Wireless microphones
Shure BLX14/P31 Review: The Right Idea With a Cheap Capsule
Quick answer
The BLX14/P31 puts a headworn capsule about an inch from the mouth, which is worth roughly 12 to 18 dB of gain before feedback compared with a lavalier on the same preacher. At $379 it is the cheapest real fix for a church that fights feedback every week.
Buy the BLX14/P31 if your preaching channel is a lavalier that squeals, because moving the capsule from a lapel to the corner of the mouth is the single largest improvement available for under four hundred dollars. Do not buy it expecting the included PGA31 capsule to be the last headset you own, because it is the cheapest component in the box and it is the one that limits the result.
This review is drawn from published specifications, manufacturer figures and the consensus of verified owner reviews, not from testing on this site. The bodypack and receiver here are the same BLX platform reviewed at the BLX24/SM58 review, so this page concentrates on what the headworn capsule changes.
On this page
Why a headset beats a lavalier by so much
It is the inverse square law and nothing else. Level changes by 20 times the log of the distance ratio, so every halving of the mouth to capsule distance returns about 6 dB. A lavalier clipped to a lapel sits 8 to 16 inches from the mouth. A headworn boom sits about 1 inch from the corner of it. That is three to four doublings, which is 18 to 24 dB of raw level, and after allowing for the different capsule sensitivities the practical gain before feedback improvement lands at 12 to 18 dB.
No equaliser returns that. Four narrow parametric cuts, done properly, are worth 6 to 8 dB in total, and a feedback suppressor is worth 3 to 6 dB. The headset beats both combined and it does it without removing anything from the voice. This is why the ranking on lavalier versus headset for preaching is not close, and why the feedback guide starts with placement rather than with EQ.
The second benefit is consistency. A lavalier changes level every time the speaker turns their head, because the capsule is fixed to the chest and the mouth is not. A headworn boom moves with the head, so the level the console sees is steady from the first word to the last, which is what lets a volunteer set a compressor once and leave it alone.
Published specifications
Note the battery line: the bodypack drives a condenser capsule and still returns the same 14 hours as the handheld.
The BLX14/P31 pairs a BLX1 bodypack and a PGA31 cardioid headworn condenser with a 300 foot range and 14 hours of battery life, at a catalog price of $379.
| Specification | Figure |
|---|---|
| Transmitter | BLX1 bodypack |
| Capsule | PGA31 headworn condenser |
| Polar pattern | Cardioid |
| Band | UHF, sold in fixed band letters |
| Operating range | 300 feet, line of sight |
| Battery life | 14 hours, two AA cells |
| Connector | TA4F, so capsules are interchangeable |
| Catalog price | $379.00 |
Figures are Shure’s published specifications for the BLX series and the PGA31 capsule. Nothing here was measured on this site.
The compromise: the capsule is the cheapest part of the package
Shure sells the PGA31 capsule on its own for $54.00. That is what is in this box. The receiver and bodypack account for nearly all of the $379, and the microphone doing the actual work is a fifty dollar part. It is not bad, and it is dramatically better than the lavalier it replaces, but it is thin in the low midrange compared with better headworn capsules, the headband is light plastic that a preacher will eventually sit on, and the windscreen is the first thing to go missing.
The upgrade path is the saving grace, and it is why this system is still the right purchase. The bodypack uses a TA4F connector, so any compatible capsule plugs straight in. A church can buy the BLX14/P31 now and move to the SM35 at $115.00 when the P31 breaks, or to the Countryman E6 directional earset at $511.13 when the preaching channel goes on camera and a visible headband becomes the objection. Both plug into the bodypack you already own.
Plan that replacement into the budget rather than discovering it. A realistic two year cost for this position is the system plus one better capsule, and it is still the cheapest 12 dB in the building.
What owners consistently report
Published owner reviews converge on one observation above all others: churches that switched from a lavalier to this system stopped having a feedback problem. That is the dominant theme and it is reported by small churches and large ones alike. Ease of use is the second theme, since a bodypack with one capsule and one gain setting is about as simple as wireless gets.
