# BMW E39 540 SQ Audio System (Fyrnista Audio)



## Oneminde (Nov 28, 2015)

*BMW E39 540 SQ Audio System (Fyrnista Audio)

PART 1: TWEETERS*

Alright, I think it’s time to start an article/thread for my audio system. I have many questions, thoughts and ideas and I need a place to sort them out, get tips and knowledge from other audiholics, so the decision was simple.

To start this thread I would like to inform everyone about one fact: I am an SQ person and couldn’t care less about SPL. The audio and sound is for me and not for bystanders, so my focus is 100% in sound dampening, absorption and speaker element quality. But I am not loaded with cash, so there will be some limitations towards cost but not so much that my demands suffer. Every frequency is equally important and while bass is a huge part of a big sound stage, so is tweeters and midranges. I will give each speaker they required attention.

Whit that being said, let’s move on to the fun part. What on earth should select – this will take some time and is one reason why I started this thread, to buy myself to plan everything down to its finest detail. So before I start arguing with myself and possibly other members, here is a list of speaker element producers that I am interested in – no specific order:

•	*Audio Technology*. - (used by Sonus Faber, Lansche Audio)
•	*Tymphany.* - (Vifa, Tymphany, Peerless)
•	*SEAS.*
•	*Scan Speak.* - (used by Sonus Faber etc.)
•	*Accuton.* – (used by Tidal, Marten etc.)
•	*Jantzen Audio.* 
•	*Dayton Audio.*
•	*SB Acoustics.*
•	*Morel HiFi.*
•	*Gladen.*
•	*Dynaudio.* - (used by Sonus Faber etc.)
•	*Bowers & Wilkins.*

There we go, that is the list of interesting manufacturers, but I can reveal that one company that ranks very high when it comes to the 3 way system is ScanSpeak. They are loved by many and praised as one of the best. Not cheap, but well worth it. Amplifiers, cables, DPS and so forth will be covered later.

I am very early in the planning process and as I mentioned, there are many things that I am considering. That I will use a 3 way system is very clear, but I have considered 3 way + a dedicated 7-8” bass to get a fuller bass in the front, unless the 6.5” is sufficient – time will tell. The 3 way system will also be used in the rear unless I go for 2 way to keep things a bit more simple there. After all, the rear system is fill only and for the times I have passengers which is not going to be that often. Then ofc, 1-2 pcs 10” or 12” sub. There the question is if I will benefit from using two… good question. Again, this relates to SQ and not SPL. I’ve always used just one sub, so that is my reference. I used Soundstream in the late 90’s. 

Everything would be very simple if we could construct a coaxial speaker with a range of 12-20 kHz, the sound came from one source and “less is more”. But this is ofc very difficult or ells that would be the dominant speaker. It is also very difficult for manufacturers to produce a 2 way system that cover the Hz range equally well as a 3 way system does. The problem with a 3 way system is keeping the speakers close to simulate a one source sound stage. Does the perfect speaker exist ?

*My tweeter experience.*

This, the tweeter, is according to me, one of the most important aspects of the entire sound system. This is the speaker I will focus most on; both in terms of technology and membrane material/diaphragm. I have an excellent hearing and have no problem picking up sound or pitch in the 18 kHz range. It is unusual yes, but there are some people who can actually do that and I am one of them. I can hear and complain about stuff the generic human can’t hear. Due to my excellent hearing, there are not many tweeters that pass my judgement which is in itself a bad thing, I am high maintenance.

If we go back in time to a moment that changed my life and 1998. I remember walking into a store called HiFi Klubben in Norway (Scandinavian audio equipment store chain) and walked into one of their listening rooms. There they had a pair of B&W Nautilus 802 paired with Electrocompaniet two 180 monoblock’s. I was in love.










At the time, realize that my preferences were kind of slim, but it was love at first “sight” or “Love at first word” or whatever fits … LOL. The details and crispness was unparalleled and I still remember it. So in a sense, I am still very much in love with this speakers, and the design … oh my, the design, very unusual and unique. 
I am B&W Nautilus 802 bias, oh sure, no doubt and it is nothing I am hiding. The overall sound from these speakers fits me well, I like it. So that is mine and your preference for everything ells. 

I am well aware of the fact that B&W Nautilus 802 is old by now, but not obsolete. Older is not equal to bad, things change and they have changed since 1998 for B&W as well as for other producers. But in reality, the change isn’t that much. We are talking about tiny evolutions per generations.

One sort of big step that happened was the diamond diaphragm; back in 2002 I think (B&W 800D) which are produced by Thiel & Partner GmbH in Germany. You also have the Accuton and Jantzen Audio diamond tweeter. But before the diamond tweeter, Yamaha (NS-1000) produced the very first Beryllium tweeter (and midrange) between 1975-1987, so not a new material. And ofc, the soft dome tweeters. Before I move on, I’m going to past some quotes regarding diamond tweeters:

_“I have not been nearly as impressed with B&W's effort by comparison as they seemed to jump on the Diamond bandwagon more for marketing reasons after the big-guns had already paved the way. Much like Usher going to Beryllium long after Focal paved the way with the success of the Utopia and Electra Be series. The material is only part of the equation, it is how you use it, form it, what the motor assembly is, and what you do with the surround that really counts.”_

The next quote comes from a private conversation with a very talented and good loudspeaker designer and builder. 

_“Regarding tweeters, the dome material is only part of the equation. The best tweeter I have ever used (to my ears) is the Accuton D30*6*036, stupidly expensive but so clean, smooth, natural and detailed that there is just treble, no tweeter signature at all! A tweeter for people who just want to forget the technical side of HiFi and just listen to music. I have also used the smaller D20*6*031 but that lacked the luscious, rich lower treble that the 30mm dome does so well. Thinking I would get (nearly) the same but for much less money, I have also tried the Jantzen Audio JDT*1024 but that was no comparison. A good tweeter but nowhere near as revealing as the Accuton, the Jantzen didn't excite me at all.

Moving on to Accuton ceramic tweeters: these are very difficult to get right. The ceramic material is very revealing but also very unforgiving. Any "mistake" down the line seems to be magnified by the tweeter, maybe because distortion is very low on ceramic drivers but when there is distortion it is mainly 3rd*order harmonic. The treble produced by ceramic domes is dry and precise. They become more forgiving if some copper foil capacitors are used in the crossover.

Beryllium tweeters are for me the best compromise between cost and ultimate sound. They are revealing like ceramic tweeters but are smoother in presentation, so lots of detail without getting harsh. Clean treble with a little bit of warmth to make them pleasant. The ScanSpeak D3004/664000 and D2908/714000 do need a little attention when it comes to the crossover. They both have a peak in the output level at about 5kHz which needs correcting otherwise the "s" sounds etc. will be emphasized. Aluminium and aluminium / magnesium tweeter come in all types, some can sound rather edgy, others quite pleasing. SEAS seem to have got it right with an extreme budget tweeter that sounds 4x the price: the 22TAF/G. It is well detailed and smooth at the same time and very easy to work with. Most of their 27mm types are also very nice considering the price.”_

Tweeters mentioned so far:

*B&W Nautilus 800 series aluminium tweeter*: ZZ11770 - $144.80 Each - $289 a pair

*B&W PM1 aluminium tweeter:* (alternative) ZZ25607 - $69.50 Each - $139 a pair

*Yamaha NS-1000:* Beryllium Tweeter: JA-0513 - Used part

*Accuton diamond tweeter*: D30-6-036 - $2900 each - $5800 a pair

*Accuton diamond tweeter*: D20-6-031 - $2900 each - $5800 a pair

*Jantzen diamond tweeter*: JDT-1024 - $2060 each - $4120 a pair

*ScanSpeak Illuminator Beryllium tweeter*: D3004/664000 - $457 each - $914 a pair

*ScanSpeak Relevator Beryllium tweeter*: D2908/714000 - $488 each - $976 a pair

*SEAS Prestige Aluminium tweeter*: H1283 22TAF/G - $38 - $76 a pair

*A review of SEAS 22TAF/G*
Reviewed by Seren2
09/27/2012 - 11:56:46 AM

_“I ordered a pair of these 22TAF/G tweeters a few days ago, as I write this. After they got here, I hooked them up to a third-order Butterworth filter crossed over at 3000 Hz, with an added Zobel network strapped across the tweeter terminals. I originally purchased these because I was looking for a 3/4" dome tweeter that would be capable of low distortion and high output. Originally, I was going to get a pair of Hiquphon OW-1 tweeters but a fellow speaker builder suggested that I try out these much cheaper Seas tweeters instead. "Why spend more than a hundred bucks apiece, if you can get the same sound from Seas for a lot less?" he pointed out. Well I was skeptical but for less than forty bucks each, I figure that I could take a chance on these Seas units. Well after a full day of testing them, I got to say that these Seas 22TAF/G tweeters must be one of the best kept secrets in the realm of small dome tweeters. I have listened to hundreds of tweeters during my lifetime, and VERY few of them sound anywhere near as beautiful as these Seas units do. 

That includes other tweeters made by Seas, some of which cost anywhere up to five or six times what the 22TAF/G costs. For starters, these gorgeous little metal dome babies sound almost as good off-axis as they do on-axis. There is almost no sibilance at all, no matter how loudly I play them. Cymbals sound nice and crisp, without any "ringy-ness" or other such undesirable distortion. The overall output level from these drivers was surprisingly high. I had to pad them down a bit with some resistors in order to tame their brightness. Once their level had been properly adjusted, they simply sound crisp, clean and smoooooth as silk with none of the harshness that I usually associate with metal dome drivers. There are certainly better tweeters on the market but not for anywhere near this price. Highly recommended for applications where they will be crossed over at 2500 Hz. or higher. You definitely won't regret it.' Review by Richard Chapman.”

Link: https://www.madisoundspeakerstore.c.../g-h1283-alum/magn.-alloy-22-mm-dome-tweeter/

- End of article -

I don’t care, diamond tweeters is out of the question. It does not matter how well they play, I am not spending that kind of money. So we are left with a few options so far, ScanSpeak Beryllium and the SEAS Prestige Aluminium tweeter as well as B&W’s Aluminium tweeter. But I have a feeling B&W is going to fall out of the picture later, but so far they will remain on the list.

Another tweeter that I come to think of is ScanSpeak’s classic D2905/950000 soft dome tweeter. Praised by many as one of the world’s best tweeter. Further there is ScanSpeak classic D2904/9800 Aluminium Dome tweeter, used by Alpine in their F1 series back in the day. You also have ScanSpeak Illuminator D3004/6020 soft dome as well as Classic 2904 tweeters.

*Lpg, Avi, Sinfoni, Scan-Speak tweeter review*
http://www.diymobileaudio.com/forum...pg-avi-sinfoni-scan-speak-tweeter-review.html

“Last one to the far right is the Scan-Speak 6000-1. It is similar in Build to the 6000, but with a grille and a somewhat different frequency response. The sound overall is very forward, focused, and full bodied in nature, with a very soft and laid back top end. Typical Scan-Speak sound except a bit more aggressive in nature. The Build quality is superb, with a rear loaded chamber and SD-1 motor, which features dual copper rings for lower distortion. It's no surprise then that this tweeter can play flat down to 750hz, and has no problems handling crossover points from 1.5-2khz.

Scan also built that tweeter for Alpine's SPXF17T speakers, and it's available from pacparts for 60 bucks Look for part number D2904/610001. Specs (and build quality) are identical to the Scan original.
Can also get flush mount hardware and a nice surface mount cup too

ScanSpeak (Madisound) part numbers: D2904/6000-00, D2904/6000-01, Alpine part number : D2904/610001
Part numbers are not identical, but the published specs are identical”

- End of article -

ScanSpeak have updated their Beryllium line with D3004/604000 and D3004/604010. And then there is D2905/9500 and 9700 and 9900.

The first one comes from Göran over at audioexcite.com.
*ScanSpeak Textile Dome vs Beryllium Dome!*
www.audioexcite.com Â» Blog Archive Â» ScanSpeak Textile Dome vs Beryllium Dome!

















Left: The ScanSpeak D3004/660000 1” Textile dome.
Right: The ScanSpeak D3004/664000 1” Beryllium dome.










Blue = The ScanSpeak D3004/664000 1” Beryllium dome.
Green = The ScanSpeak D3004/660000 1” Textile dome.

Frequency:









*Normalized, Tweeter On-axis (0deg) 1m measurement:*
Red = The ScanSpeak D3004/664000 1” Beryllium dome.
Blue = The ScanSpeak D3004/660000 1” Textile dome.

The frequency dip at 3.5kHz is caused by baffle diffraction and is evened out with increased off-axis angle.

*Conclusion:*
•	Normalized, Tweeter On-axis (0deg) 1m measurement:
•	Red = The ScanSpeak D3004/664000 1” Beryllium dome.
•	Blue = The ScanSpeak D3004/660000 1” Textile dome.
•	The frequency dip at 3.5kHz is caused by baffle diffraction and is evened out with increased off-axis angle.

*Differences:*
•	The D3004/664000 tweeter dome diaphragm is made of 99% Beryllium, versus the D3004/660000 is made of a Textile dome diaphragm.
•	The Beryllium tweeter costs roughly 2 ½ times more than the Textile tweeter.
•	The Beryllium tweeter has about 0.5dB lower sensitivity and slightly higher impedance than the Textile tweeter.
•	The Beryllium tweeter has a sharper and higher impedance peak at the driver resonance frequency.
•	The Beryllium tweeter has a small frequency dip centered at 8.5kHz that might be caused by the metal protective grill.
•	The Beryllium tweeter has a downwards sloping frequency response from 13kHz.
•	The Textile dome tweeter has an upwards rising frequency response from 13kHz.
•	The Textile dome tweeter has about 7dB higher output at 20kHz.
•	The Beryllium tweeter has lower distortion throughout the driver unit usable frequency range, compared to the Textile tweeter.
•	Beryllium is highly toxic and should be handled with care if it breaks.

*The question is:*
*1.* Are they interchangeable with each other in the same loudspeaker design?
*2.* Which one has the best overall performance?
*3.* Which one has the best price/performance ratio?
*4.* Do they sound the same?
*5.* Which one sounds the best?

