DIY Speaker Building, Repairing, & Upgrading

[kareface]

Originally Posted by Big Daddy

They have nice speaker plinths at OregonDV (Sound City), but they are expensive.

http://www.oregondv.com/Floor_Standi...ds_Plinths.htm

I haven't decided what I will do with my new DIY speakers. They are made of plywood and I am leaning toward stain and varnish. You can't put stain on MDF wood. I am leaning toward cherry color.

I know about that place. I can't use those because they don't get the speaker high enough for the bottom port.

For your stain I can't recommend this site enough:
http://www.barbarabutler.com/onlinestore.php

I mixed their Bing Cherry and Autumn to get my speaker stain. Their colors are very vibrant and look way better then any of the other ones I tested.

[crazyBLUE]

Sentinal ~ The speakers look great , Congrats on an Excellent Job !

[crazyBLUE]

Originally Posted by Big Daddy

They have nice speaker plinths at OregonDV (Sound City), but they are expensive.

http://www.oregondv.com/Floor_Standi...ds_Plinths.htm

I haven't decided what I will do with my new DIY speakers. They are made of plywood and I am leaning toward stain and varnish. You can't put stain on MDF wood. I am leaning toward cherry color.

I have wanted to do that with the Bostons , But it would be impossible with the bottoms of them .

That place is 45 minutes from me in Salem .

[Beerserker]

Originally Posted by sentinel41

Here is a side by side with my unpolished left speaker. Just to give you an idea of the before and after. I really couldn't be happier with the results. It took about 12hrs to do one speaker, but it was worth the effort.

Ooooh, so shiny!! I am waiting for the "OOH MY ARM IS SO FING SORE!" update tomorrow!

If you are careful you can save yourself some sanding by starting with a coarser grit and working to 2000. Take 70% of the orange peel off with say 1000 grit, move to 1500 to kill the rest of the peel, then final sand with 2000 before the polishing. I would never dream of just sanding with 2000 if I was doing a car, it would take a month. The 1000 will also level the paint a bit to remove the slight rippling effect. If your paint is reasonably thick and you are careful you'll get better results faster. Just go slow on the first side till you get a feel for it. I'm not dogging you results though, they look great.

[kareface]

I haven't had luck finding sand paper near me. I ordered the 2000 from out of state but the local shops seem to be rather lacking. I'll call around once more before I start the next speaker to see if anyone had it in stock. I was lucky, my arm was fine, but I was pretty tired the next day. I think it's because I wasn't applying much pressure. I'm using those speakers as a test for the final product. I plan to start building some new ones at the end of this year. I'm still debating which ones to build, but I'm going all out on those.

[Beerserker]

You should see if there are any auto-body supply stores near you. They will have everything you could need for this job. Places like Home Depot or Lowe's don't have this type of stuff. It's too specialized. An orbital sander with a buffing and polishing pad is worth the money too. Especially if you plan on doing a few sets of speakers.

[kareface]

Originally Posted by Beerserker

You should see if there are any auto-body supply stores near you. They will have everything you could need for this job. Places like Home Depot or Lowe's don't have this type of stuff. It's too specialized. An orbital sander with a buffing and polishing pad is worth the money too. Especially if you plan on doing a few sets of speakers.

I did, lowes doesn't carry car polish, lol. Honestly that sand paper has been a pain for me to find.

[kareface]

Just finished the second speaker. I also found a better solution for taking pictures (I.E. coffee table, lol).


It's not 'perfect', but it's better then I was expecting to be able to get.

[prerich]

Originally Posted by sentinel41

I haven't had luck finding sand paper near me. I ordered the 2000 from out of state but the local shops seem to be rather lacking. I'll call around once more before I start the next speaker to see if anyone had it in stock. I was lucky, my arm was fine, but I was pretty tired the next day. I think it's because I wasn't applying much pressure. I'm using those speakers as a test for the final product. I plan to start building some new ones at the end of this year. I'm still debating which ones to build, but I'm going all out on those.

