Lowyat.NET: Latest topics by kevinlim001

AV Basic 101

kevinlim001 — Fri, 23 Oct 2020 11:19:05 +0800

Some information I had compiled to share with those who is new to audio visual world. I will share information about speakers, cables, connectors, av receiver, amplifier etc etc.

1.0 Speakers
1.1 Types of Speakers
1.1.1 Active Speaker - Also known as powered speaker where there are build in amplifier within the speaker cabinet itself. Its easily recognized as this type of system comes with power cord. Most of the PC speakers system are active speakers. Popular among newbies as you will get close to perfect audio output with proper pairing of amplifier and drivers done directly by manufacturer.

1.1.2 Passive Speaker - Speakers that required external device (amplifier) to power them. This type of speaker open up more possibility in trying and upgrading. This is like a DSLR with interchangeable lens. When you change the lens (speaker) it give you different output, or you take the same lens (speaker) to another camera body (amplifier), it give you another kind of feel. Popular among old timer with experience in audio field.

1.1.3 Hybrid Speaker - Combination of passive and active speaker within the same cabinet. Rare but brand like Definitive Technology produce such speakers. Binding post for passive connection with LFE input for powered sub.

1.2 Speakers Parts

1.3 Speakers Spec
1.3.1 Frequency Response - Human audible frequency range is between 20hz to 20khz. A proper audio setup is trying to mimic what we can hear and often divide the range into 3 groups from low (bass), mid (vocal) and high (treble). Ideally, a proper speaker design should be capable to produce frequency between 20hz to 20khz (or try to get close to it) without any dip in volume in any frequency level. However, in reality, we often will observe dip in low frequency where the normal drive isn't capable to drive low frequency loud (due to the power demand, due to physical size, etc etc). Hence, subwoofer comes into picture to cover the low frequency.

There are cases where some speaker flag themselves with frequency response >20khz and classified themselves "hi definition speaker". Well, most probably you cant hear the high frequency with your ear but manufacturer claims that this help on high frequency positioning. Similarly some subwoofer can dive below 20hz, you may not be able to hear it but you will certainly feel the vibration from these low frequency if you are sitting close enough.
In speaker spec, the wider the frequency range, the better/fuller the speaker will sound. Professional speaker manufacturer often will share their frequency response graph. db vs frequency response graph. This graph is useful to tell how good the speaker perform in all frequency range. If you see a dip in the graph, most likely you will experience muddiness when your music is being play at that frequency. Similarly, if you see peak in the graph, you will experience that part of frequency is brighter as compare to other frequency. Understanding of frequency response graph will allows you to compare different types of speakers and see how well they perform against one another.

1.3.2 Nominal Impendence - the resistance of the speaker. Often goes from 2 ohm, 4 ohm, 6 ohm to 8 ohm. The higher the number the more resistance and required more power to drive this speakers. You can imagine 2 ohm speakers is like a car carrying 2 person and 8ohm speaker carrying 8 person in the same car. Will impendence affect the sound quality? Unlikely, its mode to the design of the speaker. In general, we wont says 8ohm will sound better than 4 ohm or like wise.
Understanding impendence is important because you need to know if your amplifier is capable in driving your speakers. If you have a 4ohm capable amplifier and you have 8ohm speakers, your amplifier may work extra hard to drive the speaker to your listening volume. Modern amplifer/avr often capable wide range of speaker impendence. However, understanding impendence will help you to read and understand amplifier power output rating. These amplifier often advertise themself with the highest output while connecting to their lowest supported impendence speaker output. If an amplifier advertise the capability to deliver 125w to 6ohm but if you are having a 8ohm speaker connected, you will only get 95w for your speaker.

1.3.3 Recommended Power - the required power to drive the speaker. Normally its a range between 20W to 300W. Normally determined by the speaker sensitivity and driver size. Bigger the driver, the more power it required.
Underpower - small amplifier driving big speaker. If you are playing high high volume (most likely you will because the amp is need to push hard to drive the speaker), the amplifier will lose it efficiencies, and clipped signal will be send to speaker and can cause irreversible damage to speaker (tweeter normally will go first).
Overpower - big amplifier driving small speaker. Although this often is the ideal case but playing it too hot will damage your driver coil.

1.3.4 Finishing - this contribute to the look of the speaker and play minimal effect to the sound of the speaker. Entry level speakers often made from compressed mdf board for its cabinet. Expensive speaker use solid wood and some uses rare wood for their cabinet finishing. Often, the sound that we hear from the speaker is not 100% coming from the driver itself but also the resonance within the speaker cabinet itself. That's why the same driver if its being place on a bookshelf cabinet will sound different if the driver are being installed on a floorstand speaker.

