My Experiment

[amandarae]

I learned that the 604 series were 515 + 802. So I tried using my 604-8G with an 802D/811 horns by defeating (max attenuation) the HF for the 8G. I copied the N501-8A XO.

http://www.hostboard.com/forums/atta...1&d=1286700479

So far, so good. I am very surprise at the result of using the 612C cab. I also have a pair of 416-8B and 511 horns (components for A7 500-8A) but I will enjoy what I have now and substitute them later on. To say that I am happy with the results is a major understatement. Room is 24' x 22' and listening position is about 10 feet away. 612C cabs about 2 feet from the front wall. Amps are type 45 and 2A3. The ST 70 does not come close to the DHT's but are passable.

regards,

Abe

[Panomaniac]

Very cool!

Last year I ran a similar rig. 604s for woofer and tweeter, 811B for mids. It worked nicely.

[theebadone]

I tried the same thing, but with a 802-8G, I have really tried to like the 515Bs, but I think for the best results in a nice 2 way system the 416s are tough to beat. I have been trying to buy a nice set of 604E duplexes from a friend,but the fact that it is a 515, has really swayed my opinion about tryin so hard to buy them. I have tried about everything to get decent bass out of the A-7 design, using the 515Bs but it just isn't happenin. So i switched out the 515s for 416As, and they do much better in the A-7, coupled with the 802-8Gs on 511Bs crossed at 500HZ. and i have spent more time listening to the votts than i ever have.

[amandarae]

theebadone,

Thanks for posting your experience. I will install the 416 as soon as I am back from my business trip.

I will be sleepless for the next couple of nights from anxiety because of your post for sure! But all will be well, I hope

thanks again!

[Mustang Marvin]

I to am trying an experiment. I am using an 805 horn with 399's on the high end and 416's on the low end. An 8 cu ft cabinet and crossed at 800 hz 16 ohm because of my tube amp. Keep us informed.

[theebadone]

Don't forget the eq/att. 30904, or 30923 if you plan on bi-amping

[GM]

I have tried about everything to get decent bass out of the A-7 design, using the 515Bs but it just isn't happenin.

The 515 trades some LF gain for more mid band efficiency, so for it to make bass like a 416 it requires some form of EQ which historically has been to drive them with a high output impedance to flatten them out, lower its F3. Once dialed in you get the best of both since you now have the 416's bass with the 515's superior HF response. Ditto 604 Vs 605.

GM

[theebadone]

The 515 trades some LF gain for more mid band efficiency, so for it to make bass like a 416 it requires some form of EQ which historically has been to drive them with a high output impedance to flatten them out, lower its F3. Once dialed in you get the best of both since you now have the 416's bass with the 515's superior HF response. Ditto 604 Vs 605.

GM

Cool, thank you for that info. i will try the 515s again this weekend, using your suggestions.

[amandarae]

Update, if anyone is interested.

After amassing coils(iron and air core) and capacitors (oil and polyprop) experimenting with XO's for both 500 and 800 cycles, my impressions are as follows.

Using a 6.8 ft3 cab(612C) with 515B (half of 604-8G) and 802D set to 8 ohms:

1.) First order XO sounds better than second order Butterworth, the N501-8A, (of course tweeter polarity reverse for second order) in my room.

2.) 811 horn suits my room better (22 x 24 ft2) than the 511.

3.) 511 horns gives sound so big, feels like a movie theater as compared to 811 which I think is better for home use.

4.) Oil caps sounds different and less focus when use in the HF section, polyprop sounds better to me using SET (where warmth is not an issue). Faster transients and better definiton of detail too when using polyprop in my experience.

5.) For low power amps, what I am using, iron core or air core on the woofer seems to sound the same and I cannot discern any difference between the two.

Will add more info for the 416-8B use as a woofer section later on.....