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Author Topic: do EAW LA400 subs improve low end response in pairs/quads?  (Read 4925 times)

James Heyser

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do EAW LA400 subs improve low end response in pairs/quads?
« on: August 11, 2011, 05:21:27 pm »

I read somewhere years ago that they are spec'd as an individual cabinet, but that in pairs (or fours) their frequency response extended downwards.

-10db@40hz is intolerable, but they would be quite attractive if they went down to 30 or below, they would be a very attractive option for smaller gigs.

Anyone own some that has spec'd them in pairs or quads?
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Ivan Beaver

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Re: do EAW LA400 subs improve low end response in pairs/quads?
« Reply #1 on: August 11, 2011, 06:16:22 pm »

I read somewhere years ago that they are spec'd as an individual cabinet, but that in pairs (or fours) their frequency response extended downwards.

-10db@40hz is intolerable, but they would be quite attractive if they went down to 30 or below, they would be a very attractive option for smaller gigs.

Anyone own some that has spec'd them in pairs or quads?
All horn loaded subs extend their response down lower when used in multiples with the mouths coupling.

But it may not be as much as you want.

The only way to tell is to measure 1 cabinet-then add another and another 2-while keeping the measurement conditions exactly the same.

Then you would be able to see what is really happening.

You also need to consider when looking at spec numbers, that you are really comparing apples to apples-especially where the low freq is concerned.  Don't just go by the "simple numbers".

In some cases, the low freq on the spec sheet is not tied to the sensitivity or as is also common, A +-3dB spec is considered "flat"-so the response can be down 6dB and still considered flat.  Then they go down another 3dB (-3dB????) and give that number.

The only way to tell is to actually meaure the cabinet-or compare the manufacturers response graph to the published spec numbers.

If you are comparing to another cabinet-make sure the "scales" of measurement are the same.  One persons -3dB is another persons -9dB.  Not exactly the same-but the level may be equal.
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Ivan Beaver
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Mike Christy

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Re: do EAW LA400 subs improve low end response in pairs/quads?
« Reply #2 on: August 11, 2011, 06:43:29 pm »

All horn loaded subs extend their response down lower when used in multiples with the mouths coupling.

But it may not be as much as you want.

The only way to tell is to measure 1 cabinet-then add another and another 2-while keeping the measurement conditions exactly the same.

Then you would be able to see what is really happening.

You also need to consider when looking at spec numbers, that you are really comparing apples to apples-especially where the low freq is concerned.  Don't just go by the "simple numbers".

In some cases, the low freq on the spec sheet is not tied to the sensitivity or as is also common, A +-3dB spec is considered "flat"-so the response can be down 6dB and still considered flat.  Then they go down another 3dB (-3dB????) and give that number.

The only way to tell is to actually meaure the cabinet-or compare the manufacturers response graph to the published spec numbers.

If you are comparing to another cabinet-make sure the "scales" of measurement are the same.  One persons -3dB is another persons -9dB.  Not exactly the same-but the level may be equal.

Ivan,

It is not all relative? Does it extend down, but also is additive such that the 75Hz bump (for example) is now +9db higher as well?

So you have to EQ/process more to even it out?

Mike


 
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Chris Davis

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Re: do EAW LA400 subs improve low end response in pairs/quads?
« Reply #3 on: August 11, 2011, 11:05:02 pm »

I read somewhere years ago that they are spec'd as an individual cabinet, but that in pairs (or fours) their frequency response extended downwards.

-10db@40hz is intolerable, but they would be quite attractive if they went down to 30 or below, they would be a very attractive option for smaller gigs.



No.  You will need a larger sized bass horn (or a different type of cab) to reach down to 30 or 40 Hz.  These go down to about 50 Hz.


 

Ivan,

It is not all relative? Does it extend down, but also is additive such that the 75Hz bump (for example) is now +9db higher as well?

So you have to EQ/process more to even it out?

Mike



Yes, this applies to these cabs.  Very much so...  :o


« Last Edit: August 11, 2011, 11:14:09 pm by Chris Davis »
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Ivan Beaver

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Re: do EAW LA400 subs improve low end response in pairs/quads?
« Reply #4 on: August 12, 2011, 08:07:29 am »

Ivan,

It is not all relative? Does it extend down, but also is additive such that the 75Hz bump (for example) is now +9db higher as well?

So you have to EQ/process more to even it out?

Mike
Yes and no.  Several different things start to happen.  And you only really see them when measured exactly the same way.

You don't have to eq any more than you would with only 1 cabinet.  In fact the overall response will be flatter-due to the larger mouth area "filling in the holes" in the response that exist because the mouth is to small for the wavelengths being reproduced.

So multiple horns go lower and have a flatter response than a single horn.  That is assuming the horns that we normally deal with, in which the mouth area is to small-not some of the huge horns that the hi fi guys use-you know the ones that extend 30' into their back yards with a 4" driver.

Yes the overall response will be louder (generally), so any humps will also be louder by the same amount-so no additional eq is needed.  However-due to the impedance loading of the larger mouth, the low end will extend down lower (besides already being louder due to the additional cabinets).

Something that is usually not talked about is what happens at the top end of the response (say 100Hzish give or take).

You may not see as much "gain" as you do, at say 60Hz.  This is due to some cancellations due to the physical spacing of the devices at the shorter wavelengths.  We aren't talking much here-on the order of a dB or so.  But when you measure low freq extension by going 2 or 3 Hz lower, it is all relative.

Yeah it does not affect most people, and you don't see it unless you take careful measurements and compare them.
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Ivan Beaver
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duane massey

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Re: do EAW LA400 subs improve low end response in pairs/quads?
« Reply #5 on: August 13, 2011, 03:04:13 am »

I'm in agreement with Ivan. The horns that I normally build have a low flare rate, and coupling two or even four definitely extends the useable range. I would suspect that if a horn had a higher flare rate (above 40 or 50hz) this would not be as pronounced, but the mouth size would also be a factor.
Trust Ivan, he has a lot of experience with horns.
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Duane Massey
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Ivan Beaver

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Re: do EAW LA400 subs improve low end response in pairs/quads?
« Reply #6 on: August 13, 2011, 11:20:24 am »

Ivan,

It is not all relative? Does it extend down, but also is additive such that the 75Hz bump (for example) is now +9db higher as well?

So you have to EQ/process more to even it out?

Mike
Here is a graph of 1,2,3 and 4 horn cabinets (not the LA400's in question).  Measurement distance is at 30' and all we did was add additional cabinets.  So nothing changed.

You can see how the low end extended down a little bit, how it got overall smoother etc.

« Last Edit: August 13, 2011, 11:46:14 am by Mac Kerr »
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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!

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Re: do EAW LA400 subs improve low end response in pairs/quads?
« Reply #6 on: August 13, 2011, 11:20:24 am »


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