Speaker cabinets

[Bigchasbroon]

I have a pair of good quality speakers tannoy 605s.
I'd like to make floor standing enclosures and use the drivers tweeters and crossover from these. Has anyone done something similar and how easy is it to mess up the sound? The existing enclosures are six sided.

 

[johnleve]

Yes and no

The shape of the box could be important to the sound but from what I know the most important aspect is volume.  If you can match the volume, porting, and fill it might turn out well.

 

[wow]

Yes and no

The shape of the box could be important to the sound but from what I know the most important aspect is volume.  If you can match the volume, porting, and fill it might turn out well.

Don't forget about density of the wood. You will probably need some HDF rather than mdf if you drive them very hard.

 

[Bob Gerritsen]

I think you should really investigate as much as possible before getting the tools out. The thing with reproduction of sound is that a lot of things are at play at the same time. The drivers, the filter, design of the cabinet, material of the cabinet, dampening... And it all influences each other. I know that some speakers cabinets are designed to be as dead as possible, others get a lot of low mids and bass from the cabinet, so the cabinet vibrating actually makes the overall design better. Many highly rated speakers turned out great despite being flawed on paper and vice versa. The simple fact that many different brands are highly different designs tells something.

Didn't those Tannoys also come in a floor standing version back then? I'd consider trading yours for those maybe or at least checking out what's different between the two models.

I do know those Tannoys are diamond shaped to reduce internal vibrations, it might well be those drivers and filter sound crap in a simple box design.

I'm just saying there's no saying what you'll end up with if you simply jump in and build something.

 

[johnleve]

Looking at the pictures I don't know that you have too much to worry about, I think the shape is largely about aesthetics.  From what I know the problem that can arise is a standing wave but I believe that can be addressed easily by using something like Blackhole 5 or another foam to break the wave.  I have used MDF in the past when I have made speakers and it has always worked out well.  I don't think that HDF is necessary but a lot of manufactured speakers use it.  I use 1.5" thick MDF so perhaps using HDF you could cut down on that but I don't know that it would have any great effect on the sound.  My suggestion would be to figure out the internal volume and then use some MDF to mock-up a standard box.  Take the internals out and give it a go. 

While not a precise science there are generally guidelines that if followed result in an acceptable sound.  I have used Focal drivers in the past and the spec sheets that come with always give guidelines for the volume of the enclosure and then a couple of options for porting (or not as is my preference) and frequency response as well as other details that are used to design crossovers.

This can be well worth the effort.  I spent perhaps $750 on parts to build a speaker bar into the built-in that I made.  The sound that comes out of it easily rivals the sound my friend gets from his Klipsch setup with two Icon XF-48 speakers that cost double and stick out like sore thumbs while mine is unobtrusive.

 

[Bigchasbroon]

Ok thanks gents. I suppose it wouldn't be hard to mock up a prototype using mdf to see what they're before going all out on a veneered board.

 

[woodie]

Have you considered building pedestals that match the shape of the Tannoy's instead? I have a few speakers from Triad that use pedestals. Their speakers cabinets have a threaded insert on the bottom allowing you to couple to the pedestal. The pedestals have a tube down the middle to conceal the speaker cable and an opening in back that allows them to be filled with lead or sand.

Here's a link.

http://www.triadspeakers.com/products/irpeds.html