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Old 12th September 2009, 23:23   #1
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Illusion Electra - Getting them right

Hi posting this in perhaps what is the right sub-forum to discuss issues with installs. I have installed Illusion Electra components in my Santro, connected to Clarion DXZ785USB hu and JBL 1004 amp. Despite using these time-tested and acclaimed components, I am somehow not hearing the sound I wish to hear. Illusions are universally termed as laidback, I am finding them a bit too bright (the tweeters pinch and pierce my ears on sufficiently loud volumes).

Secondly, I feel that some frequencies are rolling off or are missing the necessary decibels. I suspected midbass to be at fault, so checked them for polarity issues etc. using 3 track tracks- 2 with 1 ch inverted (Lch, rch) and 1 normal. Not surprisingly, the normal track sounds best (this when subwoofer is off).

The tweeters are temporarily mounted at base of A-pillar (resting on dash), their off-axis performance is now a bit tolerable, but they shine too much when on-axis (right-side tweeter firing at passenger's head rest, left side firing straight at me- the driver). I even changed the tweeter gain to -3db from the crossovers to see if it would help, but looks like it doesn't.

I think above is sufficient background information, so now jumping straight to questions to the gurus:

1. Can you read anything blantantly wrong in my description as above? Anything I am not doing right?

2. Could bumping up the component gains from the amp a little bit help matters (I am assuming that it will provide more power to mid-bass, while the crossover will act as a shield for the tweeter getting more power, thus helping overall balance of the system)?

3. Is smearing a big reason for this perceived harshness (ear-pinching) of the tweeters? Would moving the tweeters to the doors, facing each other (I could still get left-side tweeter on-axis) help my case?

4. Lastly, should I first try going active- using HU's speaker outputs for powering tweeters (mid-basses and sub-woofer will continue to be powered from amp). As far as I see, going active will not just help me set the speaker gain on tweeters to my taste (Clarion supports 0 to -20db), but also help me get possibly better crossover settings- that improve both mid-bass and tweeter performance.

5. A bonus question for the gurus- is it true that some amount of phase cancellation is inevitable when 2 mid-basses are firing at each other?

Now waiting for Gurus' comments, suggestions etc... Come on guys I really need your help to get my ride sounding just right!
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Old 13th September 2009, 02:45   #2
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Originally Posted by greenh0rn View Post


1. Can you read anything blantantly wrong in my description as above? Anything I am not doing right?
If the sound from the midbass is not lacking any bassline than I suppose they are running in phase. When polarity is wrong, the speakers will be out of phase. One will move in, while the other moves out. At the listening position (right in between the speakers) the displaced air from one will be cancelled out by the other. This effect - stronger at lower frequencies - will result in a loss of bass. It also drastically distords the stereo imaging.

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2. Could bumping up the component gains from the amp a little bit help matters (I am assuming that it will provide more power to mid-bass, while the crossover will act as a shield for the tweeter getting more power, thus helping overall balance of the system)?
Have more head room is always better however since you are running it through passive crossover the effect of bumping up the gain will not only effect the midbass but also to the tweeter.

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3. Is smearing a big reason for this perceived harshness (ear-pinching) of the tweeters? Would moving the tweeters to the doors, facing each other (I could still get left-side tweeter on-axis) help my case?
It looks like you are facing some issues with the reflection here. Here's what I would strongly suggest. Measure the distance from the center of midbass to your forehead in your driving position of both Left and right midbass. Now try and measure the location where you would mount the tweeter in way where the distance that you got from the midbass equates to that of the tweeter. The location could be anywhere on the door or the sail panel or the A piller. The path length difference in measurement of distance between midbass and tweeter should be within +/- 2". This way you would have the midbass and tweeter coming in at the same time. Than try with setting the TA and see if it sounds balanced. Make sure the tweeter is the facing up to the winshield best as I had mentioned earlier would be making them face eachother. What you could try is using the EQ you could cut the high freq. as desired at may be 8khz or 10khz. You could also achieve further 3db reduction by setting the tweeter on the xover out of phase.

