72 replies to this topic

[~thematt~]

muzzy66, on Nov 10 2009, 08:54 AM, said:

- every other one tested performed mediocre including Velodyne.

You've got your woofers mixed up. Velodyne is a manufacturer, and the 'Velodyne' that is so well talked up is called a Direct Drive unit (or DD models). These have accelerometers built into them that allows the woofer to correct its movements almost instantaneously. They are, by design, more accurate and have lower distortion then comparable conventional units.

The unit in the test is an SPL style unit, not a direct drive. Apples and Oranges.

data_mine, on Nov 12 2009, 06:37 AM, said:

In a car environment I'd say the sub box makes more of a difference.

As for trusting the numbers, you either have to measure everything yourself, or trust the manufactuers all do their testing the same way so the numbers are actually comparable.

In that case, I suggest, unless you review/measure yourself you can't trust what you're being told, third party review, or manufacturers specs.

Br85 is right. Environment is the big factor. The subbox is waayyy more important then the sub itself, but its the relationship/interaction between the alignment and the environment that produces the final result.

Here is a question for everyone who says you 'cant use manufacturers specs'. What EXACTLY are you referring to? Which specs specifically, do you think are incorrect in the car? T/S specs? Distortion, FR plots?

[data_mine]

~thematt~, on Nov 12 2009, 10:38 AM, said:

Here is a question for everyone who says you 'cant use manufacturers specs'. What EXACTLY are you referring to? Which specs specifically, do you think are incorrect in the car? T/S specs? Distortion, FR plots?

My assumption there, was BR85 talking about FR plots.

Frequency Response, as we already know is affected, by the enclosure and environment greatly. So unless everyone tests using the same enclosure and environment the FR graphs are not comparable. (Is there a ISO standard for this? Is this what Klippel is supposed to solve?)

t/s specs should be fairly accurate only differing due to manufacturing tolerances. Since I got my WT3 t/s spec measurement device, I've tested the various speakers and subs I own, the results are within a bees d*** of published specs. I do use 'better' brands though. I guess some BOSS audio stuff may be further out of tolerance, having said that my Cadence sub measured with 1% of spec.

Edited by data_mine, 12 November 2009 - 09:47 AM.

[Matt VIP]

your cadence sub has also recently been nominated for UN secretary general.

Needs a big box though...

[data_mine]

Matt VIP, on Nov 12 2009, 11:11 AM, said:

your cadence sub has also recently been nominated for UN secretary general.

Needs a big box though...

You've always been jealous of it, I'll swap you it for your JL amps.

Thenyou can have some non-muddy bass (and you've got a big enough boot for it), and I can have some nice new amps. Everyone's a winner.

[Gobbledok]

out of curiosity, what cadence sub is it? i was actually having an argument with a mate about how accurate t/s specs are when published. (by cheaper brands)

[data_mine]

GTi-FTW, on Nov 14 2009, 04:25 PM, said:

out of curiosity, what cadence sub is it? i was actually having an argument with a mate about how accurate t/s specs are when published. (by cheaper brands)

An ancient (must be near on 10 years old now), UD-104 10" 4ohm SVC

[~thematt~]

data_mine, on Nov 12 2009, 07:45 AM, said:

My assumption there, was BR85 talking about FR plots.

Frequency Response, as we already know is affected, by the enclosure and environment greatly. So unless everyone tests using the same enclosure and environment the FR graphs are not comparable. (Is there a ISO standard for this? Is this what Klippel is supposed to solve?)

t/s specs should be fairly accurate only differing due to manufacturing tolerances. Since I got my WT3 t/s spec measurement device, I've tested the various speakers and subs I own, the results are within a bees d*** of published specs. I do use 'better' brands though. I guess some BOSS audio stuff may be further out of tolerance, having said that my Cadence sub measured with 1% of spec.

The only point of t/s specs are to create an enclosure. They are worthless otherwise. That being said, you dont need them to get a good/great enclosure. It just gets you there with less iterations.

The Klippel doesnt test FR. It allows you to test the real parts of a motor system that impact audible response. Things like BL curves, Mechanical Compliance, Suspension Stiffness, inductance and symmetry are all incredibly important. This is the type of data that the Klippel pumps out.

Frequency Response is very useful, if you use it properly. The problem has never been with the specs, but the knobs that read them. Looking at a graph and going 'geez, that bump at 2k dont look too good, I dont like this speaker' is just downright foolish.

[Fury♫]

Polar measurements and power response is far more useful then your "standard" frequency response graph.

Anywho we're digressing from the topic at hand a wee bit.

[Riley.]

fury, on Nov 14 2009, 11:38 PM, said:

Anywho we're digressing from the topic at hand a wee bit.

and you are surprised? this may as well be the Off Topic section some times....although every question goes the same way

- question
- one slightly related theory
- a different theory arguing
- a distributor comes in and says "hey everyone buy my product"
- more arguing
- someone posts up a whole heap of graphs/specs
- more arguing going further off topic
- someone goes "oh hey this is a bit off topic"
- question isnt really any closer to being answered

[fuddbutter]

- Someone sum's up the thread in a witty point form

[Green_machine]

there's no best sub on the market, every one has the own opioin on subs. Mybe just youtube a few 8" subs and see which one you like

[broadz]

as youtube is OBVIOUSLY the best way of choosing speakers/subs... wtf?

I think i have narrowed the best 2 eight inch subs to the Focal Be 8 and the JL 8W7 (which i ended up buying). however i think it is too much of a compromise in output over the dual twelves I'm upgrading from.

Edited by broadz, 15 November 2009 - 08:12 PM.

[~thematt~]

3seven7, on Nov 15 2009, 06:01 PM, said:

Mybe just youtube a few 8" subs and see which one you like

Oh my god. I'm laughing so loud its making me cry!!!

[broadz]

do we have quote of the year?

[Gobbledok]

broadz, on Nov 16 2009, 08:18 AM, said:

do we have quote of the year?

i would certainly hope so!