Danley SH96HO

Re: Danley SH96HO

I am with Ivan in this too. It is not a simple answer. Any simple answer will be wrong.
If i tell you that in some of my boxes the crossover is set at 3.5Khz that will be true to the point when you measure the HF and you see that it actually goes down to 1000Hz.
So which answer is the right one? 3.5KHz or 1000Hz. That is a very wide band we are talking about.
And then there is the LPF that Ivan talks about on top of that that is at about 7.5Khz.
So pick any of those 3 points. They are all correct.
 
Re: Danley SH96HO

The electrical response of a good crossover will flatten the amplitude response of the various drivers, time and phase align the relative pass bands while taking into account the impedance of the drivers, their individual phase response and their physical locations. So it will not match any text book electrical response.

Is probably best to ask; what is the acoustic crossover point? The answer to that is simple. It’s either:

· XXXHz
· XXXHz asymmetric e.g. 24 dB LR + 18 dB Bessel
· or they overlap with the 4” running up to about XXXXHz and the HF driver down to about XXXHz

To that you can add detail about the relative slopes, and if there is an overlap, how that is done.

In the case of a synergy horn, the crossover points are related to the position of the entry points of the various drivers into the horn.

The maximum frequency (for example) of the 4 inch drivers has to be such that the dimension of the horn at the entry point have to be small in respect to the shortest wave length it produces … about 1/4 of a wavelength (rule of thumb) from the apex of the horn and each other. If you don’t do that you will get all sorts of reflections and ugly stuff happening inside the horn.

The other trick is that 15” drivers are in front of the 4”drivers which are in front of the HF driver. This means with some tricky passive crossover design you can reduce the total amount phase “displacement” (for want of a better description) needed to get it all to work.

If for example, the 4 inch drivers entered the horn about 4 inch from the apex of the horn, ( FWIW I don't know where they do) the maximum desired crossover point would be about 800Hz, however you could more or less run the HF driver as low as you like.
 
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Re: Danley SH96HO

Mike Pyle said:
To be clear, I did not ask you to do any of that. Rich Frembes said "It's best if you can eyeball actual on- and off-axis magnitude graphs plus a phase response graph." To which I replied "I agree. If they graphed the magnitude and phase response of the drivers in each passband that would answer my question. But the published graphs do not." Nowhere in that exchange do I suggest that you DO anything at all, merely that if the information were available it would be useful.
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I will not go through the explanation again. but exactly HOW do you suggest we "grab a response" of the individual pass bands of each speakers in a PASSIVE system?

THAT is what I was trying to explain to you. Please reread my last post about the problems with trying to "simply grabbing a passband response" and getting an accurate number that actually means something.

So let me pose THIS question.

Can you point me to ANY OTHER PRODUCT that shows the passbands of individual components in a passive system?

I am not aware of any.

Why do you need it on this product-and not every loudspeaker?

And just how is that information going to change anything that you do?
 
Re: Danley SH96HO

Maybe this will help somewhat.

I am not talking about the mid/high crossover here, but rather the low mid crossover point when in biamped mode.

The HP on the mids is 300Hz, and the lowpass on the woofers is 600Hz.

This DOES NOT IN ANY WAY suggest that the acoustical response of either of these bands will be measured as going to those points and falling off.

The lows fall off MUCH sooner than 600hz. This is due to both the acoustic low pass filters in the cabinet and the large self inductance of the woofers voice coils.

The mids don't go that low. The passive HP on the mids is still in the circuit when in the biamped mode.

The ELECTRICAL filters are where they are to get the best PHASE response.

But if people simply look at the "simple numbers", they would "think" that the crossovers are all wrong, would start to second guess the numbers.

In a loudspeaker is the COMPLEX SUM of the individual working together, NOT each section simply added together.

OK OK-I know that mathematically the sum is adding individuals together-but I could not think of a better way to say it. So let's not go down that road-------

Again-I am not trying to be an ass or a jerk-just presenting the facts and that "simple numbers" DO NOT describe what is actually going on.
 
