Skip to main content

Electro-Voice EV 209-8A - 8" Full-range


During a visit to Sakuma's Direct Heating website, I encountered a cool SE 801 amp schematic designed for either a Lowther PM6 or an Electro-Voice 209-8A. I googled the EV 209-8A and nothing came up in Audio/DIY centric English language websites. But there were a lot of US dealers stocking the driver from as low as $18 each.

basic specs

After downloading and studying the detailed specifications at the EV website, I chose the cheapest internet seller and phoned-in an order for a pair. 


It cost $40/pair from Full Compass delivered within a couple of days to my doorstep. In spite of their great customer service, their packing left a lot to be desired - see the slightly wrinkled whizzer in the above right picture - the drivers were free floating in the box, not even tied down face to face ;( 


Due to lack of resources to build the recommended 1.8 cubic foot sealed cabinet, I loaded the EV 209-8A in a Heathkit 1.2 cubic foot ported cabinet, which used to house a Jensen P8RL + RP103. 

Heathkit 1.2cf + EV209-8A

Sharp fall off below ~ 90hz, otherwise the in-room RTA result was satisfactory. The tonal balance reminded me of a good mini-monitor speaker with no upper midrange nasties. It was also quite extended in the high frequency and at no time did I crave for a super tweeter.

Further internet research yielded this Japanese website which did an in-depth study of the EV 209-8A. Based on Chrome browser translation, transmission line loading was used to get around the bass deficiency.


Regardless of Qts values ;) and in keeping with JE Labs tradition, a trial in an open baffle is de rigueur. Since my original pair of OBs are currently in storage, I improvised a 55" wide x 32" high flat baffle using a 24" x 24" x 1/2' thick pine plywood baffle from my experiments in the 90s as the core, supplemented by cardboard extension wings.

OB + EV209-8A

Despite the even sharper fall off in mid bass response as shown in the RTA, subjectively, the bass extension was similar to the EV209-8a/Heathkit box combo. But the scale of the sound field produced by the EV209-8A/OB combo was a lot larger than when it was loaded in the Heathkit cabinet.



Since I discovered that my very first high efficiency speaker (a green KS 14703/Altec 755C) was carefully stashed in a box in the basement, I installed it in the OB to take a trip down memory lane. 

OB + Altec 755C

I've covered the Altec 755C in the Sound Practices No. 17 Homebrewer feature many moons ago, so I will spare adjectives to describe the subjective performance of the KS14703/755C. Suffice to say that the above RTA graph shows it all. It is just in a different class sonically and affordability! Perhaps not a very fair comparison for the EV209-8A because this driver with an intact cone and voice coil is worth about 20 times more when they come up for sale.


So even if I couldn't coax Altec 755C performance from the EV209-8A, its street price, efficiency, relatively flat impedance curve and midrange to upper frequency performance quality impressed me enough to bring it to the attention of the Audio/DIY world. 

Comments

  1. Hi, Thanks for great article, Which app do you use for measurements?

    ReplyDelete
    Replies
    1. Octave RTA by Onyx -https://itunes.apple.com/us/app/octave-rta-real-time-sound-frequency-analyzer/id569156857?mt=8

      Delete

Post a Comment

Popular posts from this blog

Altec 2-way horn system redux

Truth be told, I was never fully satisfied with the performance of the Altec 2-way which is why I never uploaded the old article in the Arkiv.
Let's recap how the 2-way horn system evolved...


The project was conceived in mid 1998 because I needed a monitor system that was more efficient than the OB/755 so I could listen to SE amps with 2 watts output and below.
I commissioned my cabinet maker neighbor to build 614 bass reflex cabinets and loaded them with Altec 419A 12" drivers + 811 horns (early version/heavy sand cast) and 804A compression drivers gathered from hamfests and radio shows. Crossover was a textbook 1st order/6dB/octave hinged at 900 hz and the horn padded down to match the sensitivity of the low frequency driver.

Eventually I acquired proper 12" woofers - Altec 414As, which lack the upper midrange nasties of the 419As. The 414As have great midrange quality even if they lack the bass end of their larger 416/515 brethren.

802D compression drivers replaced t…

2017 Update: Hi-Fi Room

One year progress report

Stereo
Garrard 301 + Ortofon RMG 309/SPU GME or SME 3012 + Denon DL103 Altec 4722 MC step-up
Digital line level sources processed  through UTC A20 transformers

JEL Stereo Preamp DX
JEL Stereo SE2A3 DX amp with Tango NY15S OPTs
Altec 2-way Altec 414As in 3.5 cf bass reflex enclosures + Altec 32A horns with 802D compression drivers
or
Mono Neat P58H 4 speed idler turntable + Velvet Touch viscous damped tonearm with Denon DL102 or GE RPX cartridges

je2a3 mono integrated amp

Stereo > Mono Line Level Mixer

Mixing line level stereophonic signals into full dimensional monophonic ;)
Here's a DIY project for mono aficionados that's so basic, I should have uploaded it many years ago. But other things got in the way.

Just like an MC step-up, these are entirely passive devices. 

The simplest way to convert stereo to mono is to connect left and right channels via a Y connector. But there's a more elegant way than just shorting two channels.

Resistors can blend two signals into one better by...

...using Allen-Bradley carbon composition for warmer sound ;)
We can end the mixing quest here but...

...the most elegant way of mixing two channels as was done in the studios by audio pros of yesteryears was through transformers.


This single UTC A-20 transformer was in a box lot of tubes and parts I picked up at a radio show. It's a high quality transformer designed for mic, mixer or line matching applications. Instead of trying to find a mate for MC step-up duty, I repurposed it for a g…