E130 in 100hz Edgarhorn info

[spkrman57]

I had a pair of E130's reconed w/paper dustcap and had played with them in vented 2.5 cu ft cab tuned to 60 hz.

I found they sounded great off-axis, but I had midrange problems and decided to try them loaded in Dr Edgars 100 hz midbass horn.

Back compression chamber outside dimensions are 17" x 17" x 8.5" sealed w/no stuffing.

Testing on WT2 says fsb is 99.5 hz on one, and 100.5 hz on the other, Qtc on both is 1.15. While I am not a expert, it seems to be good figures to work well.

I am still getting parts together to play this system, but thought I would share some specs on the midhorn/E130.

Midrange horn is Edgarhorn round tractix 500 hz (crossover limit is 800hz), driver is Great Plains 399 (1.4").

Crossover will be 1st order, 1.5 mh on midbass, 24 ufd oilcap on midrange and 1 ufd oilcap on tweeter TBD (2402 - 2404).

Theoretical efficiency: midbass horn - 111db/midrange horn - 115db

Tweeters: 2404 - 105 db and 2402 - 110 db

I will try 2404 first, if there is not enough efficiency to keep up with rest of system I will go to the backup 2402 and accept the lower HF rolloff.

More to follow as I get further in this project. Just thought I would share this if anyone is interested.

Ron

[matsj]

I think mr Edgar recomend´s a second order filter to his Edgar horn.

mats

[spkrman57]

Mats,

This is my 2nd Edgarhorn system. Bruce started out in the 80's with 2nd order and found out the improvement with 1st order and using enameled magnet wire(copper).

If one used a bass reflex for the bottom end he does recommend a 2nd order for the LF and 1st order for HF section.

Most folks using Edgarhorns systems are powering them with less than 10 wpc. I will start with EL84 SEP (5 wpc) until I tweak the bugs out. I have a pair of Welborne DRD 300B amps for the long haul(7 wpc triode).

If the rain quits sometime today and I get motivated, I will have more to report on.

Ron

[matsj]

OK i understand.

mats

[spkrman57]

I now have the "breadboarded" Edgarhorn system wired and running.

Initial listening showed every flaw in my system. My Almorro EL84 SEP amp has too much hum for this system, at this efficiency every flaw shows its ugly head.

I removed my Zu cables (siver wire - no shielding), that helped out some and the hum is bearable now. Mostly heard inbetween songs.

I originally ran EH EL84's and swapped them out for some Mullards that are softer in nature.

The 2404 tweeter adds just enough air on top to be presentable.

Amazing thing is the response of the E130 in the horn has much more midbass detail than in a BR enclosure I had used previously.

I still have much alignment to tweak out (phasing) to get the most out of this horn system.

Another problem is the 5 wpc amp has 10 times the wattage necessary for this horn system. A 45 SET amp would be more practical.

My room is only 12' x 16' and does sound best when listening in the kitchen(another 8 ft back). Of course that was to be expected since Bruce recommends the system be 8 - 12 ft apart and listened to at 12 - 16 ft back.

What really is impressive is the energy this system has with little power fed into it, low level sounds and whispers come across with amzing detail.

I hope to get my "photoshop" updated and take pics of my ugly system soon!

Ron

[spkrman57]

I had a problem witht he E130 in the 100Hz Edgarhorn and wondered why I had such a problem with getting a decent output out of the horn.

I did some searching here on the forum and came across the use of damping resistors across JBL drivers. I usually just thought of using them for compression drivers mainly.

I noticed, after more scrutiny(paying more attention) that JBL used resistors across not only the compression drivers, but also most of the modern systems have them across all the drivers.

I tried a 20 ohm resistor across the E130 terminals and found the resonance problem to be much less annoying.

I solved the 2khz peak issue by crossing the horn at 800hz and well out of the region where the peak occurs. By the way, the peak is 110db at 2khz and the driver is better rated at 101 db/watt for use under 1khz.

I'm still working on the issues with the system, but currently using a Altec 511B horn/902 driver for 800hz on up. With the 902 driver and placing the bell of the 511B flush with the front of the Edgarhorn leaves the compression driver directly above the E130 voice coil which helps in keeping phase on the system.

Crossover currently is 2nd order lo-pass and 3rd order hi-pass.

Eminence Omega 18" in 15 cubic ft sealed sub fills out the bottom end. A friend of mine built it and then realized it was too big for his house. The sub measured a system "Q" of .49 and Fsb of 31.4hz. Perfect for classical, but not for rock and roll music.

Thanks to Techbot for posting E130 freq response graph along with all that good technical data.


Ron