[shrivz]

This is what I feel:

The JBLs have their typical 50Hz resonance band so they boom a lot. This however can be controlled to a certain extent by chosing a lower x-over point, but at the same time you'll need real good mid-bass drivers to counter that effect.

The GZ subwoofer in question is a great VFM product and can reproduce some serious bass. They are better controlled and precise as compared to the JBL. Moreover the GZ integrates very well with the Illusions.

Now, as far as the amp is concerned. The 75.4 is a legend. Its worth every penny you pay at Rs. 8000/- (if available)
If not that, then the GZTA 4.120MK² is the next option you could consider along with the JBL GTO1004

[navin]

Originally Posted by mohang_j

Navinji,
You mean to say 2nd or 3rd order XOs to be used, and which is better- 3rd order considering phase shift?
What is acoustic crossover.

I should have said electrical slope and acosutic slope.

2nd order phase shift is around 180 deg which can be compesated for by reversing the wires of the tweeter.

Now we are talking in general here (beucase ech driver and car envrioment is different) but...

I have found that a quasi-4th order acosutic slope is "just right" for most car door installs. This works well when the tweeter and woofer are about 12-18" from each other.

I say quasi becuase the natural roll off of a driver (woofer or tweeter) is not linear in most cases it begins gradually and then falls rapidlly untill breakup (in the woofer's case) or Fs (in the tweeter's case) after which all hell breaks loose.

Becuase of the anamolies of the frequency response (we are not even getting into impluse response and phase yet) I prefer to have the drivers padded down atleast 20db before breakup/resonance. 30db is preferable.

Once one brings in the phase and impluse respnse complexities into the equation it seems that in most cases a electrical 12db/oct slope is the "right fit" for the natural roll off of most drives without affecting transient and phase response greatly. To push the F(-20db) point down a bit faster a L-R filter is usually employed as this gives an added 3db of attentuation at the turnover point. Hence a good starting point is a 12db/octave L-R filter. It requires few parts (which can then be of highest quality) and is also compact.

Ofcourse there will be applications where the designer will prefer a 3rd order or 4th order filter but if you tear open 10 filters used for 6" 2 way components you will find 5-6 of them using 2nd order.

I am sorry for my rather short answer here but this is primarily a car forum and this topic is well dicussed at diyaudio.com and other such forums.

[Bass&Trouble]

Originally Posted by greenhorn

Personally, I feel first orders are best

First order crossovers are great because they do not introduce any phase shift. But in entry to mid level speakers, a first order usually means that the tweeter is cut off very high 7~8kHz (As Navin explained, due to power handling issues etc.). I dont like the sound of such sets. Also, due to greater amount of mid frequencies prouced by the midwoofer, the soundstage is also low.

[greenhorn]

Originally Posted by Bass&Trouble

First order crossovers are great because they do not introduce any phase shift. But in entry to mid level speakers, a first order usually means that the tweeter is cut off very high 7~8kHz (As Navin explained, due to power handling issues etc.). I dont like the sound of such sets. Also, due to greater amount of mid frequencies prouced by the midwoofer, the soundstage is also low.

Ah ok, got it! Much clearer now Thanks

[mohang_j]

Originally Posted by navin

I should have said electrical slope and acosutic slope.
I am sorry for my rather short answer here but this is primarily a car forum and this topic is well dicussed at diyaudio.com and other such forums.

Navinji,
Thanks for the information.
you don't have to say sorry, your replies are always to the point and highly informative-helps us in getting the idea/solution.Can you help me in making coils(correct winding procedure, some website/pdf.Already googled but all talk about calculations not winding ideas).Yesterday i tried using 16gauge wire could not wind on a 1inch pvc pipe.May be

[DerAlte]

Originally Posted by amit_mechengg

sorry sir, but i have used both the subs for quite a while.

Why are you sorry for that, Amit?

Originally Posted by amit_mechengg

i find there is a total difference in the way they beat. ... to be frank i enjoyed both the subs. but u need some time to get accustomed to the different sounds of both the subs.

Well, in a way you have proven what I said, that there is very little to differentiate. A matter of logic: 99.9% of the time the user would generally hear the music as a whole, and not concentrate whether the bass beats are giving a kick at a certain frequency (unless this is very irritating) or a soft soothing punch throughout a band (unless they take away dynamics completely). Since neither one nor the other is completely detrimental, there is little to differentiate.