Nice job SENTINEL41!!!!!

[kareface]

Originally Posted by prerich

Nice job SENTINEL41!!!!!

Thanks a lot. I think I found the next speakers I'm going to build too. I'm almost done with this set and I'm thinking of getting started on another.

[Big Daddy]

Originally Posted by kareface

Thanks a lot. I think I found the next speakers I'm going to build too. I'm almost done with this set and I'm thinking of getting started on another.

Did you use lacquer to get them shiny?

[tbizzle]

That finish looks fantastic, nice job man! Those are some gorgeous speakers

[kareface]

Originally Posted by Big Daddy

Did you use lacquer to get them shiny?

You can, but I didn't.

Normally to get that degree of finish they suggest using 20 sum odd layers of primers, lacquers and clear coats. This was just too costly and time consuming. I did a little research and talked with a good HVLP painter and found out about a cheaper and faster solution. M.L Campbell makes a really nice primer called Clawlock which is designed specifically for use with MDF. They also make a great varnish called Resistant. Both are super thick (45-55% solids formula) and require a catalyst to use. Also you don't require a clear top coat using this method. The advantages of going this route are: a fraction of the coat needed to achieve a good result, the paint is much more durable and because it's pretty solid it's harder to make a critical mistake when sanding or polishing.

I would suggest using 3 layers of each, sanding every 2 layers. So 2 of primer, sand with 600p, 1 primer and 1 varnish, sand with 1000p and finally 2 layers of varnish. They suggest not using more then 2 layers of primer and 2 layers of varnish but I talked with them and if you sand down as suggested above you'll be ok. You just don't want to have the paint be so thick it'll crack once it cures. They are oil based, so you'll need a good mask and a well ventilated area. They suggest waiting a month for the paint to cure but I decided on 2 just to be safe.

Other then that it's business as usual for the polishing process. I can detail that process as well if you want.

P.S. In the image above the white in the space between the front and the sides is a little left over polish I needed to clean off. That's where the line for the tape was and I didn't notice there was a little left over.

[Beerserker]

Originally Posted by kareface

Thanks a lot. I think I found the next speakers I'm going to build too. I'm almost done with this set and I'm thinking of getting started on another.

They are turning out brilliant! So have you come to a final decision on the two channel build yet? I'm hoping you do the Aria and let me know how it is, that's the one that has been on my mind.

[kareface]

Originally Posted by Beerserker

They are turning out brilliant! So have you come to a final decision on the two channel build yet? I'm hoping you do the Aria and let me know how it is, that's the one that has been on my mind.

Someone suggested and really got me thinking about the PMS's. I'm still in the process of deciding tho. I'd have to keep them in the living room till I moved into the next house, but my plan was always to build with the next home theater room in mind. I'm going to take my time and consider a few more options before I make the final decision. I've got time, it'll likely be a month before I can even consider starting the building process. I think I could really make something beautiful with that design tho.

[Big Daddy]

In reference to the DIY speakers that I built recently and described in Post #116 of this thread, I decided to order two Audio Nirvana full-range drivers and experiment with them and compare them to the Fostex full-range drivers. I have plans to build another pair of full-range speakers for my family room to be used with the big 73 inch Mitsubishi TV. I haven't decided which pair of drivers I will use for them.

The Audio Nirvana full-range drivers were delivered a couple of days ago and I got busy tweaking. Here are some pictures.

The gold colored part in the middle is called a phase guide. The Fostex driver comes with a whizzer cone and vented dustcap. On more expensive drivers that reproduce higher frequencies, you typically find a phase plug instead of dust cap. The bullet shape of the plug is designed to reduce the phase cancellations that may occur between the dust cap and the driver's cone. By reducing the phasing issues at these higher frequencies it is possible to improve and flatten the frequency response, resulting in more clarity and depth in the sound stage.

