4 Ohm Mini Speaker
|Item Number: 14618 SP|
|Gento P/N ZSP99023A |
Mini, 2" , Foam edge, paper cone speaker with 1oz. ferrite magnet.
Imp: 4 ohm
SQ: 2-1/16" T: 1-1/4" WT: .27
||great little driver
|Im a newbie here, I only discovered MPJA because I was looking for more information on this speaker that I bought elsewhere and paid more for. ............
Eyeballing it, there doesnt seem to be anything special about it, nothing that says superior quality or superior design. But heres what I found, and why Im taking the trouble to post a review.
When you push the cone, theres good compliance. I measured SRF at 260 Hz. The Q of the SRF is judging by ear the lowest of any small inexpensive driver Ive tested.
Most drivers fall off like a rock below SRF. This one tapers off much more gently than most, seemingly in defiance of basic physics. .............
Above SRF, frequency response is smooth without any pronounced resonances up to at least 14 kHz, the limit of my hearing. Its particularly strong in the 2.5 - 3.5 kHz range, and a bit weak in the region of 5 kHz like so many other inexpensive speakers. ..................
When it comes to sensitivity, the 90 dB number offered here, I regard as probably conservative. I raced it against several other drivers in the same size range and it equalled or beat them in most frequency ranges, and below 500 Hz or so it kycked their keisters. Most of the other drivers were communications grade speakers, which typically have good efficiency but lousy frequency response including so many resonances that its hard to make sense of the published frequency response graph if any. .....................
I also experimented with front-loading and with providing rear enclosure. It seemed to respond well to almost anything I did to it. ................
The problem Ive got now is to figure out what to do with it. Ive got several extremely divergent driver applications even using one to power a calibration table for accelerometers, but the only app Ive got for good fidelity + efficiency in a compact size is one where Im using a 4 inch speaker with a horn cannibalized from a Radio Shack $40 powerhorn. .................
A couple years ago I got fascinated with line arrays for inexpensive small venue PA, but the fatal flaw in my scheme was that it was designed around inexpensive communications grade drivers. Line arrays require phase coherence and com grade drivers cant deliver. Im no longer in love with line arrays, but the Gento SP99023A driver has smooth enough frequency response that I think it would make a great driver for a slender line array. ...........
||Surprising little speakers
|These units are not well documented but put out quite a lot for their size. They could have better lows, the open air resonant frequency was around 275 Hz, but that is what a woofer is for. As soon as you hold one you will notice the mass of the magnet. For an OEM speaker this is a good hint at the output level. I tested my unit to 10 Watts of sin wave input and it held fairly well. That was it though anymore and you bottom out the suspension. The bottom line for the price these are great little yet loud drivers.|