*The answer is:* 
1. Basically *YES*, but minor adjustments might be required for perfection.
2. The Beryllium tweeter has slightly better distortion figures otherwise they both have “top notch” performance.
3. My personal opinion is that the Textile dome has better price/performance ratio, due to significant lower cost.
*4. NO*, in my opinion they don’t sound the same. The Beryllium tweeter sound to my ears a bit more neutral in the character than the Textile dome tweeter, which in turn has a bit more “airy” character. I know that it’s a vague description, but they both share the same qualities and the differences aren’t huge.
5. At this point I can’t really say which one that sounds the best. I would say it’s more of a personal taste, metal versus soft dome tweeter. I personally isn’t a huge fan of hard dome tweeters, but the ScanSpeak Beryllium dome tweeter is definitely the best one I’ve so far have listened to. The Beryllium tweeter is a bit more analytic in its character than the Textile dome, which in turn is a bit more forgiving sounding on the less good recorded albums. This might change over time because the Beryllium tweeter seems to need some significant time to burn-in, compared to the Textile tweeter. Out of the box the Beryllium doesn’t sound impressive at all, but after about 24 hours they start to loosen up and deliver nice performance and my guess is that they over time will continue to improve.

Both these tweeters are world-class performers. If you want the “top of the line”, something exotic and isn’t cost-sensitive, go for the Beryllium. If you don’t like hard domes or have a limited budget, go for the Textile version.

Over and out…. 

/Göran

*ScanSpeak Illuminator Beryllium tweeter*: D3004/664000 - $457 each - $914 a pair
*ScanSpeak Illuminator Textile tweeter*: D3004/660000 - $195 each - $390 a pair

The next review comes from our Danish friend Troules Gravesen.

*ScanSpeak tweeters, D3004/660000, D2904/710003, D3004/664000 and R2908/714000.*
SS-domes

For future projects, a pair of 6600 and 7100 tweeters were acquired. The basic differences between these two tweeters are the magnet system and the dome, where the 7100 has a ring of damping glue to the dome. The ring neodym magnet of the 7100 tweeter provides a whopping 95+ dB sensitivity, suitable for fairly high-efficiency systems where the 6600 does well up to 92 dB/2.8 volts. The 6600 display some inconsistency in sensitivity, around 1 dB and although I don't regard this as a serious problem, a little disappointing. Only two units were available for the 6600 tweeter. I had another pair of 7100 for test, hence 4 samples on display below. All of these are consistent in sensitivity and only display minor differences between 15-20 kHz, probably due to the damping ring applied. I wonder why SS added the damping ring as the 6600 display less distortion in this area compared to 7100.

Both of these domes appear suitable for two-way systems with a very low point of crossover and from clients' project I know the 7100 can do well down to 1.5 kHz with a simple 2nd order crossover. The 7100 tweeter was tested in experimental designs and proved well down to 1.4 kHz, 12 dB/octave. Very impressive.
The 6640 and 7140 Be domes were added later to my collection.

The 6600 and 6640 tweeters present some challenges with regard to crossovers, because these tweeters go so low the can play midrange! The 7100 with its steeper low-end roll-off due to the very strong magnet system is easier. Taking the 6600 and 6640 down to 2 kHz and using a 12 dB/octave filter makes it necessary to apply impedance linearisation to render a smooth roll-off profile.

- go to page to see graphs from the test.

*D2908/714000 Beryllium dome.*

My expectations are high on this new tweeter and nothing below suggests I should be disappointed. The Revelator magnet system is stronger compared to the Illuminator motor, thus an 8 ohms voice coil is used here. On top of this a titanium voice coils former, not seen before on ScanSpeak tweeters. Most noticeable is Qm, 7.3 according to specs. My measurements suggest a little lower, but nevertheless, nothing I've seen before. High Qm means low mechanical damping and some may fear this will make a too lively treble. Time will tell. I've heard reservations towards this 7140 tweeter based on the response graphs displayed at SS website. The use of a 10-100.000 Hz range doesn't make things look better on paper. Looking at the 1.000-20.000 Hz range alone (see below) display an usually well behaved response and initial modeling suggest an easy tweeter when it comes to crossovers. And let me say that I couldn't care less about the dip above 16 kHz towards 20 kHz. Some people are obsessed about a flat response to e.g. 30 kHz. There are much more to good treble performance than a ruler flat response to 30 kHz.

Now, all measurements above were done on a large flat panel, but how does it look when it we use a small baffle like the one I'm going to use for the next ATS 4-way speaker? A quick cardboard mock-up, approx. 13 x 20 cm, and some midrange cardboard panel below display the red response above compared to the large flat panel (green). Not bad at all! I took the measurement to my simulation software and it looks easy. And no equalizing step needed. Looking forward to implementing this tweeter in my next construction.

- End of article –

*ScanSpeak Revelator Textile tweeter*: D2904/710003 - $260 each - $520 a pair.
*ScanSpeak Revelator Beryllium Tweeter:* D2908/714000 - $488 each - $976 a pair

Okay, so there are a few options. But we are not done yet. 

ScanSpeak D3004/604010 and D3004/604000 is a rather new product from ScanSpeak, released this year (?). They are both Beryllium tweeters and ScanSpeak points out that these are very well suited for automotive use. That is kinda good news. The other good news is that these tweeters cost “only” $321 each and $642 a pair.

That mean that they are roughly 35% cheaper than the other two Be tweeters ScanSpeak offer. But are they 35% less sound? Both come from the Illuminator series.










Troels Gravesen did a review of the D3004/604010 shy of a month ago. So far, it seems like this is the only one available on this. Now, let’s keep it fresh: The normal Be tweeters from ScanSpeak is praised as one among the best tweeters in the worlds, so what happens when ScanSpeak shrink the speaker and change a few things here and there, let’s find out. 

*Test: ScanSpeak Be dome D3004/604010.*
D3004-604010

Last year I made a pair of minis for the ScanSpeak exhibition at the Munich HighEnd show. These minis featured the prototypes of this D3004/604010 beryllium dome tweeter. Here one year later, ScanSpeak has finally launched the tweeter with a slightly modified grille incorporating a small phase plate in front of the dome, presumably smoothing the 15-20 kHz range. The tweeter also comes in a car version with reduced rear chamber depth. (that is the D3004/604000)

Now, these tweeters sell at 318 EUR/each incl. VAT compared to 444 EUR for the D3004/664000 and 475 EUR for the D2908/714000. Hmm… quite some money to be saved. For comparison, check out my tests of the 6640 and 7140 Be domes here.
Generally we can now get a high-quality Be dome at the same price as state of the art soft domes like the 7100 ring radiator.

To cut a long story short, I can't wait to incorporate these domes in the Illuminator-5 and AudioTechnology 3-Way Classic. Based on the measurements below, I would be very surprised if they don't perform as well as their more expensive siblings.

The domes feature a metal face plate, or should we say mounting ring. All-metal non-resonant rear chamber. Only thing to take care of is the soldering tags. These are for good reason mounted on plastic sockets and just don't add too much heat from your solder iron.
Only thing I miss here is ScanSpeak supplying 6 black screws fitting the mounting holes. Not easy to find some that also look good!

“These may not be as quite as clean as the 7140 tweeter, but better than the 6640 at the low range. By any standard an excellent performance.”

*ScanSpeak Revelator Beryllium Tweeter:* D2908/714000 - $488 each - $976 a pair
*ScanSpeak Illuminator Beryllium tweeter:* D3004/664000 - $457 each - $914 a pair
*ScanSpeak Illuminator Beryllium Tweeter:* D3004/604010 - $321 each - $642 a pair
*ScanSpeak Illuminator Beryllium Tweeter:* D3004/604000 - $309 each - $618 a pair

For complete data of the test, check the website.

Okay, so Troels swear by these, should we do that as well? I have two respected sources that swear by the ScanSpeak Be tweeter as one of the best in regards to price vs performance. There might be only one tweeter above the Be which is better and that is the Accuton Diamond Tweeter and if you remember, that is a big no no.

Looking at the data from ScanSpeak (picture above) they perform very similar, but the 604000 is a tad cheaper besides using a shorter back-cup, so it is optimized for car installation. With the 604000 ScanSpeak is really competing with Focal Be TBE tweeter (Utopia Be) which is close to 10 years old by now. A pair cost circa $1000 and compared to that, the D3004/604000 is a really good price.

*Final words on tweeter.* 

Everything point towards ScanSpeak and their Illuminator tweeter line, unless you consider the H1283 22TAF/G which cost $78 a pair. For some, even that is a large sum of money for tweeters. You also have the Hertz ML 280.3 tweeter for $229 a pair and Audison Thesis TH 1.5 Violino tweeter, none of them are referenced here at all, not because they are bad, but because I think I am more of a ScanSpeak person – it’s a gut feeling.

Before I say my last words about tweeters in part one there is something ells I want to address and that is the: Front system only or rear as complimentary. I don’t know how many of you “audiholics” that swear by using one or the other, but I have a few things I consider to play a big role in my decision. 1. I am building this system for me, so a big ego trip … ha ha. 2. I rarely have passengers in the rear. 3. I rarely use the rear speakers as part of the soundstage and 4. Music is as a rule a two channel / front stage experience. The only reason I would recommend front & rear is when we get into 5.1 or surround sound which is “reserved” for movies. I have never felt I need to be surrounded in the music when I experience it, I get a better experience from stereo than the other. Maybe I am old school or something, but my heart beats for a front system only, so that is what I will base my system on. 

Meaning I will only need two tweeters and don’t worry about that “extra” cost for a rear system. Meaning I can spend some extra money if I so desire, but that does not mean I should – just saying.

So, in reality, there are now two tweeters left that I am really considering. The D3004/604000 Be and D3004/660000 Textile dome. I am also considering adding a waveguide with them, specifically the Visaton Waveguide WG 148 R

















The really big question is if I want to pay $618 a pair or $390 a pair for tweeters. We will see when the day comes.

*Oneminde.*_


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## GERMANIKS (Dec 7, 2013)

I run Gladen RS 130 2 ways components in my 540i and they work great
I updated the tweeters to a higher end Gladen ones though, can't remember the model. But this is very smooth and very detailed.

I use the RS 130 low profile for the rear speakers.

I want to go full active too but for now I am using a small Gladen crossover in between the RS 130 and the tweeters.

I have a Gladen RS 8 VB subwoofer too and the amount of bass is very decent (I have folding seats).

Now mid bass is lacking as you can imagine, and I am planning to install a pair of Gladen shallow 8" woofers in the rear doors.
I do not like 3 ways on the front. I love when the bass is coming from the rear.

I run the Mosconi 130.4 too. Sounds a little bit better I found compared to the previous model, the 120.4

Those cars are pretty well isolated from road noise. I see no point of going bananas to install sound deadening all over.
Sound deadening is mandatory though, all over the plastic speakers enclosures on the front and rear.
I did another e39 2 weeks ago and there is absolutely no ratling etc.

I also use rolls of butyl and apply it to the back of the speakers where it makes contact with the plastic enclosure.


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## Oneminde (Nov 28, 2015)

Welcome to the thread GERMANIKS.

Kewl to hear you are running an upgraded sound system in your 540. I guess we can exchange ideas and (future) experiences with one another 

So, what made you choose GLADEN to such an extent ?

Sound deadening or isolation serves two things. 1. It prevents outside noise to enter the vehicle. 2. It prevents sound from escaping out. Both is equally important. For me, if there is one thing that pisses me off, then that is unwanted road noise or other types of noises that distract me. I want my driving experience to be quiet in that regards. So, besides sound deadening - which will likely be GLADEN products - I am going to install the double glazing BMW offers for the E39. As a bonus, its better security.

Oh and I hate rattling sheet metal that so many SPL focused car owners don't give a **** about. The music experience is for me 

A heads up: I intend to have 3 way the front and considering; tweeter, midrange, midwoofer (upper bass) as well as dedicated bass (lower bass) and 1-2 10 or 12" in the rear. But all of that info will be revealed later.


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## Oneminde (Nov 28, 2015)

I am starting to write part 2 where I will look at midrange and the options there. Part 3, 4,5 etc will contain subwoofer, crossover, amplifiers etc.


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## GERMANIKS (Dec 7, 2013)

Oneminde said:


> Welcome to the thread GERMANIKS.
> 
> Kewl to hear you are running an upgraded sound system in your 540. I guess we can exchange ideas and (future) experiences with one another
> 
> ...


I know what sound deadening is thanks 

What I am saying is that those BMW are pretty well isolated from road noise, you may have noticed. Sure you can cover the floor, roof etc with sound deadening, yes it will be better. But that is a lot of work which is not necessary if you ask me to achieve great sound quality.

The thickness of the floor carpet is very thick.

Other car brands are not as well isolated.
Now with a subwoofer in the trunk etc, yes sure you need sound deadening there too. And a good bit.

Keep us updated


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## Oneminde (Nov 28, 2015)

GERMANIKS said:


> I know what sound deadening is thanks
> 
> What I am saying is that those BMW are pretty well isolated from road noise, you may have noticed. Sure you can cover the floor, roof etc with sound deadening, yes it will be better. But that is a lot of work which is not necessary if you ask me to achieve great sound quality.
> 
> ...


I know you know, I was only adding info for the thread  - and I will do so in the future. This thread is sort of a blog for me so everything that is involved, either as a part or a topic will be debated.

Yes, BMW overall has a better deadening compared to many other brands, hence why it is a good platform for more . My friend drives a Renault Clio and its a nightmare. There isn't only road noise, but there is actually "road winds" inside the car. 

The trunk is a whole chapter on its own.


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## Oneminde (Nov 28, 2015)

This is my fifth post, so congratulations to me. Now I can edit the first post and add links and pictures


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## GERMANIKS (Dec 7, 2013)

Oneminde said:


> The trunk is a whole chapter on its own.


Tell me about it


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## Oneminde (Nov 28, 2015)

GERMANIKS said:


> Tell me about it


What is the plan? Focuse on sound only, or both sound and the visual aspects ?


