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Help me for Speaker Crossover related issues

Wharfedale Diamond 11 Series

Ashish_Jamesh

New Member
Joined
Aug 18, 2012
Messages
5
Points
3
Location
Ahmedabad
Hello Friends,
I have few question for Speaker's Crossover

1. I would like to know that whats the difference in sound quality or Crossover efficiency if we change polyester caps with electrolyte caps?
2. Floor standing have 2 woofer, 1 mid, and 1 tweeter so why it having a 3-way crossover? So can we change it to 4-way crossover?
3. Is it possible that crossover's polyester film caps and inductor damaged by wrong wiring or over powering the speaker?
4. How to get correct value of inductor? If one speaker need to change Inductor and we have another complete working speaker with that inductor than how to get same valued inductor for damaged speaker?
5. How to measure speaker's specification? Means If I buy few used speaker drivers like woofers and tweeters from local market and I want to make a good pair of speakers either book shelf /floor standing or center speaker. So i have to make crossover for it and for good crossover I need specification for those used speaker drivers. So I decide that which driver can use as woofer, which one for mid, which one for tweeter? So how to get correct info for this drivers?
6. Whats difference in sound absorbing material in speakers like glass-wool, dunloap foam sheet etc...?
 

pranavkumar

Active Member
Joined
Aug 13, 2012
Messages
163
Points
43
Location
New Delhi
Hello Friends,
I have few question for Speaker's Crossover

1. I would like to know that whats the difference in sound quality or Crossover efficiency if we change polyester caps with electrolyte caps?
2. Floor standing have 2 woofer, 1 mid, and 1 tweeter so why it having a 3-way crossover? So can we change it to 4-way crossover?
3. Is it possible that crossover's polyester film caps and inductor damaged by wrong wiring or over powering the speaker?
4. How to get correct value of inductor? If one speaker need to change Inductor and we have another complete working speaker with that inductor than how to get same valued inductor for damaged speaker?
5. How to measure speaker's specification? Means If I buy few used speaker drivers like woofers and tweeters from local market and I want to make a good pair of speakers either book shelf /floor standing or center speaker. So i have to make crossover for it and for good crossover I need specification for those used speaker drivers. So I decide that which driver can use as woofer, which one for mid, which one for tweeter? So how to get correct info for this drivers?
6. Whats difference in sound absorbing material in speakers like glass-wool, dunloap foam sheet etc...?

Hi,
To Answer most of your questions,

1 : Polyester caps and electrolytic caps are very different, both are designed for different applications. An electrolytic cap maybe a highly efficient model as it can provide a higher capacity in a small space, due to heavy amounts of dielectrics present in it. Due to the presence of this dielectic there are leakages , etc... losses basically ! Its not advisable to use electrolytic caps in crossover units due to losses one, if you see carefully.. an electro- cap has a polarity, so during the negative half of the sine wave ( audio signal), this cap will be biased in a reverse way, which is not healthy for the cap.
Using Polyester or polypropylene caps is much advisable, they are said to have more tonal quality and less distortion.
But these polyester caps are available uptill a certain value, and you might have to use electro-caps for higher valued caps.

2: Its difficult to say what configuration your speakers are connected in. One of the two woofers could be a passive radiator, or connected in series with the other or most commonly connected in parallel with the other. The woofer is designed to handle low frequencies, in your case both the drivers (woofers) are doing the same job (i assume), calling it a 4-way setup is not correct.

3: What do you exactly mean by wrong wiring ?
Yes, over powering can easily blow the inductors and the capacitors.

4: To get a new inductor wound for the damaged set, you would need to calculate the inducatance first. means that you will have to disconnect the inductor from the network and perform an experiment. You could use a LCR meter to know the inductance.
Another fundamental way to calculate inductance is a 3-Voltmeter Test, a 3-Wattmeter test can also be applied. This merely gives you the phase angle, knowing the frequency at which the test is performed, you can calculate the inductance easily.

5: To design a good crossover, you need most of the speaker parameters also known as TS parameters. Calculating the TS parameters is not easy. to my knowledge, one need sophisticated equipment to do so.

6: The damping solutions are very much dependent on the enclosure design. Depends if the enclosure is a bass reflex type or sealed or TL type.


Hope This helps !
Cheers ! :)
 

Ashish_Jamesh

New Member
Joined
Aug 18, 2012
Messages
5
Points
3
Location
Ahmedabad
Hi Pranavji,
I upload few images of my Jamo Classic 10 & it's Crossover so please look at them and suggest me that how can I make good crossover for it. Classic 10 contain 2x8" woofer (both work as woofer, not as passive radiator). And one image shows component value which used in crossover (I am unable to get inductor's value). And another images shows what I need for my speakers? In Ahmedabad I am unable to get any polypropylene caps, inductors & 3-way crossover pcb so can you guide me that from where I can buy it?

http://s18.postimage.org/5dyxcovux/crossover_1.jpg
http://s13.postimage.org/jv95nzbxj/Jamo_Front_Back.jpg
Can you tell me whats the type of my crossover is? Do you find any technical issue in it (by observing images)?
*************
2: Its difficult to say what configuration your speakers are connected in. One of the two woofers could be a passive radiator, or connected in series with the other or most commonly connected in parallel with the other. The woofer is designed to handle low frequencies, in your case both the drivers (woofers) are doing the same job (i assume), calling it a 4-way setup is not correct.

