[bhatmaster]

Yes, I considered buying a used componenet set too. But, problem is that from my personal experience, these drivers are absolutely crap. JBL Power series compnent P650C supposed to be among the better ones, but it's pretty pathetic in my exp ( may be the cross-over design was not correct, I'm not sure) and I felt even a low range driver like Dayton RS150 will beat it hands down.

I'm thinking of using the above mentioned driver with with Vifa D27TG35
tweeter and designed the following cross-over ( derived based from data data sheet given from manufacturers , not real world test data though) -



But, this is more or less considering the open /infinite baffle , needs suggestion from you all to make finer adjustment to correct this according to car's environment. I never had done this before and hence need help from you. I don't have any advanced equipment to derive the real , in car SPL curve and hence suggestions from you prior experience are most welcome.
And another point, where we can fit the dome tweeters in Car. If placed in the door, will it obstructs the glass movement?

[navin]

Originally Posted by bhatmaster

Yes, I considered buying a used componenet set too. But, problem is that from my personal experience, these drivers are absolutely crap.

I'm thinking of using the above mentioned driver with with Vifa D27TG35
tweeter and designed the following cross-over ( derived based from data data sheet given from manufacturers , not real world test data though) -

Attachment 480777

I never had done this before and hence need help from you. I don't have any advanced equipment to derive the real , in car SPL curve and hence suggestions from you prior experience are most welcome.
And another point, where we can fit the dome tweeters in Car. If placed in the door, will it obstructs the glass movement?

Originally Posted by bhatmaster

Nobody seems to be willing to help me out. :-(
Was wondering if there is any option other than this 4th order Linkwitz-Riley.

bhatmaster,

the issues you will face with using a home audio speaker in a car audio enviroment are this.

• Impedance - however this can be overcome becuase today many manufacturers make 4ohm and 8 ohm versions
  
• size - the flange daimeter of most home audio tweeters are usually much bigger but you do get flange less tweeteres like the venerable Vifa D26NC and you can als deflage a home audio tweeter (I have deflanged a pair of ScanSpeak 2905-9900 for a home audio speaker).
  
• reliability - car audio drivers have surrounds and cones made from UV resistant materials. home audio woofers do not nesscarily have to UV treated.
  
• cost - for the same quality a car audio speaker (especialy subwofers) are far cheaper than home audio woofers. However there are exceptions like Vifa, Peerless (DK) and Dayton.

If you need to understand more about the use of home audio speakers in car audio please also read the DYIMA (DIY Mobile Audio) forums.

That said.

the XO you have shown is not a 4th order L/R schematic. The HP section is 3rd order and the LP section is 2nd order. Since I do not have the driver's curves I cannot tell if the final response (acoustic+eletrical) would be indeed 4th order.

Also in a car enviroment where the relative distance of the listener from the tweeter and woofer is much greater than in a home enviroment (where the listener is almost equidistant from woofer and tweeter) I do not recommend very high slopes. 2nd/3rd order electrical slopes are fine. Just make sure that the drivers do not have crazy peaks to be nothced out and that the HP XO is atleast 2x the tweeter's Fs. which leads us to...car audio tweeters

Becasue car audio tweetes are usualy devodi of flanges or back chambers their dispersion and resonant frequency is not in the same league of a home audio tweeter. For eample you can get a home audio tweeter like the Vifa XT which has superb dispersion (almost flat 45 deg off axis) or the Morel Supreeme 110 (or ScanSpeak 9900) which has a Fs around 500Hz. You cannot get a car audio tweeter with very low Fs of with simialr specifications. car audio tweters will have significant off axis roll off above 10k and will have Fs in the region of 1500Hz.

In fact when we deflanged the 9900 it's Fs jumped to 1200-1300hz because we also removed the back chamber hence we had to XO is around 2500Hz. Now this tweeter power response was not affected as it was not ferro fluid cooled in the first place but other home audio tweeters would be also loose some of the power handling capability (if they are ferro fluid cooled and if the back chmaber is removed).

I do not want to disaude you from using home audio drivers in car audio. I just wnat you to fully understand the implications of doing so. I am sure Gurus like Sam Kapasi, Gunbir, B&T willl chip in soon.

[bhatmaster]

Hi Navin,
Thanks for your detailed post. Couple of questions -

1) How can I deflange a tweeter? I never modified any tweeter before. Is it removable or has to be broken to get it deflanged?

2) As I don't have any advanced equipment, how to measure the revised Fs after the abovesaid modification? Then entire SPL trace and crossover design will be changed. How did you draw a new response curve for that?
- Considering this is not possible for me, where can I fit in the tweeter with 3" face place, any idea? My car is Zen 2005 model.

My current slop if LR 4th order acoustic, not electrical 4th order. But, to keep the response curve flat, the slope has to be in that order and my x-over point is around 1900 Hz with Fs of Vifa at 750.

