[DerAlte]

Ask the gentleman at Pratham to get you that exact language (ECU, HU, subwoofer etc.) on a Ford letterhead from someone reasonably senior at FoMoCo. Otherwise, tell him to educate himself.

[parik_ind]

Called Maruti regarding this and the helpline person had no clue so I called Pratham and spoke to an executive and she said that it will not void any warranty on the car.

The sales person has been very helpful so far. I just that they are equiiped with correct information and do not cause any confusion.

Parik

[filcord]

I want to retain the stock HU, to enjoy the Steering remote, etc.
The HU has rear RCa pre-outs.
My installer suggested I take the signal from the RCA to a 2-channel amp, and supply this to new JBL 6.5 inch components in front. The stock rear door speakers are to be fed off the HU. Of course this means I'll be interchanging front and rear when doing the balancing.

I was thinking of installing a JBL 4-channel amp (which has speaker-level inputs), feeding this off the speaker outputs from the HU, and supplying to JBL components in front and new JBL 6 in coaxials at rear.

Any suggestions welcome.

[viraj_s85]

Originally Posted by filcord

I want to retain the stock HU, to enjoy the Steering remote, etc.
The HU has rear RCa pre-outs.
My installer suggested I take the signal from the RCA to a 2-channel amp, and supply this to new JBL 6.5 inch components in front. The stock rear door speakers are to be fed off the HU. Of course this means I'll be interchanging front and rear when doing the balancing.

I was thinking of installing a JBL 4-channel amp (which has speaker-level inputs), feeding this off the speaker outputs from the HU, and supplying to JBL components in front and new JBL 6 in coaxials at rear.

Any suggestions welcome.

Thanks you for typing my query in advance

same situation here 2010 ZXI.. I have a 4 channel JBL amp and 1100 W JBL Sub which I would like to install on stock HU... I have 2 questions

1: It is possible?
2: Will it give same effect which I use to get while running with 3RCA Pioneer HU?

[filcord]

Whilst researching my issue of whether to use the speaker-level signal to feed the amplifier (whci is the most cost-effective one for me) I chanced upon this beautifully expounded essay which appears in http://www.8thcivic.com/forums/i-c-e...question.html:

"As stated, in theory, the high level speaker signal is cleaner and more powerful than a standard unbalanced, low level RCA connection for two main reasons.

First is input voltage. A basic LOC is as you stated, merely a resistor type device which does two things - steps down voltage to a usable level by the amplifier input circuitry, and unbalances the signal for use with standard RCA inputs. You can make one pretty easily using a few parts from Radio Shack (which is why they tend to cost between $5 and $20 bucks). In electricity, Voltage is analogous to pressure in a hydraulic system (everyone always uses fluid mechanics to explain how electricity works...), so stepping down voltage is the same as lowering pressure. As you step down voltage, the audio signal is pushed with less pressure through the cables, and therefore needs to be stepped up more by the device at the end in order to generate the same level of output. The bad part is that this increased step up factor also applies to any noise in the signal, which raises the effective S/N ratio (obviously a negative outcome). However, while higher voltage is indeed better for signal transfer and reducing noise, the input stage on the amplifier only allows for a certain level of adjustment – meaning that if the input signal voltage is too high for the design of the unit, the adjustment on the gain cannot compensate for the high input voltage, and the output signal will be clipped, even with the gain all the way down. So when you use signal from the high level speaker cables (Which is typically much higher voltage than the signal coming out of the RCA pre-outs) to power a device designed for an RCA input signal, you need to step down voltage to a usable level... which is part one of the job of the LOC. Often times the LOC is designed to step down voltage by a factor of 10 to 1, meaning that ten volts in becomes 1 volt out. That explains part one.

Part two involves understanding the difference between a balanced and an unbalanced signal. These terms explain how the "-" portion of the signal is handled (more specifically, the impedance of the "-" side relative to the "+" side). Balanced signals utilize a separate return path for each channel, plus a ground for the device. Each speaker has its own "+" and a "-" wire when you are dealing with speaker wires, aside from the ground. In theory, this balanced flow of impedance should even out any discrepancies in the signal by splitting them between the paths. A standard unbalanced RCA does not allow for this. Standard unbalanced RCAs utilize a single signal wire connected to the inner prong that handles both "+" and "-", and are grounded through the outer casing. Since the ground impedance then becomes a factor of the cable length and resistance, and is not necessarily the same impedance as the input signal, you have the potential for the outer cable shield to pickup extraneous voltage on the ground side, creating a small amount of current. This current is not part of the audio signal - AKA, "noise".

