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Author Topic: Rcf 8006 and 9006  (Read 5892 times)

Scott Holtzman

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Re: Rcf 8006 and 9006
« Reply #30 on: October 02, 2018, 01:56:28 am »

Scott,  the "next axioms" to go with:

1) The wrong product at the right price is still the wrong product
2) Buy once, cry once

3) Profit potential/expense minimization is set at the time of initial purchase decisions
4) Excess capacity is infinitely expensive and lateral moves are usually just plain dumb
You have shared all of those before Tim.  I have taken all to heart.

People never learn and we see these posts with folks hoping for huge performance gains or clients to flock to them with a new set of xXxX.

I do know the economics change at the top end of the business.  The rest of us need to spend the time running our business, improving process, marketing ot just listening to your customers,

All this teeth knashing over gear selection seems a grand waste of time.

Sent from my VS996 using Tapatalk

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Scott AKA "Skyking" Holtzman
River Delta Audio is now:

Ghost Audio Visual Solutions, LLC
Cleveland OH
www.ghostav.rocks

Mark Wilkinson

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Re: Rcf 8006 and 9006
« Reply #31 on: October 02, 2018, 09:55:12 am »

The problem is the "simple paper numbers" only give part of the answer.

There is much to the sound that simple numbers simply cannot do.

And unless they are measured in the same way/conditions, simply numbers can give very misleading answers.

A much better way than the simple numbers is to look at the UNPROCESSED freq response, for a giving input signal level and measurement distance.

THEN you have something to start to compare actual capabilities.  You must assume the wattage rating is accurate, so you have a know multiplier for the total SPL.

But you also don't know the distortion etc, which can greatly affect the sound, or what they sound like with the max applied signal.

That is where the side by side tests come into play.


Sure, side by side testing is the only real way to know. For sure.

And yes, looking at unprocessed response curves is much better than paying any attention to simple numbers.
I mean look at the TH-118XL curve for example, compared to its simple number sensitivity of 108 dB.
Heck, the only time the curve shows above 108, is between maybe 120 to 170Hz.....?????

In fairness, the Architech specs say 105 dB....but my read of the curve says I better knock that down a couple, given I shoot for a 35Hz f3 and low pass at 100Hz.

I know we've had this discussion before, but IMSO, all real world side by side listening and measuring, should be done with processing in place
Sensitivity can be measured, not eyeballed against a curve. 
Max SPL and distortion needs to be heard with processing in place, as we push subs at equal levels.
Who cares what unprocessed response is when the rubber meets the road?

Besides, with so many of today's subs being self-powered, the whole processed vs unprocessed comparison becomes moot...
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Mark Wilkinson

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Re: Rcf 8006 and 9006
« Reply #32 on: October 02, 2018, 10:02:13 am »


All this teeth knashing over gear selection seems a grand waste of time.


Amen.  The more time I spend getting competent with what I have....the smaller the variances between new gear and old.

I get reminded of the golf adage by Lee Trevino .....'"a pro will beat you with an umbrella"

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Ivan Beaver

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Re: Rcf 8006 and 9006
« Reply #33 on: October 02, 2018, 04:22:11 pm »


Sure, side by side testing is the only real way to know. For sure.

And yes, looking at unprocessed response curves is much better than paying any attention to simple numbers.
I mean look at the TH-118XL curve for example, compared to its simple number sensitivity of 108 dB.
Heck, the only time the curve shows above 108, is between maybe 120 to 170Hz.....?????

In fairness, the Architech specs say 105 dB....but my read of the curve says I better knock that down a couple, given I shoot for a 35Hz f3 and low pass at 100Hz.

This is a good example of where the data from engineering gets entered wrong by others.

Thanks for the heads up-I have already passed the error onto the "parties that be" to be changed.

It got missed somewhere.

The sensitivity should be 105dB.

Regarding where someone feels the "low freq point" should be, is exactly why the data is presented.

just like impedance.  We provide a standard number, but the user can look at the curve and determine what they feel best represents the actual number-since a simple single number can't do that.

Without a graph, there is no way to know where the numbers came from
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A complex question is easily answered by a simple-easy to understand WRONG answer!

Ivan Beaver
Danley Sound Labs

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David Morison

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Re: Rcf 8006 and 9006
« Reply #34 on: October 03, 2018, 04:08:25 am »


just like impedance.  We provide a standard number, but the user can look at the curve and determine what they feel best represents the actual number-since a simple single number can't do that.

Without a graph, there is no way to know where the numbers came from

Just looked at the pdf and webpage for the 118XL - no impedance curve in sight. Don't suppose you could get that fixed too please?
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Ivan Beaver

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Re: Rcf 8006 and 9006
« Reply #35 on: October 03, 2018, 08:19:12 am »

Just looked at the pdf and webpage for the 118XL - no impedance curve in sight. Don't suppose you could get that fixed too please?
I sent in that request also.

BTW how many other manufacturers show impedance curves of products?

Not very many it seems these days.  Most don't even show a freq response plot.


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A complex question is easily answered by a simple-easy to understand WRONG answer!

Ivan Beaver
Danley Sound Labs

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Ivan Beaver

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Re: Rcf 8006 and 9006
« Reply #36 on: October 03, 2018, 08:21:43 am »

Just looked at the pdf and webpage for the 118XL - no impedance curve in sight. Don't suppose you could get that fixed too please?
Here it is
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A complex question is easily answered by a simple-easy to understand WRONG answer!

Ivan Beaver
Danley Sound Labs

PHYSICS- NOT FADS!

David Morison

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Re: Rcf 8006 and 9006
« Reply #37 on: October 03, 2018, 08:46:39 am »

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Peter Morris

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Re: Rcf 8006 and 9006
« Reply #38 on: October 03, 2018, 11:14:01 am »

This is a good example of where the data from engineering gets entered wrong by others.

The sensitivity should be 105dB.



...and if you measure it the same way as almost everyone else 102 dB w/m :)
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John Schalk

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Re: Rcf 8006 and 9006
« Reply #39 on: October 03, 2018, 11:52:06 am »

Regarding where someone feels the "low freq point" should be, is exactly why the data is presented.

just like impedance.  We provide a standard number, but the user can look at the curve and determine what they feel best represents the actual number-since a simple single number can't do that.

Without a graph, there is no way to know where the numbers came from

If RCF published frequency response graphs for the 8006 & 9006 perhaps there would be fewer requests from Labsters for the subjective opinions of others as to how they compare.  I particularly appreciate Ivan's remarks regarding how a frequency response graph allows us to make our own determination of the -3dB spec (or whatever) for a given sub.

The band I work for owns EV PX2181s.  They are an incarnation of EV's "horn-loaded sub-scoop" design.  The spec sheet lists them as -3db at 45Hz, but when I look at the chart (thank you EV), using the response from 60-90 as the reference, I conclude that the -3dB point is a bit higher than that.  That's helpful to me because one possible sub that I might buy is the ThMini 15 which has a -3dB spec of 50Hz which sounded too high to me until I looked up the actual response of the subs I mix on every week.

Unfortunately, almost none of the big boys publish the frequency response of their subs anymore.  A great illustration of this issue is the DVA S30n.  It has a published -3dB spec of 30Hz and a maximum output of 141dB.  Sounds great!  However, I found a Youtube review of the sub by TrinityProSound that includes some informal objective response information which makes it clear that this quasi-horn design has very limited response below 50Hz relative to the 60-90 range.  I have no idea how they can give it a -3dB rating of 30Hz based on what is shown in that video and we all must assume that the same thing is true for all of the other claimed responses that aren't backed up with object graphs.
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