Tweeter Dimming, DIY Tweeter Pad

Are you suffering from high frequency fatigue each time your are listening to music on your stereo system? Is your HT system too bright sounding, that your ears bleed from gun shot sounds and what nots? Maybe you only experience high frequency love bites on certain CDs or LPs?

The above symptoms common with many beginner set ups. They are a result of a variety of possible causes. Chief amongst them are poor speaker to room placement, seating position error, room modes to speaker interaction, poorly matched equipment, cheap or fake silver cables, wrong tweaks application, and probably many , more reason caused by poorly set up system. On the flip side, is bass boom, or simply not enough bass. Well, that's another side of the problem.

Saw this tweak available for lunch money and thought maybe I should just try it for fun, even though my system never exhibited any of the high frequency symptoms as mentioned above. My system at some point many moons ago did exhibited some of the high frequency issues but I have since learned to fix them on a fundamental level, i.e. fix the source of the issue, not treating the symptoms with band aid. I think this tweak clearly belongs to the band aid category, if one is looking to fix an overly hot tweeter issue!  

The tweeter pad came as a pair, it's a square felt like material die-cut with generic tweeter hole and comes with double side tape on one side for easy application to tweeter. 

My PMC IB2i before tweeter pad treatment

And tadaa! with tweeter pad treatment

I bought the item and went home with the merchandise. As I started to play some music, I started the first 30 minutes just listening my system as is. Then I stopped the music, and put on the tweeter pad to the tweeter on my speakers. The whole process is rather easy as all it took was 10 minutes or less.

I restarted my music, the very same music I played 30 minutes ago. Right away, I noticed some minor difference to the sound. The good thing is that the vocal size became 50 cent sized(using old Malaysian coin standards, which are much bigger in diameter than the current 50 sen coin), which is certainly a good thing for vocal biased audiophiles. The cons(in any tweak no matter the cost, there is always pros & cons! You invariably win some & lose some too!) are, my system had lost it's spatial cues, yes, the back ground was blacker(if there's such a thing!) but the sound became less airy too! Yes, the vocal was now super focused, but it sounded like the singer needed lozenges to sooth his or her throat, i.e. vocal sounded dry! I kept the tweak on my tweeter for a few days, just to let it settle down, hoping the cons will be reduced in time, or maybe we just get used to the sound!

However, it was not to be, I still hear the cons as mentioned above more then any pros the tweak made to my system. I finally decide to remove the tweak for good. Maybe pass it on to someone who need a band aid for hot tweeters. My advise is to work on fixing the fundamental issues if one's system has a problem. Band aids are just that, they help your to cover up the rough spots, but at what price? What other compromise? I think band aids like this can work if your speakers are truly stuck in position due to home minister approval requirement, or for room aesthetics matter, then it may be a solution. However, it's not my preferred solution.    

Add Oil Baby! Duelund DCA20GA XLR Interconnects

I have long admired boutique products from Mundorf & Duelund. Today we talk about Duelund DCA20GA interconnect cables. This are DIY cables that one need to buy the required cable length,  x 2 if RCA and x 3 if XLR. In my case, since I only use XLR cables, it's 3 meters of cable stock to make 1 meter of the finished XLR cable. Then you need to buy some soldering wires, sleeve, some heat shrink jacket for cable dressing and also 2 pairs of required XLR or RCA plugs. Once all the materials are in hand, then one must DIY to put it all together. In this case, it was my good buddy Julien Lee who did all the hard work! Nice work man.........

A very excited Julien came to my place with a finished Duelund DCA20GA cable with Neutrik XLR plugs & WBT silver solder. He said "you gotta try this, it's tin copper but soaked in oil!" I was like "Ooo, soaked in oil? I likey.... already". I remembered the sonic effect of those silver in oil Mundorf caps gave me when I was playing with them.

I used Neutrik XLR plugs to go with the Duelund DCA20GA cables, because the Neutriks are industry standards and priced reasonably. there are better options out there to be considered at multiplied cost factor of x 5 or more, but considering the actual Duelund cable cost, I choose to stay with Neutrik just to make it rather affordable(that's a relative term, ani't it?). 