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4. Lastly, should I first try going active- using HU's speaker outputs for powering tweeters (mid-basses and sub-woofer will continue to be powered from amp). As far as I see, going active will not just help me set the speaker gain on tweeters to my taste (Clarion supports 0 to -20db), but also help me get possibly better crossover settings- that improve both mid-bass and tweeter performance.
Active will deffinately helpful even in terms of improving the SQ. As the caps on passiver xover tend to rob some power and setting them Active always improve the quality through out the freq. range.

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5. A bonus question for the gurus- is it true that some amount of phase cancellation is inevitable when 2 mid-basses are firing at each other?
Phase cancellation only happens when either of them have their polarity set out of phase. It doesn't matter whether they are running on-axis or off-axis.
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Old 13th September 2009, 10:34   #3
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Rishi, try reducing treble from your 785.
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Old 13th September 2009, 11:42   #4
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Thanks again Invinsible...The mid-basses 'appear' to be in phase, and I might set tweeters out-of-phase and see their response (this will also slow them down a few milliseconds, right?)

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It looks like you are facing some issues with the reflection here. Here's what I would strongly suggest. Measure the distance from the center of midbass to your forehead in your driving position of both Left and right midbass. Now try and measure the location where you would mount the tweeter in way where the distance that you got from the midbass equates to that of the tweeter. The location could be anywhere on the door or the sail panel or the A piller. The path length difference in measurement of distance between midbass and tweeter should be within +/- 2". This way you would have the midbass and tweeter coming in at the same time.
My big hunch is that flush-mounting the tweeters in the doors could sort out a lot of my problems. The only big question now is- is it possible to get on-axis response from tweeters in the doors? Flush-mounting them in the doors is really a one-way street for me, I can't go back to a-pillar after that. So need to be absolutely deadsure that this is indeed a better place (I am equally concerned with imaging and soundstage).

Gurus, please comment!!!

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Active will deffinately helpful even in terms of improving the SQ. As the caps on passiver xover tend to rob some power and setting them Active always improve the quality through out the freq. range.
I think I got lucky in finding this old thread and specifically this post - I think LBM also had some issues with on-axis hearing of the tweeters, something he solved through - guess what - going active! And setting the speaker gains on tweeters a little lower than mid-basses! Ha, sounds like a solution!

http://www.team-bhp.com/forum/ask-gu...tml#post834608

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Rishi, try reducing treble from your 785.
Thanks Panky bhai, I tried that, but felt that what I actually lost is a bit of resolution and detail, not the ear-pinching harshness :(

I think my problem can be cured by either going active, or by putting tweeters in the doors. Maybe an active set up can be tried first, hopefully next weekend.
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Old 13th September 2009, 11:48   #5
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Doesn't the cross-over have a switch for reducing high frequencies? There is usually a 0dB and -3dB setting, you need to use the -3dB setting. If there is no switch, it should be a simple exercise of reducing the treble by adding a resistor. Ask B&T or LBM.
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Old 13th September 2009, 12:07   #6
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The switch is there, but seems to not help matters much even when used at -3db setting (if tweeters are on-axis). Although, -3db setting works wonders for off-axis placement (on A-pillar's base).

DA, if you were me, would you experiment with an active set-up?
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Old 13th September 2009, 12:09   #7
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Folks who are running Electra (there are so many of you), could you please post your experience in tweeter placement and how they behaved in your car? If nothing, I might start doubting the HU to be playing a little spoilsport here.
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Old 13th September 2009, 13:42   #8
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Little OT :
I was just checking the crossover in the morning. GZ crossover has +3,0,and -3db setting with current jumper set on 0.
Now i do find ear pinching from tweeters in some of Rock Songs. Can i change the jumper to -3 ?
Also it would be helpful if Gurus throw some more gyaan on this thing.
Thanx.
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Old 13th September 2009, 14:49   #9
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Also try with setting the gain little lower. As at times little distortion which is sometime not audible could also peak some freq. range.
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Old 13th September 2009, 16:02   #10
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Originally Posted by greenh0rn View Post
... if you were me, would you experiment with an active set-up?
No, I wouldn't. I would first try to give a set of drivers some time and try different passive ways (XO modification being the first) to come to it's optimum performance. Brightness will not be the reason why I would go active. Why are you trying to listen on-axis anyhow?

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... Can i change the jumper to -3 ? ...
Why not go ahead and try it out at that setting? The 'pinches my ear' is different for different people, and the settings - which reduce the power that effectively goes to the tweeter, are meant for that.

Last edited by DerAlte : 13th September 2009 at 16:03.
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Old 13th September 2009, 16:24   #11
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Also try with setting the gain little lower. As at times little distortion which is sometime not audible could also peak some freq. range.
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Old 13th September 2009, 19:18   #12
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@greenh0rn
Your observation on tweeters is absolutely correct! I have mounted them on the A-Pillar. Initially, the left tweeter pointing towards the driver and the right towards the passenger and the treble was a little bit harsh. Reduced the treble setting to -3dB and shifted the axis of the tweeters slightly forward. The sound-stage was effected slightly but the treble is perfect now.
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Old 13th September 2009, 21:07   #13
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Also try with setting the gain little lower. As at times little distortion which is sometime not audible could also peak some freq. range.
I think my gains are set already and sufficiently lower. The strange thing with Clarion HU is that there's no clipping even with HU volume pushed to max (33 setting), this when amp gains are set to minimum. At my present gain levels, I still hear no clipping when pushing the HU to it limit. It just gets a bit too loud

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No, I wouldn't. I would first try to give a set of drivers some time and try different passive ways (XO modification being the first) to come to it's optimum performance. Brightness will not be the reason why I would go active. Why are you trying to listen on-axis anyhow?
DA, this might be entirely personal (or perhaps psychological even), but I somehow feel that my ears don't catch all musical detail when hearing tweeters off-axis. If it weren't for this pinching harshness, I really like them on-axis-, they really perform up to their reputation in bringing out the musical detail!

Yes, I am all prepared for XO modification - although I'm a total noob in hi-fi audio, but somehow feel that I just need to level down the power going to tweeters to make truce with my speakers. Could you please point me to the right direction?

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@greenh0rn
Your observation on tweeters is absolutely correct! I have mounted them on the A-Pillar. Initially, the left tweeter pointing towards the driver and the right towards the passenger and the treble was a little bit harsh. Reduced the treble setting to -3dB and shifted the axis of the tweeters slightly forward. The sound-stage was effected slightly but the treble is perfect now.
Thanks man, really good to hear that I am not alone, and that my ears are not out-of-this-world sensitive types
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Old 13th September 2009, 21:44   #14
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first of all, sorry for not being able to take your call, sir. I was in a bad coverage area.
Secondly, congratulations on your new ICE setup. Choice of equipment is spot on for this budget.
Thirdly, I would like to think, going active is not your solution. Try mounting the tweeters off axis. You will have a better experience.
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Old 13th September 2009, 22:23   #15
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first of all, sorry for not being able to take your call, sir. I was in a bad coverage area.
Secondly, congratulations on your new ICE setup. Choice of equipment is spot on for this budget.
Thirdly, I would like to think, going active is not your solution. Try mounting the tweeters off axis. You will have a better experience.
Arre kya Frank, why sorry? When on a highway, driving is more important than resolving ICE problems Thanks anyways for still patiently explaining what I needed to do...

But I still have an affinity for on-axis placement, as I feel that off-axis placement makes some high-frequency details lose out, is it correct or not? One thing I want to try tomorrow is to wire tweeters out of phase and see if their levels get a little more corrected (read somewhere that this technique works if the distance from mids to tweeters is high, eg mids in doors and tweeters on dash/A-pillar).
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