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Tendean17?s - Nissan Grand Livina 2007 with 17 speakers

45K views 149 replies 37 participants last post by  stixzerjan 
#1 ·
Tendean17’s - Nissan Grand Livina 2007 with 17 speakers

Hi .. This is my second build for my family car, but first build log post in this forum. I’ve limited tools, skill, knowledge, experience and english ( sorry for that ) .. so please advise me if I’m wrong .. This weekend the Build and Install project kick off. I live in Indonesia and this is my car :

Nissan Grand Livina 2007





Dashboard ( Picture from Nissan )



Interior ( Picture from Nissan )

 
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#2 ·
Tendean17’s - Nissan Grand Livina 2007 with 17 speakers

Steps to make it more organized :

1. Objective and Background.
2. Blueprint and Layout.
3. Equipments.
4. Some Weapons and Bullets.
5. Previous Build.
6. Design and Prototyping.
- Dashboard
- Subwoofer
- Midbass
- Midrange + Tweeter
- Center Speaker
- Rear Speaker​
7. Build and Install.
- Front High ( Midrange and Tweeter ).
- Front Low ( Midbass ).
- Center.
- Rear.
- Subwoofer.
- Head Unit.
- Power Amplifier and Processor.
- Build Passive xover for Midrange and Tweeter ( Front, Center and Rear ).
- Prepare for Calibration / Measurement.
- Acoustic Level matching using RTA all Front, Center, Subwoofer and Rear.
- Capture Frequency Response for xover point and avoid cancellation.
- Acoustic treatment to reduce reflections.
- Final Tuning in repetitive and iteration process from installation to final steps.​
 
#3 ·
Tendean17’s - Nissan Grand Livina 2007 with 17 speakers

Objective and Background.

At the first build (no log) I hear something missing in the sound and response .. I make a note .. find the answer and cause .. sometime find the answer .. sometime not .. many mistakes at installation I’ve done before but I hope not for this time. I’m not professional in this car audio industry, not for scoring my car audio too .. I do this just for my hobby.

My Objective is a car with good sound .. very simple.

I try minimizing modification. I’ll obey the law of acoustics & physics and take the compromise installation in a car audio. Sometimes I need something different for fun and experiment with refer to the success constantly from other member as my reference and knowledge base of science. I design this build several months ago and plan the build takes about 1 to 2 months .. do that at weekend and my spare time in home ( my wife, son and daughter know and understand very much that this is my hobby ) with help from my brother and sometime from my friend.

I read some full build log and technical forum, every each gives me different ideas .. I know what work in their car not always work in my car .. what I see is not always what I get .. but .. give me a chance.

Highly’s build 2010 and 2011 .. Pionkej’s build .. AcuraTLSQ’s build .. Gary Summer’s build picture .. Bikinpunk’s various build and Klippel test .. MattR’s build .. Mic10’s various build .. BigRed’s build .. thehatedguy’s build .. Neil_J’s build .. CVJoint’s build .. and many others I can’t remember .. including all my friends in Indonesia .. they all gives me tons of ideas.

Thanks everyone for share their knowledge .. Andy Wehmeyer, Lycan, Patrick Bateman and many others, so people like me can understand better about car audio. I follow thousands of their posts.

Oh .. although I know a little from their knowledge and experience .. it doesn’t always make me success in building car audio .. but I think it will be very helpful to know which will work for me or not and why. I read plenty post from this forum i found that even the expert had different theory and reason for their post and sometime contrary with each other.

For my real world .. i heard some beautifull installation and big modification car audio .. sometimes the efford does not help and effect to the sound .. Now I understand clearly that before I have car audio, I should know at least how the speaker works, basic of installation and limitation .. if not, i’ll always blame the equipment and fall in the dark side. That’s why i think that i must find my own way just for me to have it constantly and consistently.
 
#5 ·
Re: Tendean17’s - Nissan Grand Livina 2007 with 17 speakers

Equipments.