As I already have the tweeter with me, I have to go with it to keep the cost down. I dont wanna go for the option of buying another one, just will ship the driver from PE. I prefered Dayton RS150 here as it is not a paper cone and hence the life in car might be little better.

[navin]

Originally Posted by bhatmaster

1) How can I deflange a tweeter? I never modified any tweeter before. Is it removable or has to be broken to get it deflanged?

2) As I don't have any advanced equipment, how to measure the revised Fs after the abovesaid modification?

My current slop if LR 4th order acoustic, not electrical 4th order. But, to keep the response curve flat, the slope has to be in that order and my x-over point is around 1900 Hz with Fs of Vifa at 750.

I prefered Dayton RS150 here as it is not a paper cone and hence the life in car might be little better.

Bhatmaster,

again I do NOT want to disuade you but from your earlier posts I assumed you had much more experience with loudspeakers.

1. In some tweeters the flange (americans call it a face plate) are screwed on by 3 or 4 screws hence the face plate can be easily removed. In others it is glued on and it reqires a careful use of an exacto knife to pry the face plate off the tweeter. see troels's post here
Acapella SEasThe non-

2. To measure T/S specs you will need access to measuring equipment. LEAP/LMS (LinearX) is the best option for DIYers.

3. Other than access to measuring software you will also need access to a crossover designing tool like Calsod, Clio etc..the best option for DIYers is LsPCad.

4. Most paper cones are doped and also quite impervious to moisture. The first part of a woofer to deteriorate is the surround so only stick to UV resistant rubber surrounds. UV treated foam surrounds will last 5-7 years in US/EU conditions but wont last as long in India or SE Asia (Tropical climes).

Consider a company called SB Acoustics as they manufacture in SE Asia and their production is quite good.

I think you have a good place to start now. I am sure you can Google instructions of how to remove a face plate etc..so I wont get into those details as you will need photos and possibly a video to show how to do it. Google will be able to find this.

[bhatmaster]

Hi Navin,
Yes, I had/have a bit of experience in the cross-over designing, but I dont have proper measuring tool to trace a SPL curve and derive T/S parameters of any driver. Unfortunately I did not get anybody in India who used to have those infrastructure ( It requires a lab itself to measure correctly) and hence posted in this site for advice from you experts. Glad to know you have it already.

I know people like Zaph and Jay kim have those facilities (But they are professionals) and they helped me in my earlier designs too, but I never dreamed of building up my own lab for this. Only have little instruments for acurate cross-over desiging ( Above everything else, economic restrictions shows it presence)

Some of my cross-over designs are posted in DiyAudio forum, but I had never tried with any unknown products whose parameters are not known to me.

Yes, for the cross-over design , I use LSP Cad too along with SPLTrace and the above posted cross design was also the outcome of them. I'm trying to fine tune it, will post a revised one soon once I get time. Problem is that I'm using the trial version and it doesn't allow me to save the project.

And since I'm out of India for another few days, cannot exactly verify right now how the face plate is fastened on my Vifa tweeters. But do not foresee it is an option.

I very much know about SB acoustics and used their tweeter SB26 too which is excellent. But, never tested any of their woofers, but on the value proportion , I guess Dayton offers a bit more ( From PE though).

How much vol ( In Cubic Ft and litre) we get behind the plastic panels of the doors of a Zen, any rough idea anybody?

[navin]

Originally Posted by bhatmaster

Unfortunately I did not get anybody in India who used to have those infrastructure

Some of my cross-over designs are posted in DiyAudio forum

How much vol ( In Cubic Ft and litre) we get behind the plastic panels of the doors of a Zen, any rough idea anybody?

Why not ask Anandiya Mukherjee (of Sonodyne). He is based in Kolkutta.

The guys over at Diyaudio are very helpful. What is your handle there?

Car doors are lossy so cannot be considiered as a sealed box. The volume would be about 0.5 cu. ft. but given the lossy nature of car doors woofers with high Qts (0.7-1.1) work best there.

[bhatmaster]

Hi Navin,
Actually I'm currently out of Kolkata and don't have any contact of of Anindya Mukherjee. I only know him by name.

But for me, just to modify a tweeter, it'll be too much hassle to contact Anindya frist and then get it measured. I assume I need to run quite a bit after that to get it done . If you can help me by measuring it in your lab, I can deflange and courier it to you though once I'm back in India :-)
Rather can't I just fit the tweeter with face plate somehow in the car door? That solves all the problems.

My current cross-over design is based on the infinite baffle response from Woofer and tweeter. I assume nothing is lost behind the baffle as car door (Metal sheet) acts like a reflector here. Do you think from your experience it is correct or I need to adopt certain other assumption?

