Purchasing Used Sound Equipment

Buying Sound Equipment Second Hand

Buying sound equipment second hand can be a somewhat daunting endeavour for the unwary. Here is an article that may take some of the stress out of the experience and put you in a position from which you will have a good idea of what to look for, what to test  for and hopefully, what to avoid.

The first thing to remember is that there is no way you can be completely sure that what you are purchasing as used equipment will be completely free of faults or the risk of future failure unless you are fully aware of its history. An example of this would be that as a member of a church group you have been offered a set of loudspeakers following an upgrade. You know for a fact that the speakers concerned have never been thrashed or abused and have been well maintained since their original installation. This must be a good indication that, provided the price is right, you are going to get good value for money. Any equipment that is or has been part of a permanent installation will be free of the rigors that transportation causes. Sound equipment that has been bounced around in the back of a van or a car boot for several years may well have a lot of loose screws or may even have internal components that have actually come loose and caused some damage.

Starting at the microphone end, let’s go through the signal chain item by item and examine the things you may need to look out for prior to parting with your hard earned cash.

Damage to the pop filter i.e.: dinging or indentations are a sure sign the mic has been dropped. Even if it is straight you still can't be totally sure that it has not been because a competent person can do a good job of straightening out a pop filter so you would never know it has taken a wallop. Most brands of good microphones can be dropped a number of times and not suffer any serious damage that will affect the sound quality.

The problem is you have no way of knowing how many times. A Shore SM58 for example can take up to six floor drops before becoming useless. It always pays to listen to a microphone before buying it. At least this way you will know for sure it still sounds alright. Check the input socket and make sure the pins are straight.  Make sure the on off switch is intact and working if it has one and provided the handle is not too badly scratched you cannot do much more than this. As a general guide I would not pay more than half retail for a mic that had no warrantee or known history unless it is clearly in as new condition and shows no sign of having ever been dropped. Always take the filter apart and clean it thoroughly before using it with a toothbrush and soap. You never know where it’s been.


Buying mixers is always difficult unless you are looking at one that is in mint condition and has a very short history. The big problem with mixers is that they hate getting wet. Any mixer that has taken a 'bow wave' as we call it may be as good as useless yet the exterior may look like new. The problem is you may not know this has happened because on the outside it has been well cleansed using a sponge, toothbrush and soapy water. The external evidence of its past disaster has long been cleared away. Taking it apart is the only way you can be really sure it has not taken a serious drenching from a misguided double Bourbon and Coke. Mixers hate getting soaked with water or juice mixed with sugar. It can do terrible damage. Suffice is to say that if this stuff has got into the buzz connectors and or other push button switches you may as well heave it out.

Assuming the mixer you wish to purchase has never had a misadventure with a glass of juice or alcohol there are several things you need to check before committing to buying it. First of all look closely at the condition of the graphics, especially around the slider pots. See if they are badly worn because this kind of wear and tear has a very negative impact on its potential resale value. It may also be an indication of the condition of the pots themselves but you should still turn it on and go through the functions of each channel one by one to be sure everything is working correctly. Mixers are very complex animals and can be expensive to repair as well. If you find some channels that do not go at all, push a jack plug into the insert jack sockets because they made only need some use to work again. Insert jacks are the main reason input modules fail. They go open circuit through a lack of use and are easily cleaned by a few jack plug insertions. Check all the pots for scratchiness. If they crackle they will probably need to be cleaned or even replaced so the cost of doing so should be deducted from the true second-hand value. Scratchy 'rotary pots' are a very good reason not to buy a mixer or a powered mixer because they can be very time consuming to replace and the cost of doing these repairs may easily exceed the value of the product itself. Slide pots may be costly as a component but the labour is fairly cheap as they are very easy to get at and change. Mixers can fail after a long period of use in the sun due to a power supply that overheats. This one is difficult to check unless you can actually use it outside on a hot day. Make sure the meters are all working and check the subgroup outputs as well. A mixers value decreases quickly with age and use. Some brands hold their value better than others. Don’t buy an orphan just because it looks impressive. All that glitters is not gold! Find out if it comes with a flight case and check its condition for road wear as well. If it has an external power supply pay attention to the mains and interconnecting leads and the connectors themselves. If they are really sloppy or worn looking this is a sure sign it has had a lot of touring or general gigging use. Taking the lid off the back and checking the graphics are the two most important things you can do when evaluating a mixer. A mixer that has been idle for a long period in damp conditions such as a domestic garage may have suffered corrosion problems due to a lack of use and poor storage conditions. Be very careful with this one. If it’s filthy do not buy it. Its owner did not give a toss about it.

Power Amplifiers.

Amplifiers are the engine room of the sound system and as such often suffer from a problem known as thermal recycling. This is caused when something that gets very hot and then cooled again many times over.

This is only a problem if the correct running temperature of the amplifier is consistently exceeded. The two main items that suffer are the power transformer and the output transistors.

Check to see if the fan vents are clogged up badly. If they are there is a good chance the amp has been overheating. Check the rack mounting lugs for bending, wear and tear. An old worn power amp is not worth much money. Say one third or less of its original retail value. Make sure both channels work and get a power test done if this is at all possible. Check the on off button and the interface connectors are in working order and not lose or sloppy and make sure the mains lead is safe and legal. Here again the condition of the outside casing is a good indication of how well it has been looked after. A burnt smell can be a good indication of overheating. If it smells burnt don’t buy it.