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## GERMANIKS (Dec 7, 2013)

Oneminde said:


> What is the plan? Focuse on sound only, or both sound and the visual aspects ?


This is a customer's car here

My own car I mainly focused on sound quality. But will need to move my amps and build a nice rack in the spare wheel as I will install a double din radio on the left side of the trunk.


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## Oneminde (Nov 28, 2015)

GERMANIKS said:


> This is a customer's car here
> 
> My own car I mainly focused on sound quality. But will need to move my amps and build a nice rack in the spare wheel as I will install a double din radio on the left side of the trunk.


OMG ... its you ... ha ha, I thought I recognised the name. Well then, an extra welcome and nice to have you on board. I plan on adding the BMW NBT to my car - the one I will get in other words - but that is many chapters later from now. I intend to be extra picky about everything I do and having OCD for details does help 

So I guess this thread will be a good mix between "all things BMW E39" and SQ audio. Its going to be very biased in the end ... ha ha


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## GERMANIKS (Dec 7, 2013)

Any pics of your car, would be nice to see.
I am a big fan of the e39


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## Oneminde (Nov 28, 2015)

GERMANIKS said:


> Any pics of your car, would be nice to see.
> I am a big fan of the e39


Sorry for that, but I don't own one yet. I've been a student since 2012 and had to cut all my expenses. But that time is soon over. That is why I started planing already now, so that I ensure I have plenty of time for everything I want to do to it. I am planing to buy one this summer or early fall. 

Still not sure if I should go for the sedan or the touring, but it will be a 540iA. I did own a E38 730 some time ago, so I am familiar with over all technical solutions they both have.

Oneminde


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## Oneminde (Nov 28, 2015)

*Part: 0.1*
I want to dedicate 0.XX to stuff that is either related to the car itself or stuff that is related but perhaps brand and model specific.

So I'll start with something I've wanted since I had the E38 730. I meant to spend time and money to make it look like I wanted, similar to what I will do with the E39, but that did not happen for many reasons. The time is different now and I think I will be happier in an E39 to be honest, and possibly the sedan version. Lets start with something that is related to sound absorption and isolation. I like quietness and comfort. Yes yes I know, the M5: "Probably one of the greatest BMW ever made" - but read the article *Four Reasons Why You Need To Buy A BMW E39 540i Right Now* and consider what the dude is telling you.

One thing that like about BMW is all the options they have for their cars. Few brands offer this much technology and I mean few, there are essentially only a handful of brands out of several hundred that exist and they have been leading the development for decades. (Yes I am BMW biased, deal with it )

The image bellow show the Insulating Double-Glazing. Added benefits besides noise insulation is the fact that this is glass-lamination-glass configuration which increase the difficulty in breaking into the car, its not impossible, it just takes more time and that is what we want, delay the process. 










So this serves an important part of my expanded security system. I am not going to talk about my expanded security system mainly because that defeats the purpose of having one. Lets just say that it will be a pain in the ass trying to steal my car or stuff . 
Another type of glass that I will add is the Climate comfort windscreen. This type of window has in inbuilt IR (infrared) deflection which makes the car cooler on the inside, and I think it looks cool as well. The picture shows an E90 M3, but the tech is the same.










As a service, I'll include the BMW part number for the double-glazing in case you want that on your own car.

*5' E39 540i GLAZING*









_This is for the European sedan, if you have the touring, make sure you check at BMW for parts number._

*01 Climate comfort windscreen:* 51318238668 --- $673,24
only in conjunction with sealing: 51488224782  --- $9,05
*01 Climate comfort windscreen and rain sensor:* 51317059699 --- $721,45
only in conjunction with sealing: 51488224782  --- $9,05
_(If you have the Auto beam assist, the windscreen does not affect that._

*02 Insulating double glazing: Side Window Front LEFT:* 51328160981 --- $354.83
*02 Insulating double glazing: Side Window Front RIGHT:* 51328160982 --- $354.83

*03 Insulating double glazing: Side Window Rear LEFT:* 51348160983 --- $289.76
*03 Insulating double glazing: Side Window Rear RIGHT:* 51348160984 --- $289.76

*04 Insulating double glazing: Fixed Door Window LEFT:* 51348160985 --- $193.48
*04 Insulating double glazing: Fixed Door Window LEFT:* 51348160986 --- $193.48

*5' E39 540i DOOR WINDOW LIFTING MECHANISM FRONT*









_This is the part for the wider door-rubber-list need for the thicker glass. The rest is the same. _

*04 Insulating Glass; Front LEFT Window Guide:* 51328226871 --- $54.23
*04 Insulating Glass; Front RIGHT Window Guide:* 51328226872 --- $54.23

*5' E39 540i DOOR WINDOW LIFTING MECHANISM REAR*









*11 Insulating Glass: Rear LEFT Window Guide:* 51348193139 --- $48.10
*11 Insulating Glass: Rear RIGHT Window Guide:* 51348193140 --- $48.10

*Some interior inspirations.*
Together with the audio installation, I will redo the entire interior. This car will seriously upgraded.










I like black. Its technically not a colour but the absence of light. But, instead of playing around with the mixing of different colours (primary & complementary) I will use the magic of gloss and matt textiles and surfaces. Its under appreciated technique to create something interesting, subtle but interesting, like different shades can create different effects, this is very similar. So when I say "a black theme" its not just black 

The pictures used in my mock-up comes from the BMW F10 M5 30 Jahre edition. The instrument cluster is ofc impossible to incorporate into the E39, but no one said a hybrid is impossible. The main reason that I like this one is that it reminds me of the Mitsubishi Galant V6 I had. It had a nice layout and when turned off, it was completely dark, but shined with a nice white and bright light, similar to the Lexus LS400. I liked it so much in fact that I became very happy when I saw BMW used that solution in the F10, with the benefit of its wonderful orange-red light when it gets dark. 

Oneminde


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## robolop (Mar 10, 2008)

This is a topic which will be very interesting to follow.
The BMW e39 is one of the best car for good sq.
20 years ago the Swedish best sounding car's (IASCA) were bmw e39.

GO 4 IT


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## Oneminde (Nov 28, 2015)

robolop said:


> This is a topic which will be very interesting to follow.
> The BMW e39 is one of the best car for good sq.
> 20 years ago the Swedish best sounding car's (IASCA) were bmw e39.
> 
> GO 4 IT


And hello to you too 

I have no doubts that is true. I have no real experience with the sound quality possible in an E39, but if it is like you say, then that is a very nice bonus.


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## Oneminde (Nov 28, 2015)

*Part: 0.2*

Sometimes you see something and think: "Yes, yes. That's it." but at the same time its something you usually do not pick out as a thing you want. I often spend my days researching on the internet for ideas. I look at what others do, solutions and so forth and down the line, I will find my own take on it. This time its a white E39 touring which has the M5 mirrors, High gloss shadowline, Alpina front lip and Rotiform 20" wheels. The only change in the image is that I painted the wheels-spokes in Anthracite. I've looked at this image many times, but it does not leave me. I usually go for black when it comes to BMW, but I think this one is very tasteful, like I want it.

I have considered a B&W theme before. But I am surprised that the colour of the car can impact me so much that a white colour makes me want the touring and black colour makes me want the sedan. But for now, this white touring is on the top of my list.









_Original image: 2013 LTMW Spring Car Meet - European Car Magazine_

Rotiform SNA Wheels

Here is another touring with 20" wheels.

Link: https://www.youtube.com/watch?v=OwYijoEvUzU

*Double-glazing for the touring.*

*03 Insulating double glazing: Side window rear LEFT:* 51348193115 
*03 Insulating double glazing: Side window rear RIGHT:* 51348193116	

*04 Insulating double glazing: Fixed door window LEFT:* 51348193119
*04 Insulating double glazing: Fixed door window RIGHT:* 51348193120

Oneminde


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## Oneminde (Nov 28, 2015)

Kazuhiro said:


> Did you say you were going to have a dedicated speaker for "upper bass" and one for "lower bass"? So this will be a four way front stage + subwoofer?
> 
> What driver sizes and models have you got in mind? I havent seen this done before, I suppose you are going all out with fabrication too.


As I am writing this reply, I am trying to remember what the speaker position on the dashboard is called, were you use the windscreen to direct the sound, similar to an omnidirectional speaker, the windscreen spread the sound. To get this reply going, I am throwing in two pictures: One omnidirectional and one installation with the midrange placed like I describe in a BMW E39. And please, don't feel offended if I write something you already know, my reply is not entirely directed to you personally, but a way for me to get things down onto "paper", express my mind and collect them in one place. 
















_Linkt to the DLS page: DLS - Peter Wilhelm_

The questions you ask are fundamental questions that will dictate this build, and I am spending large portions of my day asking the very same questions.. he he. What do I want and how do I want it (?). As you have noticed from my Part: 1 post, I am taking this build extremely serious, OCD serious. And if it is one thing that surrounds my build like a halo, then that is seriousness. And I guess one can, in a way, answer such questions with; *What I don't want*, and that is in-fact a bit simpler.

Audio and sound is a HUGE topic, its an entire science field in itself and people spend their entire life researching, building and testing different solutions. Heck, some even educate themselves as sound engineers. With that in mind, one can't simply say; *Copy & repeat what others have done, it works for them.* Well, that is the thing, do we really know if it does? Here, I am not referring to: "It sounds good" because that answer might be bias in nature or you are asking someone who has very little experience or have a low level of requirements. I can use an my own experience for that.

Many years ago, a distant friend made a half hearted effort in building a sound system in his car (Volvo 740), woofer in the door, midrange on the dashboard and directed tweeter + 2 subs in the rear. The tweeter sounded horrible, sure, it played music, but it broke every note and it would not play well at higher levels, it sounded broken. So I told him to find a better tweeter that would play well, equally well, at low dB as well as higher dB. What I implied was a quality tweeter that could handle the entire pitch or hertz range of a tweeter as well as doing that good at any dB range up to 85-90 dB. So he went and bought a new one that indeed played loud, Well beyond 100 dB. But again, found a tweeter that was horrible, it made the "S" sound emphasized and I think at one point, my ear's was bleeding ... LOL. So I said to him: "Congratulations, you have a tweeter that plays louder, but it is still a crappy tweeter" - I think that pissed him off 

I am hard to please, I know that, but I can live with that, because I know the requirements or goals for what I want is not unachievable. You simply need to understand what is involved and how to optimise it. You need knowledge, and I believe I have some of that, but is it enough (?). Speaker element design, diaphragm material, coil design / arrangement, big enough magnet etc, all of that is something I am not really going to devote my time on because I do not develop speaker-elements. However, I can spend my time in learning and applying the knowledge of how to utilise and implement that speaker-element in the best way and the best way is in part; What the speaker-element need and in part how far I can go in that regard.

So one very obvious limitation is the size of the car. All cars have a limited space or volume which you can use for a speaker, that's used how things are. So, you need to turn that limitation into a benefit. *Loudspeaker cabinets* must become a topic on its own, so I am not going to spend time now writing about that, because I have not reached that level of the thread yet, but speaker enclosure, especially for midrange and woofers is something I will spend some time on as well.

*Lets get back to your first question;*


> Did you say you were going to have a dedicated speaker for "upper bass" and one for "lower bass"? So this will be a four way front stage + subwoofer?


 Yes that is what I am implying. But I would not go as far as calling this a 4 way system. It is in a way because I would use 4 speakers, but it is still a: Tweeter + midrange + woofer configuration. 3.5 way is perhaps more correct ? So were did I get the idea from ? *Troels Gravesen*. He built a speaker, called *ATS-4* with a specific philosophy that I happen to like. I'll let Troels explain it.










*Philosophy:*



> So, how do we make good things even better? Hmm...One obvious thing is aiming at even higher sensitivity and greater bass dynamics. The Jenzen ATS is some 6 dB below my DTQWT and it can be heard/felt on a few recordings. The Jenzen ATS offers better transparency compared to the DTQWT, but the DTQWT can play a few tricks in terms of overall dynamics. If size was not an issue the answer would be simple. An AudioTechnology 12D77 + 10C77 bass drivers and a d'Appolito arrangement of two 18H52 middrivers. The ScanSpeak Be dome can cope with systems up to 95-96 dB sensitivity, no problem there. But size is an issue and if I settle with 91-92 dB system sensitivity, then what? Rather than paralleling two 10C77 bass drivers, then how about mating a 10C77 and a 8-10 Ohms (DCR) 8C77 or 23I52*? We might get another couple of Decibels and still maintain a decent impedance for passive crossover solutions.
> 
> My thinking here is primarily to improve the 100-200 Hz range by a dedicated bass driver in an aperiodic or closed cabinet with a smooth roll-off towards lower frequencies delivering a fast and dry bass and then having the 10C77 dealing with the rough part of pumping low-end bass - because the 10C77 is good at it. The 8C77/23I52 might perform as a kind of filler-driver in between the 10C77 and the 18H52. The 8" bass driver could be fitted with either a sandwich cone or a PP cone and somehow I felt more sympathetic towards a PP cone better mating the sonics of the excellent 18H52-06-13 SDKA mid-driver. The question was if Per Skaaning could make me an 8" PP driver with a mechanical Q of not less than 5? The default 8I52 on AudioTechnology website is "only" 1.85 (alu voice coil former) but SDKA (kapton reinforced with alu) and appropriate suspensions should increase Qm. What we're talking about here is low-loss suspension and aiming at an aperiodic cabinet I might get along with a quite low Fs driver. The ATS-4 is not really a true 4-way system despite having four crossover sections, rather a 3½-way system due to the upper bass not having a high-pass filter except for what the cabinet provides. It will have to be seen if the different transfer functions of the bass crossover sections may interfere with the transient response of the overall bass system. So, time was ripe to pay Audio Technology a visit.
> 
> ...