[navin]

Originally Posted by mohang_j

Can you help me in making coils(correct winding procedure, some website/pdf.Already googled but all talk about calculations not winding ideas).

best to wind a coil is using a small lathe.

many mnay years ago i used lalena.com as a resource, today there are better resources (LBM is the master of this) but i find lalena.com works for me.

remember I am old. very old. and my audio days have been left long behind, anythng I post is usually dated.

[anupmathur]

Originally Posted by navin

remember I am old. very old. and my audio days have been left long behind, anythng I post is usually dated.

Navin, this is quite OT, but your submission above has made me ask here, since it's not worth a new thread:
Any locally available cartridge to substitute for the original Pickering V-15 that came as OEM on the KLH Model Eleven?

[DerAlte]

Originally Posted by anupmathur

... Any locally available cartridge to substitute for the original Pickering V-15 that came as OEM on the KLH Model Eleven?

They are still available (check this), but not sure if they would be available in India.

There used to be that old HMV shop in the inner circle of CP, is it still there? That would be a good place to start enquiring, if any of the old-timers are around. Otherwise behind Red Fort on Sunday morning - shayad qismat chamake aur V15 haath lag jaaye!

[anupmathur]

Originally Posted by DerAlte

There used to be that old HMV shop in the inner circle of CP, is it still there?

Thanks DerAlte; you are referring to either Bercos or Maharaja Lal & Sons.
Bercos has been serving Chinese food for many years now! And they moved out very recently from the inner circle.
As for Lajpatrai Market, I haven't mustered the courage to go there yet. It is a daunting expedition now, quite unlike the old days. Though old man Dewan is still there!

Yes, I'll have to do the legwork if I seriously want to restore the old Henry Kloss classic!

[mohang_j]

Originally Posted by navin

best to wind a coil is using a small lathe.
i find lalena.com works for me.
remember I am old. very old. and my audio days have been left long behind, anythng I post is usually dated.

Navinji,
Old is gold.
Technology may change with time but not the basic concept.
I am using hand drill for winding.(courtesy google).Today found one good article,after reading i will post the link, may be some one like me will get some idea.
Even i had left DIY 8 years back, its TEAM-BHP & google+youtube made me start once again.
First DIY-100/90 watt headlight,successful ICE installation,sub box and now XO after that i am planning for some fiberglassing (component door mounting and may be sub enclouser).
Planning to will bug all T-BHP gurus.

[navin]

Originally Posted by anupmathur

Any locally available cartridge to substitute for the original Pickering V-15 that came as OEM on the KLH Model Eleven?

Originally Posted by DerAlte

They are still available (check this), but not sure if they would be available in India.

the place i'd look is here
XV-15/625E Cartridge - XV-15/625E
only they dont ship to India.

this is where I'd look for all things vintage
Antique Radio Forums :: Index

John's Radio Web

[greenhorn]

a friend of mine has gotten a spark, and the 4" comps are hard to come by.
My doubt - Is mounting 5" comps on the dash with an MDF spacer do-able , and is it a good idea? He doesn't want to do any cutting-shutting of the door panels

[adityamunshi]

I dont think installing spacers on the dash will be a good idea. Better to get 4" comps from illusion or kicker. If the budget is a problem Illusion audio's coax are excellent speakers. Ive installed 6.5 " coax in my car.

Originally Posted by greenhorn

a friend of mine has gotten a spark, and the 4" comps are hard to come by.
My doubt - Is mounting 5" comps on the dash with an MDF spacer do-able , and is it a good idea? He doesn't want to do any cutting-shutting of the door panels

[navin]

Originally Posted by greenhorn

a friend of mine has gotten a spark, and the 4" comps are hard to come by.

Illusion and Kicker make 4" components. I have not heard either but most here (TBHP's ICE section) prefer the Illusions. Bass & Trouble represents Illusion so PM him for details.

If I ever buy a car with dash pods for mids I'd be tempted to have a 3 way in the front by mating the 4" dash speakers with a 6" midbass in the door.

The biggest problem with in car audio is that the bass is almost alwyas stuck in the back. Using Time Aligment is one solution but nothing beats having as much bass in the front as possible.