Broke down. Got a duplex.

[cradeldorf]

Tell me that speaker is not just balancing there like that!!!

[Alien_Shore]

Congrats on your first coil! I've seen worse - I own worse.
Wow, that's a lot of caps back there - what going on?

Thanks Pano!
That's the prototype LF filter. It's a 10th order Bessell, so yeah, it's got quite a lot of components.

Tell me that speaker is not just balancing there like that!!!

My cat likes to play with it, he thinks it's an oversized top! I'll get it spinning real good and he tries to hang on

I am really hoping to get a cabinet built for this speaker over the holiday vacation, so I can start some real listening tests. The preliminary tests with the free-standing driver are pretty amazing. I just lay it on it's side to get some good floor loading and put on my Nat King Cole CD. I'm anxious to get this HF filter built and then hook up the LF and the HF together...it's kinda scary how revealing this speaker is. I can hear the engineer tweaking individual mics on the recording... unreal.

[cradeldorf]

I know what your saying, I have heard things in recording that were clearly not supposed to be there. I can't wait till you hear it in a cab. They are impressive.

[donaldpatten]

Alien Shore

Mike:
Hope you had a good holiday.
How is the new speaker cab. coming?
You will be surprised when you hear it all tuned up

Don

[Alien_Shore]

Thanks Don! Yep - Holidays were great. Our son came down from NYC to visit for a few days and we hooked up with some friends and family.
I am working on an Altec 620 clone cabinet to test with. Should be done within a week. I have built the HF filter portion to mate up to your time-delay Besell filter for the woofer...so I think we're all set to test this thing out once the test cabinet is finished.

[Alien_Shore]

OK, 2 months later that I thought, but I finally have my 604E mounted in a test box:



Right now, its a sealed box. I will probably put a PVC vent in it with threads so I can adapt the size of the vent easily, or cap it off if I want it sealed. So far so good, oh, and before you guys start ragging on my crappy construction let me just say it's my first cabinet ever so go easy.

[Phil-G]

that was one fast week.
box looks ok . nothing a beltsander can't fix

[cradeldorf]

That box looks better than mine. and trust me your gonna be making a lot of boxes.

[Earl K]

@Alien_Shore

Mike, nice to see you kicking around these old haunts again.

If ( when ) you see this, can you answer a question or 2 please?

A good decade back you displayed a pic of the response of your 604E using the N1500a as the crossover.

"Was that with your GPA refurbished 604E's after Bill ( GPA ) had used the lower than expected impedance voice-coils ( more or less 8 ohms versus 16 ohms )" ??

If so, I'm really intrigued at how well your non-604E ( 8-ohm ) elements actually modelled for LC values originally chosen ( by Altec ) for the N1500a and it's higher impedance drivers.

Also, do you remember what distance you used for the off-set of the 2 drivers Acoustic Centers ( within PCD )??

Thanks! EarlK

PS: ( link included below for a much larger version of the pic >> if a member at HFH )

Log in | HiFi Haven

[Alien_Shore]

I'm looking through some of my old posts, computer files, notes, etc. to see if I can answer your questions. Yeah, it's been a minute hasn't it!?

Mike, nice to see you kicking around these old haunts again.

Hi Earl and thanks - sorry for the lag in replying here - the holiday rush has had me strapped for time.

A good decade back you displayed a pic of the response of your 604E using the N1500a as the crossover. Was that with your GPA refurbished 604E's?

The graph I posted was not from a FR test, it was the sim output from a model that I had done with PCD. In that model, I had imported the FR curves and impedance data, so I presume that data was from the drivers with the refurb'd VCs. Glad to publish those data if you want to see it! Looking at the sim in excel, it appears that a parallel two-way config was used. Driver offsets were zero. The woofer design in the sim is 2nd order L/R crossing at 1.5 kHz 70 dB. There is a series RC (Zobel) with C=13 uF and R=10 Ohm, followed by the lowpass 2nd order section with L2=1.5 mH and C2=8 uF. For the HF section, it was 2nd order parallel with C9=6.0 uF and L9=1.0 mH, with a 0.3 Ohm DCR. There is a 3.0 Ohm series resistor after the HP section AND there is an 8.0 Ohm resistor in parallel leg 1. It will take me a bit to draw this out in a schematic, as I'm sure this description is confusing