Here are a few pictures of my new active monitors. These are using a 6" Kevlar midbass unit coupled to a low resonance soft dome tweeter. Both drive units are sourced from Peerless India and diyaudiocart.com. The project was started because I want to start recording again, having no job and little else to do. Since I sold my Dynaudios and the accompanying amplifier a year ago, I did not have a nearfield reference speaker, which IMO is absolutely critical for recording and mixing. Since the money I had was not enough to buy me a good pair of monitors, I decided to go homebuilt.
Amplification is 70W on the tweeter and 140W on the woofer, though sustained power levels are gain-limited to 100W due to the very low crossover point of 1.6KHz (4th order, Linkwitz Riley textbook slopes). Speaker drivers are sensitive enough that I've never had to exceed -15dB level (about 25W total). Tweeter will explode if played at full power for sustained duration, but the additional headroom helps to avoid clipping at normal power levels. Sinks are warm to the touch - about 50 degrees - as the power supply voltages are a wee bit higher than I am comfortable with. However many, many parts including the very old transformers were from my spares bin, and little higher voltage is fine because it was free
The box is fully closed, resulting in final frequency response 65Hz-22Khz, and there is a matching subwoofer in the oven right now to get this down to about 38Hz. I chose sealed alignment for a flatter response, low distortion and improved power handling. Also, since the monitors will typically be heard from very close distances in untreated rooms, ported boxes would mean poor integration and I would have had to plug the ports anyway. The Peerless woofers are not very flexible, they need quite a large box to extend down to the low 40s, though their parameters mean they can work very well in small sealed boxes with only the slightest of midbass humps. I suspect these are less than optimal for home speakers, but I can't judge that right now.
The speakers sound flat, clean and extended when used in 'monitoring' trim, allowing me to hear deep into the mix. I still have some tweaking and cable management to be done after I get used to the sound and can work out the next set of changes, specially for the 'hifi' trim. The BSC and tweeter levels are tweakable with two three-position switches on the rear plate, resulting in a variety of different options to optimise the response for different rooms and listening axes/preferences.
The finish is hand-sprayed matt black out of a 'rattle can' - or six of them - and the attempt was to disguise the wood ancestry of the speakers. The box is constructed in 1/2" exterior-grade MDF, with a double-thickness front baffle. The wood thickness was kept low to give me additional internal box volume, and compensated with a vertical window brace across the depth dimension as well as mass-loading the walls with bitumen sheets. Also, exterior grade MDF absorbs less moisture and is easier to paint and stays together for longer.
I'm glad I built them. I learnt many new things along the way, specially things like painting which do not suit my ten left thumbs. In the end I can gladly say that these are better than the Dynaudios I sold in many ways, specially the driver to driver integration and the nicer, if not as extended, bass presentation. I hope to put them to duty by early next year once the recording rig is built. With no income, one goes about these things very slowly and carefully.
Amplification is 70W on the tweeter and 140W on the woofer, though sustained power levels are gain-limited to 100W due to the very low crossover point of 1.6KHz (4th order, Linkwitz Riley textbook slopes). Speaker drivers are sensitive enough that I've never had to exceed -15dB level (about 25W total). Tweeter will explode if played at full power for sustained duration, but the additional headroom helps to avoid clipping at normal power levels. Sinks are warm to the touch - about 50 degrees - as the power supply voltages are a wee bit higher than I am comfortable with. However many, many parts including the very old transformers were from my spares bin, and little higher voltage is fine because it was free
The box is fully closed, resulting in final frequency response 65Hz-22Khz, and there is a matching subwoofer in the oven right now to get this down to about 38Hz. I chose sealed alignment for a flatter response, low distortion and improved power handling. Also, since the monitors will typically be heard from very close distances in untreated rooms, ported boxes would mean poor integration and I would have had to plug the ports anyway. The Peerless woofers are not very flexible, they need quite a large box to extend down to the low 40s, though their parameters mean they can work very well in small sealed boxes with only the slightest of midbass humps. I suspect these are less than optimal for home speakers, but I can't judge that right now.
The speakers sound flat, clean and extended when used in 'monitoring' trim, allowing me to hear deep into the mix. I still have some tweaking and cable management to be done after I get used to the sound and can work out the next set of changes, specially for the 'hifi' trim. The BSC and tweeter levels are tweakable with two three-position switches on the rear plate, resulting in a variety of different options to optimise the response for different rooms and listening axes/preferences.
The finish is hand-sprayed matt black out of a 'rattle can' - or six of them - and the attempt was to disguise the wood ancestry of the speakers. The box is constructed in 1/2" exterior-grade MDF, with a double-thickness front baffle. The wood thickness was kept low to give me additional internal box volume, and compensated with a vertical window brace across the depth dimension as well as mass-loading the walls with bitumen sheets. Also, exterior grade MDF absorbs less moisture and is easier to paint and stays together for longer.
I'm glad I built them. I learnt many new things along the way, specially things like painting which do not suit my ten left thumbs. In the end I can gladly say that these are better than the Dynaudios I sold in many ways, specially the driver to driver integration and the nicer, if not as extended, bass presentation. I hope to put them to duty by early next year once the recording rig is built. With no income, one goes about these things very slowly and carefully.