Hi everybody
So I'm currently desining a budget sound quality (SQ) system for my car and I was wondering if I can build some kind of passive stereo separation network for my rear channels in order to widen the soundstage and make a good use of my rear channels. The network has to go between the amp and the speakers because I don't have access to the input stage of my head unit amp.
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What I want to achieve is a circuit that can give a decent amount of stereo separation while providing a relatively healthy load to the amplifier. In the attached photo I give my own first thoughts on the network.
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I'm afraid that whatever resistor value we choose for the circuit, the cross-connection load will always be less than the speaker load, preventing us from achieving an acceptable result.
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I really don't know what I'm doing so I want your help!
So I'm currently desining a budget sound quality (SQ) system for my car and I was wondering if I can build some kind of passive stereo separation network for my rear channels in order to widen the soundstage and make a good use of my rear channels. The network has to go between the amp and the speakers because I don't have access to the input stage of my head unit amp.
.
What I want to achieve is a circuit that can give a decent amount of stereo separation while providing a relatively healthy load to the amplifier. In the attached photo I give my own first thoughts on the network.
.
I'm afraid that whatever resistor value we choose for the circuit, the cross-connection load will always be less than the speaker load, preventing us from achieving an acceptable result.
.
I really don't know what I'm doing so I want your help!
Attachments
In the SQ community they do rear stereo separation by utilizing a DSP module. I can't because of the budget limit. And I'm only driving the mids and highs with the head-unit amp so I don't mind if the circuit efficiency isn't perfect.
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Soongsc, thanks for reply. The address you gave is vague, do you know how can I find the circuit? Any keywords or ideas will do.
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Soongsc, thanks for reply. The address you gave is vague, do you know how can I find the circuit? Any keywords or ideas will do.
The finest car stereos in the world still have trouble with separation and imaging. Interior design, materials, seating position, speaker placement, purposeful and accidental reflections all would seem to be more important then rear channel separation.
Even when you have a full dsp unit and design the interior yourself the results are good but not extraordinary.
Even when you have a full dsp unit and design the interior yourself the results are good but not extraordinary.
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No opinions still?
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Indigent Audio, yes I think I've researched enough to know how hard it is to even 'remotely' get close to HiFi in a car, let alone doing so on a limited budget. But when it's the system you're gonna listen to everyday you've gotta squeeze every drop of capability out of that. DIY'ers and tweakers are familiar with the feeling!
So you advise me not to touch the "rearfill" issue? Oh you're not discouraging me to give up on my car completely do you?
What do you suggest as a major upgrade to stereo imaging or other aspects of sound quality? I already have Bi-amping in my program, which is a solid upgrade and consists of 4ch class AB driving mids and highs, and 6ch class D driving woofers and subs. I've also got this idea of modding the placement of mids and tweeters to achieve best frequency response and, hopefully, balanced level between left and right. Then I'm gonna add some basic functions using my head unit, like basic EQ and time alignment. Oh, and I'm gonna fire my subs and 6×9's back to the trunk to get a nice infinite baffle, tight and deep bass from relatively cheap speakers.
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Just so you know how far I am from a true SQ system, you should know that I've got 6×9's in the rear deck!
This is the best I could do to get the maximum sound level (just so that I don't deal with the non-linearities of the overpowered drivers or any annoying thing like that). To be specefic, Pioneer 6990F's in the back and Pioneer 1680's in the front door. A pair of 8 inch subs. 12 sqm of damping mat. JVC 462BT head unit, a 6×100W class-D homemade amp +homemade crossovers is all I got for my car. Not really fancy nor top-notch, but if I can squeeze the quality out of it, that'll do just fine for me.
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So any ideas? I'm still looking for my stereo separation tho!
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Indigent Audio, yes I think I've researched enough to know how hard it is to even 'remotely' get close to HiFi in a car, let alone doing so on a limited budget. But when it's the system you're gonna listen to everyday you've gotta squeeze every drop of capability out of that. DIY'ers and tweakers are familiar with the feeling!
So you advise me not to touch the "rearfill" issue? Oh you're not discouraging me to give up on my car completely do you?
What do you suggest as a major upgrade to stereo imaging or other aspects of sound quality? I already have Bi-amping in my program, which is a solid upgrade and consists of 4ch class AB driving mids and highs, and 6ch class D driving woofers and subs. I've also got this idea of modding the placement of mids and tweeters to achieve best frequency response and, hopefully, balanced level between left and right. Then I'm gonna add some basic functions using my head unit, like basic EQ and time alignment. Oh, and I'm gonna fire my subs and 6×9's back to the trunk to get a nice infinite baffle, tight and deep bass from relatively cheap speakers.
.
Just so you know how far I am from a true SQ system, you should know that I've got 6×9's in the rear deck!
This is the best I could do to get the maximum sound level (just so that I don't deal with the non-linearities of the overpowered drivers or any annoying thing like that). To be specefic, Pioneer 6990F's in the back and Pioneer 1680's in the front door. A pair of 8 inch subs. 12 sqm of damping mat. JVC 462BT head unit, a 6×100W class-D homemade amp +homemade crossovers is all I got for my car. Not really fancy nor top-notch, but if I can squeeze the quality out of it, that'll do just fine for me.
.
So any ideas? I'm still looking for my stereo separation tho!
Yes I know those drivers are coaxials and don't do well in OEM speaker positions. I'm gonna mod the drivers, separating mids, adding some high quality tweets to them and placing the mids and tweets up on the dash corner facing the non-existent sunroof. Or maybe toed in a little bit more.
I'm not gonna remove the mids and tweets from the 6×9's but I am gonna give them a nice angle so that the on-axis waves don't hit the rear glass.
I'm not gonna remove the mids and tweets from the 6×9's but I am gonna give them a nice angle so that the on-axis waves don't hit the rear glass.
Didn’t mean to discourage you, you built your own subwoofer amp for 12v, a major accomplishment and you seem to have gotten a long way toward your goal...that being said separation or imaging is the holy grail of car hifi. Let’s see if we can show improve here. For the rear you have 2 6x9s on the back tray right? are the pointed forward or faced up reflecting off the rear glass? For separation I would face them forward and not bouncing off glass. Are the 6x9s crossed over on the low end? With woofers to cover the low end I don’t think it will matter much if the are OB or in an enclosure. As an experiment you could take a spare speaker with the same impedance and connect a null or pseudo center channel in the rear (connect the + from the R and L of the 6x9s to the + and - of the spare speaker) Run up an older preferably live track, at minimum this will show you the difference between channels and give you more information about separation issues, at maximum it will improve your imaging and you can leave it in place. FYI I haven’t connected a null channel in 20+ years and I imagine modern recording methods could effect the outcome.
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