Introducing SPL Chart

Anything not covered elsewhere.
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anomalous
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Joined: Tue May 16, 2006 6:40 pm
Location: Sydney, Australia

Re: Introducing SPL Chart

#106 Post by anomalous »

I've done a bit of rta, mostly for getting the eq on my system set up correctly. I use smaart6, a behringer ecm8000 (not superb, but does the job), and a motu ultralite soundcard. I have a friend with a secluded rural property where i go when i want to make measurements.

With that, you'd think I'd be able to get consistent reliable measurements. what I do get is good enough for me to do a good basic eq on my system, but i dont know that i would trust the results enough to make them public. one thing i have found, especially with units like the DR200 and DR250, is that tiny variations in mic placement (forward and back, as well as on/off axis) make a massive difference. i try and counter this by doing measurements in a variety of positions, and then trying to guess what features of the response are due to the driver/cab design, and what are environmental, and try and arrive at an eq curve that works ok over the widest range of positions. but again, this variability suggests that the response plots we all love to pour over and compare are maybe not as solid as they look, and that what you said - that people in the know tend to not fall into making comparison just with the plots - is very true.

the bummer is that there isnt a BFM Listening Library on every corner, containing multiples of every cab in the stable, available to try. :(

oh well.

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anomalous
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Re: Introducing SPL Chart

#107 Post by anomalous »

Chris_Allen wrote:Here are the T60 charts:
is there a 30" T60 loaded with a pair of Lab12's? ( I'd have thought this would have been the first one up...)

WB
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Re: Introducing SPL Chart

#108 Post by WB »

anomalous wrote:but again, this variability suggests that the response plots we all love to pour over and compare are maybe not as solid as they look, and that what you said - that people in the know tend to not fall into making comparison just with the plots - is very true.
So true.
Tomorrow I'm going to stop procrastinating - WB

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Bill Fitzmaurice
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Re: Introducing SPL Chart

#109 Post by Bill Fitzmaurice »

anomalous wrote:
Chris_Allen wrote:Here are the T60 charts:
is there a 30" T60 loaded with a pair of Lab12's? ( I'd have thought this would have been the first one up...)
http://www.billfitzmaurice.info/T60.html

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anomalous
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Re: Introducing SPL Chart

#110 Post by anomalous »

:lol: Ho ho. yes. I meant in splchart format - so it can be easily compared with other charts.

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Chris_Allen
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Re: Introducing SPL Chart

#111 Post by Chris_Allen »

I'll get those sampled too.
Built:
6xDR200, 2xT39, 2xT48, 2xJack110, 1xOmni10.5, 1xAutotuba, 1xT18, 1xSLA Pro, 1xW8, 1xW10

harolis
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Re: Introducing SPL Chart

#112 Post by harolis »

I don't understant Mackie1501 and Mackie1501M charts, because Mackie1501M chart is much more better. And one chart shows (Mackie), another (Bill..), which to belieave? What the difference?
Thanks.

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Bill Fitzmaurice
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Re: Introducing SPL Chart

#113 Post by Bill Fitzmaurice »

harolis wrote:I don't understant Mackie1501 and Mackie1501M charts, because Mackie1501M chart is much more better. And one chart shows (Mackie), another (Bill..), which to belieave? What the difference?
Thanks.
It may have my name on it but the source was Mackie. All I did was to transpose their chart.

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Chris_Allen
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Re: Introducing SPL Chart

#114 Post by Chris_Allen »



The chart from Mackie's original documentation was stated as 1W/M and transposed by Bill. I sampled from Bill's hence the accreditation, the chart disappeared from Mackie's docs but then reappeared having gained 7dB. The new chart is stated as 100dB @ 100Hz reference, so I'm not sure if they were trying a marketing trick to make the cab look better.

The chart can be found on page 11 of http://www.mackie.com/pdf/swa1501_om.pdf
Last edited by Chris_Allen on Sun Jan 07, 2018 10:22 am, edited 1 time in total.
Built:
6xDR200, 2xT39, 2xT48, 2xJack110, 1xOmni10.5, 1xAutotuba, 1xT18, 1xSLA Pro, 1xW8, 1xW10

harolis
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Re: Introducing SPL Chart

#115 Post by harolis »

Thank You, Chris_Allen. Clear. :clap:

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Bill Fitzmaurice
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Re: Introducing SPL Chart

#116 Post by Bill Fitzmaurice »

Chris_Allen wrote:

The chart from Mackie's original documentation was stated as 1W/M and transposed by Bill. I sampled from Bill's hence the accreditation, the chart disappeared from Mackie's docs but then reappeared having gained 7dB. The new chart is stated as 100dB @ 100Hz reference, so I'm not sure if they were trying a marketing trick to make the cab look better.

The chart can be found on page 11 of http://www.mackie.com/pdf/swa1501_om.pdf
Tomfoolery afoot. :cop:
I used the original Mackie chart as my source, it was 1w/1m. Their 'new' chart is not 1w/1m, and is as useful as tits on a bull. Speaking of bull... :roll:

moo
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Re: Introducing SPL Chart

#117 Post by moo »

Hi Chris.
Thanks for producing an excellent resource for us BFM Users.
I am on the verge of building a quartet of high performance OT12 with either Delta Pro 12 or 3012HO.

I presume the standard OT12 chart is with 2512, but can not find any charts or plots for Delta Pro 12 or 3012HO in the OT12.
Any chance of these being produced? as I am not the only one curious about the performance of these alternative drivers.
Sims I have done in Hornresp suggest that mids increase, but lows roll off with these drivers. It would be nice to see if this correlates with real world measurements, and would also put an end to a lot of the speculative hot air written (partly by me) about the alternative drivers.

Bill - I know its more work for you, but If these charts don't exist, would you consider measuring them and adding them to the OT12 Plans?

Thanks.
Moo.
I live the smell of birch ply in the mornings... Smells like... Victory!

Turntablist
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Re: Introducing SPL Chart

#118 Post by Turntablist »

This chart might give you and idea of what the 3012HO can give in sensitivity you over the 2512 driver. It's not the OT but still..
Image
That together with the higher powerhandling and longer X-max and you've definately got a better driver. Bill would not have recommended it if it weren't worth it's price.
-2 T48 3015LF
-2 DR250 2510 crossfired

moo
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Re: Introducing SPL Chart

#119 Post by moo »

I am aware that the 3012HO has better sensitivity, greater power handling and therefore more than twice the output of the 2512.

What I am concerned about is the cab tuning of these drivers in the OT12. My sims suggest that the 3012 and Delta Pro work better in smaller boxes, and predicts that they will roll off fairly steeply below 250hz in the standard OT12 tuning.

Has anyone measured these Drivers in OT12s?
I live the smell of birch ply in the mornings... Smells like... Victory!

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Chris_Allen
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Re: Introducing SPL Chart

#120 Post by Chris_Allen »

Afaik, the OT12's were measured with the 2512. I do have charts for the 3012HO which I need to get sampled.

As for the Delta Pro, I don't recall anyone with the capability of measuring them building one. (Unless they are buried somewhere in Bill's charts)
Built:
6xDR200, 2xT39, 2xT48, 2xJack110, 1xOmni10.5, 1xAutotuba, 1xT18, 1xSLA Pro, 1xW8, 1xW10

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