The consistent criticisms are all about the capsule and the headband rather than the radio. Owners report the boom losing its shape over time, the headband being uncomfortable for longer services, windscreens disappearing, and a sound that some describe as thin relative to a premium earset. Owners who replaced the capsule while keeping the bodypack report exactly the improvement the price difference would suggest.
Alternatives worth considering instead
Same platform, different capsule, because visibility is the usual objection: the BLX14/CVL lavalier system at $359.00 is the same bodypack and receiver with an omnidirectional lapel capsule. It is the wrong choice acoustically and the right choice when the preacher will not wear a headset, and being honest about that trade is better than selling a headset nobody puts on.
Step-up alternative, because a cardioid headworn on a digital link is the most stable thing available: the Sennheiser EW-D ME3 headset set at $669.86 combines a directional headworn capsule with a 56 MHz digital system and no gain to set wrong.
Capsule only, because you may already own the bodypack: the PGA31 capsule at $54.00 converts an existing BLX lavalier system to headworn for the price of a cable. If your church already has a BLX14/CVL, buy this before buying anything else on this page.
Who should buy it, and who should not
Buy it if your preaching channel feeds back, if your room is live and hard surfaced, or if the pastor moves around the platform. Buy it if you are equipping a first wireless preaching position from nothing, because starting at the capsule position that works is cheaper than starting at a lapel and buying the headset anyway a year later.
Do not buy it for a pastor who has already refused to wear a headset, because an unused microphone helps nobody. Do not buy it as a worship vocal microphone: a headworn condenser in front of a band is a different and harder problem, covered at the worship leader microphone page. The full field is in wireless headset microphones for churches.
Sources
- Shure published specification sheet and user guide for the BLX wireless series
- Shure published specifications for the PGA31, SM35 and CVL capsules and the TA4F connector
- Inverse square law and the 6.02 dB per doubling figure, standard acoustics
- Consensus of verified owner reviews published on major retailer listings
Frequently asked questions
How much feedback margin does a headset really gain over a lavalier?
Twelve to eighteen decibels in practice. The raw distance maths gives more, since going from 16 inches to 1 inch is four doublings and 24 dB, but capsule sensitivity and pattern differences give some back. Either way it exceeds what four parametric cuts and a feedback suppressor can return combined, which is why it is the first change to make.
Can I use a better capsule with the BLX bodypack?
Yes, and you should plan to. The BLX1 bodypack uses a TA4F connector, so the SM35 performance headset, the Countryman E6 earset and the CVL lavalier all plug straight in. Buying a replacement capsule is far cheaper than a new system, and the capsule is the part that wears out first on a headworn microphone.
Does the P31 capsule need phantom power?
No. The condenser element is powered by the bodypack transmitter from its own AA cells, which is why battery life is quoted at the same 14 hours as the handheld. You do not enable phantom power on the console channel for a wireless receiver, and doing so accomplishes nothing because the receiver output is already line level.
Is a cardioid headset better than an omnidirectional one?
For a church, yes. An omnidirectional headworn capsule picks up the room and the loudspeakers equally in all directions, which gives back some of the margin the close placement earned. A cardioid rejects what is behind it, which in a preaching position is the platform and often a monitor. The trade is that a cardioid is more sensitive to exact boom placement.
Will a headset solve feedback if my speakers are badly placed?
It will help a great deal and it will not fix bad aim. If the mains are behind the preaching position or firing at the platform, you are feeding the loop no matter what the capsule is. Fix the loudspeaker aim first where you can, then add the headset, and expect the two together to transform a room that neither would fix alone.
Researched, not professional advice. This page is compiled from published manufacturer specifications, operator manuals, FCC rules, published standards and owner-review consensus, not hands-on testing. Sound system design, rigging loudspeakers overhead, and any electrical work are jobs for a qualified professional: have flown loudspeakers and their attachment points signed off by a structural engineer or a certified rigger, and have all wiring done by a licensed electrician to your local code. Wireless microphone rules change, so confirm the current FCC position before buying. As an Amazon Associate we earn from qualifying purchases.