My A7-500s. A journey

**Panomaniac** · August 9th, 2011, 07:29 PM

Thanks GM, I'll experiment with wings. I tried a pillow in the gap between the top of the bass horn and the bottom of the 1005 horn - all that did was give me more junk below 200Hz. It's easy to see the results in the measurement. Real wings on the sides should be a different story.

Good luck with the house stuff!

**Steve Mac** · August 9th, 2011, 08:45 PM

Originally Posted by Panomaniac

Thanks GM, I'll experiment with wings. I tried a pillow in the gap between the top of the bass horn and the bottom of the 1005 horn - all that did was give me more junk below 200Hz. It's easy to see the results in the measurement. Real wings on the sides should be a different story.

Good luck with the house stuff!

With that big mid range horn you really need to splurge and just build the big mid bass horn.
That will be the only way to make that big altec mid range horn happy.
Two altec 515s and a mouth bigger than Rosie O'Donnell's.

**Panomaniac** · August 9th, 2011, 10:58 PM

I've thought about, I really have. But for the moment, I'm tired of building speakers!

**dominique-tanguy** · August 10th, 2011, 09:57 AM

Hi Panomaniac,

I am convinced that you cannot get the best of a VOT without using the port.

a) The effect on the bass extension is significant
b) The effect on the quality of the medium is also very noticeable

I am very impressed by the overal result I have obtained so far. I will now concentrate on the room response issue in order to continue optilisation, but the actual result is already excellent, with a very well balanced sound.

I understand that one of the issue is that these cabinets can be fitted with very different loudspeakers (416-8A and 515-8G for example) and the tuning cannot be the same... Considering the datasheet, it is even very surprising that both could give good result in the same cabinet.

Regards,

Dominique

**Panomaniac** · August 11th, 2011, 05:50 PM

Yes, port and wings for sure.

I did a little port work today. Thought I'd make a "slot port". I.E. a rectangular port right at the bottom with the box bottom being one wall of the port. So now I have a 4" tall hole at the bottom the full width of the cabinet. Could not get it to tune worth a fart no matter how deep or shallow it was, but it does add a very nice 6dB or more at the bottom. Just what I needed! At 1M, the response has its problems (floor bounce, I suspect), but there is certainly more bass. Back at the listening sofa, it's more a more even response and that's great. Now I gotta bring the horns up.

Experimented with one wing, it does smooth things out a bit in the 200-300Hz range, so I will probably go with two. Progress.

GM · August 11th, 2011, 06:56 PM

If you're still in an experimenting mood, take off the lower panels and make one to slope back down to a full width 4" slot at the bottom back to create a horn loaded vent.

GM

**bfish** · August 11th, 2011, 07:12 PM

Halibu' idea!

**Panomaniac** · August 12th, 2011, 09:24 AM

GM:
I'm not getting the picture. The 4" slot would be the smallest part of the "horn port" - its throat? And the horn part would live inside the cabinet?

**Altec Best** · August 12th, 2011, 03:48 AM

Originally Posted by Panomaniac

Yes, port and wings for sure.

I did a little port work today. Thought I'd make a "slot port". I.E. a rectangular port right at the bottom with the box bottom being one wall of the port. So now I have a 4" tall hole at the bottom the full width of the cabinet. Could not get it to tune worth a fart no matter how deep or shallow it was, but it does add a very nice 6dB or more at the bottom. Just what I needed! At 1M, the response has its problems (floor bounce, I suspect), but there is certainly more bass. Back at the listening sofa, it's more a more even response and that's great. Now I gotta bring the horns up.

Experimented with one wing, it does smooth things out a bit in the 200-300Hz range, so I will probably go with two. Progress.

Pano can you snap a few pictures !

A pictures worth a thousand words.

**dominique-tanguy** · August 12th, 2011, 03:53 AM

Originally Posted by Panomaniac

Yes, port and wings for sure.

I did a little port work today. Thought I'd make a "slot port". I.E. a rectangular port right at the bottom with the box bottom being one wall of the port. So now I have a 4" tall hole at the bottom the full width of the cabinet. Could not get it to tune worth a fart no matter how deep or shallow it was, but it does add a very nice 6dB or more at the bottom. Just what I needed! At 1M, the response has its problems (floor bounce, I suspect), but there is certainly more bass. Back at the listening sofa, it's more a more even response and that's great. Now I gotta bring the horns up.

Experimented with one wing, it does smooth things out a bit in the 200-300Hz range, so I will probably go with two. Progress.

Congratulations! Good to hear that you are progressing in the right direction. Good luck for the next step! I am interesting to hear about the experiment with the "Horn Port".