XMA3 Frequently Asked Questions (FAQ) - Part I
It's a bit long SORRY but, we've been getting a lot of good questions and wanted to make sure that everybody was well informed so here goes...
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XMA3 Frequently Asked Questions (FAQ)
1. What does XMA3 mean?
XMA3 is an abbreviation for crossfeed mixer amplifier – three inputs.
2. So what does it do?
The XMA3 is a headphone amplifier that can mix together one stereo and up to two mono sources. It was designed to allow motorcyclists to listen to a stereo music source and monitor up to two other audio sources at the same time (like a radar detector and cell phone ringer, GPS, etc.) Unlike some other offerings in this arena, the XMA3 was designed and built for audiophile sound quality. It is, quite simply, the best sounding headphone mixer-amplifier available on the market. At any price.
3. What do you mean when you say 'Audiophile Quality' and what determines that the XMA3 is audiophile quality?
By 'audiophile quality' we mean a frequency response that is flat within +/- 0.5dB across the entire human hearing range (20Hz – 20kHz), noise below audible threshold even to the quiet-adapted ear, and distortion below 0.01% at rated power. The XMA3 handily exceeds all of these requirements and the proof is available from testing it with such programs as RMAA 5.1.
4. Does it really make a difference how good it sounds on a motorcycle?
Truthfully, probably not - but, then again it all depends on what you are listening to, it's sound quality and what you have for headphones. However, the XMA3 could be used in less noisy locations – like while jogging, riding a bicycle, watching a movie on your portable DVD player while on a plane or playing MechWarrior on your PC – and in those cases it will really shine. It really is a good amplifier and we feel it will hold its own against dedicated headphone amplifiers that cost over twice as much.
5. What is crossfeed?
Basically, crossfeed lets headphones mimic speakers. It does this by blending and delaying the signal from each channel into the other below a set frequency (1.6kHz). This duplicates the way the ears hear sounds normally – such as when you listen to speakers, the sound from the right channel does not exclusively go to your right ear, but it pretty much does when you listen to headphones. This produces a “super-stereo” effect that is exciting at first, but fatiguing to most people over longer periods of time – Some can not even stand the feeling that the sound is coming from inside of one's head that listening to the super-stereo effect causes, so crossfeed is a real blessing!
6. If crossfeed is so great, why is there a switch to turn it off?
Good question – we wondered that, too, every time someone asked us to put a bypass switch in, but we put on in anyway. However, if you are a purist, and don't like crossfeed for whatever reason, or you want to use the XMA3 to act as a mixer for a larger amplifier connected to speakers, then being able to bypass the crossfeed network is not such a bad thing.
7. How do I use the XMA3?
Connect your stereo music source to the stereo input using a standard mini-plug male to male patchcord and make sure the volume is set on the low end – remember, the XMA3 is an amplifier, and boy does it ever do just that! Connect any additional mono (or stereo) sources to the remaining mono inputs using either stereo or mono patchcords. Set the volume of those sources as well. Headphones or helmet speakers plug into the stereo output jack. Turn on each source device then turn on the XMA3 to prevent any “turn-on thump” from rattling your skull. Turn on Crossfeed if you want by pressing the pushbutton in. Crossfeed is a very subtle effect that may be hard to notice at first but it proves its merit after extended listening through headphones.
8. What type of battery does the XMA3 battery powered unit use and how long will it last?
Any 9V battery (NEDA 1604) can be used and only one is required. The battery life will depend on the type of battery (lithium is longest, NiCd rechargeable is shortest) and its state of charge, of course. A premium alkaline chemistry battery (e.g. - a Duracell) will deliver an average of 24 hours use at maximum undistorted volume into 64 ohm headphones.
9. How does the bike powered version of the XMA3 get powered?
The bike powered version of the XMA3 uses a standard cigarette lighter plug to standard “barrel” plug (aka – 5.5mm OD x 2.1mm ID coaxial plug) for power. The jack on the XMA3 is polarity-insensitive so it doesn't matter whether the inside or the outside of the barrel is positive. The XMA3 can also be powered from a “wall wart” DC power supply as long as it puts out between 10 and 16V at 200mA. It is very important that the XMA3 not be subjected to too high of a power supply voltage or it will be damaged in a warranty-invalidating way. Various other connection methods are possible (as long as they terminate into a 2.1mm coaxial plug) such as SAE 2 connectors (like used on some heated vests), inline taps, spade lugs, and many other potentially destructive means of leaching off of your bike's electrical system! Finally, if you have a BMW motorcycle, there are various manufacturers of adaptors for the standard cigarette lighter plug to BMW accessory socket plug.
