i made a true comparison of 9515d and xxx15 with frequency response!!!

[helotaxi 5,000+ posts]

There are several alignments used when designing a ported enclosure. They use a different volume and tuning to achieve a different goal with the speaker, ie smooth frequency response, minimal group delay, best efficiency, etc...

You cannot make a fair comparison between two subs in a ported box using the same box for each, unless they want the same box for the same alignment (very rare). Each sub has its optimal enclosure size and tuning. Using something other than that will keep the sub from performing as well as it can and will not allow for a fair assessment of its capability or quality. It is possible that the DD sub in your comparison was better suited to the enclosure that you tested them in than the XXX. It is LIKELY that the enclosure was far from optimal for either and that putting them both in their optimal enclosure will yield far better performance from both of them.

 

[Shaunly 10+ year member]

There are several alignments used when designing a ported enclosure. They use a different volume and tuning to achieve a different goal with the speaker, ie smooth frequency response, minimal group delay, best efficiency, etc...
You cannot make a fair comparison between two subs in a ported box using the same box for each, unless they want the same box for the same alignment (very rare). Each sub has its optimal enclosure size and tuning. Using something other than that will keep the sub from performing as well as it can and will not allow for a fair assessment of its capability or quality. It is possible that the DD sub in your comparison was better suited to the enclosure that you tested them in than the XXX. It is LIKELY that the enclosure was far from optimal for either and that putting them both in their optimal enclosure will yield far better performance from both of them.

just like what he said...x2

 

[Warbleed 10+ year member]

xxx needs strong midbass to match frequencies over 50hz.don't even think about using this sub for house music with beats around 80hz.the only thing you will hear is voom,voom,voom.you hear only the harmonics of the fundamental at 80hz with a lot of delay.of course that's not a problem with 1 8 inch midbass or 2 6 inch each door.of course with rap you will never need that kind of midbass.
dd has more enjoyable sound.plays more clear and detailed.

that xbl thing must be a marketing hype.i have never heard any difference in sound quality and distortion between xbl motor and normal motor long gap/long coil(as dd).or maybe the only one can hear it is a measurement device.so what's the point for humans if they can't hear the difference?

xbl is like saying that so many years all that great subs with normal motors was junk or not the real performer in other words.but that old subs was awarded a lot of them as reference material.don't make me to name them.

so IMO xbl doesn't worth the hype.

Definitely not marketing hype. More like highly effective motor design. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

The XXX has a higher inductance and that is the ONLY reason it's frequency response is more limited.

Do any of you actually understand how speakers work? I'm sensing quite a bit of confusion....

The difference between a driver with flat BL and a totally parabolic BL curve is night and day. Just because YOU can't hear it, doesn't mean it isn't there, or that it isn't audible to someone who knows what they are listening for...

 

[luv2bass 10+ year member]

Definitely not marketing hype. More like highly effective motor design. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
The XXX has a higher inductance and that is the ONLY reason it's frequency response is more limited.

Do any of you actually understand how speakers work? I'm sensing quite a bit of confusion....

The difference between a driver with flat BL and a totally parabolic BL curve is night and day. Just because YOU can't hear it, doesn't mean it isn't there, or that it isn't audible to someone who knows what they are listening for...

i don't think you would ever hear a difference in distortion between an xbl and long gap/long coil design if no one had told you about xbl technology.it's all in your mind.human hearing is not so perfect at low frequencies.

maybe a midbass could benefit better of xbl.

 

[Warbleed 10+ year member]

i don't think you would ever hear a difference in distortion between an xbl and long gap/long coil design if no one had told you about xbl technology.it's all in your mind.human hearing is not so perfect at low frequencies.
maybe a midbass could benefit better of xbl.

That's a pretty ignorant statement. I don't believe you are adequately educated on what the differences are.

You do know that Adire even demos two essentially identical PA woofers, one with XBL^2, and one without. Everything else is the same. People have no trouble hearing the differences.

Another huge difference is power compression. Yet again, easily noticeable. Have you actually bothered to pay attention to ANY research or information about the effects of BL distortion at all?

You do realize that BL distortion accounts for about 70% of all distortion in ANY loudspeaker, right? Yet again, not debatable, nor are the effects of dramatically reduced distortion.

The difference in distortion between an XBL^2 (or any flat BL technology which is properly implemented) and an LGLC is HUGE.

BL distortion is by far the largest cause of all power compression, and that makes more and more of a difference as you increase power (and consequently, excursion).

 

[luv2bass 10+ year member]

That's a pretty ignorant statement. I don't believe you are adequately educated on what the differences are.
You do know that Adire even demos two essentially identical PA woofers, one with XBL^2, and one without. Everything else is the same. People have no trouble hearing the differences.

Another huge difference is power compression. Yet again, easily noticeable. Have you actually bothered to pay attention to ANY research or information about the effects of BL distortion at all?

You do realize that BL distortion accounts for about 70% of all distortion in ANY loudspeaker, right? Yet again, not debatable, nor are the effects of dramatically reduced distortion.

The difference in distortion between an XBL^2 (or any flat BL technology which is properly implemented) and an LGLC is HUGE.

