I had purchased the newer black coned Hi-Vi M5N-B a little while back, finally swapped one into on of my AlTi speakers and tested it against the original M5N. The frequency response overlaid nearly perfect, so those are a drop in swap for this design if you like the look of the black woofer cone over the original M5N's light copper/gold color. Added some new photos of that woofer on the few posts.
Hi Matt, Thank you for this design, I am currently looking for my first DIY speaker project and this one looks very promising. I was originally considering the C-Note kit but the AlTi looks like should sound better. I'm slightly worried about this part of your description : I going to be using them in my living room, where I'll frequently be more than 20 degrees off axis. Should I except an audible degradation in higher frequencies in this case ? My current amp is a small class D so I'll add the resistor to the crossover. I read that C-Notes don't play well with class D amps (notable rise in HF). Should I expect similar issues with the AlTi or is the resistor going to help with this issue ? Thank you for your patience !
The extra rolloff in that range doesn't result in any kind of drastic change in the balance or timbre, it's just a subtle decrease in some of the sparkle or air in the treble. It won't be too different then many regular dome tweeters off axis. The resistor prevents a capacitive load in the ultrasonic range which many class-D amps don't play nice with causing audible distortion, noises or shutdown issues. This is separate from the frequency response variability issues certain class-D amps have with differing load impedance. I did test the AlTI among several other speakers in some measurements looking for the frequency response issues of class-D amps, and it shows basically any speaker design that does not have a flat impedance and phase over the top two octaves will result in some form of response irregularity on any class D amps that are susceptible to that issue. Unfortunately that does include the AlTi. Here is a link to that testing I did: https://www.mtg-designs.com/tips-tr.../amp-frequency-response-variability-with-load
Hey Matt, I'm in the process of modeling the cabinets to prepare for the cnc machining and I noticed a difference between the flange thickness in post #2 (5/32") and the 3D render in post #25 (5/16"). I checked the woofer and tweeter, the thickness is indeed 5/32". It would be great if you could edit the render to correct this.
Thanks for pointing that typo out, crazy enough the 3d render has the correct dimensions it's just that I manually changed the text from the decimal 0.15625" to fractional to make it easier to read and made a typo putting 5/16" instead of 5/32".
Hi amigos, Just finished my Alti bookshells. I opted for some higher-end components for the Crossover. Regarding the speaker cabinets, I wanted to make them myself from Bamboo wood but due to lack of time, I opted for a pair of pre-assembled high-density MDF cabinets with a volume similar to the original project. I used 2.5mm² copper cables for the woofers and 1.5mm² for the tweeters. I also paid particular attention to sound insulation by opting for three different materials: a 12mm Vibrofiltr Felt acoustic panel with a cork backing to absorb vibrations, and high-density acoustic foam for the upper of the speakers. The crossover is covered with a high-density wool sheet made of 85% cotton and 15% polyester with a density of 600g/m2 Pictures here: