Need Single Throat adapter

[djnagle]

Hi Guys, As you might have read, I just bought a pair of 1005B horns each with two 288c drivers. Call me a whimp, but to keep the WAF up there, I am going to sell two of the 288c and both adapters, so I need to find two single driver throats. Does anyone out there have a pair they would like to sell or donate (had to ask). Thanks. Dennis

[GM]

OK, WIMP!

The horns are WAF, but not two drivers?! So build a pretty box to mount them in. The performance gains are well worth it if digital EQ shaping is used.

GM

[djnagle]

Interesting late bit "If digital EQ is used" Can you explain a bit more. Are there big hills and vallies to deal with in these horns? Thanks.

[GM]

All non-optimum horns have huge peaks/dips in their response, it's the 'nature of the beast', though they smooth out somewhat over distance. Adding a second driver has no real impact on the FR beyond increasing its output. As I noted in your other thread, there's efficiency and sensitivity gain that can be used to shelve the response to a lower Fc and maintain the same efficiency as with one driver. This also gains you ~ +3dB of usable HF BW.

If you use passive correction, i.e. a R/C notch filter (R to flatten it and C to 'lift' the HF), then the combined resistance the amp 'feels' may be too high, but with a line level R/C passive, or better still, in-room corrected digital EQ you can fine tune it to a fare-thee-well. Using foam inserts will attenuate the HF comb filtering somewhat, making them beam more, though no worse than a 311/511/811 unless you use too dense a foam or wad it up too tight.

If you know/believe that you can do this correction with a single driver and still have sufficient efficiency/low distortion, then go ahead and sell the drivers/throats, but long term, unless you just move away from large format drivers altogether, I believe you will regret selling them, especially considering how scarce those adapters are.........

GM

[djnagle]

GM, you be able to tell me: I found three part numbers for the single throat adapters for these horns, the first one #30162 and is 4.5 inches long, second is #30210 and is 4.75 inches long, and last is #30166 and is 7.5 inches long.

What will the length do to the sound or does it really matter in home use? Thanks

[oldaudio]

Dennis :
GM said :
"All non-optimum horns have huge peaks/dips in their response, it's the 'nature of the beast', though they smooth out somewhat over distance."

While this is generally true, it is not always the case. Get yourself a RTA and check them in your room. I have always had to EQ my Altec 210/1005/288,and 210/805/288, until I moved to my present location. They now measure ruler flat from about 100HZ to about 10Khz. Of course there is response above and below those frequencies, it just falls off.
My room is 18 X 24 X 9 ft. My 210 cabinets sit in a L,C,R, position with the L & R cabinets angled inward about 30 degrees. My mixing position is about 13 feet back from them. The HF horns are
mounted inside the horn of the 210 cabinets and oriented VERTICALLY ! Much more focused that way.
I have used Altec for 40 years and this is by far the best sounding setup, all with NO EQ.
Thanks, Durff

[djnagle]

Durff, 210 in a home set up? Your place must rock. I am tapped out with this system now so an EQ is out of the question anyway. I am sure it will sound better than my daughter's boombox, so there you go.

[GM]

>GM, you be able to tell me: I found three part numbers for the single throat adapters for these horns, the first one #30162 and is 4.5 inches long, second is #30210 and is 4.75 inches long, and last is #30166 and is 7.5 inches long.
What will the length do to the sound or does it really matter in home use? Thanks

====

These are not interchangeable AFAIK, though I've never tried to see if they physically are. If so, then as the length increases, so does its LF loading (lower Fc) and HF pattern control, though the higher throat pressure would roll it off faster, so no 'free lunch'.

30162 = 803/805 lens

30166 = 1505

30210 = 1003/1005

====

>While this is generally true, it is not always the case. Get yourself a RTA and check them in your room.

====

I've found it to always be true, and recent simming programs show them up quite well. They are fairly high Q though, and since we are amplitude oriented creatures we tend to process this 'sawtooth' or 'sinewave' pattern as an average, weighted towards the peaks, so they don't sound nearly as bad as they measure.

WRT using an RTA, unless it has at least 1/6 octave resolution you won't begin to 'see' the patterns and 1/12 to 1/24 for a true plot, but just the averaged response and why 1/3 octave resolution is the most common. The first high res plot I saw was of a 511/802. It was a shocker, and what got me motivated into learning about how we hear/process sound to help me be a better designer.

====

>I have always had to EQ my Altec 210/1005/288,and 210/805/288, until I moved to my present location. They now measure ruler flat from about 100HZ to about 10Khz. Of course there is response above and below those frequencies, it just falls off.
My room is 18 X 24 X 9 ft. My 210 cabinets sit in a L,C,R, position with the L & R cabinets angled inward about 30 degrees. My mixing position is about 13 feet back from them. The HF horns are
mounted inside the horn of the 210 cabinets and oriented VERTICALLY ! Much more focused that way.
I have used Altec for 40 years and this is by far the best sounding setup, all with NO EQ.

====

I can believe it, the large horns attenuate a significant portion of the 210's loading, but you make it up by using a third cab to ~uniformly pressuize the room, and mounting the 1005s vertically narrows the horizontal dispersion considerably, though the super wide vertical dispersion needs damping for best coherence at the listening position. Did you address this issue and do you use digital time delay to account for the rather severe XO phase offset?

GM

[djnagle]

GM, Great, thanks so much for your wealth of information. I know now to look for the 30210 and that makes me feel better. It is wierd to think that information can be a gah-gah blanket. Cheers.

[Jack6428-2]

I realize this is a pretty old thread, but I thought I would use it with my question since it has a good summary of what throat pn?s to use on multi-cell horns.

Does anyone have one pn 30166 throat adapter for a 1505 horn for sell or know of someone / place that might?