1.3.5 Sensitivity - This is a reference value provided by manufacturer to tell you how easy the speaker can be driven. Normally its being measure in dB. The higher the number the easily it can be driven. Speakers are given same power and being SPL output being measure at the same distance to give this reference value.

1.4 Speakers Terminal
This is where you will connect your speaker wire. There are 2 types of common terminal.

The right terminal is the spring clip and the right terminal is the binding post.
1.4.1 Spring clip is often found in entry level speaker with limited option of connector available. Will discuss this is speaker cable chapter.

1.4.2 Binding post is often provided with higher ends speaker that support more speaker cables connectors.

Some high end speakers often come with more than 1 set of terminal.

This kind of speakers terminal will allow you to do bi-amp/bridge connection. Split the terminal to drive high frequency and low frequency to maximize your speaker potential.
Take note the polarity - red vs black. Mixing up the polarity will cause your driver to be push in a different way causing very thin sound and you will feel the lack of bass.

1.5 Cabinet Design
1.5.1 Sealed Cabinet - Sealed cabinet design doesn't have air vent / port in the cabinet of the speaker. This kind of design will allow more flexibility in the placing of speaker. Also, you will expect tighter low frequency with better control of the driver.

1.5.2 Ported Cabinet - Ported cabinet design will have 1 or more air vent / port for air to be push out from the cabinet generated by the movement of your driver. You need to be careful where you are going to place speaker with ports. The ports shouldnt be blocked by your external furniture. Thus, its not recommended for ported speaker to be placed close to wall (for rear port design) or being place in an enclosed cabinet. Speaker with ported cabinet design often will provide wider frequency response compare to sealed cabinet design.

1.6 Speakers Layout
How many speakers i need to buy? the more the better?
1.6.1 Stereo HiFi - If you are serious in music only experience, the basic setup would be Stereo (2 speakers left and right). You can also extend it to 2.1 (2 bookshelf or floorstand speakers + 1 subwoofer) OR 2.2 (2 bookshelf or floorstand speakers + 2 subwoofers). Normally, we wont setup more than 2 speakers for our main system, as anything more than that is going to be complicated having the frequency response interfering one and another causing peak/null for some frequency range.

1.6.2 Home theater - 5.1? 7.2.4? What does the number stand for?
X.Y.Z
X stands for number of speakers that you have for traditional surround effect for your movie listening. Conversation, music, sound effect will be played from these speakers. Each speakers will have their role to play in a surround system.
Y stands for number of low frequency capable sub woofer. This gives the impact to your movies on action movies - gun firing scene/explosive scene.
Z stands for number of speakers that you have setup for sound effect that comes from the top of your main listening position. This is relatively new format only being introduced for object based surround technology (Atmos / DTS:X)
If you are starting on a budget for home theater, you can start with configuration below by sequence:
1) AV Receiver + 1 pair of bookshelf/surround speakers (bookshelf normally more expensive and have better frequency response compare to surround speaker)
2) Center
3) Mains/Fronts (can be a floorstand and demote your existing bookshelf to make it your surround)
4) Surround back / height / Atmos speaker
After step 1 the sequence is interchangeable and if you pay enough attention here, i may have left-out subwoofer. I do not have a recommendation on when you should be buying your subwoofer. It can as early as step 2 and it can be as late as step 3 or even after step 4. Its up to you to decide, if you think low frequency is more important than center, you can push back center after you have your subwoofer. Put more weightage of budget over critical speakers like center / fronts / subwoofer where most of the sound will be focused on. For tonal balance, you are encourage to use the speaker from the same brand if not same model family. Tonal balance is important for surround, esp. when you are experiencing a Ferrari being drive from left to right on your screen and your sound that you hear is different when the sound span from your left to center then to right again. The selection of AV receiver is important when it comes to the number of speakers you plan to install along your upgrade path.

Speaker Cables / Interconnect

kevinlim001 — Thu, 22 Oct 2020 16:12:36 +0800

The audio cable debate has also generated a number of myths that have continued to circulate through the years. To clear up some of the misconceptions, we’ve compiled a list of myths and truths to help you make the best decision possible when sorting through the great audio cable debate.

Myth: Audio cables have no effect on the performance of your system

Truth: Low quality speaker and line-level component connections can be susceptible to different forms of interference and other signal degradation, which has been proven to add noise and affect audio signal quality. Replacing it with properly shielded, high quality cables lets your system perform to its full potential.

Myth: Rare Materials and prohibitively expensive engineering techniques are required to make premium audio cables

Truth: If cables are rigorously engineered with proven design principles and high quality materials, you can achieve the same level of performance at a fraction of the cost of the mega-expensive cables.