These equipments will be install in my car .. Maybe change during installation and tuning.





Head Unit : Clarion HX-D2
Processor : JBL MS-8
Power : JL Audio HD900/5
Power : JL Audio HD600/4
Midbass : Scanspeak 18W_4531G00
Midbass : Scanspeak 15W_4531G00
Midrange : Scanspeak 12M_4631G00
Tweeter : Tangband 25-1719S
Rear : Seas PW165 + Tweeter : Phass NT28BM
Rear : JBL GTO 528 Coaxial ( Midbass + Tweeter )
Subwoofer : JL Audio W6V2
 
#6 ·
Re: Tendean17’s - Nissan Grand Livina 2007 with 17 speakers

Some T/S Parameter and Frequency Response from Manufacture :

Scanspeak 18W_4531G00 T/S Parameter :
fs=33Hz ; Qms=5.2 ; Qes=0.38 ; Qts=0.35 ; D=138mm ; Sd=150cm2 ; Vas=41.9L ; Sensitivity=90dB@2.83V/1m ; Re=3.4 ohm ; Le=0.3mH ; Voice Coil=38mm ; Linear Excursion=6.5mm ; Max Excursion=11mm.



Scanspeak 15W_4531G00 T/S Parameter :
fs=40Hz ; Qms=4.6 ; Qes=0.34 ; Qts=0.32 ; D=110mm ; Sd=95cm2 ; Vas=15.8L ; Sensitivity=87dB@2.83V/1m ; Re=3.4 ohm ; Le=0.25mH ; Voice Coil=38mm ; Linear Excursion=6.5mm ; Max Excursion=9mm.



Scanspeak 12M_4631G00 T/S Parameter :
fs=75Hz ; Qms=5.57 ; Qes=0.35 ; Qts=0.33 ; D=79mm ; Sd=49cm2 ; Vas=2.3L ; Sensitivity=89dB@2.83V/1m ; Re=3.2ohm ; Le=0.22mH ; Voice Coil=38mm ; Linear Excursion=3mm ; Max Excursion=7mm.



Tangband 25-1719S T/S Parameter :
fs=800Hz ; Sensitivity=90dB@1w/1m ; Re=3ohm ; Le=0.002mH ; Voice Coil=25.4mm ; Freq.Response 800Hz-30kHz.



Seas PW165 T/S Parameter :
fs=53Hz ; Qms=2.47 ; Qes=0.5 ; Qts=0.41 ; Sd=136cm2 ; Vas=17L ; Sensitivity=91.3dB@1w/1m ; Voice Coil=39mm ; Linear Excursion=8mm

Scanspeak 10F-4424G00 T/S Parameter :
fs=90Hz ; Qms=3.2 ; Qes=0.32 ; Qts=0.29 ; D=68mm ; Sd=36cm2 ; Vas=2L ; Sensitivity=89.8dB@2.83V/1m ; Re=3.2ohm ; Le=0.1mH ; Voice Coil=20mm ; Linear Excursion=2.6mm ; Max Excursion=7mm.

JBL GTO 528 Coaxial T/S Parameter :
fs=92.1Hz ; Qms=6.38 ; Qes=1 ; Qts=0.87 ; Sd=86.6 m2 ; Vas=3.58L ; Sensitivity=91dB@2.83V/1m ; Freq.Response 65Hz-21kHz.

JL Audio W6V2 T/S Parameter :
fs=25Hz ; Qms=7.1 ; Qes=0.48 ; Qts=0.45 ; Sd=0.0502m2 ; Vas=79.9L ; Sensitivity=85.9dB@1w/1m ; Re=6.75ohm Series ; Max Excursion=16.5mm ; Recommended Sealed=1.25ft3 / 35.4L.
 
#7 ·
Re: Tendean17’s - Nissan Grand Livina 2007 with 17 speakers

Some Weapons and Bullets.

