GoodSoundClub - Romy the Cat's Audio Site

In the Forum: Horn-Loaded Speakers
In the Thread: Deep End DIY - Australian take one Macondo.

Post Subject: Alignment using impulse response, acoustics and congratsPosted by kodomo on: 1/22/2016

Great project! I have a similar project going on. Your frame ideas are looking beautiful, however I decided to take a more utilitarian road. I can adjust all my channels in horizontal or vertical axis. I am finishing my crossovers as of these days, and they are 6db except for the bass towers which are 12db. I had to do impedance equalisation to be able to use the 6db filters to work. Months and months of listening and measuring for me and even after everything is finished. The channel attenuation according to my space will continue for a few months more until I am fully satisfied... You can see my project here:

http://www.romythecat.com/Forums/ShowPost.aspx?PageIndex=2&postID=22406#22406

May I suggest using impulse response when aligning the relative drivers. This is the most accurate way of doing it as far as I know.

You need a sound card with at least two inputs, and a microphone. REW is free and is able to help you with this. If you need further information on how to do it, I would try and explain it in more detail to you.

I would also look at acoustics of your space. I am an interior architect and studied acoustics. I have also worked in music studios and am a musician who owns a private music studio as well. Please do not skip on spatial acoustics, they have as much effect as any part of your signal chain. I have made some acoustic panels according to my needs too. They are multi-purpose and effective panels. The outer shell is 1d diffusor that works up to 4500hz. I have special fabric behind it and then 10cm of 100kg/m3 mineral fibre, which is quite effective (about 1 sabin from 150hz and upwards) down to lower cutoff of my upperbass 110hz horn. If you can put spacers in between the wall and the panel you can bring it further down to about 80-100hz effectively. Believe me, if people tell you they can effect 20-40hz with their panels, it is either to a very low effect, or an incredibly thick panel that is alos strategically placed or they don't know what they are talking about. Some panels with resonators in perfect spots may have an effect lower than 80hz, if there are enough of them in your space. Anyway, here are the panels I built. They are known as BAD panels commercially. I need 12 of these panels, plus 4 thicker panels in my space. I also needed about 12 of 60x60cm quadratic 3d diffusors. Oh and yes I am a bachelor Smile

You can easily find the ideal amount of absorption you need in your space to get the right amount of reverberation. This will result in units of sabin. Only after choosing the right treatments, then you can start treating the first and second reflection points. Do not forget the ceiling. I also suggest appropiate quadratic diffusors if you are far enough from the walls and ceiling to be placed around your seating position.

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