Okay, so 4-way, lets just call it that for simplicity. What I will do different - if I go with a 4-way system is that I will use:

*Front System:

1" Tweeter.
4" Midrange. 
6.5" (upper bass) mid-woofer.
8" (lower) bass.
*I would ditch the rear system or rear-fill and ofc using subs. Still not sure if I want to use 10 or 12 inch diaphragms, or if I want/need 2 subs. I've always used 1 sub and find that a quality subwoofer often will take care of the lower bass segment in the music. However, the music we listen to is stereo, so, will the subwoofers use this and if so, then do we benefit from it? If I have a LEFT and RIGHT system in the front then perhaps I should use a LEFT and RIGHT system for the subwoofers. But with two 8" bass in the front, they will take care of the snappy bass that I desire while the 12" then would become fill bass for deeper hertz. So perhaps I just answered my own questions... hmm.

*Rear System:
2 pcs 12" subwoofers - L and R channel.
* *Part 2:* of my main entry's will take care or analyse the 4" and 6.5" mid-woofer and 8" lower bass. *Part 3:* will take care of subwoofers.

*Did that take care of your first question Kazuhiro ?*

*Lets look at your second question:*


> What driver sizes and models have you got in mind? I haven't seen this done before, I suppose you are going all out with fabrication too.


I think I answered the first section regarding driver size and models. Specific models will be covered in part 2 & 3. But you are right, 4-way systems in a car is very unusual. I guess it happens, but unusual. But maybe one justification for a for 4-way system is that I am building this for me, the owner and driver. I will never sit in the back and hardly be a passenger. So all focus is directed to the driver (seat). And as I mentioned, the majority of all the music we listen to is 2 channel audio.

*Returning to omnidirectional sound.*... not entirely done with that.

One problem, because it is a problem, all loudspeaker producers struggle with is replicating a speaker that can produce all of the sound from one speaker, that would be the ideal. But I've never heard a coaxial speaker that does this well. Perhaps I've not listened enough to a wide range of producers, maybe someone have and know exactly which one. Maybe it exist as a concept, I simply don't know. So I can therefore only use what I am aware of. But one thing we know is that high frequency's are very direct, pin-point, while low frequency's is the opposite. Also, low frequency's tend to resonate with its environment, so lower midrange pitch's and bass is not as sensitive to their physical placement, while upper mid's and tweeters are. So lets look at one horrible tweeter position in a car. 










Do you see that expensive Focal Utopia Be system, the tweeter is positioned off-axis to the driver... WTF. The installer obviously have no concept of the narrow sound image a tweeter has. Its almost like a needle, very pinpointed and ofc, I am talking about the so called sweet spot which is right in-front of it. Place your ear at 0 degree at you can clearly hear much higher pitches and frequency's than at 20, 45 and 90 degree's. The Utopia Be tweeter is facing 90 degree (or so) away from the listener, so a large portion of the upper hertz cannot be heard, that is like hiding the tweeter. What a shame.

We are now entering a very exciting and interesting topic of *omnidirectional* and *ALT- Acoustic Lens Technology.*


> The term omnidirectional implies an equal sensitivity in all directions. An omnidirectional microphone, for example, will pick up sound from all around it, in all directions. An omnidirectional antennae will send or receive signals equally well in all directions.


Because the tweeter is so direct, this causes problems, it means that you can only experience the best of the tweeter at a narrow area. This is ofc not ideal, so you want a tweeter that is equally good on, on- as off-axis. That is why you sometimes see tweeters that use a small *faceplate* to make it sound more even and also help the diaphragm to breakup less at certain frequency's. For ScanSpeak Be that around 5 kHz. To help the tweeter even further you need to add a "sound lens"

If you have excellent hearing, like I do, and you can hear the high frequency's a bat produces, you know by experience that it is a very narrow sound image, for a reason (object location). We are not looking for object location when listening to music, simply want to hear all of the instruments and well, that is the tweeters job, to take care of the higher frequency's, not to focus them at a specific point, but it is unavoidable. Enters sound engineering at a higher level. Many people are aware of the fact that in a car with respect to the driver, (left hand driver) the speaker on the left side is closer than the speaker on the right side. So, we can adjust the balance and force the closest speaker to play lower than the right in order to simulate a more balanced sound stage. This is cheating. Now enters a *DSP - Digital Sound Processor* Even though some speakers are closer than others, a DSP Upgrade makes the speakers sound as if you’re sitting in the centre of the car. The stage is balanced – wide and continuous all the way across without holes. You can either do this by reducing the "expression" the speakers have or you can move the speaker out of the car so that the perceived distance is equal. But this only one take on sound engineering and also THE ONE considered to be professional audio installation in a car. You know you are serious if you have a DSP.

Well, I am taking audio installation *to the next level* with acoustic lens technology. I have two options as I see it. 1. Build it like you see with the first picture I posted showing omnidirectional engineering, or 2. I can use Bang & Olufsen ALT.











> Acoustic Lens Technology​
> Traditional loudspeaker design dictates that the listener needs to be positioned within an acoustic ‘sweet spot’ in order to get the most from the listening experience. Our acoustic lens technology creates an improved sense of space and realism while maximizing the area in front of the loudspeaker where the sweet spot exists. Sound is dispersed over a 180° angle, so whether you are at the wheel or a passenger watching the countryside slide by, it will feel like you have a front row seat in one of the world’s best auditoria.
> Acoustic lenses spread the high frequencies horizontally around the room so that they cover more listening area while reducing reflections from the floor or ceiling. Walk around a room and the Bang & Olufsen sound performance remains unchanged and ideal.


Here is a close up of the ATL used in one of Mercedes models.










An article on Bang & Olufsen ATL.



> *Acoustic Lens Technology*
> For Bang & Olufsen more than twenty years of acoustic research, experimentation and development went into the development of Acoustic Lens Technology. The first product to bear the fruits of ALT technology research was the high-powered BeoLab 5 active speaker. Bang & Olufsen engineers had been working with the scientific development of acoustics to answer the basic questions of “What constitutes good sound?” and “How do people perceive sound as good?” ever since the 1980s.
> For decades, one of the key concerns for loudspeaker designers worldwide had been to control how higher-frequency sound waves spread, and in which directions. Being able to control these higher frequencies is crucial, because it is these that carry most of the sonic information about what you are listening to, and about where you perceive the sounds as coming from. That’s why traditional stereo speakers sound best if you’re midway between them and right in front.
> Finally, some chance meetings and contact with Sausalito Audio Works in California resulted in a completely new way to tackle this fundamental challenge – one which was appropriately designated Acoustic Lens Technology, or ALT
> ...


And two PDF's that cover the concept if you want to study further.

1. The Use of an Acoustic Lens to Control the High Frequency Dispersion of Conventional Soft Dome Radiators.
2. Bang & Olufsen Beolab 5.

ATL or Omnidirectional is a physical attribute to engineer a better listening experience while the DSP is digital engineering. So when I talk about SQ, I really mean that ... REALLY mean that. But don't mistake SQ as a substitute or lack of SPL. Music still need good bass, just not as much as pure SPL system, because SPL is redicilous and has nothing to do with music. SPL is noise and competition oriented. 

*So, we can now divide my system into 4 main category's.

Speaker element selection.
Speaker Position and Sound Engineering.
Cable, power and amplifiers.
Enclosures, sound absorption & dampening and visual aspects.
*How many car audio custom installations focus on omnidirectional engineering ? That is a serious question. If you know about one or two, please do mention it. I am still learning and would like to look at what others have done.

*Kazuhiro* You did also mention; *"I suppose you are going all out with fabrication too."* Answer; You bet. I will actually visit some loudspeaker engineers to get their opinion regarding crossover design (component selection) since I in part will involve such people, and what way is better than giving them a chance to listen to something they were involved in at one point or another. But yes, the fabrication will be very high in terms of material choices as well as visual aspects. 

Much more to come in that regards. As you understand, or beginning to, I need time to make this right and even if the car purchase is 6 months away or so, just repapering the car will take time. Then I need to measure and build the power and speaker cables etc 

Oneminde


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## Oneminde (Nov 28, 2015)

Interesting day tomorrow and entry. It will be a main entry: Part 1.5 Tweeter and engineered sound stage.


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## Oneminde (Nov 28, 2015)

Just a short one before bed. There is a lot of eco in this room but if you listen to the behaviour of the sound image of the tweeter, you at least get an impression of the lens at work.


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## Oneminde (Nov 28, 2015)

Did not have the time to write anything, but here is more reference for the upcoming article.


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## Oneminde (Nov 28, 2015)

Still waiting to get the time available to write the very interesting entry on Bang & Olufsen ATL. But instead found the wheels aka rims for the car. Its all in the details


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## Oneminde (Nov 28, 2015)

*Part 1.5 Tweeter and engineered sound stage.*

[by David Moulton: Sausalito Audio Works Acoustics lens Technology.]

This entry is going to be rather lengthy in order to collect as much data as possible. I in part write this so to collect all the info in one place and in part share my findings with you whom follow this tread.

I have located some very useful info which allows me to construct the ALT or Waveguide for my BMW. I will use the ALT for two speakers: the tweeter and the midrange – Bang & Olufsen use a 3” midrange while I will use a 4” (most likely) and these two speakers is target for the ALT. In order to know what is going on with the math, I need to understand and apply the relationships used and that is the reason for the lengthy entry. While researching the internet, I found 2 forum threads where Patrick Bateman (also a member here) contributes as well as some original info. I am not going to copy the threads to 100 % since they are many pages long, but instead re-capture the essence and most important parts. 

In a private conversation with Patrik he mentioned: “They are not omnidirectional, they have narrow vertical directivity and wide horizontal.” – which is ofc correct. I do or did consider them omnidirectional, but that is misleading. The ALT helps spread the sound or re focuses it.

The ALT was developed by David Moulton and Emanuel LaCarrubba – that is the name in the patent. Patent Number: 5,615,176 – approved Mar 25 1997

*ABSTRACT.*
An acoustic reflector is disclosed, which is formed from the surface generated by an ellipse rotated about 180° about a ling passing through one of the focal points of the ellipse where this line of rotation intersects the major axis at an acute angle. A transducer placed at the focal point on the line of revolution will, when energized, generate waves that will be reflected from the surface back through the arc of second focal points of the generating ellipse.










There is also patent: *6,068,080 - US20040065500A1 - US6820718B2 - US 2014/0119588* A1. The US 2014/0119588 A1 is the latest and was approved 2014.

Let’s start with the oldest thread.

Cloning a $3200 Speaker for $400 - diyAudio

*Patrick Bateman 12th March 2010.*

I am very happy with my home speakers, but I've been working for the past few years to get some of that magic in my car. I've tried everything from tractrix horns to Unity waveguides, and everything in between. Recently I stumbled across a design which looks promising, so thought I'd document how to clone it.

The speaker is a Beolab3. It uses an unusual enclosure shape to reduce diffraction, and an acoustic lens and waveguide to shape the polar response of the tweeter.

•	Both are two ways
•	Each uses a waveguide on the tweeter
•	Both enclosures used curved surfaces to reduce diffraction
•	Both designers focus on the power response over the frequency response

In my opinion, these are all excellent goals for a design.

Here's a quote from an article about the company:

"There was a lot of talk about the importance of the power response (the power response of a loudspeaker signifies the sound pressure averaged over all directions of radiation rather than just one - basically the combination of the on and off axis response in 3 dimensions ) over the frequency response. They believe that having a smooth power response is more important than a smooth frequency response for a speaker."

In a nutshell, I'm hoping that the Beolab 3 might give me a fraction of my home speaker's performance, but in a much MUCH smaller footprint.

Note that cost is no object here; I'm simply trying to reduce the size to a point where it will fit in my car.

*Patrick Bateman - 12th March 2010.*

The "secret sauce" in the B&O speaker is clearly the "Acoustic Lens Technology" (ALT) licensed from Sausalito Audio Works (SAW.)

After studying their patents, I have a fairly good grasp of how it works. But first, some background.



















A conventional piston begins to "beam" at a frequency equivalent to its diameter. For instance, we'd expect a 1" dome to "beam" above 13500 Hz. (Speed of sound/diameter) In the graph above, we see that the "rule of thumb" is true. The dome measures flat on axis, but the response falls quickly off axis.

The reason why this is A Very Bad Thing is that a great deal of the sound that we hear is reflected, and the rolled off response off-axis contributes to the unnatural "hi-fi" sound endemic to conventional loudspeakers.










Waveguides have been discussed in-depth on this forum, and they're an excellent solution. In the graphs above, we can see that the on and the off-axis response of a waveguide is consistent. This helps to create a realistic soundstage, and reduce listening fatigue. Unfortunately, waveguides are BIG, and there's no getting around that.

Or is there?

From what I read in the patents, I believe the SAW acoustic lens is small because it works over a narrow bandwidth.










The measurements above show the polar response of the ALT device. The top pic is the response at 20khz, and the 2nd is at 10khz. You can see that the response off-axis is stable out to 90 degrees.

On the other hand, the waveguide in my home speaker words down to 900hz. 900hz is 15" long, and that's why the waveguide is that big. From what I'm seeing in the SAW patents, their lens isn't working at all frequencies. It's basically tuned to work at frequencies where the piston is beaming.

For instance, the 1" Scan Speak tweeter is beaming from 14000 and up; therefore you only need a lens that works in that narrow range, just a fraction of an octave. In the rest of it's range, it's basicaly omnipolar, and no lens is needed.

That's why their lens/waveguide is so small.

*trusound - 3rd June 2010.*

I had a few conversations many years ago with Manny Lacarrubba who is the inventor of the lens and it's applications for cars... and due to the non-compete with B&O, it didn't go anywhere. But after years of installing and listening... nothing has.. and I mean nothing has worked better than a traditional 2 or 3 way placed optimally, lessening tactile energy transfer... you really need to go to a MECA finals and listen to these cars before over complicating things

*Patrick Bateman - 12th June 2010*

That's unfortunate to hear. I listened to the top of the line from B&O in Portland a few years ago, and was impressed. It reminded me a bit of my Summas. The treble seems a bit "wonky" at first, because we're not accustomed to constant directivity. Once your ears adjust, it's difficult to go back.

OTOH, their top of the line speaker is much less compromised than the lower models, because it uses a larger waveguide and a larger enclosure.

