Thursday 5 June 2019

6" Reference bookshelf speaker

A while ago I built a pair of bookshelf speakers using some car audio speakers. They did the job just fine but after a month I decided to sell them. I felt like this was the time to pull out all the stops and build myself a pair of high-end bookshelf speakers.

I opted for a two-way configuration, using a Dayton Audio RS150P-4A mid-woofer for the lows. This woofer has a large frequency range which gives me more freedom for the tweeter choice. Because the RS150P-4 performs best in a relatively small enclosure, I was able to design a nice and compact enclosure for it. I chose the Dayton Audio ND25FA-4 tweeter to cover the highs because the sensitivity is about the same as the woofer’s sensitivity and it has a surprisingly large frequency range as well. Another reason to choose this component is that they are both 4 ohm drivers. This makes designing the crossover a lot easier.

The crossover was designed as a second-order Linkwitz-Riley with a crossover frequency of 4,500Hz. For each crossover I used two Dayton Audio 4.7uF Polypropylene capacitors and two Dayton Audio 0.30mH Air Core Inductors.

The enclosure is a bass reflex enclosure, this boosts the output in the lows quite a bit. The enclosure itself is made out of 18mm MDF and I used the Goldwood 1 ½” ID x 4” L Flared Speaker Cabinet Port because it had just the right dimensions. The cut-outs for the speaker were done with a DIY circle jig but I’m planning on using a genuine Jasper jig in the future to make the process a little easier. Painting MDF is a bit of a pain in the back so I decided to finish the enclosures in white vinyl and walnut veneer. Finishing the speakers in glossy white and walnut gives them a very premium look.

I added some Dayton Audio BPA-38G HD Binding Posts for an easy and durable connection between the speakers and the amplifier. These gold plated binding posts really contribute to the premium look that I was going for with these speakers.

At the moment the speakers are still being powered by a Dayton Audio DTA-120 class T amplifier but I am already eyeballing another amplifier: The Dayton Audio DTA-2.1BT Class D 2.1 Bluetooth amplifier. I’m currently building a matching subwoofer to support these bookshelf speakers in the low-end and the DTA2.1BT has an output for an active subwoofer. Furthermore, the DTA2.1BT has Bluetooth connectivity which is a nice little added feature.

My name is Myrddin Tieleman and these are my Premium 6 inch Bookshelf Speakers. The speakers completely surpassed my expectations, they sound amazing!

In the long run, I would like to design and build speakers for resale and I think that SoundImports could be a very good partner in the future. More info: MAD speakers

Used components

Dayton Audio RS150P-4A mid-woofer