Here goes, after plug in, replacing my long serving Cardas Golden Reference XLR interconnect. We were immediately impressed with how organic and unforced the Duelund cable sounds.  Vocals have chest in their delivery, not just the head, and that very smooth highs, if a little rolled off. Bass delivery was totally rich, full, solid yet remained agile. In comparison, while the Cardas also had that rich, full, solid bass, it always sounded just a tad flabby. Notice I said we?

That's when both Julien and myself were there in my man cave for more than an hour! Then Julien said, "I have a better idea, you keep this pair running in, while I make another pair using Oyaide silver solder! Let's see what sonic changes we get" And then he left me to do 100 hours or so of running in. He came back a few weeks later with the 2nd cable. 

As soon as we plug in the Oyaide soldered cable, the first thing we noticed was that slightly rolled off highs were gone, replaced with an airy, finely extended smoothness. The vocals still had the pizzas, when listening to Barry White, his signature baritone voice was all there! Tsai Ching never sound more seductive & mellow. This kind of mid range can make many audiophiles go crazy & just say, "go on, just take my money!" I have not experience this kind of  magical mid range delivery, not since those heavenly Skorgarnd cables about 10 years ago. 

With the Oyaide silver solder, something had to give, right? Remember in every audio change, up grade or down grade regardless, one rule always applies, you win some, you lose some. Just hope when you upgrade, you win more then you lose. The thing about the Oyaide silver solder, the bass lost that richness, but still remaining solid and agile. So for my bi-amped system the solution was simple, I use that first WBT silver soldered Duelund interconnect5 for my bass channels, and use that Oyaide silver soldered Duelund cable for my mid & treble channels! And so like a true blue audiophile, I told Julien "go on, take my money please, and leave those 2 XLR Duelund interconnects here!" 

If you're not bi-amping unfortunately, then you'll have to choose the lesser of the 2 evils. With both Duelund cables in my system, it's almost like having the Skorgrand cables in my system, at a small fraction of the asking price! Now I start to believe in saving for the last, and the almighty has a path for you.  So don't be sad if you didn't get what you wished for! 

Dual DCA20GA has an extra oil cotton(black) jacket wrap over which gives further damping and resistance to oxidation. When used as interconnect, use an extra cable jacket or sleeve to give it further protection & professional look. The other function of the extra sleeve is to prevent your hands from getting oily while handling the finished interconnect.

 

With what was written above, I must caveat that the result was with my use of Audioquest Sky silver interconnects from source to pre-amp is what brings out the details in the music, then using the Duelund in the pre-amp to power amp stage to give music it's  rich tonality, that magical golden mid range, and truly kick ass bass quality. If you're using some copper cables further up stream, then your results may be somewhat invariably different. I guess it all depends on system synergy and cable matching as well, as in all things hifi. However there's no running away from one thing, if you love those paper in oil or silver in oil, or anything in oil sound character for the matter, this Dueland DCA20GA cables, is surely right up your alley, your must try product. That's all I am saying!

Did you also noticed I didn't mentioned price? For me at least, it worth every penny of Julien's asking price. Leave a PM comment if you want to give Julien some $$$!

Bass Tuning! Bose Acoustimas Series Woofers

Dr Amar G Bose started his career as a Professor in MIT. Later he would start the Bose Corporation by licensing his amplification algorithm for American military use & the likes of NASA. It was much later that consumer products like the Bose 901 series speakers hit the market. The 901 series speakers was a polarizing product as people in general either loved or hated it. The Bose 901 series speakers does hold some scientific promise, but was the result reflective of those published scientific papers? That's what makes it so polarizing.

Many years later, Bose moved away from conventional box speaker products and started moving in to the Acoustimass series of satellite speaker with sub woofer combo. Still very based upon the earliest premise of Direct/Reflect Sound Technology, but also add to the premise that low frequencies, a.k.a. bass becomes omni-direction below 80Hz. This comes at a time when urban living became more dense, homes got smaller, but people still wanted good sound with room filling bass. And judging by the Accoustmass series sales numbers, it was a home run!

Now, I know many audiophiles have some kinda beef with Bose, due to the construction & materials used, and that smoothing, well rounded, limited bandwidth sound ani't what we call hifi either. However, to the other 98% of the world population, that didn't really matter at all, despite those high price tags which resulted in fat margins. Fast forward to recent years, Dr Amar G Bose wanted to cash out, hence sold Bose Corporation to Apple Inc. Apple already own Beats By Dr Dre. And now Apple have merged both entities to become Beats By Bose!

