Frequently Asked Questions or FAQs

Forum and General

Forum FAQs are tips for posting on any of the speaker forums such as Madisound, PartsExpress or AudioAsylum.

Which speakers should I buy?
Which receiver should I buy?
Which subwoofer should I buy?
Which system should I buy?
Which component is my weakest link?

This is where many new recruits begin. We get a lot of questions about comparing speakers, receivers or wanting something that sounds good for set dollar amount. Most audiophiles will contradict the request and direct people toward more expensive equipment. Sometimes forum members will make suggestions only to be challenged by other forum members. These kinds of questions are difficult because audio is really about buying what sounds best to you. There is no perfect system or sound and debating the issue is part of the hobby. This can be confusing to beginners. For better results, phrase your question carefully. We cannot know what sounds best to you, what your budget is or what your room sounds like. You will get better responses with "Please direct me toward some better brands of equipment to audition within X price range". The price range is important. If you are only looking for a part of a system, make sure to list your other components.

Can you give me basic buying advice?
Yes. Make your purchases based on what sounds best to you and is within your budget. Do a lot of research.

What priority should I give to each component?
Everyone will give a different answer to this one, so trust no one. While everything makes a difference to some degree, a speaker upgrade can make the most difference. We suggest putting the most money into speakers, power amp, source, then everything else in that order. A weak link at any point will degrade the whole system.

Why don't I get any answers to my post?
Posts that are too vague, seemingly obvious, or that have been answered many times generally get less response. Make sure you are posting in the right forum. Make sure you are asking a question that needs an answer. Your subject line should lead into the question. Subjects like "I need help", "Speakers", "Comments Please" or "My System" rarely get responses. Also, your question may have been answered recently. Search the archives.

Why do people suggest I "search the archives" when I ask a question?
Many questions are answered several times per month. People get tired of typing in the same answers again and again. A couple of key words in a search will usually bring up a number of answers.

Why I am getting conflicting information on some of my questions?
These are open forums and anyone can post. Many of the forum regulars are quite knowledgeable and helpful. Other people are new or respond thinking they are funny. Some people are passionate about their equipment and will promote only that equipment. Audio is about finding what is best for you and not basing decisions solely on what other people think. Browse the posts and you will see consistently good advice and learn to spot the questionable posts. The best advice is to use your own ears to decide and buy equipment within your price range.

What do LOL, LMAO, IMO, NT, etc., mean?
NT=No Text. It tells the readers all the information is in the subject line and there is no need to open the posting.
LOL=Laughing Out Loud
LMAO=Laughing Harder
ROTFLMAO=Rolling On The Floor Laughing
IMO or IMHO=In My (Humble) Opinion
TIA=Thanks In Advance
OT=Off Topic. It means you are bending the forum rules and posting something that is not audio related. Use with caution.
A complete Internet dictionary cab be found at: ivillage

What does Troll mean?
Troll is a term for someone who writes a post attempting to get a fight started or create controversy.

Why should I register?
The basic benefits of registration are that you can secure your name/moniker. This lets everyone know who you are, reduces the incidence of "too many Bobs" and prevents someone else from using your name on posts. Registration also allows you set your preferences.

Why do some poster's names appear in bold, and other's in grey?
Bold posters have registered. Gray posters have not.

What is everyone's problem with Bose?
Most of the people on this forum consider Bose a waste of time and money. People who post Bose questions here are either trying to "troll" (see above) or are at a level most people don't want to respond to. See the Bose FAQ

What is a sock-puppet/shill/identity hoax?
This is when someone creates a post using someone else's name, usually to create controversy or troll. If caught you will be outcast.

How are moderating decisions made?
When a post falls outside the posting rules, one of the moderators may halt or delete a post. Users generally don't have any say in the matter. This keeps the forum friendly and on topic. If one feels the rules are too restrictive, there are many other less restrictive forums.

What are "White Van" speakers?
Someone stopped me in a parking lot today and tried to sell me speakers. They said they were overstock from a delivery and didn't want to upset the boss by returning them. Was this a good deal?

No, this was not a good deal. This scam has been going on for some time and is still active today. I group of (usually) college age kids stop people in a parking lot and tell them they have some speakers for sale out of the back of their (white) van. They have some story about overstocks, delivery errors or warehouse surplus. The speakers are always very poorly constructed and have a brand name that sounds familiar. Don't buy them under any circumstances. These have also been turning up on ebay a lot lately.