You can cheat ways around this, either by "lifting grounds" on some of the devices (not a great solution, safety wise especially)... or by using a transformer to break the ground signal (neat byproduct of transformer operation that happens to work well for audio use)... Thus creating the a market for "balanced line drivers" for use in SQ systems.

While some high end car audio head units and processors utilize balanced line signal technology in their interconnect systems, the average RCA connection on 95%+ percent of car audio equipment is setup for an unbalanced signal. Why? It makes more sense when you consider the evolution of the "RCA cable". Around 1940, RCA initially developed what we now know as the standard "audio interconnect" as a means for connecting record turntables to receivers in home audio systems. These systems ran on 110V AC current, and the cables were used only for very short runs. Under these conditions, the potential for noise was far less of a concern than in the automotive environment. For whatever reason, the "RCA" took off with soaring popularity, and quickly became a standard for connecting all types of electronic equipment - including car audio. Naturally, since most larger companies aim to maximize the compatability of their products with those already in the field (to increase their potential market), you wind up with almost everything utilizing a standard, unbalanced RCA signal. This is just how things have come to be. Not that its the best by any means, but like I said previously, most people don't know that.

With regard to your statement about the "amplifier in the head unit coloring the signal and adding distortion", bear in mind that in a typical head unit, the signal coming out of the RCA jacks is the same as the speaker level signal... its merely stepped down in voltage (The voltage for the RCA pre-outs has to come from somewhere...). Going back to part one, we now know that it contains the same characteristics of as the speaker level signal - except that since its lower voltage, it needs to be stepped up by a larger factor at the external amplifier - meaning overall S/N Ratio decreases (which is one reason why people use line drivers, and Hi-Volt head units - to try to counteract this). It is for this exact reason that you should never try to power speakers with the head unit's internal amplifier if you are using the pre-outs to drive external devices. Since the pre-out signal mimics that of the head unit's internal amp, powering speakers with head unit places a load on the amp, increasing distortion, and if the signal is clipped, transferring that clipped signal through the RCAs to your other equipment (Hope all you guys out there telling people to run their rear fill off of the head unit are reading this...). This (along with added space for larger and more spaced/ insulated components) is a primary reason why most of the really high-end decks don't offer speaker level amplification. However, without the added load of powering speakers placed on the internal amplifier, most "decent" quality heads offering speaker level amplification will produce minimal distortion and not clip the signal through the RCAs, even at full volume (assuming all processing is off or flat). So don't think you "need" a head unit without speaker level outs to produce reasonable SQ..."

[filcord]

So I finally took the plunge.
My main issue was trying to retain the stock HU of the SX4 Zxi, as it has Aux, USB and steering controls, besides the dangers of ruining the cosmetic look of the dashboard.

I therefore opted to take the speaker-level outputs of the stock HU and feed it to a 4-channel amp, eventually to new speakers in the stock locations in all four doors.

Amp: Cerwin-Vega HED 300.4 giving 60W rms x 4ch
Front: JBL 609c 6.5 inch components in stock location in the door
Rear: JBL 266 6.5 inch co-axials in stock location.
The amp is placed under the passenger seat as the back of the rear seat is a flimsy sheet of plastic. I've placed it on an old laptop cooling pad to give it some space underneath for proper circulation. Now need to tie it down securely with velcro, next week-end project maybe.

I'm happy with the Sound quality. However I am finding the front compos a little bright, the vocals seems to thrust itself on you. I must re-check the relative gain levels and whether the treble boost/cut switch on the cross-overs needs attention.

After a lot of fiddling around, finally settled on a custom setting which sounds good to me. Bass boosted by +1, treble cut by -2, and fader set to R1. this gives the mellow sound that I was looking for.

In my Baleno I had a JBL CS60.4, 4-ch amp driving GTO637 coaxes in front doors and GTO937 ovals in the rear shelf. I revelled in the sound quality of that system.