My notes for driver location and something relevant from peoples that much more experience and knowledge than me .. they help me so much for my next installation :

“Primary width cues are in the midrange. Primary stage width will be dictated by placement of whichever drivers are responsible for midrange frequencies. Ambient width can be augmented with treble placement. I've heard this called 'stage boundary' width …” Highly.

“… So YES, IMO the goal is always to get the speakers as far away and as wide as possible and away from as many direct reflecting surfaces as possible … Use all the TA you want, you will not increase width…” Mic10is.

“At a minimum-keep all drivers especially mid and tweet on the same vertical plane. moving them off that same plane will cause some imaging issues, especially in the depth department. So having something like a Mid in a kick panel and then doing tweet in a Sail or door panel can cause some serious issues bc the tweet is just too physically close to the listener-no amount of TA will compensate for it.” Mic10is.

“Depth is one of THE most confused and misused terminology in car audio and in many instances its often one of the most misjudged areas in competition. Depth is the distance from the front of the stage to the rear of the stage. It is NOT how far away the stage is in relation to the listener .. I would not separate speakers if its avoidable. Multiple locations leads to multiple problems especially above 200hz or so. Depth in home audio refers to the ability to hear beyond the speaker location and not hearing the speakers.” Mic10is.

“I wouldn't worry about depth when discussing tweeters. To me, that's one of the easiest things to line up given it's driven primarily by levels. Especially when crossing higher. I'm not saying phase doesn't matter, but it's less important than the location of a midrange given wavelength. Once you get your tune right, a lot of the stage aspects of the audio system will fall in to place. You just have to focus on getting your left side and right side response to match up.” Bikinpunk.

“… Simply stick the speakers in a corner. The way that this works is that the car itself acts like a waveguide. We're not getting away from destructive interference, we're just sticking the speakers so far in a corner, the effect is less audible…” Patrick Bateman.

“… with the speakers very very close to the corners it 'pushes up' the frequency where comb filtering will begin. Once you figure out that frequency, you'd have to make a choice and either live with the comb filtering that will occur above that frequency, or filter it out and reduce the bandwidth of the driver …” Patrick Bateman.

“… On the other hand, listening off axis *does* reduce the audibility of that 3rd harmonic distortion, because it attenuates the driver mechanically not electronically … This is why low distortion speakers sound so much better.
” Patrick Bateman.

“… Midbass is not very critical for stage width or height, but is essential for depth. Also, if the path length difference is too large, say over 6 inches for the midbass range from 100 to 400 Hz, the imaging will be shifted to the close side …” Mark Eldridge.

“… Tweeters mounted only in the pillars... I'd put them next to the mids, maybe mounted just above, or in front of them, or where ever you get the best staging properties. Mounting them so far away from the mid up in the pillar can cause problems with creating a coherent wave front, and possibly comb filtering. The results can be phase related problems causing depth, height, and imaging problems … ” Mark Eldridge.

“… Based on real world physics of sound. If your tweeters are not arriving at the same time your mids are you will have comb filtering through the crossover region and your soundstage will not be correct … ” Gary Summers.
“... If you are able to build a system in your car where all the speaker drivers output arrive at the listener's ear at the same exact time, then you don't need TA …” Gary Summers.
“… These are the main reasons why "aiming" tweets in car may very well lead to surprising (or at least, non-obvious) results. It may be that aiming somewhat centrally to minimize reflective intensity ... in other words, aiming so that the PHANTOMS are as OFF-AXIS as possible ... may ALSO result in acceptable attenuation for each near-side listener. Hence, my comment about dome-light aiming. When you consider reflections, you may ponder this question : Do you want your main tweeters MORE on-axis, or would you rather have the phantoms MORE off-axis? Bottom line : "on-axis" tweeters might make sense in a larger, less reflective environment for more centrally-seated listeners. But don't try to force-fit home-audio thinking where it just doesn't apply.” Lycan.