And how do you have them installed in your room? I had a hell of a time coming up with a good location for my Summas, since constant directivity loudspeakers are sensitive to early reflections. (In a conventional loudspeaker the treble "beams" forward, so preventing reflections can be as simple as rotating the loudspeaker. In a CD loudspeaker, the off-axis response is quite similar to the on-axis response, so pulling the speakers away from the walls makes a noticeable improvement.)

*If you take your mobile phone speaker and cup your hand around it, you can get an appreciation of what a lens does. To me, it improves the sound and captures the output better. But yes it is different.

*whgeiger - 7th October 2010.*

An AES paper [1] is available that discloses details of the "lens" design used in the Beolab3. While it exhibits the behaviour of a divergent acoustic lens, it reflects acoustic energy, it does not refract it. When signal wavelength becomes comparable to, or larger than its dimensions, the device loses its divergent properties; i.e., it becomes "transparent" to a low frequency signal.

File: AESP-5648
Title: Driver Directivity Control by Sound Redistribution
Author(1): Pedersen, Jan Abildgaard
Author(2): Munch, Gert
Affiliation: Acoustics Research, Bang & Olufsen, Struer, Denmark
Publication: AES-P No. 5648, Cnv. 113 (Oct-2002)
URL: AES E-Library: Driver Directivity Control by Sound Redistribution
Abstract1): The directivity of a single loudspeaker driver is controlled by adding an acoustic reflector to an ordinary driver. The driver radiates upwards and the sound is redistributed by being reflected off the acoustic reflector. The shape of the acoustic reflector is non-trivial and yields an interesting and useful directivity both in the vertical and horizontal plane. 2D FEM simulations and 3D BEM simulations are compared to free field measurements performed on a loudspeaker using the acoustic reflector.
Abstract2): The resulting directivity is related to results of previously reported psychoacoustic experiments.

*glasswolf – 7th October 2010. *

Waveguides (HLCDs) are outstanding in a car, but the trick to using them is that for them to sound right, you have to use 1/3 octave EQs on each horn, and tune them with an RTA. Otherwise they are far too difficult to control, particularly in such an adverse environment. I've worked with horns in cars before, and it's quite a bit of work.
*
Patrick Bateman – 28th January 2011.*

I have been thinking about the Sausalito lens. I am betting that the dimensions of the lens are based on the lower limit of the device. For instance, the lens in the Beolab 5 is 19.3 across. The crossover point is 500hz. 19.3" is equivalent to 700hz. So I'm guessing that the device works to 700hz, but they're crossing over a bit below it's cutoff, since the response would like be falling. (IE, that dropoff will make the crossover simpler.)

I don't think I will be cloning the small beolab speakers - kinda scared of my power tools nowadays.

But I think the lens could be useful for a lot of situations. For instance, when I auditioned the Beolab 5 I found that it was difficult to pinpoint where the sound was coming from. It's like a giant cloud of sound. This could be handy in situations where it's not practical to sit on axis.

I am considering building a lens for my current car project. I would like to use an 8" midrange, and I could use the lens to mount the woofers under the dash and redirect the speakers energy horizontally. (IE, there's no way we're going to get response past 500hz or so if we're listening to it on it's axis, but with a lens, it's do-able.)

If anyone wants to read up on it, here's a list of patents. I'm too lazy to Google the numbers.

Emanuel LaCarrubba - acoustic reproduction device
Emanuel LaCarrubba - acoustic reflector
Emanuel LaCarrubba - Apparatus for the redistribution of Acoustic Energy

*Patrick Bateman – 20th August 2013.*

I've been thinking about these SAW lenses for a few years now, and had a 'Eureka' moment today. Basically, I think I figured out how they work. More importantly, I believe there's a way to improve them, and also a way to make them full range. Here's my 'hypothesis' on these lenses:

First off, these lenses work in the same way that a horn does.










In a constant directivity horn, like these Electrovoice HR90s, there are multiple stages. The first stage provides gain; the second stage defines the horizontal and vertical beamwidth; and then the third stage 'flares out' to provide a smooth transition to the room.

The lenses from Sausalito Audio Works function in a similar fashion; the major difference is that they don't *look* like a horn, and there's a reflector built into the device.










Here's a pic from the Beolab 5, where I've tried to illustrate the various stages of the device. The first stage is the one that everyone notices; that intriguing 'teardrop' lens. What's interesting is that once you do the math, you'll find *that the lens isn't doing a whole lot!
*
Whether it's a horn or a lens, the directivity of a device is dictated by its size. And based on the diameter of the lens in front of the Beolab 5 tweeter, it's only working above 18,000hz! This calculation is based on its diameter; with a width of just 0.75", the lens is basically invisible to frequencies below 18khz.

Surprisingly enough, the baffle *behind* the tweeter is playing a bigger role here. With a diameter of approximately 4", the baffle *behind* the tweeter is constraining its output from 3375hz and up. 

The 'saucers' above and below the tweeter aren't just for show; they're functional. The saucers act like a radial horn, basically redirecting the energy of the tweeter away from the floor and from the ceiling.

And due to their significant size, they have this effect across the entire bandwidth of the tweeter. As show in the illustration, the "top" saucer works from 955hz and up, while the middle 'saucer' works from 330hz and up.










Here's the polar response of the Beolab 5, showing that the lens itself doesn't work over a wide bandwidth. (Note how the directivity improvement in the tweeter only spans a fraction of an octave.)

IMHO, the most important element of the design isn't the lens; it's the saucers and the baffle behind the drivers. The saucers are acting like a radial horn, preventing the drivers from radiating towards the floor and the ceiling. The baffle behind the drivers prevents them from radiating towards the back of the room.

It's basically a radial horn; albeit one that looks great, and one that radiates low frequencies across the entire listening room. (Which reduces distortion, in the same way that increasing the size of the mouth does?)

*yakmurph - 20th August 2013.*

Last year, I built new SAW-based lenses for my Alesis dome tweeters. Experience has taught me that stiffer material is better and I think that these glazed ceramic reflectors/baffles/horns work very well.

The main benefits, which have kept me interested in improving my speakers, are the wide sweet-spot and increased efficiency. Increased efficiency... to me, means: any speaker that moves is distorting, so, if it is barely moving then that means it's not distorting as much as it could. My SAW loaded Alesis domes are throttled way back. Wide dispersion is a good thing. It just sounds right to me, but these are my ears and the sound is decoded by my brain... such as it is. I've always liked the sound of dome tweeters in my SAW clones;
these ceramic sculptures sound the best, by far, to my ears.

You can see that they are not even close to an actual SAW clone, mathematically.

Go figure.

-Steve.

*Patrick Bateman - 20th August 2013.*

Here's a pic I made, which illustrates how the midrange in the Beolab5 radiates. In this pic, I am only showing the horizontal radiation. If you look at the speaker, the round shape might imply that the radiation is 360 degrees. But it's not. It's basically 180, similar to what the NAO Note II would radiate if it was a monopole. The reason that it radiates in 180 and not 360 is because of the small baffle that's behind the drivers, a baffle that's basically twice as wide as the radiator. That's just big enough to restrict radiation into the forward lobe.










In the illustration above, I have used the wavefront simulator in Hornresp to demonstrate that the Beolab radiates into 180 degrees, not 360. The illustrations is based on the midrange in the Beolab 5, which is a 3" dome. Here's some obsevations about the radiation:

1) The midrange is 3" in diameter. 4500hz is 3" long. When the sound is 4500hz it's radiated towards the listener. The top right sim from hornresp shows this; it's only radiated into the forward lobe. The wavelengths are small enough that they're constrained towards the listener.

2) The baffle behind the mid is 5" in diameter at it's midpoint. 2700hz is 5" long. When the sound radiated by the midrange is 2700hz, it's still radiated into the forward lobe., toward the listener.

3) Below 2700hz, the baffle in the Beolab5 is no longer constraining the radiation of the midrange. This is because the wavelengths exceed the width of the baffle. Basically the sound 'wraps around' below 2700hz. The simulation from Hornresp illustrates this. At 1000hz we see that the midrange is now radiating into 360 degrees.

Note that these statements only apply in the horizontal axis. In the vertical axis the directivity is completely different. For instance, the platter below the midrange is 19" in diameter, and that's big enough to keep anything from 710hertz and up from 'bouncing' off the floor.

In summary, in the horizontal axis the output of the midrange is restricted into the forward lobe. From 2700hz and down, the radiation begins to broaden, until it's radiating in 360 degrees by the time it hits 1000hz. But the broadening happens gradually. I haven't been able to find anything that documents where the crossover points are, but my 'hunch' is that the baffle width tapers so that the radiation is always in 180 degrees at the crossover point. For instance, the midrange baffle is 5" wide at it's midpoint; but the center to center spacing between the mid and the tweeter is about 5.5". Assuming that the center to center spacing is one octave, then the xover point may be 2500hz. That's a good choice, as the baffle width of the mid keeps it's radiation consistent with the radiation of the tweeter.

There's a very interesting advantage to using a full circle for the platter, insted of the half circle used by the JBL radial horns:












> Originally Posted by gedlee
> Lets be clear that almost all of the gain comes from the compression ratio which happens even before the horn and phase plug. The horn itself is simply a means to better couple the area ratio decrease into the sound field. There isn't necessarily any gain at all.
> 
> For example, a direct radiating tweeter on a waveguide only sees a very small increase in power output, the gain comes almost completely from the narrower directivity. The SAW would likely have no gain at all.


Yeah I think the SAW lens itself - the 'eye shaped' cutout - isn't doing a whole lot. I'll have to build one to be certain, but the big 'lightbulb' went off when I realized that the platters below and above the drivers and the baffle behind the driver isn't just for show. The platters are narrowing the vertical directivity, and the baffle behind the driver is changing it from an omnipole like the Duvel to a monopole like a typical baffled speaker.










It was your comments and Dave Smith's comments over in the JBL M2 thread that clued me in to this. Looking at the polars of the JBL biradial horn from the 80s, it occurred to me that the 'horn' doesn't necessarily need to be in the box, it can be 'outside the box.'

The pic above shows both speakers to scale, which makes it easier to appreciate how big the platters are. They definitely change the vertical directivity. The biggest platter is 19" in diameter.

*Patrick Bateman – 20th August 2013.*



> Originally Posted by freddi
> is there "significant" cavity volume and thin walls? - or are they like Steve's ceramic lens?


The cavity in the SAW lens is supposed to work the exact same way as the reflector in a Paraline. It's designed to take the energy directed UP and turn it 90 degrees. The reason that it's not a straight line is that a straight line wouldn't keep the wavefront in phase; that curved line WILL. Or at least it's supposed to!










The reason I believe that the effect of the SAW lens is relatively minor is the measured response. We know the dimensions of the lens, so we know what frequencies it works at.

And based on it's dimensions, it should work at 18khz and up on the tweeter, and 4500hz and up on the midrange. In the measured response of the loudspeaker we see a 'narrowing' of the polar response at 5000hz and at 18khz. I think that's caused by the lens, but note that it's very very narrow in bandwidth.

So, long story short, my 'hunch' is that the lens isn't doing a whole lot. But the platters and the baffle, which seem completely cosmetic, ARE doing a whole lot acoustically.

As for the construction of the lens, it's aluminum. Likely hollow, as B&O uses aluminum hydroforming for some of their other speakers, makes sense they'd use it for their flaghsip. (Same way that aluminum bicycles get their crazy shapes.)

*Patrick Bateman – 25th August 2013.*

This afternoon I've been doing some experiments with spiral horns. The reason for this is to vary the expansion ratio of the horn. (I believe that the parallel walls of the radial horns that I've been building is leading to comb filtering; breaking up the parallelism spreads out the resonances, and should make the dips in the comb filtering less severe.)

While looking at a Fibonacci spiral, it occured to me that each segment should reflect the sound into the next segment at 90s degrees. IE, a Fibonacci spiral may have good high frequency output, because each segement 'reflects' into the next.

So it's possible that a Fibonacci spiral may have superior high frequency response to other spiral expansions.

While looking at it, it occurred to me that the shape looks familiar...










Ha! The SAW lens is a Fibonacci spiral, with the driver at the apex.

roflynn – 2nd June 2014

Using the ripple simulation applet from Falstad:

I see a number of effects that would guide the designer to use small platters relative to the wavelength.

Firstly the wavefront radiates spherically until it contacts the waveguide. It then reflects and converts to a straight / cylindrical? wavefront. Two wavefronts exit the waveguide which is a distortion which might be measured as group delay ?

Secondly the wavefront reaches the platter edge and creates a diffractive wave. this seems stronger at the top in the lateral directions where the guide is more open at the base?

Thirdly the waveguide has an acoustic structure that forms a low pass filter with a cut off near where the opening is close to one (or is it half?) a wavelength.

The directivity of the driver would mean that the waveguide would only be called on to redirect the wave off the driver axis at the higher end of its range so presumably the actual dimensions of the parabola and platter are key characteristics determined by the driver diameter and the crossover frequency?

Note: The app can generate a parabola and it is close to the display edge so I only generated half the guide.










Patrick Bateman – 25th September 2015.

I've built a BUNCH of these. I wouldn't be surprised to find that I've built more than the inventor has. (When they invented this years ago, 3D printing wasn't readily available. Now that it is, it enabled me to try a zillion different variations.)










Arguably, this was the most successful shape. It's the lens from Sausaliton Audio Works, merged into a JBL progressive transition waveguide.










Here's the polars. They're not as smooth as the best waveguides I've measured, but they're close. The advantage of this contraption is that it can be used with a $25 tweeter, and the tweeter can me mounted straight up. The one that I printed was also a small fraction of the size of the big waveguides that perform well.

Which begs the question, if I'd scaled it up to a large size, would it perform better? I'm inclined to say "yes"

* The rectangular QSC waveguide is the smoothest I've measured. But it also requires a compression driver and it's much larger. All told, the cost is about quadruple.

*Patrick Bateman – 25th September.*

If anyone out there wants to build these, here's a short summary of what worked for me, and what didn't.

