OH-BOY AUTO TUBA!

[mzisserson]

The auto tuba seems to get very little attention. I helped a friend of mine build one and it is very nice. Puts to shame most 2x12" systems I have heard. It was refreshing to be in a car and hear the bass line AND kick drum in everything from Hip-Hop to Blues.

I used a 100W amp with it and it was more than enough. The gain is at about 11 o' clock, no boost x-overed at 60Hz. I would not reccommend running too much mid-bass through it as it is a real SUB woofer and did not like anythhing above 80. I am running high pass filters at 30Hz also for protection.

The bass had a compressional quality to it as well, it sis not just shake you, it pressureized teh entire cabin. During testing I had it in my bar room which is 12x17 driving it with a Dayton 70W sub amp and it was easily pressurizing the room with little effort. In a room it will not give you 20HZ at 100dB, but it is plenty deep and loud enough for most needs. Accurate to boot!

Overalll Value is a 10, preformance is a 8 (I would have liked to see it maintain integrity to 100Hz but I could have missed a detail tuning and did not cut the box which I had to repair for him...he has less skills that I in regards to carpentry), and the coolness factor of having a horn sub in your car is priceless!

Here's the pics.

http://picasaweb.google.com/zoe0416/autotuba

[Bill Fitzmaurice]

I would have liked to see it maintain integrity to 100Hz

It does, but with the rising response curve of a horn this small a graphic EQ is a necessity to reduce the response above 80 Hz and to roll-off everything above 100.

[mzisserson]

Bill,
Worked like a charm. I belivee it is da mn near flawlwss when used as intended.

[Mikey]

I would have liked to see it maintain integrity to 100Hz

It does, but with the rising response curve of a horn this small a graphic EQ is a necessity to reduce the response above 80 Hz and to roll-off everything above 100.

So, what is the lowest frequency/slope crossover recommended with an AT? 80hz/24db?

[Bill Fitzmaurice]

I would have liked to see it maintain integrity to 100Hz

It does, but with the rising response curve of a horn this small a graphic EQ is a necessity to reduce the response above 80 Hz and to roll-off everything above 100.

So, what is the lowest frequency/slope crossover recommended with an AT? 80hz/24db?

It wil run to at least 200 Hz, but the rising response must be EQ'd down. It's almost the same horn as the woofer section of the David, which crosses to the midbasses at 200 Hz, with the crossover optimized for flat response.