Why is there a hum coming from my speakers?
This is most likely a ground loop. This is caused by something in the system not being properly grounded, usually the TV cable. You can do a quick test by removing the TV cable and see if the hum goes away. If it does, you have a ground loop. If not the cable, then try the other grounded components one by one. Note that the offending component may not be the one that solves the hum when disconnected. There are a number of methods and devices to resolve this. If it is the TV cable, the easiest method is to properly ground the outer part (not the center wire) of the TV cable, preferably as close to outside the house as possible. Many audio shops carry ground isolation devices. Do not solve this by disconnecting the ground from your amplifier or TV plugs.

Do expensive cables and speaker wire really make a difference?
Everything makes a difference. Will you be able to hear the difference? Who knows? The best advice is to spend money on the improvements you personally can hear and are of good value to you. Some investments can make dramatic changes while others are more subtle. Many audiophiles tout dramatic changes with obscure tweaks ("Even my wife heard it!"). Keep in mind psycho-acoustics is in full force here: You will hear it if you believe it. Buying expensive cables for a lousy system may improve the sound, but the same money may have brought greater improvement in other areas. Very generally, look at speakers, room, power amp, source and then everything else in that order. Any seriously weak link in the chain will degrade the whole system. This is a hot topic and no two people will agree on any of this.

Does bi-wiring help?
Some say yes and some say no. From a physics standpoint, bi-wiring will increase the overall gauge of the speaker wire. It may also change the type/amount of distortion the speaker wires pick up along the way. Experiment and see if you can hear a difference. Look at the advanced papers for more theory.

Does bi-amping help?
Some say yes and some say no. Bi-amping will change the type/amount of distortion and the amps will be running at different frequency ranges. The majority of wattage is used in the first couple octaves, so the woofer amp will be working a lot harder than a mid/tweeter amp. If you are using a sub then you are in essence bi-amping your system. Experiment and see if you can hear a difference. Look at the advanced papers for more theory.

Does CAT5 cable make good speaker wire?
Some people think so and there are lots of opinions on this. Key points: Many think the weave of the CAT5 is important, so expect a lot of work and research. The copper in CAT5 is the same as regular speaker wire. If you go by the theory that electrons flow on the surfaces of wire, CAT5 will have less surface area than many common high count speaker wires. If you think the wire coating is important, then you can get high grade coatings in both CAT5 and regular speaker wire. Search the Internet for more information. Experiment and see if you can hear a difference.

What is bass, mid, high?
This is subjective. See the music range chart for a graphic representation.

low bass: 20 Hz - 40 Hz
---mid bass: 40 Hz - 80 Hz
------upper bass: 80 Hz - 160 Hz

low midrange: 160 Hz - 320 Hz
---midrange: 160 Hz - 1,300 Hz
------upper midrange: 650 Hz - 1,300 Hz

Treble: 1,300 Hz - 20,000 Hz
lower treble: 1,300 Hz - 2,600 Hz
---mid treble: 2,600 Hz - 5,000 Hz
------upper mid treble: 5,000 Hz - 10,000 Hz
----------high treble: 10,000 Hz - 20,000 Hz

What is the practical range of human hearing?
20 Hz to 20,000 Hz is considered normal. However, most adults start to lose the ability to hear frequencies above 16,000 Hz. very early in life and the upper range decreases as we get older. A reasonable guess would be that most of us can hear well from about 30 Hz to about 10,000 Hz.

What is speaker efficiency/sensitivity?
Every speaker driver has sensitivity, that is, how well it converts electrical energy into sound energy. Sensitivity and efficiency can be measured a number of ways and are often confused. The three most common numbers tossed about are: Efficiency in a watts-in vs. watts-out formula: Voltage sensitivity as an SPL (loudness) measurement with a mic at one meter and 2.84 volts applied to the driver: Power sensitivity in SPL at 1 watt/1meter. Most woofers and mids are in the 84-89 decibel range. A higher sensitivity woofer would be 90+. Because tweeter dome areas are small and light, the sensitivity of tweeters tends to be higher. That is why most crossovers have an "L" circuit on the tweeter to attenuate (reduce) the output. When you compare finished speakers next to each other (called AB testing) there will be some fluctuation in loudness due to sensitivity of the entire speaker with crossover. It may be too small to notice, but our brains are wired to think louder sounds better. So when AB testing similar speakers, the louder speaker will always sound a little better even if you cannot tell it is louder. Salesmen know this and have been known to move the volume control up slightly on speakers with a better profit margin.