I started with a little history & background of Bose, because I am squarely in the 2% of the worlds audiophile population, yet I am one of the few who loves Bose products for what they are today, lifestyle. My household is just all Bose sound mostly, in the non audiophile areas. And lastly, I find the Acoustimass bass modules, or woofers just so useful to have around, especially the passive ones. they are easy to integrate in to any existing sound system, and with guarantee extra room filling bass. What else do you want? Me, I always find the Acoustimass modules bass to be a little flabby, and when playing loud, port chuff becomes very apparent, especially the older series 1 models. Which is what I have exactly in my home office/study area.

And here, I set about doing something about that port chuffing sound. This DIY work is rather easy, and I think every Bose Acoustimass woofer user should try it. Do you know you can tone down that flabby bass & port chuff sound by just stuffing the Bose Acoustimass woofer? Here's a step by step guide how to do it. 

Bose Acoustimass series I bass module.

Once turn around, you will find back panel access screws & speaker input & output connectors.

You'll need to unscrew all the screws on the back panel, including those holding the 4 feet.  Do not unscrew the speaker terminal screws.

The back panel open, revealing all the internals inside, you will notice there is already some poly fill inside. Those white fluffy pillow fill. Just look at the materials used by Bose, woodchip board, crappy looking Pasar Road drivers & cheap x-over parts. Nothing special, but industrial grade only.

A closer look at the cross-over, all stuck to the rear panel.

Add more polyfill or pillow fill, there are generally 3 types on window fill, you can have foam or feather, both sadly are no good for this application. Then you have polyfill of various density, which will work for this case. What I have is of rather high density polyfill.

After filling the accessible side of the box to about 70% including the original polyfill. I stop and work on closing back the rear panel, making sure all the wires are still connected and in contact. As it quite common for Bose Acoustimas bass modules to fray & delaminate around the edges & corners of the box, so I wrap my module corner & edges with black duct tape to keep it protected. Even if the Acoustimass bass modules are designed to lie down, they can be placed in various positions, those liitel red feet you see are actually rubber door stoppers available from your local hardware shop. 

The bass quality after stuffing of polyfill in to the Bose Acoustimas bass module is tighter, cleaner and certainly less bass port chuffing effect. The immediate feeling is that the upper bass has been toned down, with slightly less kick and an overall bass volume reduction. So in essence, you gain some and you lose some. but for me it certainly an easy mod that takes just 20 minutes or so and it work a joy. Here are some other Bose Acoustimas bass modules that have gone thru similar bass tuning process.

Bose Acoustimass series III, I use this to complement the main hifi rig in my man cave. I loev this passive sub because even though it's one box, there is actually 2 units of  6.5 inch drivers inside running in stereo configuration! 

Here is how the Bose Acoustimas series III looks inside, still 2 units 6.5 inch drivers inside working as stereo pair. The box chamber design is totally different, but you can still access the box via the back panel where the speaker connectors are located. With simplified construction, all you need to do is to uncrew 6 screws in back panel to be accessible to the chamber which I have circled in RED. You just need to stuff the polyfill in to the chamber(as circled in RED) by 30-50% for bass tuning, results depends on your preference & room acoustics interaction.

I not only use Bose in my home, but also inside my car too. I use this Bose Acoustimass Canon in my car boot to augment bass to the OEM system in my car. I also need a 2 channel amp to drive this too. Again my main issue here is port chuffing & car interior panel vibration.

There are 3 chambers inside the bass canon. You can stuff polyfill in to the center chamber as circled in RED by 50-70%. As I preferred tight bass in my car, I filled the middle chamber by up to 70%. The chamber is accesi8ble via the tuning ports with end caps on the long port side. You just need to unscrew all the screws around the tube diameter on the end cap. For my interior panel vibrations, I added sound dampening materials to them. With panel vibration gone and bass tuning to very tight less, I some times can sit in my car, after reaching the destination. just to finish the song, before getting out!  

Bose Acoustimass Canon for home theater use. No I don't have this, but one of my buddies used to have it in his HT den, back then in the 1990's. These Bose Acoustimass Canons were considered high end at the time! I remembered my friend demo-ing Top Gun movies in his Dolby Digital 5.1 HT system. They were pretty convincing back then. However, the Bose Acoustimass Canon is very rare now, and hard to find in the used market.

