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!