My speakers say "Digital" on them, is this better?
No. All speakers are analog. The word "digital" sounds cool and sells speakers.

My sub shuts down during music and some HT?
If your main speakers are set to "large", your HT will only send data marked as Low Frequency Effects (LFE) to the sub. Since CDs do not have LFE marked data the sub will auto-off for lack of input. Also, if a movie does not have a lot of data marked LFE the sub may shut auto-off. So if your sub is shutting off, try setting your main speakers to "small".

Analog on my HT sounds bad?
Which has the better DAC, HT or DVD?

These two questions have the same answer. Most HT receivers use digital volume and tone controls. The logic is that since the input is most likely digital from the DVD there is no reason to add expense with analog tone and volume control circuitry. So if you use the analog inputs on your HT receiver, the signal will have to be reconverted to digital for the volume control and then back again to analog for the amps. If you are trying the DVD DAC (digital analog converter) you are actually going through the DVD DAC once and the HT DAC twice. This is why the sound can get degraded. Generally, anything coming into the analog side of the HT receiver will sound worse than the digital inputs. There are few exceptions to this.

How do I balance my HT speakers?
Matching HT speakers can dramatically improve the overall HT experience. But matching speakers by ear is very difficult. Radio Shack db meter is an excellent investment and will help balance home theater speakers correctly as well as help integrate sub woofers into your system. Most people prefer the analog version of the RS meter because the needle is easier to read. Place the meter in the seating position with the mic pointed toward the ceiling. Set the meter to 70-80 decibels and the switches to "slow" and "C" weighting. Play white noise through each speaker and balance the speakers so they are all at the same volume level. Note that the RS SPL meter is a great tool but is not very accurate. So don't try to "test" anything like speaker response with it. There is a mod for the unit to increase accuracy: look at the Wallin page. There is also a chart of the most common RS meter variances on the net (could not find it).

How do you match voicing on the center speaker in HT?
The main downside to unmatched voicing is noticing when sounds are carried from left to right on screen. The general rule it to get a center channel that is voiced the same as the left and right main speakers. But center speakers rarely are very close. A center speaker from the same manufacturer as the mains is a good bet but even then the voicing is often not perfect. As long as the voicing is similar, it is OK. Setting the center speaker to "small" helps with matching as does careful positioning, especially if the center is an MTM type.

Do I have to match amp wattage and speaker wattage?
No. Both numbers are vague and have little value or standardization. Speaker wattage ratings have no bearing on how the speakers sound. The watts listed on your speakers are an indication of how much heat the voice coil can take in extreme conditions. 99% of speakers will never reach this level even when played loudly. What kills speakers is when the amp is extended beyond its capabilities and starts clipping. This corrupts the signal to the speakers and overheats the wires in the voice coil, permanently damaging the driver(s). So the more wattage the amp has, the less likely you are to blow your speakers due to clipping, regardless of the speaker wattage listed. At some point playing speakers very loud will also damage other components or your ears.

Is there really such a thing as a tube motherboard?
Yes and we have all seen it a million times. Check the archives. No, nobody cares.

How do you fix a dented dust cap or tweeter?
Method 1: Gently stick some masking tape to it and pull it out.
Method 2: Kiss it like you kissed your first girlfriend.
Method 3: Use a vacuum cleaner and hold your fingers between the pipe and the dust cap so the vacuum never fully engages the cap. Be careful as some vacuums can suck the cap right off. This is very tricky.
Method 4: Buy two new dust caps and carefully glue them on after very carefully cutting the old ones off.
Method 5: On tweeters, order new voice coils from Madisound .
Method 6: Make a tiny pin hole in the dust cap and bend the pin so you can pull the dent out.
Method 7: Pull the driver out of the speaker and blow air into the back vent while holding the cone from moving. The air in will have to exceed the leakage for this to work.

Do marker pens help CDs?
Does freezing CDs help?
Will Armorall help CDs?
Do CD pads help?
Do anti-static compounds help CDs?