I plan to send the Fostex drivers for an upgrade. It costs $50 per driver and includes the following:

1. Installation of a phase guide.
2. A new suspension system.
3. Cone treatment to improve timbre and voices.
4. Dampening of the spokes behind the cone.

The DIY speaker upgrade consisted of two phases:

Phase 1. Initially, I had put the speakers together because I was in a rush to hear them. I finally decided to take the speakers apart and use, wood glue, caulk, wood putty, and anything else I could find to properly seal all the joints of the horn cabinets so that there are no leakages. I also added a thick layer of foam on the inner wall directly behind and around the driver and stuffed them loosely with polyfill. Because of this little tweak, the low frequency bass sound of the Fostex drivers became tighter and the midrange/high frequency sound became slightly more clear and detailed.

This was important specially because the folded horn design of the cabinet made the wall behind the driver too close to it (see picture below). The cone of the Fostex driver is paper thin and as a result some of the reflections off the back of the driver were coming through the cone and slightly affecting the sound, particularly in the midrange area.

Phase 2. I decided to replace the Fostex drivers with Audio Nirvana drivers to experiment and investigate the results. The Audio Nirvana drivers have bigger magnets, phase guides, and accordion style surrounds. On paper, they have slightly better high and low frequency extension.

I had to modify the screw holes on the cabinet to fit the new drivers and played some music through them for a few hours to test them out. The jury finally came in around 4:00 in the morning. I wish there was some way of going back and forth between the two drivers with an A/B switch. Unfortunately, I had to rely on my memory of the Fostex drivers and we all know that human memory is not very reliable. I have summarized the results in the following.

Audio Nirvana Full-Range Drivers

• Bass was deeper and stronger.
• The drivers had more oomph.
• Although I did not run any test tones to verify this, it is possible that the high frequency extension was better.
• Slightly warmer sound.
• The drivers are very detailed.
• Very efficient.
• They are not as attractive as the Fostex drivers

Fostex Full-Range Drivers

• The bass is not as deep, but it is tighter.
• They did not have as much oomph and dynamics, but may have been more musical.
• Fostex drivers are extremely detailed and revealing, particularly in the midrange. I give the edge to them.
• Slightly brighter sound.
• Very efficient.
• The high frequency may not have been as extended as the Audio Nirvana.
• They are more attractive.

Final Decision
It is a close call. They both are extremely efficient and play very loud with little power. Both of them are extremely detailed and revealing that makes them a bit bothersome. I hear things on albums that I am familiar with that I never heard before. The downside is that if the quality of the recording is not very good, the album will not be enjoyable at all. Some of the CD’s that I liked before are not very pleasant anymore. The positive is that the good albums with good music have become more enjoyable.

What is the final verdict? I like both of my children. If I have to pick one, I would pick the Audio Nirvana for HT applications and the Fostex for music applications. The good news or the bad news is that I sent my Fostex drivers to be upgraded. I don’t know what to expect anymore. I hate this job.

Warning: Do not trust everything I said. This was not a scientific test and I had to rely on my memory. These were my casual impressions that were made late at night in less than perfect room with less than perfect ears.

[crazyBLUE]

I was wondering when you are going to stain them
If it is sunny here it has to be sunny Down there

[Big Daddy]

Originally Posted by crazyBLUE

I was wondering when you are going to stain them
If it is sunny here it has to be sunny Down there

It is sunny one day and cloudy the next day with winds. I will wait a few more days until the weather improves.

[crazyBLUE]

Originally Posted by Big Daddy

It is sunny one day and cloudy the next day with winds. I will wait a few more days until the weather improves.

Have you decided on A color yet , or are you still debating between them .

[Big Daddy]

Originally Posted by crazyBLUE

Have you decided on A color yet , or are you still debating between them .

I am leaning toward cherry as they match the wood floor better. Look at the last two pictures in my post #176. Which driver do you think is more attractive? I like the Fostex white drivers better.