Myth: Exotic braiding of audio cables enhances performance

Truth: Many cable manufacturers use twisted conductors in their cable to reduce crosstalk and interference noise, but there is no solid evidence to support the claim that intricately braided wires within a cable improve performance. The purity of the cable’s conductive materials and its ability to reject interference have a much more profound effect on performance

Myth: Break-in of cables is necessary for optimal performance

Truth: This myth is much more subjective as many people claim there are perceptible improvements in sound quality after speaker and audio cables have had time to “break-in” over the first hundred hours or more. Even so, there is no scientific evidence to support an improvement in sound quality and certainly it’s not worth paying for break-in as an added service or feature.

In their view, these are the recipes in making a good cable
> Dielectric shielding for insulation, noise rejection and signal purity
> Precision metal stranding of cable wires to maximize strength and ductility
> Oxygen free 99.99% copper for high dynamic range and pristine signal transfer
> Ultra high bandwidth and ultra-low capacitance
> Highest quality materials for secure connection and long life

Source: SVS Blog

Feel free to discuss and share your experience on the cable that you are using and how you feel about the differences.

WTS Samsung Note 9 (used)

kevinlim001 — Tue, 27 Aug 2019 13:28:14 +0800

Item(s): Samsung Galaxy Note 9

Package includes: Phone, Charger & Screen Protector (applied)

Price: RM1,850

Warranty: 1 year by Senheng. Samsung warranty ended.

Dealing method: COD / Postage (Postage at buyer risk)

Location: Senai/JB, Johor

Contact method/details: Whatsapp WhatsappMe
---

Item(s) conditions: Used

Picture:

Reason for sale: Upgraded

Minor paint chip off at the bottom of the unit. Unit works great 100% functional no defect or screen crack. Battery easily last over a day under normal usage.

Unifi

kevinlim001 — Fri, 02 Aug 2019 08:21:54 +0800

Peluang apa? Bawang apa kali ini

Malaysia Weather Information History

kevinlim001 — Mon, 08 Jul 2019 14:24:58 +0800

Anyone know where i can download the information (temperature, rainfall, wind speed) for malaysia? I would weekly/monthly data up to a year.

SACD DSD Audio

kevinlim001 — Mon, 07 Jan 2019 10:05:29 +0800

Any expert here are into these realm? SACD / DVD Audio?

Mind to share your setup (hifi/pc) and recommendation of CD that you may want to recommend?

I am new to this and i would like to hear from you guys. Hope you guys tak kedekut knowledge

WTA: Brake Pedal Boot Replacement

kevinlim001 — Thu, 08 Mar 2018 14:18:47 +0800

Guys, i have some issue with my brake pedal where the squeezy sound (like the spring without grease) is generated every time i step my brake pedal. I have do some visual inspection and found it could be the brake pedal boot which has worn out.

Any of you have face the same issue before, mind to share your experience on the cost of replacement ?

I am driving a 10 years old proton LMST.

Car Spare Parts Availability

kevinlim001 — Tue, 13 Feb 2018 11:40:25 +0800

LY Car Owners,

Do you use back original spare parts for your aging car? Do you face difficulties to get spare part as your car aged. I am having difficulties to find original parts for my 10 years old saga. So i am creating this thread to see how the things like for other brand.

Feel free to discuss.

Bathroom Renovation

kevinlim001 — Tue, 12 Dec 2017 08:39:03 +0800

Dear Shifu,

I am thinking to upgrade my existing bathroom instant heater to storage heater for better water pressure and heating capability.

Consider the photo of my existing setup.

I would like to know the estimation for the cost to hack the tile to adopt hot water piping and the price of a storage water heater.

Anything that i need to be caution with storage water heater? Does waiting time required for the water storage to cook the water?

[WTS]G-Shock GA-100 series

kevinlim001 — Tue, 11 Oct 2016 21:02:14 +0800

Item(s): Casio G-Shock GA-100

Package includes: The Malaysia Warranty Case, the case and the manual.

Price: RM450

Warranty: 1 year. Malaysia wide let me know your location i will let you know the nearest place for you to claim warranty if anything happened.

Dealing method: Postage

Location: Johor

Contact method/details: PM me to check the item availability
---

Item(s) conditions: brand new

Picture:
[attachmentid=7741713]
[attachmentid=7741721][attachmentid=7741722]
Reason for sale: Trader

Note: WHY BUY FROM US?
1) We are one of the biggest watch retailer in Malaysia. More than 60 branches available in Malaysia including Sabah and Sarawak. Do not bother to send back your watch to me, just walk to the nearest store of ours. We reduce the risk to minimum.
2) Guarantee original unit. I will pay you back double from what you had pay me for any counterfeited unit you buy from me.