“… The frequency at which the first comb null appears will depend on : the time delay between primary source and reflection (or between primary source and image). The depth of the first comb null will depend on : the magnitude of the reflection (or image) compared to the primary source. If the magnitudes are identical, the null will be infinitely deep (perfect cancellation). If the magnitude of the reflection is only half of the primary, the null will only be 6dB deep. Never a really good idea to try to EQ nulls .” Lycan.

“Using reflections to create a "larger than life" soundstage is a dicey proposition. The naturally wide stage that basic stereo is capable of achieving does not "depend" on reflections to achieve it; and, consequently, we often find in small, reflective environments that taking steps to reduce reflections will actually widen the stage ... “ Lycan.

“In summary : below 200Hz, aiming doesn't matter. At higher frequencies where the driver starts to BEAM, aiming starts to matter. So the only answer to the question : does it matter how I aim my 6" drivers? is this : what frequency range are they playing? If limited to 200Hz and below, the answer is no : it does not matter how they are aimed. If playing well into the midrange AS WELL AS THE MIDBASS, then the answer is yes : the midrange "part" of what they are playing WILL be impacted by how they are aimed.” Lycan.

“Big difference between a concert hall and car: size of the acoustic space! And it's NOT just a relative difference ... there's a real, tangible threshold involved, as defined by the Haas Effect. In a car, there's a real good chance that the natural reflections will not exceed the precedence effect (about 20msec, if memory serves) ... meaning that natural reflections will only tend to smear and confuse the front stage. In a concert hall, there's a real good chance that the natural reflections will exceed the precedence threshold. So if you delay the rear fill by ~20msec or slightly more, you can create an apparent acoustic space that is much larger ... without confusing or ruining the front stage. This is a good thing Yes, we face the orchestra in a concert hall ... a classic argument against dumb rear fill ... but we also sense that the concert hall is bigger than about 25 cubic feet ... a very good argument in favor of smart rear fill ” Lycan.

“... but the real reason not to operate a speaker near its resonance is because that's where it produces the most distortion and at multiples of resonance. That distortion cannot be filtered electrically (yet), and it's high-frequency content that makes localizing the speaker easier. Couple that with all the turbulent air movement when the cone has to move a long way and it's a recipe for winning the "Where's Waldo" game. Seriously, minimize the excursion and the system will get well fast.” Andy Wehmeyer.

“... When there are two sources for a sound that are identical in frequency and time, we hear a phantom source in between. That's why we hear a center image in a stereo system. If we have a speaker and a reflection that have the same frequency response, we'll hear a phantom image inbetween. If the frequency reponse of the reflection is NOT the same, then the image will be placed differently for sounds at different frequencies. If 1kHz is louder in the reflection, 1kHz will image closer to the reflecting surface. At the frequency where the speaker and the reflection are out of phase, we'll hear two images (or no image, depending on your perspective). This causes images to wander around.” Andy Wehmeyer.

“... Putting a center channel in the top of the dash is a little different. We hope for the best in terms of the big suckout from the combination of the direct and reflected sound from the windsheild and we use the windsheild to provide a phantom image that's a little higher than the location of the speaker in the dash. This works great, but it does provide some image spread for the center because the sound of the center speaker will reflect off the WHOLE windshield and the door glass.” Andy Wehmeyer.

“… Here's the deal. Everyone explains time alignment as a way to "move the nearest speaker so it sounds like it's farther away". That's BS and it's a lazy explanation. There is a way to "move speakers electronically", but it isn't simple time alignment. Using time alignment won't make your stage wider or make sounds that come only from the nearest speaker sound like they come from a source located farther away …” Andy Wehmeyer.

“… In cars, we hear all of the reflections and the initial sound as one event - that means we hear the speaker's power response, which is the average of the frequency response at all angles. If we use the speaker above all the way up to 12k, we'll have a big fat hole in the off-axis response where the high frequencies contain far less reflected sound. If we aim the speaker so that our ears get the high frequency sound the on-axis response will have wide bandwidth, but the reflected sound will lack high frequencies. When we tune the car using an EQ, we'll want to boost the high frequencies to smooth the response, but that'll make the on-axis response too bright. It's much easier to make the car sound good if we can make the reflected sound as similar in frequency response to the initial sound. Then, when we EQ, we'll have smoother coverage over a wider listening window.” Andy Wehmeyer.