10. Do you offer a version of the XMA3 that can switch back and forth between being battery and bike powered?
Not at this time, but an adapter module is part of the current product roadmap and most likely will be available in the future.
11. Is the bike powered XMA3 going to have noise problems if other sound sources are also powered by the bike?
No. That's an all-encompassing statement, but it's true. The bike powered version of the XMA3 uses a small DC-to-DC converter that absolutely stops ground loops from occurring.
12. Is the XMA3 waterproof or water resistant?
The XMA3 is as water resistant as anything with holes in it can be (the jacks, of course). In other words, not really. However, neither are any of your source devices, we bet (excepting of course your marine GPS units; some of which are quite waterproof). That said, the unit isn't likely to immediately keel over if it gets wet, but leaving it outside, especially if you live near the ocean, will destroy it just as surely as anything else made of metal and/or electronic in nature. If the XMA3 is rained on or splashed with water, it should be allowed to thoroughly dry out before using it again. Even still, you may have started it down the long road to Shortsville. If you send the unit back to us (within a year, of course) because it quit working and you want it fixed under warranty, and when we open it up we see little chemical “whiskers” growing off of everything inside, well, you can pretty much bet that the repairs in necessary won’t be covered under a warranty claim – sorry!
13. How big is the XMA3?
The dimensions of the XMA3 are approximately 1.1” H x 2.5” W x 3.5” D.
14. What is the XMA3’s enclosure made of?
The XMA3 is housed in a black-anodized extruded aluminum case made by Lansing Enclosures. We feel that this enclosure is the most durable and appropriate given the harsh conditions that exist on a motorcycle. Battery compartments are made from impact-resistant polycarbonate.
15. Can I use my XMA3 with my existing Intercom system?
Maybe. The best results will be obtained by routing the headphone output of the intercom into a mono input on the XMA3. If your intercom system uses a proprietary connector that won't let you separate out the microphone and headphone lines, then you'll either have to connect the output of the XMA3 to the stereo input on the intercom – still giving you the benefit of additional inputs and crossfeed for the music but probably with a loss of sound quality and volume – or wait for us to make a breakout cord for your particular brand of intercom – this offering is currently under development and should be available in the very near future.
16. Why doesn’t the XMA3 have a volume knob?
The short answer is that it isn't necessary. The longer answer is that whatever added convenience one might get from having a volume knob would be more than offset by the amount of panel space required for one. Finally, volume controls of a quality level equal to the XMA3’s other internal components cost about $25 in quantities of 100, and that is a bit too pricey, we feel.
17. How do I adjust the volume on my XMA3 when there isn’t a volume knob?
You set the volume on your source devices – which you would have to do anyway, so there's no big deal involved there. The volume control most likely to be fiddled with is the music source's, and if it isn't placed in a handy location, then you already made the decision to not worry about changing the volume, right?
18. Can I plug two stereo or mono sources into the one stereo input on the XMA3 using a standard 'Y' cord?
No, unfortunately not. 'Y'-cords are meant to connect one output to two inputs, not two outputs to one input. Connecting two outputs together, even if one of the devices is turned off, could result in damage to one or both devices. As a side note, we currently have under development a multi-input switch-box module that will allow the user to have two sources plugged into a single input on the XMA3. The module will allow the user to switch between the two inputs; it will not mix the two sources.
19. How loud does the XMA3 sound?
The non-technical answer: about 3x louder. More technically speaking, the XMA3's gain is fixed at 15dB. If your source device could manage 90dB from your headphones, the XMA3 will deliver up to 105dB. That's loud.
20. Can the XMA3 get loud enough to damage my hearing?
Yes, the XMA3 is easily capable of generating sound pressure levels loud enough to cause temporary or permanent hearing loss. This is why we recommend earplug-type headphones like the Etymotic's – they block out the already loud environment of the motorcycle so that you don't have to crank the tunes up even louder to compete! Given this fact, the use of the XMA3 is at your own risk and Tesseract Mobile Electronics, LLC. accepts NO responsibility for any resulting hearing loss or impairment that results from said use.
21. Can you translate the dB crap into non-techno babble English, please?
While this is not strictly XMA3 related, it does seem that much confusion surrounds the mysterious decibel, dB. Basically, the decibel is the smallest difference in volume that the human ear can perceive. A 10dB increase in volume, then, is perceived as a doubling in loudness, but it takes 10x as much power to do so! Doubling the power only results in a 50% increase in volume. This sounds oppressive – what's an amp to do? – but, it also means that differences in power of 25% or less are meaningless. Trying to decide if that home theater system with 60W/channel is worth more than the one with 50W/channel? Don't base your decision on the wattage because you won't be able to tell the difference in loudness (only a 0.79dB increase in going from 50 to 60 watts).