[WTS] Casio Couple G-Shock & Baby-G

kevinlim001 — Tue, 11 Oct 2016 20:45:07 +0800

Item(s): Casio G-Shock GA-110TP-7A & Casio Baby-G BA-110TP-7A

Package includes: The Malaysia Warranty Case, the case and the manual.

Price: RM1200

Warranty: 1 year. Malaysia wide let me know your location i will let you know the nearest place for you to claim warranty if anything happened.

Dealing method: Postage (+RM6 for West Malaysia +RM15 for East Malaysia)

Location: Johor

Contact method/details: PM me to check the item availability
---

Item(s) conditions: brand new

Picture:
[attachmentid=7741637]
Reason for sale: Trader

Note: WHY BUY FROM US?
1) We are one of the biggest watch retailer in Malaysia. More than 60 branches available in Malaysia including Sabah and Sarawak. Do not bother to send back your watch to me, just walk to the nearest store of ours. We reduce the risk to minimum.
2) Guarantee original unit. I will pay you back double from what you had pay me for any counterfeited unit you buy from me.

Gadgets to buy from Japan

kevinlim001 — Thu, 05 Mar 2015 13:18:28 +0800

Guys, i am might be traveling to japan soon. Can you guys suggest some gadgets (appliances, watches, tablet) that can be get from Japan with lower price or Only can get from japan?

New Topics And Latest Forum Activities

kevinlim001 — Tue, 27 Nov 2012 11:17:58 +0800

Come lets poll and let the admin know about the result

Query Improvement

kevinlim001 — Mon, 12 Nov 2012 10:29:09 +0800

Hi Guys,

I have a short query here, do you guys think if there is a possibility to improve on this query to reduce IO or execution time?

CODE

select top 1 b.FailureCode from tblTest a inner join tblTestDetail b on a.ID = b.TestID where b.ispass = 0 order by b.ID desc

Thanks!

Insurance Claim

kevinlim001 — Wed, 16 Nov 2011 15:29:38 +0800

Dear Mentors,

my sis's 2 months saga had involved in a serious incident but she was in fault. The front part of the saga was several but the engine part is intact. Gear box need to change. The car who hit her was a viva which suffer even more serious problem, the viva owner will claim our insurance since my sis is the fault party. She was informed that if the total loss is 80% of the insure value, she will have to claim total loss. Below are my questions if you guys able to help to answer.

1. for the 80% does it cover our own claim only or both claim (saga n viva)?
2. If lets say we claim total loss, how much are able to retrieve back? is it the full insured value or is the full insured value - claim of viva.
3. how about the bank loan? if we claim total loss we need to get the money and pay back to bank?

Any experience mentor able to guide me on this?

Thank you.

Song Title & Artist

kevinlim001 — Mon, 05 Sep 2011 16:27:08 +0800

Guys any1 can help to identify this song? it sounds something like below

do do do do do do you get my call.. do you ....

I heard ppl use it as caller ring tone and i heard from 1 of the local FM as well.. Help appreciated. Thank you.

Its from a male singer..

Sound Card

kevinlim001 — Mon, 04 Jul 2011 11:22:16 +0800

Hi Gurus,

As per title, i would like to know the variety of sound card for my desktop.
My Mobo : Asus P7P55D-E Pro
My Speakers : Edifier C3

I would like to have steep improvement in my sound system but i dunno where to start. I am looking for a sound card within the Range of 200~300. Of course you can recommend me something higher but i will have to look under second hand trade then.

Thank you.

Hardisk Troubleshoot

kevinlim001 — Sat, 08 Jan 2011 10:49:05 +0800

Hi Shifoo,

I had attached the HD Tune result for my WD Black 1TB hardisk. I heard random noise from the hardisk like tok tok tok during heavy load. And every time the noise come the result will drop signification, Is it normal our my HD is faulty? Any 1 can help me on this?

My Rig:
Intel Core I5 760
Asus P7P55DE-PRO
Asus GTX460GX
Corsair 1600 2GB X 2

Phottix Battery Grip

kevinlim001 — Sun, 25 Jul 2010 10:59:56 +0800

Hi Gurus,

I have a photottix battery grip for my D60. I notice there is a button beside the charging lamp. Can anyone tell me what the button for? How to use it?

I try to press the button but seems like no effect at all.

Thank you

PHP Selection Dialog

kevinlim001 — Fri, 04 Dec 2009 11:39:57 +0800

Hi Gurus,

I need to create a dialog that loop data from my database that allow me to select a value and insert back into my php form. Any tutorial that can help me ? or any sample source that can help me on this?