Nice old school beta's..........
Best sub I have ever heard, especially for the price they were new. At least someone knows what they are! I keep meaning to look up that guy who said they were one of the most impressive drivers ever made, but then I don't because I am lazy.
Richard Clark review:
"Description: This big woofer is very sturdy in construction. It has a very stiff polypropylene cone coupled to its cast aluminum frame by a heavy butyl-rubber surround and two conventional spiders. It has male spade terminals for connections to your amplifier. The volume of the sealed enclosure included with the woofer is 1.5 cubic feet. Eight countersunk holes are evenly spaced around the outside edge of the basket.
Subjective: Yes, even in its relatively small box it is a big speaker, and yes, on loud rock or boom music it did have limits, but, overall, this is the best-sounding woofer I have ever heard in a car. I know such a statement can get me in a world of trouble and something could come along tomorrow and change my mind, but I seriously doubt it. If you have room for a 15-inch speaker and honestly want something besides just noise and boom, take some good advice, give this one a listen before you buy anything. Make sure it is in a similar size box and in a car, not a store showroom. The design of this speaker/box combo might not be so impressive outside a car. Also make sure the rest of the system is top notch. This might not be so easy but if you visit a few sound-offs you are sure to find this creature in a good car sooner or later.
A word of warning about the sound of this speaker. If you like classical music and don't have the money to buy this thing, don't dare give it a listen. After hearing it I would beg, borrow, or steal to have it. The first thing I listened to was Olympic fanfare from the CD Center Stage, Wilson Audio WCD-8824. I have never heard drums this good in a car. The bass was clean, clear, and well defined. The speaker seemed to have no limitations. The sound quality was so good on classical music (which I consider the ultimate test of any speaker) that I felt sort of strange listening to anything else on it. I eventually did listen to other types of music on it and found it to excel with all of them, either equaling or bettering anything else I have heard.
Objective: This system exhibited a near perfect execution because its design takes the effect of the car on the speaker into account. When reproducing frequencies below resonance, any sealed speaker will exhibit flat response below where one-half the reproduced wavelength is larger than the car. This is because the air in front of the speaker behaves like a linear spring and offsets the air trapped inside the speaker box. Forces acting on both sides of the cone affecting movement are equal but opposite. This holds true as long as the car is sealed and the excursion limits of the speaker are not exceeded. If the system resonance is close to the frequency where this starts to happen the results can be very impressive.
The Infinity Beta does this very well and the results of in-car measurements can be seen in fig. 2. Except for a small dip at 70 Hz caused by an anti-node inside the car, the response is to say the least, very extended. One watt in car sensitivity was 101 dB and maximum output below 80 Hz was 117 dB with 100 watts of power. Linearity curves were very good all the way up to 300 watts where the output began to compress below about 40 Hz. The system's resonant frequency was measured at 66 Hz where the impedance rose to 140 ohms. The average impedance of this 4-ohm rated speaker from 20 to 80 Hz was 17 ohms. The out-of-car response can be seen in fig. 1. Output peaked at 95 Hz and rolled off below this at a rate of 12 dB per octave, as is normal behavior for a sealed box system."
Links to graphs:
http://web.archive.org/web/19990422114718/www.carsound.com/reviews/infinitytest.html
http://web.archive.org/web/19990422114718/www.carsound.com/reviews/infinitytest.html