“I have many more .. but still a few that I understand clearly ...“ Tendean17 :(.
 
#9 ·
Re: Tendean17’s - Nissan Grand Livina 2007 with 17 speakers

Previous Build.

My previous build using midrange and tweeter in pillar with midbass in the door using manual processor .. After installed the JBL MS-8, add a center channel on top dash, rear channel in the back, single subwoofer in the left corner .. it’s work and good for me at single seat but for dual seat I hear something missing and I think path length different from midbass in the door and midrange + tweeter in the pillar only for single seat. Since I’ve installed the center channel so I want to take advantage from that.

I capture the response using ARTA and True RTA both tools the same result .. my driver side midbass in the door had a deep hole about 80Hz .. I think because of cancellation and gone when i move the mic at passenger side. Both side midrange and tweeter in pillar had a hole about 800Hz at driver side .. I think because of reflection from side glass. I hope for next build the Inverse square law works and i can get out that outside the pass band .. > 800 Hz are smooth frequency response.

Here’re some pictures from my previous build :

My Previous Center Speaker



My Previous Midbass



My Previous Midrange and Tweeter



My Previous Processor and Power

 
#12 · (Edited)
Re: Tendean17’s - Nissan Grand Livina 2007 with 17 speakers

I wish I was this organized! Good job. Did you do the first build? Because your limited skills, tools, etc. seems to have gotten very professional results. LOL Nice job. Jay
Not really good actually .. seriously I just use a jigsaw, angle grinder, electric drill, hammer, home tools, sand paper, some MDF board and resin to make it. Finishing with car autobody filler then using vinyl for seat covers .. i even don't know exactly the name in english .. :D .. And i always do a little of perfection, precision and accurate in some area very detail and i never satisfied and trust other people do that for me .. in case someone do what i can't do .. it must under my quality inspection. 2 years ago my installer gave up .. there's no benefit to have a client like me.

This a proof it's not really good actually .. sorry i remove the picture bc not relevant.

subd... this is very interesting and a unique build thread. Best to you! I really the amount of time and thought you have put into it.
Thanks and wish me luck.
 
#13 ·
Re: Tendean17’s - Nissan Grand Livina 2007 with 17 speakers

Design and Prototyping

For preparing next build I try many angle and location using temporary box for front midrange only, no lowpass and without midbass, to find at least a good center image with the help of my brother sitting in passenger side for dual listening position, all using ear with IASCA disc 7 drums and 3 people speaking from left, center and right side ( don’t know the title ) .. no perfect result for the response because no EQ but I found the level is almost the same, at least I know the best location and angle for me .. after all new installation done and come to tuning session, i'll using RTA to finalize that .. just to prepare my next driver location .. make a note and documentation .. now i feel confident and ready to start this build.

In the next build I’ll start with some basic install because I believe that if the basic is wrong than everything in the final result will fail and make finding a more difficult problem to solve. If the basic is right than I can improve every point step by step .. so I know the improvement work better or not, there will be iteration process here. In this build I’ll consider every inch in driver placement, providing enough power for all speakers, preparing a system that handles more headroom for better dynamic at normal listening volume .. all parameter of the best I can do and try to help MS-8 do it’s best.

I read on this forum .. some success with the MS-8 .. some people do not. But I am happy with it, MS-8 can not fix the wrong system installation but it will make and help some system sound better. I can try many configuration and hear the result from a few minutes. If I have the right installation then it will take the benefit from MS-8 with Logic7 very much .. that’s from me.