Loudspeaker Enclosures.

It is very hard to know what condition speakers are in prior to purchase. They may look great but you have absolutely no way of knowing if the voice coils have been fired or badly overheated. This is most unfortunate for the used equipment buyer because you really are sailing blind here. You may be able to pull the speaker out of the baffle to get a good look at the crossover components but you will not be able to do much more than this and even then you will be lucky if the seller allows you to do this check. The problem with voice coils is that even if they are burnt like toast they may still be working fine but then die when you least expect it. I have no advice to offer here other than to rely on your instinct. If you are lucky you will notice a burnt smell.  Speakers can be cooked the first time they are used or go for two or three years without an incident of overdriving. Unless they are completely dismantled there is no way of knowing what condition they are in. It is simply a case of let the buyer beware. Both good and poor quality speakers can be overheated. Make sure you can get replacement parts for whatever brand you buy. If the boxes look worn make sure they are not damaged at the seams or joints. An enclosure may have been dropped many times and it may only be the carpet that is holding the cabinet together. Have a good listen to them and turn them up loud to see if you can hear any rattling in the cabinet or the voice coils. Check that all the internal components are working correctly. Bass, midrange and horns etc. Make sure the entry plate is intact and not falling apart. Find out their age and reputation. Don’t buy them if they have been saturated with water unless they have been cleaned and tested for cone damage. Speakers that have sat in the sun for long periods may also have cone damage due to ultraviolet light exposure. This can harden and fracture the cone surface and the surround especially if it is made of foam rubber. Over excursion is another form of cone damage you may not be aware of.  This is caused by long-term excessive low frequency overdriving. It is often only possible to test for this if you can get your fingers onto the cone itself.  If the cone pops forward or backwards when touched and stays in either position without cantering correctly then it has excursion damage. The only cure for this fault is a full recon. Very expensive!! The speaker may still function but it will not perform up to spec.


Buying items such as graphic equalisers, compressors or reverb units is fairly straight forward providing you have not been lured into buying an item with a known but hidden intermittent fault. The overall appearance is very important as is assessing wear and tear. If it looks worn or tired it will not have much resale value at all unless it has very high credibility as a brand. After checking the graphics go through each feature one at a time and make sure everything works as it should. Leave it running for a few hours and then test it again if you can. If you are buying a very expensive item such as an Eventide multi effects processor or some other exotic high profile piece of studio gear it would make sense to have it checked out by a technician familial with the item concerned. Remember you may have no come back if you buy something for a high price that later turns out to have a concealed fault that you were unaware of at the time of purchase. This is especially so with the Trade me Auction Web site. Be very careful that you are not buying hidden trouble. Lemons often look like oranges.

Bogus Brand Names.

The internet is loaded full of these nowadays. It may look good and it may be dirt cheap but that does not mean you are not pouring your cash down an empty hole. At least with the big names and well known brands you will have a good backup. You know if it goes wrong someone will be there to fix it for you. Even if it was imported by a parallel importer the local agent may still be obligated to back it up because it has an international warrantee. For the total novice the following is a list of brands that have a long term standing in NZ and are well backed or have been on the market for many years through established importers with good credibility.

Microphones: Shure Bros, Sennhieser, AKG, Bruel and Kerr, Audio Technica, Beyer and Crown.

Radio microphones: As above plus, TOA, Db, Audio Technica and Mipro.

Mixers: Powered, unpowered and Dee Jay types:

Yamaha, Allen and Heath, Midas, Crest, Sony, Toa, Ramsa, Soundcraft, Pioneer, Mackie, Yorkville, Vestax, Rane and STK.

Power Amplifiers: QSC, Crest, Crown, Yamaha, Mackie, E and W, Yorkville, Quest, Carver, STK and Lab Gruppen.

Processors: Yamaha, Drawmer, Roland, Eventide, Lexicon, Urie, BSS, Dodd, TC Electronics, Klark Technics and DBX and Rane.

Loudspeakers: Altec Lansing, JBL, RCF, Mackie, Electro voice, B and C, Reinkus Heinz and Yamaha.

High tech Gear: With advancing technology comes complexity and sophistication but also a veritable rat’s nest of things that can malfunction. If you are intending to purchase any high tech item and you wish to be sure of its reliability see if you can take it to the authorised service technician in your region and get him to run through and test all of its various features for you. This is essential if you are going to spend say in excess of $500. This is no different to getting a warrant check done on a car before you purchase it.

A lot of gear is sold because it has a hidden fault that may only show up when you least expect it to and that may well be in the middle of a performance or a recording session. It may be worth paying an hour’s labour to a technician in order to be fairly sure you are getting what you are paying for and not a worthless piece of trash. There is no shortage of unscrupulous people out there who will rip you off without hesitation. If they refuse to let you get an item checked out then that is a good sign they are concealing something from you.

There are other good brands that may not have been given a mention here and we will be only too happy to add these if we have made an oversight or unfair omission.

For any further information on this or other blog topics please call Paul Johansen on Ph: 444 8776


Stage Sound Enterprises

Stage Sound Enterprises Ltd
Unit 4-77 Porana Road, Glenfield, North Shore, New Zealand
Phone: 09 444 8776 Email: [email protected]
Opening Hours: Mon-Fri 9 AM to 6 PM