Classic TQWT for CHR-70 gen. 3

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
I've been put on the task of doing a simple to build (for my sake) non obtrusive (for their sake) speakerset for my sister and brother in law.
I chose the CHR-70 for the project, because I think it will suit their listening tastes the best.

For aesthetic and furniture space related reasons is has to be around 100 cm high (the driver mid needs to be at about 90, to be at sitting hight and to shoot clear of the furniture). They also really would like it to have a square cross-section (equal with and depth), which I can see no problem in.

I want to do a TQWT as it's simple, small and I think well suited for the driver.

By not having it significantly massloaded I will be able to get it those ∼ 10 cm higher than what is usually done with the CHR line in QW resonators, right?

As I'm on a Mac and don't have access to a windows machine where I can sit for hours on end and concentrate and install software, I can't use MJKs software, so I'll have to rely on you guys to nudge me in the right direction.

Here is how I figured it might work best purely based on conjecture and comparison:

An externally hosted image should be here but it was not working when we last tested it.

(Adjustable feet for curved corners on old floors.)

The speakers will be corner loaded, so I think results will not be to far from FR horn Mk 3.

Edit: Ok, I don't seem to be able to get the image uploading to work, so I'll have to describe instead:
20x20x100 cm (7.8x7.8x39 inch) 18 mm ply, with a rear opening to use a corner or wall for loading, same basic idea as the frugel horn Mk 3 just without the wings.
So my question is: are the measures right for the driver and what size should the opening/mouth on the back be?
 
Last edited:
Just another Moderator
Joined 2003
Paid Member
guys the best thing to do is click go advanced (if you aren't already in the advanced editor, then click manage attachments and then upload the image to diyAudio.

I've done it :)

Tony.
 

Attachments

  • tqwt.jpg
    tqwt.jpg
    91 KB · Views: 299
I have modeled this driver in a tapered TL and it looks pretty good in a line about 150cm long with 150cm^2 area at the closed end and 50cm^2 at the open end with the driver mounted 1/3 of the way from the closed end. It shows a little bump up at 40Hz just before fall off begins which would be helpful in flattening the response when the needed high pass protection filter is added. Might be worth knocking something up for testing.

I haven't built it because I decided to switch to a small sealed enclosure with a helper woofer in a separate compartment for my application.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.