[navin]

Originally Posted by bhatmaster

If you can help me by measuring it in your lab, I can deflange and courier it to you though once I'm back in India :-)
Rather can't I just fit the tweeter with face plate somehow in the car door? That solves all the problems.

My current cross-over design is based on the infinite baffle response from Woofer and tweeter. I assume nothing is lost behind the baffle as car door (Metal sheet) acts like a reflector here. Do you think from your experience it is correct or I need to adopt certain other assumption?

1. My "lab" which is basically a friend's infrastructure (he is in the business of manufactuering speakers) is in Essen Germany. Anandiya, Damodar and co. do not like to give access to commoners like you and me to their facilties. Rajiv D'Souza of Lithos (a member here called Cream) has LEAP/LMS but he is based in Mumbai and you are in Kolkutta.

2. Sure if the door can accomodate the faceplate. Better still let me look into my "bin". I might have a few D26NCs in there (in Mumbai). THey are yours for the asking if I can find them. That will solve your problem tho na? I assume you will need atleast 2 but I believe I'd have atleast one working pair. PM me. You'll have to make arrangements for them to be picked up though. It would nice for them to finally have a home instead of the mess of other drivers they currently live with.

3. No need to correct for it. Just damp the doors with dynamat extreme or similar product. That will resolve the resonances. You cant use open celll foam in the door as when it rains the foam will abosrb the water and disintergrate shortly there after.

[bhatmaster]

Hi Navin,
I have already that pair of Vifa lying in my home. That was the main reason to start thinking if I can somehow use that in car as I don't have any recent plan to build another loudspeaker.
Many thanks for your offer, but I already have them. Thinking to get one pair of Dayton RS150 which also has a 4Ohm version, I discovered. Need to design the crossover again for that. Will publish soon.

[navin]

bhatmaster if you have Vifa D26NC then there is NO flange or face plate!

[Bass&Trouble]

Originally Posted by bhatmaster

Thinking to get one pair of Dayton RS150 which also has a 4Ohm version, I discovered. Need to design the crossover again for that. Will publish soon.

That driver is not suited to work out of a door. You'll be better off using the JBL Power series midwoofer that you already have, and pair it with your tweeters.

[bhatmaster]

Originally Posted by navin

bhatmaster if you have Vifa D26NC then there is NO flange or face plate!

Hi Navin,
Sorry for my miscommunication in the last post. I dint tried to mean I have D26NC, I have the other Vifa D27 which is with face plate. But, I wana make use of it somehow as the tweeter is reasonably good. My earlier cross-over design is based on that tweeter and dayton RS150 woofer.

Originally Posted by Bass&Trouble

That driver is not suited to work out of a door. You'll be better off using the JBL Power series midwoofer that you already have, and pair it with your tweeters.

Hi Bass&Treeble,
Request you to explain a little more why it cannot be used in the car door. Actually my JBL power is hooked up in my other car ( Verna) and I don't plan to take it off. My feeling so far is not with a great respect for that mid-woofer though.

[Bass&Trouble]

For starters, the EBP of the driver is about 115. So it definitely needs a ported box to work properly. And a leaky car door isn't exactly going to to present a favorable environment, given the circumstances.

[bhatmaster]

Originally Posted by Bass&Trouble

For starters, the EBP of the driver is about 115. So it definitely needs a ported box to work properly. And a leaky car door isn't exactly going to to present a favorable environment, given the circumstances.

Hi B&T,
Sorry, I don't find the term EBP is the T/S parameters, what is that and how does it relates to the box/port design? I never used this property in my earlier loudspeakers so far.

[ [COLOR=#000000][FONT=Verdana,Arial]* Impedance: 4 ohms * Re: 2.9 ohms * Frequency range: 50-3,000 Hz * Fs: 52 Hz * SPL: 92 dB 2.83V/1m, 89 dB 1W/1m * Vas: .43 cu. ft. * Qms: 2.67 * Qes: .47 * Qts: .40 * Xmax: 4.4mm *][/FONT][/COLOR]

I have chosen the driver because its infinite baffle response was good and above all it's pretty cheap .

[bhatmaster]

[ [COLOR=#000000][FONT=Verdana,Arial]* Impedance: 4 ohms * Re: 2.9 ohms * Frequency range: 50-3,000 Hz * Fs: 52 Hz * SPL: 92 dB 2.83V/1m, 89 dB 1W/1m * Vas: .43 cu. ft. * Qms: 2.67 * Qes: .47 * Qts: .40 * Xmax: 4.4mm *][/FONT][/COLOR]

Sorry, please ignore the last post, it is already couple of years I had done my last design and now is a bit out of touch.

However, under my calculation. this value for Dayton Rs150 is coming as 101, i.e. it can be used in open or ported baffle ( as >90) , not in the sealed one. So, as assumed earlier, I'm designing the cross-over under open baffle model and hence I fail to understand why you suggest not to use this one.