing" area of the sound, differences are more related to tranducer design, rather than cabinet design.

So, as long as one understands the difference between ABSOLUTE measurements, and RELATIVE measurements, there is nothing stopping you from getting consistent and very usable results in a non-lab setup, for the latter. And with modern, computer supported test gear, pulsed signals, wave file anayzing etc, one can do a lot even at home, or in a rehearsal studio.

I think people with various levels of experience and training in engineering and design should PROMOTE experimentation and projects, not scare people away. While gear and lab conditions are a blessing, one can get very useful results and insights with small resources, as long as there is a willingness to learn, and patience to do things right.

 

[agedhorse]

Yes, obviously, as we all know how sound changes as we walk around in a room. However:
1. The problem of different radiating patterns from different speaker designs remain, even if you do this in a sound lab. (So where to put the microphone in relation to the transducer positions on the baffle?)
Multiple microphones (or "measuring points", actually) will solve this, if you want data not only from directly in front of the baffle. Sure enough, this will also apply to the setup at home, with room resonances....
2. By setting, and adhering to, solid points of reference, you can get the same precision doing measurements at home. With sticky tape, fixed mike stands, rulers and good notes, you can get very high accuracy.
3. The irregularities and variations in "in room" response are basically inversely proportional to the frequency of the sound. So in a moderate size living room, the range that is most impactful to bass cabinet design, like below 2-300 Hz is not much affected by this. Higher up, in the "voicing" area of the sound, differences are more related to tranducer design, rather than cabinet design.

So, as long as one understands the difference between ABSOLUTE measurements, and RELATIVE measurements, there is nothing stopping you from getting consistent and very usable results in a non-lab setup, for the latter. And with modern, computer supported test gear, pulsed signals, wave file anayzing etc, one can do a lot even at home, or in a rehearsal studio.

I think people with various levels of experience and training in engineering and design should PROMOTE experimentation and projects, not scare people away. While gear and lab conditions are a blessing, one can get very useful results and insights with small resources, as long as there is a willingness to learn, and patience to do things right.

This has not been my experience, nor the experience of any of the other engineers that I have worked with.

Outdoors, with the speaker facing upward (especially if the baffle is flush with the hard surface) is generally far more accurate because it provides a solid 1/2-space environment. To convert to a full space measurement you would subtract 3dB from the sensitivity measurements.

If you place the speaker on a grass surface though, the grass-earth is quite absorptive at all but the lowest frequencies so the measurements become close to the full space values.

Since there are no boundaries (at least where I measure my speakers at) the accuracy and consistency improve greatly compared with any indoor measurements made using the same test setup.

When comparing to published numbers (which are almost always 1/2-space and anechioc), the differences can be very large, large enough that comparisons are ridiculous.

I once asked a bass magazine not to publish measured sensitivity numbers for a product I designed because the numbers were clearly wrong (ridiculously favorable) because they were impossible to obtain in any world I know of. This is the danger of being overly confident in something that’s not fully understood.

 

[AlexanderB]

This has not been my experience, nor the experience of any of the other engineers that I have worked with.

Outdoors, with the speaker facing upward (especially if the baffle is flush with the hard surface) is generally far more accurate because it provides a solid 1/2-space environment. To convert to a full space measurement you would subtract 3dB from the sensitivity measurements.

If you place the speaker on a grass surface though, the grass-earth is quite absorptive at all but the lowest frequencies so the measurements become close to the full space values.

Since there are no boundaries (at least where I measure my speakers at) the accuracy and consistency improve greatly compared with any indoor measurements made using the same test setup.

When comparing to published numbers (which are almost always 1/2-space and anechioc), the differences can be very large, large enough that comparisons are ridiculous.

I once asked a bass magazine not to publish measured sensitivity numbers for a product I designed because the numbers were clearly wrong (ridiculously favorable) because they were impossible to obtain in any world I know of. This is the danger of being overly confident in something that’s not fully understood.

I fully agree about using an open field for measurement, at least as long as you can obtain a meaningful S/N ratio.
Again, my point is to measure the difference between speaker A and speaker B. As nothing else changes between the measurement sessions, your data will obviously show the difference.
In comparing products, that could be enough, especially if you are familiar with the performance of one of them.

Edit: about published data. Yes, it is horrible to see the blatant lies that some brands publish as being technical data. Performance that extends beyond the boundaries of physics....

 

[1958Bassman]

As long as the oil remains inside the motor!

As they say, "Harley's don't leak, they mark their territory".