MS-8 configuration in one screen to make easy .. it’s free ;)

 
#14 · (Edited)
Re: Tendean17’s - Nissan Grand Livina 2007 with 17 speakers

I will install the midbass and midrange at the corner side of my car as wide and forward as possible and minimize PLD .. oh .. and it’s not only minimize PLD but it will make different wave length, amplitude, phase and reflections to listening position with the same Path Length Different. Tweeter near the midrange, I wish that I can put them in the same start knee peak impulse response relative to the midrange .. so time delay is minimize and also the phase shift at xover area for direct wave but still not for reflection wave.

Implementing real center channel other than try to find phantom center imaging. Use the biggest center speaker that fit in the dash .. so front left and right just play what in the left and right information only and some mono information ( mostly vocal range ) that reduce about -6db each side. I think the mono information will be solid in the center and If the center image is too center then i know what to do. I’ve a little experience with center speaker location and I’ll try to realize that. Adding rear channel for sense of space with signal steering .. Single subwoofer with sealed box .. Power and Processor below the seat .. etc.

That’s my ideas in the next build. Nothing fancy .. everything will looks simple .. I just wanna good sound.

Next .. I try to explain everything detail about my design inside my head tomorrow .. so everyone read this build know why i plan to do this and do that .. and the important point is .. if I make wrong direction maybe someone can suggest and correct me. Now it is midnight here.
 
#17 ·
Re: Tendean17’s - Nissan Grand Livina 2007 with 17 speakers

That's an awesome collection of useful posts you have there, and a very impressive equipment list. Good luck with your build!
 
#19 · (Edited)
Re: Tendean17’s - Nissan Grand Livina 2007 with 17 speakers

Design and Prototyping -> Dashboard

Without big modification of my original dashboard .. I can pull the 3/4 top from the dashboard so I can put midrange + tweeter and center speaker flush mount below the dash ( virtually ) like Highly's Build 2011 .. but I’m still using sealed box for that .. not IB to outside the firewall. I plan to put midrange + tweeter in the corner where firewall and side car meet each other and hope getting wide staging from that location.

I think using this location ( open flush mount ) help “reduce” 1 of first reflection problem from the DASH for high frequencies ( about >= 1700Hz @ +– 20Cm ). Oh and I hope it’s not only 1 of reflection but I think effects multiple reflection from the presence of other reflection. I can add some absorber and acoustic foam as many as possible below the virtual dash and near around the speakers and at some point above tweeter. Don’t call it BS .. give me a chance and let’s measurement peak and dip tells.

I can’t describe clearly about it and these pictures are what I try to tell about the dash.

Top of the dash.





Dashboard open on top.

 
#22 ·
Re: Tendean17’s - Nissan Grand Livina 2007 with 17 speakers

Design and Prototyping -> Subwoofer

I plan to use JL Audio W6V2.. Single subwoofer 12 Inch .. make the solid and rigid sealed box as I can .. using ¾” 19mm MDF with several layer of fiberglass mat and resin. Location is on the back car ( single cabin ) .. the driver in the middle box with up firing .. nothing special. As spec recommended volume is 1.25 ft3 in sealed box to get about QTC 0.7 I think.

I can experiment using ported box so the sensitivity will up about 3dB .. but not for this time. I’ll hear the result using sealed box first and hope this new location works with my cabin gain to get upfront bass.

Spare tire - original



Floor damping from previous build



Recommended Power from manufacture

 
#23 ·
Re: Tendean17’s - Nissan Grand Livina 2007 with 17 speakers

Design and Prototyping -> Midbass

I plan to use Scanspeak Revelator 18W_4531G00 midbass .. This 7 inch midbass is not roll off at 80Hz ( I prepare a manufacture freq. response in anechoic chamber above ) and i really like this driver impact at moving mass and of course together with midrange frequency .. If I choose a midbass that start roll off at 120Hz and about < -3dB at 80Hz so I will not highpass at <= 80Hz at any slope for that. I’ll move the midbass to corner kick panel as far away as possible to reduce the resonance frequency from door rattle, hope reduce comb filtering maybe and see if the hole still exist or not after my new system is up and take measurement again and the most important is minimize Path Length Different.

