Need help choose new car for old ICE

DerAlte · 17th June 2008, 17:58

I guess Navin would have a better description than mine. I would put it as a kind of bhrrrr effect superimposed on vocals, kind of warbling (a very mild form of the sound of gargling. Gargling!? Eugh!). It is not that much of a horror story as my description sounds.

I think Navin uses the same ones available on Crutchfield. Of course, you can jerry rig your own by making a shallow cone out of sheets of open cell foam. Cut circles, remove a sector and join the radial edges.

No downside other than the foam gradually deteriorating and disintegrating. Come to think of it, it will be a kind of protection against water droplets falling on the rear of the speakers.

navin · 17th June 2008, 22:44

Quote:

Originally Posted by nura

Crutchfield sells foam speaker baffles.
Foam Speaker Baffles at Crutchfield.com
Would these work? .

The XTC baffles are good. I have used them & they hold up very well. No one sells them in India and I did import a few pairs but when I dont have any around I make do with the opencell foam stuff Der Alte refered to.

Quote:

Originally Posted by DerAlte

I guess Navin would have a better description than mine. I would put it as a kind of bhrrrr effect superimposed on vocals, kind of warbling (a very mild form of the sound of gargling. Gargling!? Eugh!)..

actually the doppler distortion is more like warbling. Since the open cell foam's efficacy only drops of after about 300Hz and becomes useless only by about 100Hz, the warbling is not so bad. If it was 500Hz super imposed on 1000Hz you'd hear it clearly.

adityamunshi · 18th June 2008, 18:15

How do you prevent the open cell foam from absorbing water and causing corrosion ?

Quote:

Originally Posted by navin

The XTC baffles are good. I have used them & they hold up very well. No one sells them in India and I did import a few pairs but when I dont have any around I make do with the opencell foam stuff Der Alte refered to.

actually the doppler distortion is more like warbling. Since the open cell foam's efficacy only drops of after about 300Hz and becomes useless only by about 100Hz, the warbling is not so bad. If it was 500Hz super imposed on 1000Hz you'd hear it clearly.

nura · 18th June 2008, 18:49

Thanks for your replies.
My office area was flooded yesterday, so there was a lot of time to read. This is what I managed to learn.
1. Foam speaker baffles offer good protection from dust & water. But hard plastic ones are better.
2. Foam speaker baffles kill midbass.
3. Holes may be made in the baffle to get back midbass. The right size hole has to be found by trial & error. Once holes are made, naturally, speaker back isolation is lost.
4. Shallow foam baffles move with cone movement & hit the back of speaker generating noise.
My queries are
a. How much bass would my 3" midrange lose if I enclosed it in a baffle? Its rated frequency response is 200Hz - 14KHz.
b. Should we expect dome midranges with rear acoustic chambers to produce less bass? How do we explain the following difference in specs?
Hertz HD500 1.5" 500Hz - 10KHz
DynAudio Esotec MD142 3" 700Hz - 6KHz
DLS Ultimate Iridium3 3" 250Hz - 8KHz
c. Which is the lesser evil - Doppler Distortion or bass loss?
Thanks in advance.

17th June 2008, 17:58	#46
DerAlte Senior - BHPian Join Date: Mar 2007 Location: Bangalore Posts: 8,069 Thanked: 2,919 Times	I guess Navin would have a better description than mine. I would put it as a kind of bhrrrr effect superimposed on vocals, kind of warbling (a very mild form of the sound of gargling. Gargling!? Eugh!). It is not that much of a horror story as my description sounds. I think Navin uses the same ones available on Crutchfield. Of course, you can jerry rig your own by making a shallow cone out of sheets of open cell foam. Cut circles, remove a sector and join the radial edges. No downside other than the foam gradually deteriorating and disintegrating. Come to think of it, it will be a kind of protection against water droplets falling on the rear of the speakers. Last edited by DerAlte : 17th June 2008 at 18:01.
	() Thanks

18th June 2008, 18:49	#49
nura BHPian Join Date: Feb 2007 Location: Kolkata Posts: 599 Thanked: 17 Times	Thanks for your replies. My office area was flooded yesterday, so there was a lot of time to read. This is what I managed to learn. 1. Foam speaker baffles offer good protection from dust & water. But hard plastic ones are better. 2. Foam speaker baffles kill midbass. 3. Holes may be made in the baffle to get back midbass. The right size hole has to be found by trial & error. Once holes are made, naturally, speaker back isolation is lost. 4. Shallow foam baffles move with cone movement & hit the back of speaker generating noise. My queries are a. How much bass would my 3" midrange lose if I enclosed it in a baffle? Its rated frequency response is 200Hz - 14KHz. b. Should we expect dome midranges with rear acoustic chambers to produce less bass? How do we explain the following difference in specs? Hertz HD500 1.5" 500Hz - 10KHz DynAudio Esotec MD142 3" 700Hz - 6KHz DLS Ultimate Iridium3 3" 250Hz - 8KHz c. Which is the lesser evil - Doppler Distortion or bass loss? Thanks in advance.
	(1) Thanks