BL distortion is by far the largest cause of all power compression, and that makes more and more of a difference as you increase power (and consequently, excursion).

about the demos:how do you know if it's a real test and not a fake comparison between 2 signals produced by a sound program?if it's true read what i said about higher frequencies.the test is being made at a frequency that's not so "bass".

about distortion:distortion skyrockets and gets really audible after bl goes to 70% of max value.a 9515 needs over 30mm to drop to 70% of bl.the same about xxx.do you think that is easy to drive a ported sub at 30mm+ without burning it's voice coil?

 

[luv2bass 10+ year member]

Extremely easy ... 5 Hz test tone, high tuning frequency, large volume //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

that's not real life subwoofer use.we talk about music and normal tunings.no subsonic frequencies.

 

[k-mart 10+ year member]

about distortion:distortion skyrockets and gets really audible after bl goes to 70% of max value.a 9515 needs over 30mm to drop to 70% of bl.the same about xxx.do you think that is easy to drive a ported sub at 30mm+ without burning it's voice coil?

Wrong.

http://www.adireaudio.com/Files/DUMAX/DD9515b.pdf

 

[luv2bass 10+ year member]

Wrong.
http://www.adireaudio.com/Files/DUMAX/DD9515b.pdf

if you were more carefull you could have read the letter b at the end of 9515 number.

that's the b version and 12.5 mm xmax is an old story.

we're talking about d versions with 42mm long coil ang 32mm gap height.i don't think that this is only 12.5mm xmax.

adire's tempest for example with 38mm long coil and 10mm thick gap claims 16mm xmax.

do you think that a longer coil and longer gap would yield worst xmax?

 

[bigbassman Premium Member]

if you were more carefull you could have read the letter b at the end of 9515 number.
that's the b version and 12.5 mm xmax is an old story.

we're talking about d versions with 42mm long coil ang 32mm gap height.i don't think that this is only 12.5mm xmax.

adire's tempest for example with 38mm long coil and 10mm thick gap claims 16mm xmax.

do you think that a longer coil and longer gap would yield worst xmax?

hi... you're wrong...

BL drops when coil starts to leave the gap...

BL is:

B = magnetic flux in the gap

L= length of wire immersed in said gap

so when wire starts decreasing in the gap... well.. you lose BL //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

the DD has 5 mm of overhang in the gap... thats simple math... 42 - 32 = 10 / 2 = 5 mm

btw, DD has used that gap and coil arrangement for years.. on the B, C, D and E..

so no, the newer 9515 doesn't have anymore linear Xmax then the older models..

the tempest.. has 14 mm of overhang, more math... 38 - 10 = 28 / 2 = 14 mm

as verified by their respective DUMAX reports, you can use overhang to give you an estimate of what its linear range could be..

course what do I know.. I've only ran and used every line of DD woofer since 01... //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Loyd L.

 

[k-mart 10+ year member]

if you were more carefull you could have read the letter b at the end of 9515 number.

I saw it, but like Loyd said, it doesn't matter.......

 

[imready77 10+ year member]

hi... you're wrong...
BL drops when coil starts to leave the gap...

BL is:

B = magnetic flux in the gap

L= length of wire immersed in said gap

so when wire starts decreasing in the gap... well.. you lose BL //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

the DD has 5 mm of overhang in the gap... thats simple math... 42 - 32 = 10 / 2 = 5 mm

btw, DD has used that gap and coil arrangement for years.. on the B, C, D and E..

so no, the newer 9515 doesn't have anymore linear Xmax then the older models..

the tempest.. has 14 mm of overhang, more math... 38 - 10 = 28 / 2 = 14 mm

as verified by their respective DUMAX reports, you can use overhang to give you an estimate of what its linear range could be..

course what do I know.. I've only ran and used every line of DD woofer since 01... //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Loyd L.

:hilarious //content.invisioncic.com/y282845/emoticons/handclap.gif.0c301076f534e244f0460706894f19e0.gif I love when do that //content.invisioncic.com/y282845/emoticons/rotflol.gif.b453361716769b8110ddefc85ff03cd2.gif .

 

[kickerlivinloud 10+ year member]

hi... you're wrong...
BL drops when coil starts to leave the gap...

BL is:

B = magnetic flux in the gap

L= length of wire immersed in said gap

so when wire starts decreasing in the gap... well.. you lose BL

the DD has 5 mm of overhang in the gap... thats simple math... 42 - 32 = 10 / 2 = 5 mm

btw, DD has used that gap and coil arrangement for years.. on the B, C, D and E..

so no, the newer 9515 doesn't have anymore linear Xmax then the older models..

the tempest.. has 14 mm of overhang, more math... 38 - 10 = 28 / 2 = 14 mm

as verified by their respective DUMAX reports, you can use overhang to give you an estimate of what its linear range could be..

course what do I know.. I've only ran and used every line of DD woofer since 01...

Loyd L.

Ownage...//content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[helotaxi 5,000+ posts]

You can usually count on Loyd to drop in out of the blue to correct people on the tech aspects of subs.

 

[kickerlivinloud 10+ year member]

He dose have quite the tendancy to do that. Nice to see happen every now and then...

Jon