Here are a couple of graphs.

I have no idea how to interpret them, and will provide more information (enclosure, size, driver) as the thread unfolds...



Basically I want to know, are these acceptable responses for a midbass which will be considerably off axis? Which one is better? they both look the same to me...

Cheers!

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sure they are not the same driver? it looks like one has a standing wave in the enclosure and one doesn't. @ about 350hz, there is a 3dB boost.

and i dont think thats gonna give u a predicted off axis response. it looks like degree is phase, not degree off axis?

thats all assuming line 28 = SPL in the enclosure.

i havent used LEAP before, so im only guessing as to what the lines are.

if I can get a handle on what it means, is that there is about a 6db drop between 80hz (81db) and 300hz (87db) for the graph 5-50, and a 5db drop (87-82) in the graph 10-50. Considering this is the band I want to run the speaker in, is this normal? good? bad? I assume that, in all probablility according to the graphs, that there will be very little audible difference between 5-50 and 10-50.

anyone else?

are these replacing the z6's?

maybe

I cannot see the pdf's.

Got a link to a site with the info?

right well lets try again then shall we?

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righto

"printscreen" wins again
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Is that measured free air?
Looks like it rolls off a little soon, but an enclousure could help that?

pdf's are not happy

got jpg's?

He's posted .jpg's, they work fine

ahhh, site's a bit slow here tonight
I see it all now

That anomaly at 350Hz is disturbing (hahaha)

0.5dB difference from 50 to 100Hz isn't going to kill you

great!

thats all I really needed to know.

The above graphs are of my scanspeak 7" revelator midbasses, graphed with 50% fill at 1w for 5 and 10L enclosures. The one with the peak is the 10L enclosure, although I'm expecting to only get somewhere between 5-8L out of my constructions.

as long as the 5L graph looks ok, then I'm happy.


cheers gang

In that case, the graphs look HORRIBLE!
Sell me the drivers instead

Can you fit a bigger enclosure?

does it really look bad?

I dont know how to interperet these things, so if the drivers are no good, then you're welcome to 'em.

You wouldn't be trying to trick me though, would you?

How much did those drivers cost?

I think they're about AU$3-400 each?

I got them second hand for a reasonabe price.

anyone else help me on this?

Just do it.

I am!

put down another 2 layers on the boxes today, got another layer to go, then cut and route the baffles.

should be getting my extraspecial midranges this week too!

Thanks for all your advice, fury, its been, um, inspirational

got another one for you. this looks a little better.

Still modelled in a sealed enclosure, this time at 100w.

can anyone help me interpret it?

cheers!

Matt VIP

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a 100w model seems pointless as the heat might be starting to pick up. wat (max) voltage are they putting across the voice coils in this case?

ummmm....

I dont know?

wat exactly are u trying to get from these graphs?

please see my earlier response



The reason why I put this up is because I dont know how to interpret graphs in any meaningful way. I got someone to model the specs of my midwoofers for me, and got concerned when some bright spark suggested that the graphs looked cr@p and I should give them to him

so I got the guy who did the original modelling to find a driver that would work well in a small sealed enclosure (ie the last graph) and here I am.

so i'm relying on the people here who DO know how to interpret these graphs to guide me in what they might mean in the real world.

ja?

the problem with all those graphs is you can't hear them, and they're not modelled on "in-car" reponse.

what is the resonant frequency of the car? what are the boundary nodes? what is the volume of the interior, and the dimensions? what is the absorbancy of the interior (nett and near vs. far field), have you modelled the underside profile of the dash, and anything else within 2m (or so) of the woofer mounting locations?

there is a scientific approach, but it must be complete to be meaningful. Also, the actual drivers will vary (up to 5%) from the advertised specs.....

concentrate more on the surface treatments, and interior space. The sound will come to you.

did you get some cheap computer speakers to play with, to find good mounting locations for each speaker?

<<<has never heard a graph sound good

maybe Im *listening* to wrong graphs *shrugs* lol
peace
Cyberpunky

ok. it will depend on what u are trying to do. wat u have there is a predicted response @ 100w. @ 100w's i'd expect the drivers u have would start to become quite warm. when that happens, the drivers response changes completely. so a graph showing response is pretty much useless because its either produced @ 1w (which we never listen to) or the power input becomes large and the T/S specs change.

However, graphs like these are very good for desiging enclosures. thats ALL they are good for. so u have to look @ things like the F3 point, group delay, phase but most importantly u need the total Q.

SO, we cant sit here and say, yup, thats a good driver because

a) dont know how it will perform in YOUR car
b) dont know what u are trying to achieve with YOUR setup
c) dont know what sounds nice to you

thats why u have to be specific with what u want us to tell u. otherwise, we cant begin to give u a meaningful interpretation. its like giving us a car but with no directions as to how u want to get u to ur destination.