1) Whatever you do, do NOT use a large tweeter. I couldn't get acceptable results from a 29mm tweeter. A 19mm tweeter worked great. I think what's happening here is that the energy which would normally be beaming is spread out instead. IE, if you had a tweeter which played to 20khz on a flat baffle, but was beaming, it will NOT play to 20khz on a Sausalito Audio Works lens because the energy which was formerly focused into a beam is not spread out into a cone. So the overall output is wider, but the intensity level is lower. The net effect is that it's very very hard to get a 29mm dome to play to 20khz on a SAW lens.

2) Theoretically, the height of the bullet shaped part of the lens should determine the vertical coverage. In reality, I didn't notice any real difference. The authors of the patent have filed a new patent, and in the new patent the height of the "bullet" is much shorter.

3) I found that it's important that you can draw a straight line from the microphone to the dome of the tweeter. IE, if you have any type of obstruction in the way, the diffraction from that edge wrecks the response entirely. One way to verify this in person is to simply look at the device, and if you can see the dome peeking out, it will perform well. If there's ANYTHING in the way, forget about getting flat response at all. I found this out the hard way when I made one of these devices that fed a horn:










Mine looked a lot like this device from the new patent, but my device had a more pronounced "lip" around the tweeter. And I believe that lip wrecked the polars. Again, I've probably made about twenty of these now, so I have a decent idea of what works with these lenses. 75% of the ones I built were failures

**Patent: US2014/0119588 A1

Patrick Bateman – 18th October 2015.*

Quote:
Originally Posted by kasaev 
Am I right thinking that you can just scale the 3D model to get same results for midrange dome speaker?
Correct. The bullet shaped thing in the waveguide is only there to do two things: First, it concentrates the output of the driver into a point. Then it bends it ninety degrees. So the waveguide behaves as if it's being driven by a source that's small.

The thread stops here but is certainly not dead.

Next thread comes from this forum and is called bang and olufsen tweeter lens idea.

http://www.diymobileaudio.com/forum/hlcd/113901-bang-olufsen-tweeter-lens-idea.html

*Patrick Bateman – 15th November 2011.*

Check out the patents... They're VERY detailed. Just google under "Sausalito Audio Works."

The lens isn't all that complex. IIRC, the disc needs to be the same size as the low frequency cutoff of your driver. For instance, if you're using a 3/4" dome and you want to cross it over at 2khz, you'll need a disc that's just 2.15" in diameter.

That's one of the cool things about the design - it doesn't need a lot of space.

I am guessing that you could use a bigger disc if you wanted directivity below the crossover point, for instance you might opt for a 4.3" disc to control things below the cutoff.

In the patent, S.A.W. demonstrates that the technology works with compression drivers, and compression drivers also simplify the lens. (Because the wavefront of a compression driver is a flat disc - you don't have to bend the wavefront the way you do with a dome.)

*Patrik Bateman – 4th March 2014.*










IMHO, the reason that B&O used *two* SAW lenses in their first effort, but now only use one in *all* the new designs, is because of this design philosophy. Basically the SAW lens looks cool, but it's only working over a very narrow bandwidth, about one octave.

In fact, I think the platters and the shape of the baffle is having a larger effect. Because size matters with directivity, the platters are working over a wider bandwidth then the lens is.

Also, it's possible that the new speakers are using a vertical array of small woofers, because that would also get you the narrow pattern that the SAW lens does. (Odd as it seems, a *tall* speaker has narrow vertical directivity while a *short* speaker has wide vertical directivity. And Sausalito Audio Works is all about narrow vertical directivity, it's right there in the patent, they are of the opinion that wide horizontal directivity and narrow vertical directivity is the ticket.)

*Patrikck Bateman – 5th March 2014.*



> Originally Posted by cajunner
> is the air, to either side necessary?


can you just transverse-section the whole apparatus, so that there is a flat wall to either side, the way you can do with a Linaeum, and if so, is the 360 Sausalito also possible, for the "depth" of stage everyone wants?

Yep. That was one of the things that blew my ****ing mind about the lens. It basically works like a cardioid; the signal sent *backwards* is very similar to the signal sent *forwards*, but it's attenuated.

This is kinda the Holy Grail when it comes to directivity; the idea that the sound off-axis has the same shape as the sound ON axis. (There's a thread on diyaudio that's a few hundred pages long on what the "ideal" directivity is, but IMHO cardioid is about as good as it gets.)

So, long story short, YES you want air to the left, to the right, and even behind the speaker. This is part of the magic.



















*Here's a couple measurements.*

The top measurement is on one of these SAW lenses that I built, using a Celestion CDX1-1425.
The bottom measurement is an oblate spheroidal waveguide, driven by a compression driver.

If you look at the two measurements, you can see that the response shape is relatively similar. Mine looks a lot rougher, but my scale is only 50dB, whereas the scale of the other measurement is 90dB. Basically mine is 'zoomed in' which exaggerates the peaks and dips. Both devices need EQ, you can see the mass rolloff begin about 4khz. So they're going to need CD EQ to offset that.

IIRC, the yellow curve is on-axis, the orange curve is 22.5 degrees off axis, and the red curve is 45 degrees off axis. The grey curve is a whopping 180 degrees off axis.

The crazy thing about the Sausalito lens is that the response is basically identical whether you're on axis or off axis. Over a four octave span from 1khz to 20khz, the level on axis is within three decibels of the level off axis. Even weirder, if you're *behind* the speaker the shape is similar, just quieter.

These results are pretty consistent with the measurements of the 'real' Beolab by the way.

If you look at the measurement of the oblate spheroidal waveguide, you can see that the output *shape* is consistent, but it's definitely "hotter" on axis. By the time you're 45 degrees off axis, the output level has fallen by 10dB. As someone who owns a set of Gedlee Summas and who's built a Beolab lens, I can tell you that they sound very very different. The Beolab lens sounds much more 'diffuse.' Due to the diffuse nature of the sound, the speaker location isn't as critical, and aiming the speaker is virtually pointless, since the angle of the speaker doesn't change the sound very much, until you reach really wide angles, like 180 degrees off axis. It *does* like to be away from boundaries, so I'd keep it away from the side windows if possible. It might work well *under* the dash, since the windows are a lot more reflective than the carpet in a car. To find out for sure you'd simply have to build one and listen.

*Patrick Bateman – 5th March 2014.*










If you look at the pic above, the *lens* is the part in the very center.
There is also a baffle in the pic above.

So... What's the baffle doing?
The baffle is there to prevent the sound from going *backwards*. It's about 13cm wide. So the baffle will keep the sound from going *backwards* until the sound is bigger than the baffle. So, let's do the math:
*
(speed of sound / size) =

(34,000 cm per second / 13cm) = 2615hz.
*
So that 13cm baffle, *behind* the tweeter isn't just for looks... It keeps the sound from going backwards. Is the 5" width by accident? NO. I personally believe it's width is *just* wide enough to cover the tweeters bandwidth. We don't know the crossover point, but I'm willing to bet it's close to 2615hz.



















If you look at these two pics, you can see that the shape of the baffle has evolved. Eight years ago, when the lenses first appeared in the car, the baffle was bigger. As time evolved, the baffle nearly disappeared. My hypothesis is that B&O probably figured out that the windshield of the car can serve the same purpose as the baffle did. But there's a catch here; if you intend to do the same thing you'll have to get your tweeters almost flush with the windshield. If you make a lens and you put it a foot from the windshield it's not going to work.

*- End of other thread inputs -*

I have this idea to combine the tweeter and midrange like in the picture with the conceptual idea being that the tweeter and midrange merge. This must be tested.










Oneminde


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## Oneminde (Nov 28, 2015)

I would like to add Wavecor to the list of driver units of interest

*Wavecore*


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## Oneminde (Nov 28, 2015)

I wouldn't call myself a hoarder but....


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## fockus (Jan 23, 2011)

great post.

I tried to make a simple bang and olufsen looking tweeter pod for my car with bondo.
the sound was better when I inverted the fase of the tweeter.

I did not finish that project. let me seearch for the pics, so that I can share it with you.

can wait to see your progress.


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## Oneminde (Nov 28, 2015)

fockus said:


> great post.
> 
> I tried to make a simple bang and olufsen looking tweeter pod for my car with bondo.
> the sound was better when I inverted the fase of the tweeter.
> ...


Sure thing mate, input is always welcome.

Oneminde


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## Oneminde (Nov 28, 2015)

Just a short update.

I am in the process of establishing a company which will manufacture loudspeakers, amplifiers and more. Due to this, this project will be halted for a while. I have full intention of making it happen, not just yet. I am looking forward to this.


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## tyr283 (Jan 21, 2016)

Definitely subscribing to this. Learned more about the science of how sound and speakers work from this one thread than in years of reading them and doing the occasional build myself...I would be interested to see how things change when the phase of the tweeter is inverted. I did that in my personal car (E36) which has a semi-active 3 way front stage (in crappy stock locations) and it definitely opened up the sound stage


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## Oneminde (Nov 28, 2015)

tyr283 said:


> Definitely subscribing to this. Learned more about the science of how sound and speakers work from this one thread than in years of reading them and doing the occasional build myself...I would be interested to see how things change when the phase of the tweeter is inverted. I did that in my personal car (E36) which has a semi-active 3 way front stage (in crappy stock locations) and it definitely opened up the sound stage


Hello. 
I am very much looking forward to this project and much of what will be used have already been picked out actually. I will benefit from the work on my first home audio speakers that I am developing. The ALT will also benefit from this work and I think I will make it out of aluminum. Then there is the special cast material that is under development which I will use as well. 

One can say that Fyrnista Audio will be incorporated into the BMW. But I first need to develop the home audio system. I am establishing a workshop which sucks up more or less all of my free time and cash atm.


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## Oneminde (Nov 28, 2015)

I can't change the title of this thread so I am doing so in this reply instead.

I am *not* going to purchase a 540i but rather go for the 530iA inline 6. Locating a 540 Touring - yes, a touring - is extremely difficult and they retain a higher price compared to the 6 cyl models. The 530i (M54B30) have 228 hp which is more than enough for a daily commute car and a BMW should in a way have the iconic 6 cylinder straight six. There are "plenty" of 530iA Touring around here, which allow me to be picky about the car I select.

I am also considering building a special edition of the home audio amplifier that I am building for this car. Essentially, everything will be custom and unique.


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## benny z (Mar 17, 2008)

subscribed


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## Oneminde (Nov 28, 2015)

I wonder why Alpine White touring is so rare. You have better luck locating an E39 M5 Touring than an Alpine White touring... LOL. I am 100 % settled on the black and white theme. Its timeless and classic and goes wheel with the wheels I want on the car.

In the absence of the real thing, here is a photoshoped teaser with the correct wheels.


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## danno14 (Sep 1, 2009)

you just HAD to get a white one!

My favorite of the e39 world.

A great read,
Tagging along


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## Oneminde (Nov 28, 2015)

danno14 said:


> you just HAD to get a white one!
> 
> My favorite of the e39 world.
> 
> ...


HA HA .. yeah, white one. I usually don't chose white cars, but BMW can handle that, and its rare on top of that. Kinda tired of the silver versions, the market is over flooded with silver E39, then there is black which is the: "I don't know which colour I want so I am going with what I know works." Black is nice, yes, I don't mind it. But I think more than 70% of all the bimmers I see is black. Red is even more sparse than white. I have considered Mineral white as well as Brilliant white (metallic), but I think in the end that Alpine will be the best solution. I had a E28 528iA in Alpine white and I liked it.


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## benny z (Mar 17, 2008)

My last car was a blue e39. 528i manual 5spd with the m sport package. Had the style 5 bbs wheels. I did 8.5s in the doors and pillar 3s with tweeters in the OEM sail location in that car.


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## Oneminde (Nov 28, 2015)

benny z said:


> My last car was a blue e39. 528i manual 5spd with the m sport package. Had the style 5 bbs wheels. I did 8.5s in the doors and pillar 3s with tweeters in the OEM sail location in that car.


I have mentioned a 4-way system which is very interesting concept.


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## Oneminde (Nov 28, 2015)

- How about *custom 300W/ch (4 ohm load) pure Class AB OP power amplifier* made specifically for this project. 300 watt should be more than enough to drive any front end system as well as using the same architecture in monoblock configuration for the subwoofer's. This might mean I need to increase the size of the generator, add a battery & capacitor bank as well as upgrading the power line for the audio system.

A custom amplifier allow me to select superior parts to eliminate distortion and interference. 

- Then there is the custom tailored crossover network.

- Speaker cables.

- Speaker enclosure that use - when possible - our own cast material (under development) that has a superior resonance absorption and low resonance characteristics. When cast material is not possible, a sandwich construction made of Cembrit & MDF will be used. The internal enclosure volume will match that of the enclosure weight, aka a minimum 1:1 relationship. 

*A side note on enclosure:*
So not to have a resonating enclosure one must have a fairly dense material as part of the enclosure, one can say: The amount of energy in the enclosure should not be allowed to interfere the audible spectrum. This is something - unfortunately - many people forget. Compromising on the enclosure weight to save on the total weight of the car is surrendering to poor sound quality. In the end, when done right, no panel or material will absorb any frequency. If you make your enclosure or box out of a thin material, like kick-panels made of fibreglass, this material will vibrate and vibration is sound converted to mechanical energy. No matter, that is equal to losses in the audible spectrum. The goal of my installation is therefore to reduce as much as possible of the losses due to insufficient material and construction. 

*"Good sound"* is personal and subjective. There does not exist one single loudspeaker that is 100% objective and every loudspeaker or installation add its own personality or colour as some define it. But personality is not equal to bad, its just an interpretation. Just like different music styles is interpretation of what sounds good.

*A side note on crossover:*


> *The question is whether we can make a crossover at all without measurements and the answer is NO. It cannot be done, and crossovers cannot be calculated.*
> 
> We cannot use manufacturers' data sheets to simulate crossovers either, although I know some dealers do so. The frequency response data are most often taken from an "infinite" baffle that does not in any way resemble your cabinet. These data do not contain proper phase data, etc.
> 
> ...


Every installation, enclosure design and volume, listening position as well as taste will require a unique crossover. I am sure most people feel that the "kit" crossover produce decent sound and listening experience, but that is the same as "good enough" and its actually not good enough... he he. That is why the crossover will take the longest time to configure. We are talking months of listening and measuring just to tune this piece of hardware.