Re: Danley SH96HO

Let me explain just a small part of the "design process" of a passive crossover.

First we gather individual amplitude-phase-impedance curves of each pass band.

Then we start to design a crossover to get the "ballpark" response curve we want for each passband.

It is when we PUT THEM TOGETHER, that we start to change all sorts of things-freq/slopes sometimes eq (yes passive eq) and so forth.

At that point we are not so much concerned with the individual passbands, but rather the system as a WHOLE.

We do constantly monitor the electrical response of each band to make sure that things don't go beyond where they are safe.

If so, we back up and redo.

At no time are we concerned with a "simply number" or a single "crossover freq". We are looking for the overall response.

In a good design, you cannot tell where the crossover point it. That is a GOOD THING, and it doesn't matter.

In a "perfect design, it wil look like a single driver loudspeaker, with a phase response that looks like an electrical HP/LP filter combination.

Sometimes we get closer than others.
 
Re: Danley SH96HO

Forget it Ivan. I guess I didn't understand how it is impossible for you to say what frequency ranges the different drivers in the SH96HO are supposed to receive and reproduce, given all the knowledge of the system that you have, and given the opportunity to craft an answer that could be qualified in any way that you choose.
 
Re: Danley SH96HO

Mike Pyle said:
Forget it Ivan. I guess I didn't understand how it is impossible for you to say what frequency ranges the different drivers in the SH96HO are supposed to receive and reproduce, given all the knowledge of the system that you have, and given the opportunity to craft an answer that could be qualified in any way that you choose.
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Mike, can you clue in this old guy who is trying to understand why this is important to start with?
 
Re: Danley SH96HO

Prepping a rented system for a gig, I could see the initial processing was not right. Low mid crossover was set too high, I suspect high enough to virtually disable the 4" mids. I wanted more information about the function of the cabinet above that crossover point. At this point I don't give a shit. The rig is processed, packed and ready to go.
 
Re: Danley SH96HO

Mike Pyle said:
Prepping a rented system for a gig, I could see the initial processing was not right. Low mid crossover was set too high, I suspect high enough to virtually disable the 4" mids. I wanted more information about the function of the cabinet above that crossover point. At this point I don't give a shit. The rig is processed, packed and ready to go.
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Hi Mike,

Sounds like you're over it :roll: ... but FWIW the low-mid crossover is critical. If it’s too high the 15s will have an output with wave lengths that are too short relative to their entry location. This will cause problems such as reflections inside the horn instead of a synergy effect where all the drivers add together and behave as one point source.

I must admit that I didn’t think it was a difficult question. I suspect a simple answer about the acoustic crossover points was all you were after – (for example only) something like - the 15s operate from about 50Hz to 350Hz, the 4s 350Hz - 1000Hz, the HF 1000Hz to 6K3 and VHF above 6K3 - would have been good enough.

Hope your gig goes well.
 
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Re: Danley SH96HO

Peter Morris said:

]I must admit that I didn’t think it was a difficult question.I suspect a simple answer about the acoustic crossover points was all you wereafter – I suspect (for example only) something like - the15s operate fromabout 50Hz to 350Hz, the 4s 350Hz - 1000Hz, the HF 1000Hz to6K3 and VHF above 6K3 would have been good enough.
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Your guesses on the freq range would be pretty close.

But there is a difference in asking what IS the crossover vs what is the relative crossover.

Actual numbers are a lot harder to come by.

But (again-not to be rude) but the question was not about the acoustic crossover or the electrical-just crossover in general.

THAT is what makes it harder.

Part of the reasons for my posts are to help people get a better understanding about what is going on. The more you understand, the better equipped you are for more advanced questions and understanding later on.

If I had said 1K or 1.2K or 1.5K, what difference would it make in any sort of eq or adjustments? Especially since it is a passive network that should not be changed.
 
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