ra loudspeakers were the first products to be manufactured under the Signalpath
name, and were immediately welcomed on the pages of review sites, and into the homes of audio enthusiasts. The Era Design-4
reviewed here today is a Bass Reflex design with a finely tuned port to augment bass reproduction. Every review is explicit in the Era D-4 ability to produce deep tight base which belies their "Bookself" dimensions. Construction is quality is very high equaling that of mini-monitors costing many times more. The Design-4's arrived in perfect shape in a well thought out box and foam bracing system (see thumbnails). Signalpath also included a helpful manual and steel L brackets for wall mounting.
Era Design-4 Specification:
Woofer - 4" long excursion (kevlar / composite)
Tweeter - 1" soft dome (silk dome)
Power requirements - 50-150 watts
Frequency Response - 58Hz-20kHz
Efficeincy SPL 1w1m - 84 dB
Video Sheild - Yes
Impedience Nom./Min. - 5/4 ohms
Finish - Cherry, Rosewood, *Gloss black (*= review sample)
Weight - 6 lbs / 2.7 kg
Dimensions inches H x W x D - 7.5 x 4.75 x 6.5
Features - ¼-20 threaded insert for wall bracket
While craftmanship and materials are essential for a "solid" speaker, they mean little without the proper design. Era engineers braced the cabinet for ultimate rigidity, matured the correct drivers and crossover and then, perhaps most importantly as evidence is showing fine-tuned the rear port taking the Hemiholtz Principle to perfection. If there is one magazine/online source I had to choose for Audiophile and High End reading then there is perhaps no better established and educational then Stereophile
. They praised the Era Design 4 in the following Era Design-4 and Era SUB-10 review
. Another well respected source for Audio reviews is 6moons
who also found Era products surpassed their price-tag in the following, 6moons Era Mini-monitors
The Era Design-4 are one of those few products in which the whole exceeds the sum of its parts.
With grill screens on, these little beauties are both unobtrusive and ergonomic. Speaker stands are must if you want to extract your money's worth, this is critical for their ability to throw a large soundstage with well defined images within that space. You can place these on a desk, on the wall using the brackets, or literally on a bookshelf, but you'd be throwing away $600 ~ $900 (depending on finish). The test pair I received sports the $900 finish, there is no difference in the performance between the $600 model, sonics remain unaffected by finish costs.
The drivers include a 1" soft-dome silk tweeter and 4" Kevlar impregnated/composite Bass driver (click on thumbnails for close-up). Secured by 4-bolts for the tweeter and 6-bolts for the bass driver. They are mounted flush to the front baffle enclosure. I did attempt to remove the drivers for further inspection, after removing the Bass driver fastening bolts it became clear Era had used additional measures to ensure an air-tight seal. This further exemplifies the craftsmanship and one reason these rather small enclosures impress every Reviewer with bass response belonging to much larger speakers. The drivers must be held in place as if there were no discontinuity in the front baffle stiffness.
In the photo below we see the D4 is tapered to a much narrower width. The rounded sides of the enclosure and its final width most likely aid in eliminating any unwanted refractions or reflections from the room. Era is a Bass Reflex design, and as one of a growing number of speaker manufacturers who choose to invest more heavily in the R&D behind this concept, they've discovered sonic dividends are paying off. There various types of speaker enclosures and various ways to "port" a box. The Era Design-4 rear port isn't simply there to "relieve" back-wave air pressure; it is a finely tuned device. This port is based on the Hemholtz Resonator principle and its material, construction, and placement have become critical in such designs. Era has struck on a precise formula, as the D4's base extension seems to drop far below the specifications and control at the lowest frequency is taught.
As an additional bonus Era used the same 5-way binding posts found on the Decco. High quality copper posts encased in acrylic make for an attractive design while defeating oxidation that forms on all copper construction.
Onto listening tests...