The difficulty to me is my car has right steer ( right driver side ) so the gas pedal is in the right side close to the right kick panel area, cause I think it still possible to put there safety .. the midbass in the kick panel is in the corner firewall and side body. I know when speaker is lowpass below beaming point than no need to angle that but 2nd 3rd etc harmonic distortion should be consider too. I learned from Patrick and Andy when the bass note hit 80Hz then 2nd harmonic = 160Hz then 3rd harmonic = 240Hz etc and this can’t fix electronically because they all come from inside speaker it self and it can reduce the distortion mechanically, thats why i choose very low distortion driver for my equipment ( base from some review from zaph audio, this forum etc. ). If I highpass this midbass at 80Hz so it about >1 octave above FS ( 33Hz ) away from the most distortion point .. this is a good start. My angle base on size of midbass and safety from gas pedal.
 
#24 ·
Re: Tendean17’s - Nissan Grand Livina 2007 with 17 speakers

There’s hole in the body near kick panel area .. size is about 70 to 80 Cm2 ( Sd parameter of my midbass refer to the T/S Parameter is 152 Cm2 so 1/2 Sd is about 75 Cm2 ) .. I’ll use this to make my midbass breathe vent to car rail body .. or Aperiodic installation maybe .. Not much option I can do with midbass location and let’s see what I can do later.

Kick panel left location



Kick panel right location



Kick panel right location with midbass ( Left side is the same )

 
#25 · (Edited)
Re: Tendean17’s - Nissan Grand Livina 2007 with 17 speakers

Design and Prototyping -> Midrange + Tweeter

I plan to use Scanspeak Revelator 12M_4631G00 midrange with Tangband 25-1719S tweeter in a box to avoid backwave from frontwave. My build first priority is to minimize PLD ( VC to VC ) as far and wide as possible that’s mean in the corner of my firewall ( Patrick Bateman recommend that .. see his comment above ) .. I hope that I can put tweeter, midrange and midbass almost the same distance to listening position in the same side .. so minimize time delay between them.

I know we use ILD to high frequency and not easy to hear phase error in very high freq at xover point. I really want to put tweeter + midrange in almost the same distance. It will make me easy to build passive xover base on acoustic response ( relative phase ) between them with level match attenuator the best I can do .. since I plan to use MS-8 full channel so no lowpass for midrange and no T.A for tweeter .. purely depend on Intensity Level Difference at EQ works.

I hate speaker break up that cause sybilance in some song and this midrange and the other revelator series is designed to avoid that .. see the frequency response from this manufacture spec .. we can lowpass before break up but again i think 2nd 3rd etc harmonic and slope step degree from my passive xover will still have many information a few db above lowpass .. Scanspeak Revelator series are low distortion driver .. that's what i know about.

I still have Scanspeak Ring Radiator R7000 so Midbass, Midrange and Tweeter will be like EKTA Grande driver in my car .. but the tweeter is big and I wanna play a little off axis .. I’ll keep them for my home speaker. If you go to Scanspeak web site the three of my speakers are still use for their mascot.

Tangband tweeter still possible to change to other driver if I can’t handle that. Their off axis is very flat cause of the lens and too high the off axis roll off base on the spec .. but if ILD really works it will be nice tweeter and easy installation. I use 3 way front so I can cut the passive xover a little high for this tweeter. I can put the tweeter half hidden too and let’s hear the result later. Tweeter location is easily to workaround in different location maybe at side of midrange, on top, a little up etc.

My midrange location is big enough to put Scanspeak 18W without modification .. but it’s not my design in this new build. Midrange and tweeter will pointing a little parallel to windshield, location and angle refered to my trial base on midrange only above. Some day I can buy another Scanspeak 15W to change the 12M to handle midrange lowest, minimize excursion and more power handling with still more a little on axis .. modify the dashboard .. make a hole in firewall .. bigger power etc, but for this build I stick with 12M with a little dash modification as is.

