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Old 5th September 2013, 03:01 PM   #21
gedlee is offline gedlee  United States
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Quote:
Originally Posted by SpinMonster View Post
The difference in subjective listening and your test results simply shows you arent testing the variables that affect the subjective sound.
That or there aren't any differences.

Pray tell what are these missing variables? And please don't say "phase" or "group delay" - which are clearly not audible in small rooms at low frequencies (for the situations that we are discussing).
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Old 5th September 2013, 03:04 PM   #22
gedlee is offline gedlee  United States
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Originally Posted by SpinMonster View Post
Regardless of the arguments about motor strength and cone weight, the 330grm weight TC 12" cone is not doing the same start and stop performance of the 106grm 10" L26Roy.
That's called high frequency response and if it too is EQ'd to be the same then the "start and stop performance" will be the same. You need to get the physics right.
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Old 5th September 2013, 09:17 PM   #23
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Originally Posted by SpinMonster View Post
All are max flat outside the truck. A TC LMSr 12 extends to 47 hz on its own max flat.
A ported Scan Speak L26Roy tuned to 30hz is flat to 31hz.
They all sound better.

Having heard various alignments sounding tight and deep isnt the point. The fact that you hear differences using the same driver in various alignments is.
Since you don't post any response curves of what sounds "better", and you find a "flat to 31hz" ported (phase inversion) speaker to sound better than a sealed speaker that has a peaked response, I still think the major difference you are hearing in the different cabinets is the frequency response.

Comparing the L26Roy 10" in a 1 cubic foot box (factory spec sheet) to the TC LMSR 12" in a two cubic foot box (Josh Ricci Data Bass test) we see the TC LMSR 12 is -3 dB at 30 compared to 100 Hz, but is +3 dB at 45 Hz, while the L26Roy has no peak below 100 Hz, and is -7 dB at 30 Hz.

The two would sound quite different to anyone paying attention, the L26Roy would sound subjectively "tight" or "fast", the LMSR would sound "slow" or "boomy", it's response is similar to what people have complained about regarding other enclosure types.

Equalize them to the same response and I would bet you will find them to sound quite similar, other than the heavy cone mass of the LMSR does not behave well above 200 Hz.
Using a 24 dB per octave crossover that difference won't be very audible (if the out of band peaks are addressed), but with a 12 dB crossover with no EQ the L26Roy would "win".
Attached Images
File Type: png L26Roy1 Cube.png (94.8 KB, 360 views)
File Type: png LMS2CubeSealed.png (48.3 KB, 358 views)

Last edited by weltersys; 5th September 2013 at 09:26 PM.
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Old 6th September 2013, 01:36 AM   #24
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Originally Posted by gedlee View Post


So you don't buy the time/frequency equivalency?
A waterfall plot shows you can have a flat frequency response with varying time stored energy. That's why we have waterfall plots; because the two are independently measured. Flat frequency response doesn't imply a clean waterfall plot.
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Old 6th September 2013, 04:01 AM   #25
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Originally Posted by weltersys View Post
Since you don't post any response curves of what sounds "better", and you find a "flat to 31hz" ported (phase inversion) speaker to sound better than a sealed speaker that has a peaked response, I still think the major difference you are hearing in the different cabinets is the frequency response.

Comparing the L26Roy 10" in a 1 cubic foot box (factory spec sheet) to the TC LMSR 12" in a two cubic foot box (Josh Ricci Data Bass test) we see the TC LMSR 12 is -3 dB at 30 compared to 100 Hz, but is +3 dB at 45 Hz, while the L26Roy has no peak below 100 Hz, and is -7 dB at 30 Hz.

The two would sound quite different to anyone paying attention, the L26Roy would sound subjectively "tight" or "fast", the LMSR would sound "slow" or "boomy", it's response is similar to what people have complained about regarding other enclosure types.

Equalize them to the same response and I would bet you will find them to sound quite similar, other than the heavy cone mass of the LMSR does not behave well above 200 Hz.
Using a 24 dB per octave crossover that difference won't be very audible (if the out of band peaks are addressed), but with a 12 dB crossover with no EQ the L26Roy would "win".
I have 31 bands of EQ in my truck. I use a 1/3 octave analyzer to flatten the response. The head unit is an Alpine 9887 and its associated DSP unit that has some rediculous number of EQ bands and time correction. The sub amp is a RF TD4000.1bd. All of my subs were flat in truck. Using software models a sealed 1.7 cu ft TC 12" at -3db at 47hz and a 1.3 cu ft L26ROY at -3db at 32hz. Scan Speak specifies the bass data on their supplied sheet is not accurate. Run the numbers yourself in winisd.