> The crossover is the heart and soul of any loudspeaker. Even the best drivers in the world mounted in a well built cabinet can sound terrible if the crossover typology and quality of the crossover components used are not well designed and implemented.


The speaker elements I am looking at can be found in loudspeakers that cost from $1500 up to $30 000 and you can be damned sure that the difference can be found in the enclosure and crossover recipe. 

*Serious about good sound are we?* 

/ Oneminde


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## Oneminde (Nov 28, 2015)

Time for an update.

I've been thinking about the interior, quite a bit. I was searching the internet for E39 interiors and came across one that is almost a perfect match. Its called *Heritage* (nappa leather)


























The inspiration for the interior is the BMW M5 F10 30 Jahre Limited Edition which I showed a picture of a few posts back, but here it is once more.










1. Heritage was only available on the M5, meaning; It is rare as f***
2. BMW does sell it, I will list the number and price.
3. To make it look more like the 30 Jahre Limited Edition, it need white stitches / seams and it need some suede. But using suede in the seating area is unwise since it will get "nocked down" over time. So suede will only be used on the outside.
4, I am considering suede on the dashboard as well as on the upper section on the door panel (see image). 
5. All of the above demand serious changes to the original seat upholstery. But that is more or less just a question of removing sections, use as template, a reattach the sued.
6. The doors, dashboard, centre console, roof etc will all be covered in leather/sued.

The list of Heritage parts. A note is that since the M5 is a sedan, one might think that the rear seats will have issues since they are foldable in the touring. But luckily, the sedan had this as an option an BMW calls this load-through. The M-sport seats are the same in M5 and non M5 cars.
_
Green is the cheapest option, but changing color is not difficult._

*front, uphlstry, cover, Sport seat*
RealOEM.com - Online BMW Parts Catalog

1: 52102499681 - Seat Cover leather - $733,77 (x2)
2: 52102499682 - Cover backrest - $733,77 (x2)

_Black_

*rear, uphlstry/cover, load-through*
RealOEM.com - Online BMW Parts Catalog

4: 52202499808 - Seat Cover - $1096,47
5: 52202499827 - Backrest Cover, Left - $661.81
6: 52202499758 - Backrest Cover, Right - $553.54
7: 52202499947 - Lateral Trim Panel, Left - $257.80
7: 52202499948 - Lateral Trim Panel, Right - $257.80

*Tot.Price: $5762,50 or 49058,47;- Swedish kroner*

That is more than the average price for a 530 Touring in good condition. Its simply too much money.

I can get a whole hide, roughly 5 m^2 for $300 and one need roughly 3-4 hides for front and back seat. A company will do it for roughly $2400 including the material and labour. So I have a few options.


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## HulkSmash (May 22, 2011)

Good luck with this...subscribed.


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## Oneminde (Nov 28, 2015)

HulkSmash said:


> Good luck with this...subscribed.


Thanks, it sure is needed ... he he.

"One car to rule them all, One car to find them, One car to bring them all, and in the darkness bind them"


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## Oneminde (Nov 28, 2015)

Its time for an update tomorrow.


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## Jonathan (Oct 6, 2011)

What is a class AB OP Power amp?


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## Oneminde (Nov 28, 2015)

*Drivers.*










After weeks of reading and researching, its about time to reveal (in part) the drivers I've settled for. Remember that I initially stated that Scan-Speak was something that I found very interesting, they still are and I have no doubt that they would perform very well. But as time passed, I investigated other options and in a way selected so called under dogs: Drivers that people often ignore due to price and perhaps they arn't that well know. But make no mistake, these drivers are far from a poor performer. They are top class.

As you can see, I have blurred out the models just to make this entry a bit more interesting.

*Lets play a game.*
What can you uncover by picture, reviews and data alone ?

*TWEETER.*


> *** is a High Definition metal dome tweeter with wide, coated fabric surround and combines the high frequency behaviour of a ¾” dome with the low frequency characteristics of a 1” dome. Aluminium/magnesium dome for low mass and high rigidity and stability. Protected by an acoustically open Hexagrid. Precoated Sonomex surround gives low resonance frequency, high consistency and excellent stability against variations in air humidity. Voice coil windings immersed in magnetic fluid increase short term power handling capacity and reduce the compression at high power levels. The chassis is moulded from a stiff and stable glass fibre reinforced polymer material, and its front design offers optimum radiation conditions. Large ferrite magnet gives high efficiency.





> 'I ordered a pair of these *** tweeters a few days ago, as I write this. After they got here, I hooked them up to a third-order Butterworth filter crossed over at 3000 Hz, with an added Zobel network strapped across the tweeter terminals. I originally purchased these because I was looking for a 3/4" dome tweeter that would be capable of low distortion and high output. Originally, I was going to get a pair of Hiquphon OW-1 tweeters but a fellow speaker builder suggested that I try out these much cheaper Seas tweeters instead. "Why spend more than a hundred bucks apiece, if you can get the same sound from *** for a lot less?" he pointed out. Well I was skeptical but for less than forty bucks each, I figure that I could take a chance on these *** units. Well after a full day of testing them, I got to say that these *** tweeters must be one of the best kept secrets in the realm of small dome tweeters. I have listened to hundreds of tweeters during my lifetime, and VERY few of them sound anywhere near as beautiful as these Seas units do. That includes other tweeters made by Seas, some of which cost anywhere up to five or six times what the *** costs.
> 
> For starters, these gorgeous little metal dome babies sound almost as good off-axis as they do on-axis. There is almost no sibilance at all, no matter how loudly I play them. Cymbals sound nice and crisp, without any "ringy-ness" or other such undesirable distortion. The overall output level from these drivers was surprisingly high. I had to pad them down a bit with some resistors in order to tame their brightness. Once their level had been properly adjusted, they simply sound crisp, clean and smoooooth as silk with none of the harshness that I usually associate with metal dome drivers. There are certainly better tweeters on the market but not for anywhere near this price. Highly recommended for applications where they will be crossed over at 2500 Hz. or higher. You definitely won't regret it.'





> Aluminium and aluminium / magnesium tweeter come in all types, some can sound rather edgy, others quite pleasing. *** seem to have got it right with an extreme budget tweeter that sounds 4x the price: the ***. It is well detailed and smooth at the same time and very easy to work with.


DATA
Nominal Impedance: 6 Ohms 
Voice Coil Resistance: 4.9 Ohms
Recommended Frequency Range: 2500 - 30000 Hz Voice 
Coil Inductance 0.05 mH:
Short Term Power Handling: 180 W 
Long Term Power Handling: 80 W 
Force Factor: 3.3 N/A
Free Air Resonance 1100 Hz
Characteristic Sensitivity (2.83V, 1m) 92 dB 
Moving Mass: 0.23 g
Voice Coil Diameter: 19.5 mm 
Voice Coil Height 1.5 mm 
Effective Piston Area: 5.9 cm 2
Magnetic Gap Flux Density: 2.0 T
Air Gap Height: 2 mm 
Magnet Weight: 0.25 kg
Linear Coil Travel: (p-p) 0.5 mm 
Total Weight: 0.5 kg

*MIDRANGE.*


> The *** Series offers high-quality solutions for multi-way speaker systems employing vented box alignments. A powerful ferrite magnet system is coupled to a finite element analysis-designed suspension system, containing a linear spider design and rubber surround. The motor incorporates an aluminum shorting ring that reduces coil inductance, extending frequency response performance and reducing second harmonic distortion. A cast aluminum basket provides high structural rigidity, heat-sinking capacity for the motor, and additional ventilation under the spider that in combination with a vented cone neck reduces air compression effects. The Glass-Fibre Composite cone combines high strength with low moving mass, offering superb transient response and sharp definition.


DATA.
*Product Specifications*

Nominal Diameter: 4"
Power Handling: (RMS) 30 Watts
Power Handling: (max) 60 Watts
Impedance: 8 ohms
Frequency Response: 85 to 5,000 Hz
Sensitivity: 85.9 dB 2.83V/1m
Voice Coil Diameter: 1"
*Thiele-Small Parameters*

Resonant Frequency: (Fs): 89 Hz
DC Resistance (Re): 5.3 ohms
Voice Coil Inductance (Le): 0.24 mH
Mechanical: Q (Qms)2.95
Electromagnetic Q (Qes): 0.72Total Q (Qts)0.58
Compliance Equivalent Volume (Vas): 0.09 ft.³
Mechanical Compliance of Suspension: (Cms)0.55 mm/N
BL Product (BL): 4.91 Tm
Airload (Mms): 5.9g
Maximum Linear Excursion (Xmax): 3 mm
Surface Area of Cone (Sd): 56.1 cm²

*WOOFER.*


> The *** Series offers high-quality solutions for multi-way speaker systems employing vented box alignments. A powerful ferrite magnet system is coupled to a finite element analysis-designed suspension system, containing a linear spider design and rubber surround. The motor incorporates an aluminum shorting ring that reduces coil inductance, extending frequency response performance and reducing second harmonic distortion. A cast aluminum basket provides high structural rigidity, heat-sinking capacity for the motor, and additional ventilation under the spider that in combination with a vented cone neck reduces air compression effects. The Glass-Fibre Composite cone offers a unique acoustic and visual experience.





> This a great woofer with an almost unbelievable frequency response of 20 Hz to 3kHz! It is perfect for audiophile quality sound in a small enclosure. I put this woofer in a small bookshelf system with a 2nd order crossover on both the tweeter and the woofer. Everyone that listens to it is shocked at the clarity, presence, and definition, but mostly they are amazed at the bass. They say it sounds far better than any book shelf system they've ever heard and even better than most floor standing speakers.





> I am running these in my car for competition (Sound Quality) and am running them from 20-160hz and they sound amazing. I have them mounted in my doors, and are basically in an IB setup. I run them at the RMS rating and they hold their composure all the way down to 20 hz, pretty amazing for such a small driver. Only downside is the output drops off quickly under about 80 hz, but the fact that it is a 6.5" and can get down to 20hz at its rated RMS is quite amazing!


DATA.
*Product Specifications*

Nominal Diameter: 6-1/2"
Power Handling (RMS): 50 Watts
Power Handling (max): 100 Watts
Impedance: 8 ohms
Frequency Response: 20 to 3,000 Hz
Sensitivity: 88.4 dB 2.83V/1m
Voice Coil Diameter: 1.25"
*Thiele-Small Parameters*

Resonant Frequency (Fs): 46 HzDC 
Resistance (Re): 6.2 ohms
Voice Coil Inductance (Le): 0.42 mH
Mechanical Q (Qms): 3.1
Electromagnetic Q (Qes): 0.44
Total Q (Qts): 0.39
Compliance Equivalent Volume (Vas): 0.71 ft.³
Mechanical Compliance of Suspension (Cms): 0.7 mm/N
BL Product (BL): 8.32 Tm
Diaphragm Mass Inc. Airload (Mms): 16.97g
Maximum Linear Excursion (Xmax): 5.34 mm
Surface Area of Cone (Sd): 143.1 cm²
*SUBWOOFER.*


> The same uncompromising dedication to innovation, craftsmanship and sound quality that have made *** the choice of music aficionados the world over, now brings you the *** series. *** has engineered the ultimate subwoofer series to set new industry standards. The *** series has gained worldwide recognition for its high-end, extraordinary combination of musicality and high power handling. More than just deep, loud bass common to most subwoofer's, it produces a synergy of tight, clean musical and life-like bass reproduction qualities like no other, delivering the ultimate bass experience. Consistent with *** philosophy, the Ultimate Subwoofers are designed to deliver innovative engineering resulting in extraordinary combination of audiophile bass quality and high power output at a great consumer value. These drivers employ some impressive technological features such as a gigantic 5.1” voice coil, wound with a hexagonal-shaped aluminum coil wire (2-3 times thicker than standard subwoofer) for accurate music reproduction, superior durability and power handling. A highly efficient magnet system (over 90% efficiency).





> I recently did a brief subjective comparison of the 10" versions that I've been meaning to write in the reviews section. I have a *** in a 1.2 cuft sealed box and a friend has the *** 10 in a 0.8 cuft sealed box. For the test, we connected both subs to a bridged 4-channel amp (~300W per sub), then toggled between them via the RCA jacks. The xover was at [email protected]/Oct.
> 
> We thought the *** sounded slightly better with most types of music, especially jazz, classical, rock and other instrumental music. Drums and bass instruments seemed to have better resolution and dynamics, which blended better with the front stage. This may be because of differences in response, with the *** being designed for flat response out to 150Hz. The sound of the *** reminded me of the IDW15, Oz 300L, MW190, and ND12 subs, but with better low-end extension and output.
> 
> ...


DATA.

10" One piece Composite Cellular Fiber Cone
Uniflow aluminum diecast chassis
High flux double ferrite magnet system
5.1" Hexatech Aluminum voice coil
Raised spider
Aluminum VC former
Aluminum VC wire, 5.1" diameter VC, 2 layer
12.5mm Linear X-max (peak)
*Recommended enclosure:*

1.75 cubic feet with a 3" diameter flared port by 12" long. F3 is about 32Hz.
For autosound, use 0.75 cubic foot sealed for an F3 of 35Hz (assuming 6dB of cabin
gain)

There we go, all the specs and some reviews. I for one think this will be a great system


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## Oneminde (Nov 28, 2015)

Jonathan said:


> What is a class AB OP Power amp?


*OP-Amp (from Wiki).*



> An operational amplifier (often op-amp or opamp) is a DC-coupled high-gain electronic voltage amplifier with a differential input and, usually, a single-ended output.[1] In this configuration, an op-amp produces an output potential (relative to circuit ground) that is typically hundreds of thousands of times larger than the potential difference between its input terminals. Operational amplifiers had their origins in analog computers, where they were used to do mathematical operations in many linear, non-linear and frequency-dependent circuits. The popularity of the op-amp as a building block in analog circuits is due to its versatility. Due to negative feedback, the characteristics of an op-amp circuit, its gain, input and output impedance, bandwidth etc. are determined by external components and have little dependence on temperature coefficients or manufacturing variations in the op-amp itself.
> 
> Op-amps are among the most widely used electronic devices today, being used in a vast array of consumer, industrial, and scientific devices. Many standard IC op-amps cost only a few cents in moderate production volume; however some integrated or hybrid operational amplifiers with special performance specifications may cost over $100 US in small quantities.[2] Op-amps may be packaged as components, or used as elements of more complex integrated circuits.


*Class AB.*


> Class AB is widely considered a good compromise for amplifiers, since much of the time the music signal is quiet enough that the signal stays in the "class A" region, where it is amplified with good fidelity, and by definition if passing out of this region, is large enough that the distortion products typical of class B are relatively small. The crossover distortion can be reduced further by using negative feedback.
> 
> In class-AB operation, each device operates the same way as in class B over half the waveform, but also conducts a small amount on the other half. As a result, the region where both devices simultaneously are nearly off (the "dead zone") is reduced. The result is that when the waveforms from the two devices are combined, the crossover is greatly minimised or eliminated altogether. The exact choice of quiescent current (the standing current through both devices when there is no signal) makes a large difference to the level of distortion (and to the risk of thermal runaway, that may damage the devices). Often, bias voltage applied to set this quiescent current must be adjusted with the temperature of the output transistors. (For example, in the circuit at the beginning of the article, the diodes would be mounted physically close to the output transistors, and specified to have a matched temperature coefficient.) Another approach (often used with thermally tracking bias voltages) is to include small value resistors in series with the emitters.
> 
> Class AB sacrifices some efficiency over class B in favor of linearity, thus is less efficient (below 78.5% for full-amplitude sinewaves in transistor amplifiers, typically; much less is common in class-AB vacuum-tube amplifiers). It is typically much more efficient than class A.


Basically, what I will do is to use the Texas Instruments LM3886 IC (mostly known from Gainclone Power Amplifier builds). 6 chips (_3 pcs for each power rail or 3 pcs for the positive side and 3 pcs for the neagative side, making it a parallel-series_) per amplifier, meaning it will put out 228-300W 2-chn. The watt spec depend on the hertz and resistance: Higher resistance = lower power output and vice versa.

The front system will get one amp, meaning roughly 150W/side and the subwoofer will get one amp, meaning roughly 300W mono.

The circuit is proven to be very reliable, stable and have excellent musical quality. It needs to be somewhat adapted to be used in the car and the 12VDC system, but that should not be any problems either.
*
Hope that answer your question ?*


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## Jonathan (Oct 6, 2011)

Well, not really, it brings up more questions.

If I was building a custom amp (and I have, several) and designing a Power supply for it I would use better amps than that. Six of those chip amps doesnt feel like a good solution compared to building a discrete amp. Noise and distortion may not be as great in your configuration as the datasheet claims for one amp. A discrete amp shouldnt be more expensive. Many amps off shelf are better, and not expensive.
Are you building chip amps to have a custom amp?

I have never Heard of your configuration seperating the amps for each rail. Do you mean parallel bridging? Your idea sounds like a nightmare for crossover distortion.


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## Oneminde (Nov 28, 2015)

Jonathan said:


> Well, not really, it brings up more questions.
> 
> If I was building a custom amp (and I have, several) and designing a Power supply for it I would use better amps than that. Six of those chip amps doesnt feel like a good solution compared to building a discrete amp. Noise and distortion may not be as great in your configuration as the datasheet claims for one amp. A discrete amp shouldnt be more expensive. Many amps off shelf are better, and not expensive.
> Are you building chip amps to have a custom amp?
> ...


The LM3886 I am looking at is capable of:


> The THD result at 1kHz is excellent at 0.0009%, while the THD performance at 50Hz is still acceptable at 0.019%.


Which I will say is rather good. Lots of people using the LM3886 is very happy with the overall performance, not saying there are other options that are better, there is. 

Yes, parallel-bridged. But since each each channel is amplified separately via 3x LM3886, does it not mean it is Discrete ?



> The difference here is that operational amps usually amplify both audio channels at once on the same device, whereas discrete amps will amplify both channels separately on different components. The latter is usually the preferred method, but op amps can be pretty decent.


I am considering designing an amp around the the National Instruments IRFP260 N-channel MOSFET in a Push-Pull configuration. That would also mean 300W and fully discrete. But would no longer be an OP-amp but instead a MOSFET amp.

When it comes to Class D amps and chip amps, (also mean digital audio out), they can be very good. But tiny chip amps that claim several hundred watts does not mean it perform equally well compared to a transistor / MOSFET amplifier or tube amp. Watts out isn't everything  
One can't say that amp inside a integrated head unit that produce 50W RMS is equal to a dedicated 50W RMS amplifier. 

It sounds like I am expert, but I am not. I'm only expressing what I have found to have some merit so far. I have also considered Masconi, Hertz and Audison for the amp section.

*But while are are debating, what according to you is good ?*

And yes I would like to build a custom amp.


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## Jonathan (Oct 6, 2011)

Oneminde said:


> The LM3886 I am looking at is capable of:
> 
> Which I will say is rather good. Lots of people using the LM3886 is very happy with the overall performance, not saying there are other options that are better, there is.
> 
> ...


The thing with DIY amps is that the builders are a bit biased. I have listened to LM3886 and there was nothing wrong with it, but I didnt want one myself. The guy who built it wasnt very experienced in amp design (like most arent), which may have something to do with it. The layout looked ok, but probably wasnt. And when we measured the THD and noise it was ok, but far from fantastic. 

A chip amp is not a discrete design. Discrete transistors are. And bridged parallel means that both halves of the signal are dealt with by the same amp like a bridged amp. Each of those bridged amps has a parallel twin (or several). With several parallel feedback loops, not my thing... 

Why would you want a 200V mosfet for a 300W amp? You will need 50V rails. Working with mosfets in AB-amps is tricky, especially switching type mosfets. I Think BJTs are simpler to extract good performance from.

The speaker output from a hifi amp is not digital. Sound is analog, and so is the voltage/current driving the speaker. A class D amp is a switching analog amp. This is something that class D designers (myself included) try to make clear, but it is a lost cause. Using chip amp class D is not something I recommend either. Designing a discrete good sounding class D is difficult to say the least. 

I would get an off the shelf amp to use in the car while Learning to build an amp of your own. 

Get Douglas Self's book on amp design. Get hold of Tools - a distortion meter is basically necessary for serious amp design. Design and build a bunch of different amps to learn what the distortion mechanisms are. 
Similar for switch mode Power supplies. The Learning curve is a bit steeper with the Power supply though. 

My impression after Reading this thread is that you could benefit from some hands on experience. I think most of us start out thinking that we are going to do the most serious build in the World after seeing other peoples terrible installations around McDonalds on saturday evening.
You have a lot of quotes, thoughts and ideas in this thread, and that is great. An open mind is an awesome tool. But sometimes you just have to get out there and build something to learn. You could have answered my question about OP Power amp with your own Words, but you used quotes instead. Keep reading, but I recommend you to also create your own understanding of how things work. I Think you have a mindset that makes you want to know the details of how things work. Reviews are a useful guide line, but experience is king. I Think you are gonna have an awesome time if you start listening to, building and fixing speakers, amps and audio in general. And you will learn so much. I have an old DD C2a class AB amp (2x200W or 1x600W) that works. Since you are in Sweden I can donate that amp to you if you want to learn from taking that apart...


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## Oneminde (Nov 28, 2015)

*@ Jonathan.*

I am that kind of person who think out loud, it is part of how I process things. Does not matter if it is in the form of text or if it is verbally presented. Often it sounds like I am having a conversation while in fact its a monologue to hear my own thoughts ... LOL

I could have built everything and then presented the result as a post-build thread, but instead chose to go ahead in advance and share thoughts and get feedback as well as allowing others to grab ideas / concepts and get in on the whole process. Reading this thread is not mandatory and neither is reading every entry  One is free to do whatever one wants, but I enjoy reading details about how people go about doing things. I am a detail whore.

This build thread is as much for me as it is for anyone who is interested, sort of a logbook.



Jonathan said:


> The speaker output from a hifi amp is not digital. Sound is analog, and so is the voltage/current driving the speaker. A class D amp is a switching analog amp. This is something that class D designers (myself included) try to make clear, but it is a lost cause. Using chip amp class D is not something I recommend either. Designing a discrete good sounding class D is difficult to say the least.


This is an excellent opportunity to add information about amplifiers. Either you know or you don't, others might not know and I for sure did not know either a few months ago.

*All amplifiers share one thing in common: They add energy to increase the volume and amplitude of the audio signal, essentially what all tube, transistor and MOSFET'S do. They increase the audible level of the audio signal. But that is where the similarity ends.*

*1.* You have the most basic amplifier which is analog to analog such as with an record player and tube amplifier - this is a fully analog signal.
*2.* You have analog to digital to analog: Such as record player converted to digital (A/D converter) and in the amplifier you have digital to analog (D/A) - a mix between two worlds.
*3.* Then there is the fully digital version: This is basically conversion of an analog sound source to digital and it remains digital all the way to the speaker. (Class D amplifiers only) The analog conversion happens in the driver itself. After all, analog sound via a speaker is the voice coil moving in relationship to magnetic induction strength and the rate of change or rate of occurance (hertz).










One can view the digital audio signal as a PWM (Pulls Width Modulation), but is referred to as PMD (Pulse-density modulation) which is a synthetic sin wave or simulated sinwave.










*Clarion just introduced a fully digital system:* Clarion U.S.A | Full Digital Sound Products

*NAD have a series of digital amplfiers:* Masters Series - NAD Electronics

*Wiki article on PDM;* https://en.wikipedia.org/wiki/Pulse-density_modulation
*
And a PDF that explain PDM:* http://users.ece.utexas.edu/~bevans...ersion/AP_Understanding_PDM_Digital_Audio.pdf

Regarding what sounds good and not, well ... this is where fact and personal preferences often is hardcore blended. What I mean by that is; We, humans, are unique in the way our brain is wired and how well we can hear different sounds. Me, I have no problem hearing up to 18.5kHz at the age of 40, meaning I've always had excellent hearing (at a cost). I can hear things others can't but it does not mean it is always better. The cost is problems sleeping due to sensitivity to any changes that might happen. A clock might keep me awake but is literally inaudible to someone ells. 

So as with pure analog vs pure digital, except for the conversion at the driver: What is better ? This question cannot be properly answered because we have the scientific perspective and we have the human biased perspective. Is a Mercedes better than a Ferrari if your only goal is point A to point B ? What we can say is that they are different. Which one is considered better fully depend on the individual.

Is a tube amplifier that add plenty of distortion and personality, together with a resonating cabinet _(JBL often implement that solution)_ with driver membrane made of paper and a soft dome tweeter *worse or better* than a non resonating cabinet, diamond tweeter and drivers with ceramic membrane that is extremely analytical compared to the the tube system that renders a warm sound ? 

Again, depend on the person you ask but not only that, in fact if you ask me, it heavily depend on the music. A live recording of a Jazz band performing, sounds better on a tube amplifier via a well designed resonating loudspeaker and modern house track or quality recording of a women singing a ballade performs better on a non resonating highly analythical loudspeaker with a very pure audio signal... There are many ways to skin a cat.

@Jonathan: If you want to donate the amplifier, then by all means go ahead. I am willing to study and pick apart to learn. Hit me with a PM (in Swedish) for details


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## Oneminde (Nov 28, 2015)

With the Tesla Model 3 coming in a few years, the E39 539i Touring might be my last ICE car, perhaps that is one of the reasons I am planing so many things for this car 

Anyway ... here is a minor update to the "what wheels" situation I'm in. Enjoy

*Rohana RV10* vs *Farrada FR-4* vs *Work Gnosis CV201* vs *ACE Convex.*


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## Oneminde (Nov 28, 2015)

Found an entry about 4 ohm vs 8 ohm. Reposting.



> *The "Real Deal" with 8 ohm drivers*
> I've seen many people say, "Well I want to use this speaker, but I'm put off by the fact that it's 8 ohms."
> 
> Let me explain why it's ok to use an 8 ohm speaker, and why it could actually be better than a 4 or 2 ohm speaker.
> ...


Source: http://www.diymobileaudio.com/forum...d-our-members/31-real-deal-8-ohm-drivers.html


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## Oneminde (Nov 28, 2015)

I guess its time to come clean as there is no other reasons to say it but bluntly. I am abandoning the E39 project. In a way, it was difficult since I've wanted an E39 for so long  but on the other hand, the F10 for me, represents a new classic BMW look . So I am sad and glad at the same time and it's going to be great.


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## GERMANIKS (Dec 7, 2013)

You bought a M5?
Come on get out of there ...


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## benny z (Mar 17, 2008)

dr00l


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## Oneminde (Nov 28, 2015)

No, I did not buy an M5, way too expensive ... LOL
But I am planing to buy the 523i or 528i - both having a 3.0 litre 6 cyl engine (N53B30), the 523i is downgraded via software which one should be able to flash (new firmware).

523i: 204 PS (150 kW; 201 hp)@6100
528i: 258 PS (190 kW; 254 hp)@6600

*The picture:*
The improved is simply the M4 front bumper and F30 LCI tail lights, the rear bumper is F10 M5. Both upgrades require custom work. Its sad that BMW selected the F10 LCI tail light that they did, it does not look as nice as the F30 version. Perhaps a personal opinion.

This car is still some time away since I am not going to take a loan but rather save up to it. Meaning, it need to share the same financial platform as the company creation, so the time frame is roughly 2,5 years. As long as it happens I'm happy. Sooner than later is good.


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## Oneminde (Nov 28, 2015)

Hijacking my own thread a bit now 

While surfing the net, I stumbled upon a picture.









Source: BMW M5 Gold ADV1 - R1 Motorsport

BMW F10 M5 with raised tire letters and found it very nifty. Here are the guy's making it.
Tred Wear Letters - Raised White Letter CUSTOM TIRES

AMMO NYC did a video on it.
https://www.youtube.com/watch?v=Kvd0uRljLmg


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