CDs are made of plastic with a thin layer of non-ferrous foil stamped with a series of pits into it. The top is covered with a heavy ink to use as artwork and protect the foil. A very low power laser runs along the plastic side of the CD and a lens focuses the laser on the foil. As the CD spins, the pits will either reflect the laser or not. A reader senses the reflections and sends a computer chip a series of ones and zeros depending if there is a reflection or not. These ones and zeros are assembled into words of data. Each set of bit-words the computer reads has a check digit to make sure all the data is there. If not, the computer tells the laser to go back and read the area again. Some CD players have better algorithms to do this than others. At some point if the computer cannot read the disk it will drop the data and try to move on. Cheap CD players may not try to re-read the data at all.

Green markers do not help because the stray light the marker is supposed to eliminate will be so out of focus that the reader would not pick it up anyway. If stray light did affect the data, the check digit would show the data as bad and it would be re-read.

Armorall may help the reader get over scratches but the Armorall will leave a residue on the focussing lens. Armorall may also damage the plastic or the ink/foil bond.

Freezing makes no sense but there seems to be a love of everything cryo these days.

Anti-static pads/fluids may help. There is nothing in the CD that is magnetic but there may be some static electricity on the plastic which could attract dust.

CD pads may help because one real enemy of CD play is if the tracks are not on center with the spindle or the CD is out of balance, causing the tracks to be out of center with the spindle. A pad may reduce an out of balance situation. It may also increase it. The interesting thing is that (I am told) the laser management chip has a output pin that logs the errors. I would think an read-error log on the front of the player would be a great feature.

Speaker Building

I am interested in building my own speakers. How do I get started?
There are hundreds of sites devoted to DIY (Do It Yourself) speaker building. A google search will find many sites. Do a lot of reading before you launch a project. Your best bet for a first time project is to build from a kit or from a set of free plans. This site is a great starting point for kit building and rates many kits and parts: audioDIYcentral or the ldsg
Two of the larger parts suppliers are: Madisound and Partsexpress. Both have DIY forums.

Which is the best testing software?
There are many good packages at different prices starting from free to thousands of dollars. Check the links page for options. The key is that the testing software will not get you to good results. It takes some real knowledge and associated equipment like a mic, mic amp and power amp. Two of the popular low cost packages are Lspcad and SpeakerWorkshop.

Where can I get a testing mike?
The most popular testing mic is the Panasonic W60x available at Digikey (about $3 each). Order extras as they are fragile. You will also need a preamp. AudioXpress sells the Mitey-Mic for about $150, a good investment.

What is the best woofer/tweeter for under $20?
If you are asking this question you probably should be building a kit. There are a lot of driver choices in many price ranges. Keep in mind that some drivers take a lot of crossover knowledge to make a good sounding speaker. A well executed speaker with cheap drivers will sound a lot better than a poorly executed speaker with expensive drivers. A decent tweeter will set you back $18-25 and a decent 6.5" woofer $30-40. Sale and close out drivers add a variable to the mix. Check the driver recommendations page or the LDSG for more information on specific drivers.

What is the best woofer/tweeter cone material?
All cone materials have advantages and disadvantages. The three properties designers look for in cones are light weight, stiffness and lack of coloration/ringing. Exotic materials like Kevlar and magnesium are light and stiff but have ringing problems. Materials like paper, coated paper and poly ring less but can be heavier and not as stiff. It is all about trade offs. There are good drivers and bad drivers made with all cone materials. While there is a lot more to driver construction than just cone material, cone material alone can go a long way toward selling speakers. So sellers use the most exotic names they can. Very generally, the more exotic the cone material the more trouble a beginner will have taming it.

What is ferro fluid and why is it used?
Ferro fluid is an oil based liquid with very finely ground iron granules in it. It is used mostly on tweeters for heat dispersion around the voice coil. It can add some dome damping (lowering the Fs) as well. Mids and woofers generally don't use ferro fluid because the higher cone movement slops the fluid out of the coil gap.

Can I repair an old woofer or tweeter?
Yes. There are repair services listed on the Internet. Some parts supply houses (like PartsExpress) sell repair kits. We suggest having someone else do it.