I hear a difference in quality in the 3 sealed boxes for the same TC driver. Its decidedly not EQ. You cant EQ a .7Q sub to sound exactly like a .57Q sub or the industry would all use the same size sub box and EQ everything to death. Further if all subs in all boxes sound the same after EQ, then what a simple world it must be. Its all about getting that cone to stop making sound after you stop applying a signal. Varying the air spring does more than reduce the amplitude of a peak in the response. It vary the time it takes for the cone to stop moving. The weight of the cone also affects its ability to stop unless Newton had it wrong.

Last edited by SpinMonster; 6th September 2013 at 04:31 AM.
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Old 6th September 2013, 09:23 AM   #26
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" You cant EQ a .7Q sub to sound exactly like a .57Q sub or the industry would all use the same size sub box and EQ everything to death. "

Ever heard a KEF system with the KUBE?

Might change your mind.
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Old 6th September 2013, 10:49 AM   #27
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" You cant EQ a .7Q sub to sound exactly like a .57Q sub or the industry would all use the same size sub box and EQ everything to death. "

Ever heard a KEF system with the KUBE?

Might change your mind.
OK so a bass driver in one box with eq shows that all sub box sizes sound the same with eq?

I'd like to point out that this debate started because it was said that the same driver can be EQ'd to sound the same in any alignment box.....ported....sealed.....forded horn. My position was that the phase and delay of a port/vent cant be corrected with eq nor can the weight of a cone be corrected to react as fast as a lighter cone on a speaker with a better power to weight ratio. Some alignments can better suit a driver. In my case....no way a TC LMSr12 can be made to sound as good in a ported box as a sealed box of .57Qtc with eq. The scan speak sub sounded better than the TC sub because its a lighter cone with a lower distortion motor and a better power to weight ratio.

Last edited by SpinMonster; 6th September 2013 at 11:05 AM.
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Old 6th September 2013, 12:05 PM   #28
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"My position was that the phase and delay of a port/vent cant be corrected with eq nor can the weight of a cone be corrected to react as fast as a lighter cone on a speaker with a better power to weight ratio. "

Fast?

The mass corner of the driver describes how fast a driver is. I have heard vented 18s that sounded faster than sealed 10s, it's all in the design and execution.

"OK so a bass driver in one box with eq shows that all sub box sizes sound the same with eq?"

Again, it has to be done properly, KEF is a brand with several speaker systems. When I sold them the KUBE were specific for the models. It was fascinating to listen to the way the sound of the bass changed as you adjusted the Q control. I really liked the small 103.2 model with its KUBE.
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Old 6th September 2013, 01:54 PM   #29
gedlee is offline gedlee  United States
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Originally Posted by SpinMonster View Post
A waterfall plot shows you can have a flat frequency response with varying time stored energy. That's why we have waterfall plots; because the two are independently measured. Flat frequency response doesn't imply a clean waterfall plot.
Since both the frequency response and waterfalls come from the impulse response, if the system is minimum phase then if the frequency responses of two systems are the same then the waterfalls also have to be the same. The situation that you described with different Q's of the drivers was necessarily minimum phase.

If the system is not minimum phase in some frequency range, say due to multipaths, etc. then the waterfall can differ from the frequency response due to different times of arrival of the energy in those frequency ranges.

For the most part all low frequency systems are minimum phase, except for some small effects in the upper range. But at the lower cutoff, they will all be minimum phase - Hence EQ this range to be the same and the waterfall will also be the same.
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Old 26th December 2013, 04:06 PM   #30
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Originally Posted by gedlee View Post
Pray tell what are these missing variables?
[force factor driver A: MMS Driver A] vs [force factor driver B: MMS driver B]

You stop the electrical signal to the driver and one comes to a stand still first while the other keeps moving for some time longer, regardless of how insignificant it may seem. An object in motion tends to...
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