Location for my midrange + tweeter (Red) and a little cut (Yellow)

Front high left location



Front high right location



Front high right location with midbass ( Left side is the same )

 
#26 ·
Re: Tendean17’s - Nissan Grand Livina 2007 with 17 speakers

Design and Prototyping -> Center Speaker

I plan to use another Scanspeak Revelator 15W-4531G00 midbass with Tangband 25-1719S tweeter in a sealed box to avoid backwave from frontwave which cancel each other .. The midbass is 5.5 inch .. because > 5.5 inch is not enough space without big modification from my dash. This time I plan to flush mount in open dashboard ( not like my previous center speaker – on top of dash ) and as low mount as possible. Since I plan to use MS-8 full channel so no lowpass for center midbass and no T.A for tweeter .. purely depend on level at EQ works. I still think that putting the speaker in open dash like this will be different from flush mount into the dash or put above the dash .. adding some thick acoustic foam etc will be effect the final result.

Base on the spec, this midbass only roll off about 1 or 2 db at 80Hz without box ( with a box rise the Q at low as far as I know ) so i think it will work for my xover point at about 80Hz. I choose 5.5” midbass because the dispersion start to narrow is a little higher too, I know it’s related to diameter. Center midbass will pointing to windshield and a little up parallel to windshield and the tweeter maybe in front of midbass in a hole from the dash and pointing up to windshield also.

About tweeter .. I think about 2500-3500Hz the wavelength is about 10-14Cm so I will concern around 10-14Cm from the tweeter for first reflection from baffle .. add some accoustic treatment maybe .. half hidden that etc .. cause it’s possible in my build, so my limited knowledge think that below beaming where the dispersion is wide .. it will only reflect to all the windshield and a little from dash / baffle and when it comes to side glass will be weak because it’s far away. Midbass is a little different .. it will reflect off the whole windshield, dashboard and the door glass .. I think MS-8 will take care of this bc out of phase will steer to the rear channel.

Tweeter still possible to change to other driver if I can’t handle that. Their off axis is very flat cause of the lens and too high the off axis roll off base on the spec .. I don’t know it’s good news or make the tweeter too dominan, also that the sensitivity is greater than my midbass .. This will be my concern when building passive for them .. level matching between them by adding attenuator etc. Seriously .. I’m still confuse to build a full passive between midbass and tweeter or just let the midbass highpass roll off naturally and add a good nonpolar capacitor with Lpad attenuator to tweeter for level matching. It will effect the calibration process too.

At the xover point between midbass where dispersion start to narrow and tweeter still in wide dispersion .. I read about this good explanation about center speaker : “… The center is a similar dual-2-ohm 6" and a tweeter and it's mounted in the top of the dash. Is the 2-way optimum in terms of directivity ? No, but having a 6" in the dash to center the midbass and dealing with the hole between the 6" and the tweeter off axis is the right compromise.” Andy Wehmeyer.

Choose center midbass / midrange as big as possible and the more I think it make sense because if my center channel can go as low as the midbass front channel then no need for MS-8 to steer the gap from low frequency center channel to right and left midbass.

Location for my center (Red) and a little cut (Yellow)

Center location in the dash.





Center location with midbass a little on axis with parallel to windshield.

 
#30 · (Edited)
Re: Tendean17’s - Nissan Grand Livina 2007 with 17 speakers

Wow, that's alot of open space in the dash. Made me think of MattR's Nissan Murano that he built the enclosures for 8" full ranges in the dash. Jay
That’s all my ideas in the next build .. Thanks for reading. :)

In few days I’ll start the building. Entering this phase .. I think it will be a repetitive and iterative process. For efficiency of time, finding more ideas, posting to forum, problem solving etc .. So the order of installation and building will vary.

Please .. don't judge a book by it's cover.

Coming soon.
 
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