There you go, now you know my fetish for Bose Acoustimass bass module!

 

Upgrading My V! Kenwood GE-7030 Equaliser

With a pair of  Bose 901 MK VI speakers serving as the front main channels of  my 5.2.4 Dolby Atmos surround sound system, I have discovered that adding an EQ(in the form of a Pioneer GR-555) in to the mix only for the front channels improved the over sound performance of the system. What I did not realized is that  the quality of the EQ component mattered in HT too, just like in our 2 channel stereo system. Here goes......

The Kenwood GE-7030 comes with a frequency jog dial & level up/down buttons for easy band selection and adjustment. Excellent ergonomics when in use, even if all those buttons on the front face plate seemed a little daunting at first!

Spotted this unit on FB Market Place, made the inquiry, but due to it's high asking price I actually held back & thought carefully about it for more than a month if the more expensive EQ really makes a difference? I guess some times, what's meant to be was meant to be, as what are the chances that an item is still there after a whole long month or more? Based on my trading experience on FB Market Place, the stuff is usually gone after a few days if one is eyeing & not making an effort to secure the item.

Anyway, met the seller who was a really friendly guy and he gave me about an hour of his time, just walking me thru all the bells & whistles that this Kenwood GE-7030 has got. Basically, one can work this Kenwood EQ in 3 ways. First is the most common used as 14 band Graphic EQ. Next is as a 3/14 band grouped Parametric EQ. Last is the easiest, using it's 7 pre-programed stored EQ Genre curves, which includes modes such as Flat, Pop, Rock, Car, Jazz 1, Classical 1 or Classical 2. Last but not least, that matching pale bluish dot matrix text & bar display just matches my stack of other components from Denon, Cambridge Audio & Oppo. The Kenwood does not stick out like a sore thumb, unlike my earlier Pioneer GR-333 EQ which came with bright amber bar display. And believe it or not, the Kenwood GE-7030 was sold during the 1991-1992 catalog years. The fact that it's still around today is testament to Kenwood, and probably most Japanese audio manufacturers during the era, that overall high standard of build quality. The Kenwood also came in a tall, massive & deep 2U chassis, which on itself looks just like a second AVR on the rack, but weighting only 5.4kgs. Not too heavy, but for an EQ, it's a battle cruiser. 

My HT component stack. from top, Denon X-4400H AVR, Oppo UDP-203 & BDP-83 Blu-ray player, Cambridge Audio A-120 4 channel power amp, Kenwood GE-7030 EQ, and lastly Weiduka PLC and other auxiliary components, like HD Toaster & that Arcana HD Fury(hidden behind)

The Kenwood GE-7030 unit that I bought came with some minor scratches and dings on the front faceplate, which required some touching up with permanent black marker. Once marker ink dried, with a bit of elbow greasing, the touch up will look almost seem less, unless viewed up close  

With the Kenwood EQ plugged in to my AV system, allowing me to only manipulate the front channel tonal response, I played around with a variety of settings which included Parametric, Pre-Programed, but eventually  settled on that characteristic 14 band V setting on Graphic EQ mode which worked so well on Bose 901 speakers with the Pioneer EQ in use previously. With the EQ setting been custom set in memory, I can move on to enjoy my music & movies. Yes, I actually use the HT system on Denon HEOS to stream Spotify or just MP3 file loaded from my smart phone.

The first thing that hit me was how much more transparent sounding this Kenwood EQ is compared to the Pioneer EQ. It's not a fair competition either as the Kenwood is at least 2 steps up the model line, which equals to a Pioneer GR-777 in that case. However, the Kenwood EQ operates on all logic & memory control board while the Pioneer is still based on the classic electronic sliders. I am not sure if that's the advantage here, but the difference is easily heard, it's just so much more can be heard with the Kenwood, like a veil has been lifted off the sound track and music. The Kenwood is also more powerful sounding, the music & sound tracks just comes alive, as in gun shots, cannons and explosions hit harder, kick drums "kick" harder, and vocals, crystal clear and even with nice imaging thrown in when playing music in stereo mode! While vocals is crystal clear, it still maintains a degree of body within the image of the sound stage! Bass & treble definition is also improved  with the new clarity. Highs are more airy and bass lines can be followed easily. I can't say enough how well this Kenwood EQ matched the Bose 901 MK VI speakers. 