Can I upgrade the drivers in my old speakers?
This rarely works. Speakers have a set of electrical and mechanical properties which dictate the appropriate box size, crossover and configuration. Your current drivers and crossovers have been tuned for the boxes they are in. If you change a driver, the box and crossovers are no longer appropriate for that matched speaker. There are some known replacement drivers for vintage speakers at the Madisound site.

Can I upgrade the crossovers in my old speakers?
Depends on what you mean by upgrade. If you mean replace the existing components with better quality components of the same values, then yes this may improve the sound. If you mean put different value components into the speaker, then no, it is a down hill trip because you will be changing the overall design of the speaker. If you feel compelled to ignore this advice, then remove the existing stock crossovers and save them in their original state. That way in six months after you are driven crazy by your attempts to improve the speaker, you can put the old crossovers back in.

What materials make the best box - MDF/ply/solid wood?
There are fine speakers made of many different materials or combinations of materials. Every material has some advantages and drawbacks. MDF is the most widely used material for commercial and DIY speakers. Seven-layer void free ply is also used by some DIYers. Wood or wood over MDF tends to crack and is hard to make stiff enough. The goal here is to make a box that does not vibrate or add anything to the sound. The stiffer the better. Good speakers are generally very heavy. Note that there are many grades of MDF. Look for a double ground Birch with greater than 42lbs/cf weight. Home Depot does not carry this.

Can I use other materials like concrete?
Yes, some people have used concrete for speaker boxes. Search the Internet for projects. This is messy.

What is Sonotube and where can I get it?
Sonotube is a round tube contractors use as moulds to make concrete pilings. They are available at most home improvement stores and lumber yards. The wall thickness is only ¼" but because the tube is round there are less vibration issues. Most people who use Sonotube use it for sub woofers.

How do I get a piano black finish on my MDF?
The best way to get a piano black finish is to paint the speakers in the same manner as a car is painted. The seams and raw edges should be coated lightly with bondo and then the cabinets primed repeatedly until you have a good build up that isn't soaking the primer up. You can and should also use automotive paint sealer before painting the final finish to help the bleed through. The painting procedure is exactly the same as a car would be refinished. It's quite a project to do it correctly without good equipment.

What tools do I need to build speakers?
The more the merrier. A good table saw, a plunge router and drill will get you 90% there. Spend an hour dialing in your saws for faster more accurate cutting. The Jasper Jig is very helpful for cutting the speaker holes and flush mounting. You will need a ¼" bit, a flush-trim bit and maybe a 3/8" round-over. A J-roller is needed for pressing veneer to the MFD box. Big clamps are nice.

Which saw blade should I use?
Generally a combo cut blade with 24 or more teeth will cut MDF well. Work to avoid breathing the MDF dust as it is bad for you.

What router bits do I need?
You will need a ¼" bit, a flush-trim bit and maybe a 3/8" round-over for the grille.

What glue should I use?
Standard yellow carpenter glue is best. Some people use gorilla glue but it has some sensitivity to humidity.

How do I veneer?
Follow four basic steps: practice gluing, practice cutting, test the stain, test the finish. Leave the mistakes on the test piece. Most popular is paper backed veneer brushed-on contact cement. Use in a well ventilated area. Paper backed veneer leaves lines at the edges that are a little darker than the stain. Using NBL (No Black Line) veneer will also help but it will add to the cost. Double wood backed veneer is even nicer as it is a lot heavier than paper backed, is easy to work with and covers most faults. Cut veneer oversize and put two coats of contact cement on both pieces. To hide the veneer lines glue: bottom first, then back, sides, front, top. This puts the lines in the least visible spots. Press the veneer on and roll hard with a J-roller to get good contact. Remember once the glue surfaces touch, they are stuck forever. So align carefully. Trim with a wallpaper cutter or veneer saw and finish the edge with sand paper. This is the amateur method. Take a woodworking course if you want to play with the big boys.

How do I finish veneer on my speakers?
Sand with 220 grit for the finish. Stain according to directions on the can of stain. Test first! Be careful with some stain combinations as they will hide grain patterns. Once on it is too late! I have been using Poly finishes with good results. The trick is to use fresh Poly and put it on as thin as you can. I found an artists sponge (or sea sponge) works well. Two very very very thin coats. Did I mention thin? You can add more coats of Poly as desired but I you will gain dust with each coat.

Check out Lou C's veneer tutorial.

How do I flush mount drivers?
Buy a Jasper Jig. It will save you the price of the jig in time and frustration on the first project. Cut the driver recess first, then the hole. Use drill bits sideways (as a thickness measure) to measure the recesses. Leave 1/32 uncut at the bottom of the hole so the router will not slip as you come around to release the center cutout. Then remove the router and punch out the center. The remainder should be thin enough to scrap away. You can get cut dimensions from the driver company's site.

What internal speaker wire should I use?
The short runs in a speaker have little if any impact on the sound quality of the speaker as long as the wire is 14 to 16 gauge and of good quality. Sub woofer wiring should be a minimum of 12 gauge. Silver plated 14 gauge copper wire that Menicus and Northcreek sells for $.45 a foot is good simply because it's very flexible and easy to solder.

What is the best speaker terminal connection? Bare wire/banana/other?
All of the above. The goal is to get a good connection. Any mode that allows a good tight connection is good. If you use bare wire make sure the nuts are tight but not cutting the wire. All other options should have gold plating. Banana plugs should fit tight. Friction terminals with the press buttons are the worst.

Do bypass capacitors work?
Maybe. A bypass cap is a very small value high quality cap people put next to a cheap cap on the crossovers to improve the sound of a speaker. The theory is that good electrons going through the bypass cap are somehow going to clean up the bad electrons going through the cheap cap. Some people swear by them. Our theory is that electrons are pretty stupid and any tweak that requires electrons to have intelligence is faulty to begin with. Try it and see if you can hear the difference. A better bet would be to replace the cheap cap with a good cap. Check the advanced section for more theory on this.

How much should I stuff the speaker and with what?
The recommended ratio is one pound per cubic foot of enclosure volume. The recommended stuffing is either Miraflex or Accustuff but people have been known to use pillow stuffing. Stuffing has the most effect below 100 Hz. Open cell foam is a better damping material above 100 Hz. If the speaker is ported there needs to be a good airflow to the port. Loose stuffing behind the driver is okay. There are a lot of other damping materials and systems. A very good article appeared in Audio Express a few years ago.

Should I use pre-made crossovers?
No. Every driver has electrical and mechanical parameters that dictate the correct crossover components for a given speaker. There is no standard or commonality to these driver parameters. A pre-made crossover is built for a set of fictitious average driver parameters that doesn't really exist. So no matter which pre-made crossover you buy, it will not match your drivers.

Can I mix crossover orders?
We are talking about the electrical parts on your crossover board. Yes, many speakers have mixed order crossovers. Just make sure to test that your tweeter polarity is right. If you don't have measuring equipment, run a sine wave sweep from 4000 Hz to 1000 Hz and listen for a hole in the sound around the crossover point. There is a lot of complexity with "electrical orders" and "acoustic orders". Check the advanced section for more theory.

How do you make grilles?
I make my grills out of ½" MDF from Home Depot. It is cheaper and I don't think we need higher quality for the grill. Order those plastic grill clips from PartsExpress or Madisound. When setting this up make sure you are leaving enough room for the grill clips and the offset tweeter. Cut the grill MDF to the size of the speakers and round off the outer edge with a 3/8 round router bit. Then use the Jasper Jig to cut holes larger than the drivers. Trim the holes to an oblong rectangle with a jigsaw. This is fast and accurate. Then trim the inside with a 45 degree bit. Spray the whole thing black so the wood does not show through the grill cloth. I make a little jig to drill a pilot hole for the grill clips. Then place the grills on the speaker and drill through the pilot hole in to the speaker. Then drill the right size holes in the speaker and grill for the clips.

How do I cut the hole for the port?
Cutting port holes is not a problem. The trick is to glue the port tube into an MDF block with a hole the same OD as the port tube. This block acts as a support for the port so you are not doing a butt joint on the back of the baffle. Then glue the block/port assembly on the back of the baffle with a pilot hole drilled all the way through the baffle randomly in the middle of the port. After the glue is dry, drill a 1" hole in the middle of the port through the pilot hole. Then take a flush bit and bore out the hole to the size of the tube. The flush bit bearing will run along the inside of the tube. Perfect every time.

Other resources: A complete and very detailed audio FAQ can be found in 13 parts at: AudioFAQ -Part1

An extensive resource of audio links can be found at: Steve Ekblad's mega link site

Copyright Peter J Smith 2003, Return to