Audience Auric and OHNO wire and Audience product prices
Peerless Tymphany 830880 5.25" Passive Radiators
Bang & Olufsen Redline 60 ABR modification and drivers for sale
My dual 12" Lambda center speaker
I built my first mains in 1995 using Radio Shack drivers and off the shelf crossovers when I first got my taste for speaker building. The really sounded good and I used them for 7 to 8 years until I built my new home and got my large 65" TV and then, they didn't really give me the sound to match the large format TV. There was something missing, so my quest for better sounds started. As the Eagles say in their opening line on their Hell Freezes Over DVD, "and that's how it all began"! In the picture below, the time stamp is 2004, so that is when my quest and hobby really picked up and the hobby became a passion. I finished building my new home in 2002, got my big TV in 2003, and the audio journey was started. The internet became my learning center and I spent a lot of time online learning and participating in forums asking questions. I also purchased several speaker building books from well know speaker designers and used them as some guidelines. If you are willing to venture into such a large project, get yourself some reference material like I did and study them well.
Get involved with as many DIY speaker building forums you can. I've learned a lot just by reading posts and archives of posts in these forums without ever asking a question. Many of the questions you have, are already answered in detail. Most forums have a "search box" in the upper right of their site where you can just type in a subject and then see the posts related to your specific needs or question.
One important note to remember for all of you who are new to this hobby and start participating in the forums, is to check the poster's amount of posts read their bio on the left side of the page indicating who the poster is. This will give you some kind of indication as to how much knowledge they may have and how long they have a member, which may be an indicator that you can rely on what information they are providing you and may be backed up with some experience. I have read some of the suggestions made by some posters and I could tell they were less knowledgeable than I was by their comments. A few posters are arrogant and rude so just ignore them. The world is full of them. Tit for tat in the forums is not very popular, and is certainly not appreciated by the forum members or administrators. This hobby takes time to learn, and everyone has to start sometime.
I built the speakers using the dual 4" ports, but I noticed a resonance sound. Figuring it was from not enough cabinet bracing, I added a couple of more braces to the lower half of the cabinet and didn't notice a reasonable improvement, so I attributed the resonance sound to the ports being located so close to the bottom of the cabinet. "Poor port locations can cause port noise, resonance, and other unwanted sounds to be amplified by as much as 10 times" according to Vance Dickason, a pioneer in speaker building. Purchase one or more of his books online. His "Speaker Building Cookbook" is his best seller and is packed with a lot of information, available from www.PartsExpress.com. So if you are listening to your speakers at 80 to 100 dB, multiply the resonance sound by ten times, and it will really become noticeable, like bad distortion.
The photos below show the rebuilding of the mains again, installing the passive radiators I removed from my subs. I built new baffles so the speakers would have a nice finished look instead of simply patching the 4 to 5 inch port holes in each of the mains. The 15" Eminence passive radiators are loaded to a total of 1100 grams each.
The Lambda Series TD drivers are setting a new higher standard
for performance and durability. Designed for punishing professional use, they
also have the clean sound needed for critical monitoring and audiophile uses.
The TD12S is a high sensitivity, high power handling, high excursion, wide
bandwidth driver of which there is no comparison. These drivers are capable of
reproducing frequencies of up to 2Khz off axis, and much higher with a more
narrow dispersion pattern.
They are rated for 500W continuous power handling. Power compression is perhaps
the lowest of ANY woofer currently available due to the combination of shorting
rings and the phase plug. As a result, inductance and distortion is also
extremely low. More details can be found
here
about the use of passive radiators to help with nice and clean low
bass response.
The above crossover network is what I built for each of my mains.
I had to rebuild my dual Lambda front baffles again and laminate them to have a nice finished product, as shown in picture #3. I didn't want a plug or patch job where the ports were and needed to build them to maintain a good looking speaker. Pictures 1 & 2 shows the process of installing the passives in the mains and the roll of the new Formica is in the background of pic #2. I added weather stripping around each of the passive radiator holes to make an airtight seal and also installed the seal on the back of the front baffel. By removing the ports, I removed the possibility of ports noise and resonance, and lowered the box tuning of the lower Lambda section of these mains down from 30 hz to 23 hz, a substantial difference. I've included a response chart below:
The upper right information box shows the mains after adding the passive radiators, the red line. The lower one represents the the mains utilizing the 2- 4" x 12" flared ports, the green line. Now two improvements are noticed. No more port noise, and lower cabinet tuning. What a nice combo. I wired the Lambdas and the Scan Speak midrange drivers in parallel giving me a 6dB increase over all output gain in my mains. The Lambdas are crossed at about 750 hz, then handing the midrange work to the Scan Speak mids, so the midrange drivers can perform even more efficient not carrying the lower hz. The sound from my mains are so clean, crisp, and detailed. Many loudspeakers can cause fatigue from shrill drivers and/or poor crossover design, but not these!
In this photo, the finished mains are in transit from the shop to the house. They wanted to stop in the driveway and asked for some photos to be taken with the natural sunlight. The third photo shows the new grill cover frames I made to cover the new passive radiators on the sides of the mains. They will just snap in with the fasteners I've used. Now I have 13 grills and after 10 years of rebuilds and new speakers projects, my upholstery shops have changed colors a little, so I purchased a large quantity of black audio grill cloth and am having all of them completely redone with the same cloth, at the same time for a very nice finished look to my system. Just looking at the finished mains, one wouldn't think that there are literally months and months of labor, design, redesign, and lots of money to finally have a superior quality sounding main speaker. I get a kick out of going to both the average retail and the "high end" audio stores and listening to their speakers for sale, and then relaxing in my living room appreciating the fruits of my labors and research. The high end audio salesmen call my mains, "refrigerator speakers" to taunt me. I don't mind at all because my "refrigerator" sounds so much better than theirs!