Just a caveat if you're reading this, it may not be a good idea to add an EQ in to the mix if you're not using Bose 901 series speakers in your stereo or HT system. The unique design and sound character of the Bose 901 series speakers demands that an EQ be used with it. There maybe other speaker designs with an EQ requirement, but I believe those are far & few in between, with the Bose 901 series being the poster boy of the group!  

Heart of your home cinema

Cinema is the one place that no matter what age or gender that will likely to go for some family entertainment or even with friends. Thanks to the pandemic that enjoyment is pretty much non existing for now at least. Home cinema or theater has been the next best thing to have. This days with so much high resolution content from blu ray discs to online streaming. Is totally no brainer to seat at home to enjoy the endless titles of movies. 

Traditionally, it has been the TV that dominant the home theater or I will say TV is a common hardware you can find in almost every home in nearly any countries around the world. The best thing is the prices of TV this days is very much encouraging and the size of TV is easily goes up to 85" with affordable price. Although that is the case but a relatively large screen size of 100" or more still is unreachable for most for the TV. The best alternative option is the projector. The same can be said for projector as well with much affordable price and easily bought this days.

For people who are venturing into projector or about to take the plunge, there are few things to consider to get the best of projector or the very least avoiding any blunder. Of course the first thing will be the projector itself. What kind of projector, just like TV with many different models and specs. Probably when choosing a display (TV or Projector) will think about the picture quality in term on resolution. Is either fullHD or 4k display. Is pretty straight probably for most to go with 4k however this will be also more costly. Next thing which is very important is the light source. Traditionally projector uses lamp as light source. Just like TV using backlighting as light source. Recent years, laser is being introduce as light source to the projector world. Now the thing with different light source of course will give you different kind of picture quality and so on but the thing most people will consider is the cost. Laser projector is more costly than the lamp projector. Of course the good thing about laser is the long life span compare to a lamp that might burn out in about 3000-4000 hours. Different brands of projector the cost vary as well. 

                                                                            3 LCD

                                    

                                                                               DLP

The next part of the light source is how it is use to project the image into the screen. There are 2 types which is the 3LCD and DLP. As from the image you can see that 3 LCD uses 3 pieces of mirros for 3 prime colours of red, green, blue to project the image. Whereas DLP uses a colour wheel for the 3 prime colours. DLP being the more simple setup also means the cost is lower than 3 LCD in general of course in term of picture quality, 3 LCD will be preferred as the colour is more accurate.

Of course once you know which projector to go, you will also want to know screen. There are many screen types but the main consideration to start will be the size. How big you want your screen to be. This need to depend on your projector throw as well. What is means is that, how far away the projector from the screen to have the size that you want. Every projector is different. This is best refer to the projector brand with proper calculator to get this right. Also you can consider acoustic transparent screen. Meaning the screen has micro or tiny holes for sound to pass through. With this kind of screen you can place speakers behind the screen and not blocking the sound. Finally we can choose for fixed screen or roll up screen. 

Projector and screen is done and next will be placing the projector. Some prefer to mount the projector, some will place it on some rack or furniture. Now if you do mount the projector, it is important to know the mount so you will know if that fit your projector. Not all projector will fit into standard projector mount. Also the weight need to be consider. The placement of the mount is important to make sure you can have the projection image throw into your screen. Some projector do have function to move the display or screen shift. If your projector doesn't do that, than is even more important to place the mounting accurately for the display to be in proper size and location.

Last but not least is the HDMI cable. Assuming with projector, usually you will need long run cable from player to the projector. Usually cable length is really not much of a concern, after all it is digital cable. Now the thing with long run cable is the speed of the cable will reduce on long distance. Again this is not much of a concern most of the time. Now the issue we need to consider is the 4k HDR or HDR+. To enable 4k 60hz image with full colour chroma of 4:4:4, the cable need to be able to sustain 18 Gbps speed. What happen if it fail ? The possibility of not getting any image. The audio part is fine as HDMI can carry any kind of surround format without issue. Normal copper cable is not enough to run high speed. Its like home high speed internet is usually fiber cables are use. This apply as well for HDMI. To achieve high speed requirement for the display, fiber HDMI is the answer to it.

Finally once you have your hardware setup is time to enjoy your movie with some nice popcorn.