[stefanm]

HI,

Just wandering if anyone in Mumbai is offering this service? as i wouldn't mind trying it out, rather than spend out on the kit which i would only use once or twice.

Regards,

Stefan

[speedzak]

As of now, there's nobody who is offering this service in Mumbai.
If you're very much interested, then you'll have to buy a kit or borrow one from somebody who has one.

And if you get one, please! Can I borrow it?

[stefanm]

Good answer, suprising though, since the 9887 is fairly popular and is a very good sq head unit, I just wanted to give it a try to see how good my tuning skills are, somebody must be having one???

[Bass&Trouble]

Originally Posted by stefanm

I just wanted to give it a try to see how good my tuning skills are, somebody must be having one???

If you get the imprint kit, how will you see how good your tuning skills are? The kit does the job for you.

Setting up EQ and TA manually will be a good test of your tuning skills.

[santosh.s]

Originally Posted by Bass&Trouble

If you get the imprint kit, how will you see how good your tuning skills are? The kit does the job for you.

Setting up EQ and TA manually will be a good test of your tuning skills.

Personal tuning skills is one thing, but I believe imprint definitely has capabilities beyond what can be achieved by just tuning, no matter how good it is. IMHO, good tuning is a must whether you use imprint or not. Me too was keen on this HU, but settled for manual TA in the interest of cost, didn't want to spend too much. May be a few years down the line, when mult-eq technology shall probably penetrate into at least a few other brands, I may consider an upgrade.

[stefanm]

Originally Posted by Bass&Trouble

If you get the imprint kit, how will you see how good your tuning skills are? The kit does the job for you.

Setting up EQ and TA manually will be a good test of your tuning skills.

I have tuned the system already and i am very happy with the results, using the imprint kit would be a comparison, most say the imprint is excellent, whilst a few others who have done a comparison didn't rate it so highly. Hence it doesn't make sense to spend 10k on the kit for an individual user, what suprises me is that none of the 'specialist' dealers appear to have the kit, which from most accounts would save a good few hours of tuning, i would have thought that if you are in the business and selling imprint capable h/u's it would be a worth while investment, for me i would like to unlock the treble and bass controls, for easier adjustment, as cd's have differences in recordings.

[Bass&Trouble]

Originally Posted by santosh.s

Personal tuning skills is one thing, but I believe imprint definitely has capabilities beyond what can be achieved by just tuning, no matter how good it is. IMHO, good tuning is a must whether you use imprint or not.

Imprint as addded to a HU like 9887 will not change any settings that are not user adjustable. With the exception that it will correct for frequency response anomalies as picked up by the mic, at more frequency points than that accessible from the EQ menu. After using Imprint to calibrate, and then manually changing settings is a bit like not using Imprint at all, isn't it?

Originally Posted by stefanm

for me i would like to unlock the treble and bass controls, for easier adjustment, as cd's have differences in recordings.

CDs having difference in recordings cannot be completely sorted out just by boosting or cutting at 100Hz and / or 10kHz. Better idea would be to use the subwoofer level control to cut/ boost bass, or using the EQ to fine tune. For example, you could take a couple of cds that differ vastly in the sound quality, tweak the EQ to whatever suits you best, and then save it as a preset. So the next time you have a cd like that you just switch presets which is very easily done from the remote.

[stefanm]

CDs having difference in recordings cannot be completely sorted out just by boosting or cutting at 100Hz and / or 10kHz. Better idea would be to use the subwoofer level control to cut/ boost bass, or using the EQ to fine tune. For example, you could take a couple of cds that differ vastly in the sound quality, tweak the EQ to whatever suits you best, and then save it as a preset. So the next time you have a cd like that you just switch presets which is very easily done from the remote.[/quote]


Yep already done all that, except I have hidden the remote control, i don't like anyone fiddling with the sounds when i'm driving, it impedes my concentration!

[santosh.s]

Originally Posted by Bass&Trouble

Imprint as addded to a HU like 9887 will not change any settings that are not user adjustable. With the exception that it will correct for frequency response anomalies as picked up by the mic, at more frequency points than that accessible from the EQ menu.

No, I don't think so. I believe it is more than just a parametric equalizer with abundant number of bands, much more than user controllable EQs support. Key point is that it has ability to minimize "time-domain" problems which no EQ will have. For example, it has capability to reduce echos that may arise due to room reflection (cabin in this case), and that's what differentiates mult-eq from many other "auto" setups and auto eq's. That is why many claim that clarity and imaging is vastly improved by mult-eq. Correcting or warning about phase, crossover points, TA and even system's frequency response anomalies are probably a less important subset of it's real job, because as you said one can always do it manually. (This is as per my understanding, could be wrong)

After using Imprint to calibrate, and then manually changing settings is a bit like not using Imprint at all, isn't it?

What I meant was that there is some part of installation/tuning which is not controllable by imprint, and we have to do it right manually anyway. For example, amp gains. These would be inevitable irrespective of whether one wants to use imprint or not. Things that are controlled by imprint can be left to it.

[morten]

Has anyboby used an imprint kit here and how much difference does it make as compared to manual tuneup.

[DerAlte]

Originally Posted by santosh.s

... Key point is that it has ability to minimize "time-domain" problems which no EQ will have. For example, it has capability to reduce echos that may arise due to room reflection (cabin in this case), ... (This is as per my understanding, could be wrong) ...

Was this claimed by Alpine, or by the Imprint guys? Sounds too good to be true, especially if one considers the rather anaemic processing power available at runtime in the HU (this is DSP work, not configurable resistor / capacitor work).