Reply: -
I am not saying that My speaker is 4-way speakers but I would like to know that If my speakers have 2x8" woofer and connected parallel, so is it possible that we disconnect one woofer from it and trying to build 4-way crossover for same speaker which contain 1x8" Main Bass, 1x8" Mid bass, 1x5.25" Mid Range, 1x1" Soft dome tweeter? (It's just for my curiosity) ....

4: To get a new inductor wound for the damaged set, you would need to calculate the inducatance first. means that you will have to disconnect the inductor from the network and perform an experiment. You could use a LCR meter to know the inductance.
Another fundamental way to calculate inductance is a 3-Voltmeter Test, a 3-Wattmeter test can also be applied. This merely gives you the phase angle, knowing the frequency at which the test is performed, you can calculate the inductance easily.

Reply:
Can you explain in details?
**********************************
Thanks
 

pranavkumar

Active Member
Joined
Aug 13, 2012
Messages
163
Points
43
Location
New Delhi
hi,
Sorry for the late reply,

To answer the 4 way issue, Firstly, the speaker configuration depends on the frequency division. A three way config has a band of frequencies for the woofer, a band for the mids and a band for the tweeters.
A four way speaker will probably have two bands for the mids, one would be the low mids and one would be higher mids.
To make a Tweeter-mid-mid.bass-bass setup, you will have to analyse the speaker which is fed with the mid bass signal, and if it is capable of handling those frequencies. Being a woofer, i would not recommend feeding mid freq. signals.
From the pictures that you've posted, i think the two woofers are connected in parallel, when not in the bi-wire setup.
Not sure when its bW :indifferent14:

I was able to find a link to the 3 voltmeter test. here it is:
3-Voltmeter Method of Measuring Choke Coil Parameters
Somewhere at the end, you will see equation : XL = Z.Sin(angle), This the reactance offered by the coil. We have basically calculated the angle in this experiment.
Knowing the angle we know what XL is, also XL = 2*pi*f*L, where f is the frequency of the AC signal and L is the inductance in Henry !
one can easily calculate the inductance this way.
Being an experimental procedure, it is prone to errors though.

Hope this helps !
 

Ashish_Jamesh

New Member
Joined
Aug 18, 2012
Messages
5
Points
3
Location
Ahmedabad
Thanks Pranavji....
Pranav I read in many thread that Active Crossover is far better than Passive Crossover. So I have few question regarding that.
1. Is there any Active crossover available for Home Theater use? I heard that active crossover can be used only for Professional Audio setups.
2. How to install/connect Active crossover with AV Receiver or Amplifier for Two way and Three way speaker system?
3. We have to make any specific changes in speakers for using Active crossover?
And last I sow few Vintage speakers with Multi Input like Low, Mid, Tweeter and Full Range so now these kind of speakers available or not?
This is the link for these kind of speakers
Sold - 3-way Loudspeakers

Thanks
 

pranavkumar

Active Member
Joined
Aug 13, 2012
Messages
163
Points
43
Location
New Delhi
Thanks Pranavji....
Pranav I read in many thread that Active Crossover is far better than Passive Crossover. So I have few question regarding that.
1. Is there any Active crossover available for Home Theater use? I heard that active crossover can be used only for Professional Audio setups.
2. How to install/connect Active crossover with AV Receiver or Amplifier for Two way and Three way speaker system?
3. We have to make any specific changes in speakers for using Active crossover?
And last I sow few Vintage speakers with Multi Input like Low, Mid, Tweeter and Full Range so now these kind of speakers available or not?
This is the link for these kind of speakers
Sold - 3-way Loudspeakers

Thanks

Hi,
Yes, you're right, Active crossovers and better than passive ones simply because they are more accurate !

For a HT setup, yes you can have Active Crossovers, after the AVR... The signal from the AVR can be fed into a Active Crosssover and then the signal can be amplified to drive the speakers...
But for this you will need 5x3way crossovers and 15 discrete amplifiers to drive a HT system, not economical as well as practical.

If you dont know about active crossovers:
The crossover stage is at the low level (small signal) i.e. before the power amplifier usually at the pre-stage. The frequency division is done electronically and then the three signals ( woofer, mid, tweet) are fed into three amplifiers and the output of each into the speaker.

It is more feasible to use active crossover in a hi-fi stereo setup. To do that, you need 3 stereo amplifiers.
The Signal from ur ipod, etc is fed into the crossover, which gives you the mid,highs and low signals. These signals are fed into the three stereo amplifiers.
Its Difficult because it requires a lot of troubleshooting if you are making the crossover or amps yourself (DIY).
In the Speaker setup, the existing passive crossover is removed and 3 pairs of terminals are connected to the three speakers.

For a HT setup, stick to passive components, for a stereo setup you could use a Active system.

There are a lot of advantages to an active setup,
1. Dynamic control of the three signals.
2. Well designed A.crossovers have a control to change the cut off frequency.
3. Different amplifiers are used for the lows highs and mids, so you can choose frequency specific amplifiers for each.
maybe more, but technical aspects. :)

Cheers !
 

Ashish_Jamesh

New Member
Joined
Aug 18, 2012
Messages
5
Points
3
Location
Ahmedabad
And whats about Vintage Phase Linear Speakers?

And last I sow few Vintage speakers with Multi Input like Low, Mid, Tweeter and Full Range so now these kind of speakers available or not?
This is the link for these kind of speakers
Sold - 3-way Loudspeakers
 
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