One question I would like to know. In the CVega amp, there's a Vegabass gain control, and a very cryptic two-liner in the manual stating it's for boosting bass from 0db to 12db. Is this for full-range speakers in the FLAT position or only when the amp is driving a sub, and set to LPF?

[DerAlte]

The gain control is for the sub, and usually it 'cuts' the bass. What you can do is to keep it in the middle position while tuning, so that you can 'cut' or 'boost' as per the situation. The effect is there on the full range also, but at the frequency this gain is manipulated, hardly anything is reproduced in the full range.

[filcord]

Originally Posted by DerAlte

The gain control is for the sub, and usually it 'cuts' the bass. What you can do is to keep it in the middle position while tuning, so that you can 'cut' or 'boost' as per the situation. ...

Thanks DerAlte, in this amp however the gain level reads from 0db to +12 db. Would this perhaps be only a "boost" control?
There's extremely little information on the Cerwin-Vega amp on the internet. So far the few references I found seem to be from Israel, and are in Hebrew!
However the company has a good reputation, so I had no hesitation there.

[DerAlte]

In relative terms it will be the same based on which way you turn the knob!

[filcord]

Update after tweaking the controls on the amp.

All setting were done with the HU on FLAT setting.

First I reduced the Vegabass gain control, which had been set to a boost of +5db for a frequency of 50 H. I felt this was not meant for full-range speakers such as I had, and was more suited when one was amplifying a sub-woofer. Reduced this to zero.

Then I re-calibrated the gain on the CV amp, by first setting it to zero, then setting the volume on the HU (max was 39) to about 28, then increasing the gain on the amp till I felt there was distortion, and reducing it to a tad less than this setting. Did this on front and rears separately. I don't have any CD with test tones meant for this, so I used music CD's of jazz and rock that I was intimately familiar with on my home stereo.

The results were excellent. I seem to have finally achieved the sound I wanted, a full-bodied concert-hall sound, with enough bass and clear but not overly bright highs. Incidentally I still listen mostly on FLAT settings on the HU, sometimes I boost the bass by +1, at the most. I'm pleased as I feel I have re-created the mellow and clear sound I was hankering for.

I'll now be listening for the next week on these settings, before the next Sunday's review, if any.

[Zorro4X4]

Hi Gurus,

I own an SX4 VXI which I had purchased in Nov 2009 from Maruti True Value and which came with a Pioneer DEH-2050MPG HU. A few days back a friend of mine has replaced his SX4 ZXI stock HU (w/o USB) with a Pioneer touch screen DVD player and gave me his HU.

After going through almost all the forums here in T-BHP, it seems that the stock HU is worthless in terms of sound quality so I'm confused if I should retain the stock HU (Nippon), or go for a new one.

The models that I have shortlisted are as follows sorted as per my preference.

1. Alpine CDE-W235EBT
2. Kenwood DPX-U6120
3. Pioneer FH-X759BT
4. JVC KW-R900BT or KW-R700BT

Appreciate if anyone could suggest which one would be the best and where in Bangalore I could get a decent deal for the new HU. Thanks

[Peter]

Team,

Just upgraded the HU from stock to a Pioneer FH-X559UI , pics for reference for those who may insight of what the overall layout looks like after a change

Cheers

[DerAlte]

Originally Posted by Peter

... Just upgraded the HU from stock to a Pioneer FH-X559UI ...

Looks nice, even though it looks a bit different from conventional HUs!

How much did this cost?

[Peter]

Originally Posted by DerAlte

Looks nice, even though it looks a bit different from conventional HUs!

How much did this cost?

Thanks DerAlte , the unit set me back by Rs 7550 via snapdeal plus the installtion cost of Rs 100

The stock speakers are sounding much much better with this HU

[rajneeesh]

Folks, there is a problem with the fm reception of my SX4. I have had the HU checked by Nippon Auditronics and as per them it is fine. The CD player is just fine.

As per the technicians at Nippon, the problem could be with the antenna or the cables. SInce MASS I go to ( Motorcraft) is not comfortable to attending to ICE related issues, I would appreciate if you can direct me to some reliable ice service centre.

I am based in Noida.