Imprint 'configures' the equalizer off-line (when the music is not playing) by sampling at multiple defined frequency points (same as that for the intended equalizer) and gap analysis, and calculates the buck/boost for those points. The 'equalizer', working in frequency domain, applies the same level at the those predefined frequencies. Only passive component based equalizers do it in time domain.

'Echo cancellation' as you described is a totally different ball-game - tough to achieve even using a regular PC processor. It is very easy to add echo into a signal stream (usually the 'resonance effect' provided in media players - room, hall, stadium etc.). But to detect and cancel echo one has to go on a wild goose chase trying to find which part of the signal is a repeat of which preceding part of the signal, and then suppressing it. Try 'see'ing music on an oscilloscope, the size and nature of the problem will be obvious to you.

And, ALL signal processing problems are in 'time domain'. Frequency domain is only a tool / platform to help solve problems.

[santosh.s]

Originally Posted by DerAlte

Was this claimed by Alpine, or by the Imprint guys? Sounds too good to be true, especially if one considers the rather anaemic processing power available at runtime in the HU (this is DSP work, not configurable resistor / capacitor work).

I don't think there is much information about it on Alpine's site. However, I used to read a lot about mult-eq in context of home audio. That was a few years back, when Alpine had not released any imprint enabled products I believe. Based on information on their site, coupled with so many independent reviews by different people/magazines/websites, I tend to believe that they ARE different. Their company was founded just for their room correction technology, and I think they would not have been able to convince quite a few big names in audio industry to commercially incorporate it unless it holds some water. And yes, I wanted to stress upon my impression that "echo cancellation" does seem to be their USP, and that it can not be achieved through any traditional tuning. (Except when you acoustically treat the room/cabin to such an extend that it becomes almost "dead"). I also remember following an open forum like ours where one of the founders of that company (probably CTO or the like) unofficially participated to provide people with a good level of technical details, but until an eccentric guy who got furious over something and used the four letter word against him. Go through their site (Audyssey Welcomes You) to know about people behind this, their claims and other reviews in your leisure time, and you may agree with me!

I do understand that this is done as a DSP algorithm. BTW, I have been designing similar DSP chips for a while for living, and they hold significant market share in home, car as well as pro-audio. In fact, there was a particular request from mult-eq guys (through some other company, IIRC) to provide some dedicated hardware to speed up their filters. We did that, but in a more general-purpose way, so that anybody can use it for any kind of processing.

................
And, ALL signal processing problems are in 'time domain'. Frequency domain is only a tool / platform to help solve problems.

Time domain and frequency domain are two sides of the same coin, I believe. Anything that can be described in time domain can be expressed in frequency domain and vice-versa. Just that one domain is far too easy to deal with certain problems while for others it is the other way around. For example, consider much talked about TA- how would you solve this? By definition it should be explainable in both domains. In time domain, it is as simple as just delaying audio samples. What about frequency? If you just look at frequency response of a single speaker with and without applying TA, would it be different? As per my understanding, amplitude response would be just flat in both cases (assuming the system to be ideal). What differs here is the phase response. In frequency domain, only amplitude response can not tell the whole picture unless phase response is also considered together. Another important point is that in frequency domain it is always "steady-state" response that we consider. It doesn't tell anything "directly" aobut transient behavior. I don't think we take into account the phase response at all when applying parametric EQs. Moreover, mult-eq applies unique filters to each speaker (like what TA does), whereas parametric EQ I guess applies a certain filter to all channels, right? This way I don't think it can ever achieve some of the things that mult-eq or just plain TA can. Does it sound meaningful/convincing?

[stefanm]

Originally Posted by morten

Has anyboby used an imprint kit here and how much difference does it make as compared to manual tuneup.

I want to give it a try, before i left the UK to come to India, I was following talk audio forum in UK, there the 9887 is an extremely popular hu for SQ, the majority of owners seem to be in favour of the imprint set up over there own settings, many of these guys also enter SQ competitions, also the guys over in USA on DIYMA forum seem to prefer the imprint set up. I'm just suprised that retailers of high end ICE here are not providing this sevice, they could charge say RS2000 per tune up using this kit for two passes, this equates to approximatly one hour of time or rent out the kit with a refundable deposit, this would make sense to me. No takers for the idea???

[DerAlte]

Originally Posted by santosh.s

... I do understand that this is done as a DSP algorithm. BTW, I have been designing similar DSP chips for a while for living, and they ...

Wow, terrific. Maybe you should try using one some day - the difference between a collection of blocks and an algorithm implementation will be become apparent to you.

Originally Posted by santosh.s

Time domain and frequency domain are two sides of the same coin, I believe. ... Does it sound meaningful/convincing?

Well, I thought I was understanding you. But after the first few sentences I realized I have seen rivers straight as arrows, and you were speaking too fast.

[low_bass_makker]

Originally Posted by santosh.s

For example, consider much talked about TA- how would you solve this? By definition it should be explainable in both domains. In time domain, it is as simple as just delaying audio samples. What about frequency? If you just look at frequency response of a single speaker with and without applying TA, would it be different?

The freq part will also depend on the what part of the music spectrum is being used will effect more in the lower spectrum of sound rather than the High freq part.

While doing TA in car for the sub. If we set the TA using a sine wave of 70 hz all is good till we are + , - 5 hz...when we go further up and down we see the TA going apart. So what do you think what is used in the H701...

For the Imprint they must be using delays and EQ to equalize the sound nothing more fancy in that...For the details giving on the Alpine web site some times they become a little fancy with the marketing part. Since they have to sell the product which they have manufactured