Speaker Design Q&A

0 Members and 1 Guest are viewing this topic. Read 369 times.

musiccritic5088

  • Jr. Member
  • Posts: 20
Speaker Design Q&A
« on: 18 Feb 2021, 08:39 pm »
Hi, my name is James and I am new to this forum so please excuse me if I do something I’m not supposed to.

I wanted to create this thread in order to help me and anyone else trying to learn about the fine details of speakers design and I’ll start this thread off with my first set of questions (these are the types of q&a I want in this thread).

My first questions regard to crossover design (somewhat).

     In a crossover, I am aware that all components add specific delay amounts to the audio signal, with some components having little to no delay and with others having a big delay to the audio signal. My questions are as follows.

Question 1
Are there specific crossover components that I can use to solely adjust the time delay of each driver in a multi-way speaker? Components that won’t effect anything except time delay? The issue im trying to resolve is PHASE ALIGNMENT of the drivers. My concern is that once my speaker drivers are locked in place on the baffle, once I build my crossover, some of the drivers will be out of phase with the others to a certain degree. My first instinct was to create individual moveable cabinets for each driver so that even after I design my crossover I can physically time align my speakers. I’m told that the issue with this is the possibility of reflections and diffraction due to the uneven baffle surface which will cause coloration to the audio signal. With this in mind, my next instinct is to have one baffle for all the drivers, and mount each driver a certain depth into the baffle.

Question 2 (also a continuation of question 1)
The issue I’m worried about in doing this is, for the mid and high frequency drivers, how will I mount the drivers deeper into the baffle in a way that I won’t cause coloration to the drivers due to the throat I will be making that the driver will be sitting behind.. My first instinct to solve this issue is to round the corners of the cutouts I make to mount the drivers deeper into the baffle. My concern in doing this is that I will create a boost/Horn effect to the driver at a specific frequency and up due to an effect similar to baffle step loss.

Question 3
Is there a way I can mount my drivers deeper into my baffle without coloration to the sound? Is it a matter of me being unable to mount the driver past a certain depth into the baffle so that I can avoid having a throat deep enough to effect the frequency range of a specific driver? If this is the case then it’d be nearly impossible to have no coloration to the tweeter as this is the driver I will have to mount the deepest if I want to time align each driver at the horizontal axis.

Question 4
With all this in mind, is there a shape that I can make the cutouts so that the cutouts won’t add coloration to the signal?

Question 5
Is the idea behind a tractrix horn to amplify the signal without coloration of the sound?

Edgar77

  • Jr. Member
  • Posts: 57
Re: Speaker Design Q&A
« Reply #1 on: 19 Feb 2021, 03:19 am »
In a crossover, I am aware that all components add specific delay amounts to the audio signal, with some components having little to no delay and with others having a big delay to the audio signal.

Crossovers are not about delays. They are about frequency separation.

I am sure you will find lots of details in Danny's videos
https://www.youtube.com/channel/UCIJHwsTJyrH4YznoJxZmJHQ

musiccritic5088

  • Jr. Member
  • Posts: 20
Re: Speaker Design Q&A
« Reply #2 on: 19 Feb 2021, 04:53 am »
Crossovers are not about delays. They are about frequency separation.

I am sure you will find lots of details in Danny's videos
https://www.youtube.com/channel/UCIJHwsTJyrH4YznoJxZmJHQ

Yes I am aware of this but I already know how that aspect of a crossover works. The issue I’m trying to resolve is the effect that the crossover has to the speakers phase alignment. For instance how inductors have more of a phase delay than capacitor due mainly to the longer signal path.

FullRangeMan

  • Volunteer
  • Posts: 15573
  • To whom more was given more will be required.
    • Never go to a psychiatrist, adopt a straycat or dog. On the street they live only two years average.
Re: Speaker Design Q&A
« Reply #3 on: 19 Feb 2021, 04:58 am »
Do you could see D'Apollito MTM on time delay.

musiccritic5088

  • Jr. Member
  • Posts: 20
Re: Speaker Design Q&A
« Reply #4 on: 19 Feb 2021, 04:44 pm »
Do you could see D'Apollito MTM on time delay.

I’ll check it out!

Danny Richie

  • Facilitator
  • Posts: 13517
    • http://www.gr-research.com
Re: Speaker Design Q&A
« Reply #5 on: 28 Feb 2021, 01:47 am »
Question 1
Are there specific crossover components that I can use to solely adjust the time delay of each driver in a multi-way speaker? Components that won’t effect anything except time delay? The issue im trying to resolve is PHASE ALIGNMENT of the drivers. My concern is that once my speaker drivers are locked in place on the baffle, once I build my crossover, some of the drivers will be out of phase with the others to a certain degree. My first instinct was to create individual moveable cabinets for each driver so that even after I design my crossover I can physically time align my speakers. I’m told that the issue with this is the possibility of reflections and diffraction due to the uneven baffle surface which will cause coloration to the audio signal. With this in mind, my next instinct is to have one baffle for all the drivers, and mount each driver a certain depth into the baffle.

There are no components that solely adjust phase. But all components in some way do shift phase. And there are ways to shift phase using combinations of parts so that the drivers are in phase and sum properly. And this is typically a lot easier that trying to correct for the diffraction problems associated with separate baffles.

And just because they are physically aligned does not mean they are now in phase. As soon as you start putting crossover parts on them then they are not in phase. 

Quote
Question 2 (also a continuation of question 1)
The issue I’m worried about in doing this is, for the mid and high frequency drivers, how will I mount the drivers deeper into the baffle in a way that I won’t cause coloration to the drivers due to the throat I will be making that the driver will be sitting behind.. My first instinct to solve this issue is to round the corners of the cutouts I make to mount the drivers deeper into the baffle. My concern in doing this is that I will create a boost/Horn effect to the driver at a specific frequency and up due to an effect similar to baffle step loss.

Recessing drivers into the baffle is just going to cause a whole host of new problems. 

Quote
Question 3
Is there a way I can mount my drivers deeper into my baffle without coloration to the sound? Is it a matter of me being unable to mount the driver past a certain depth into the baffle so that I can avoid having a throat deep enough to effect the frequency range of a specific driver? If this is the case then it’d be nearly impossible to have no coloration to the tweeter as this is the driver I will have to mount the deepest if I want to time align each driver at the horizontal axis.

You are confusing time alignment with physical alignment. They can be physically aligned and completely out of phase.

Quote
Question 4
With all this in mind, is there a shape that I can make the cutouts so that the cutouts won’t add coloration to the signal?

No.

Quote
Question 5
Is the idea behind a tractrix horn to amplify the signal without coloration of the sound?

No.

FullRangeMan

  • Volunteer
  • Posts: 15573
  • To whom more was given more will be required.
    • Never go to a psychiatrist, adopt a straycat or dog. On the street they live only two years average.
Re: Speaker Design Q&A
« Reply #6 on: 28 Feb 2021, 02:25 am »
Great class Danny thanks for these explanations  :thumb: