What to do with small transmission line cabinets

[VvvvvV]

That I have some well-made thigh height floor standing transmission line Cabinets that I would like to refurbish as a first DIY project.

From what I've read about transmission lines, I will have to tune the new drivers and the new crossover so that something is in phase with the length of transmission line chamber. The thing is, the lines on this cabinets are fairly short, probably about 50 centimetres long, like in the cross-section on the attachment. I have no idea if the kits for transmission lines available would have ranges that would correspond to the cabinets I have. Anyone know?

I'm not used to anything very high Fidelity, so I'd be happy with anything good, although I would typically like lots of bass and lots of clarity to do monitoring work of bass heavy music. I looked at some IPL kits, perhaps they would be all right, although I did read a review that said they were generally more muddy and slow than typical $2000 commercial speakers kind of like an old recording of Bob Marley. I've also seen active speaker kits are fairly cheap, which is quite tempting, because my amplifier is an average commercial hitachi one.

What would you do in my place, is the most reasonable option to spend $300 on a driver and crossover kit that can be tuned for a transmission line like on the IPl web site, should I spend a bit more on some homemade cabinets to achieve a grander result , are the crossovers that came with the cabinets already tuned right for any drivers?

heres some pics:

[purplepeople]

If you are working on LF-heavy stuff with LF-heavy monitors, you are likely to end up with a LF-light mix.

Now, I'm not saying you need to lower the bass, but it's always a good idea to know exactly how much is in it. Maybe consider something with flatter response 20-20K so you'll get a more accurate representation of how much LF is in the actual mix.

:)ensen.

[VvvvvV]

I guess it wouldn't be suitable for serious multitrack mixing, although I think that the important thing with bass heavy or bass capable speakers is that it is best to use bass samples and pads with extended harmonics, unlike sine basses, that would handle well even on small speakers.
Any decent clarity should be all right for the repartition of multiple tracks across the sound range while writing tunes. I'm sure that speakers that you guys use would be ample for making mixdowns of the quality of air or massive attack.

The important thing is I don't know what on earth to do with these cabinets for an investment. Flatness of the image far secondary next clarity and bass range. I was just wondering what you would do?

[purplepeople]

Well, it looks like there are two holes so you are probably going to make a 2-way. Anything else would require "adjustments" to the baffle.

For quick (but good) results, I would use the Martin King's TL alignment tables to determine what LF driver you need.

http://www.quarter-wave.com/

Cross-reference the tables with the line length which I estimate at around 1.5m or 60 inches (much more than 50 cm). It also looks like the LF driver is around 30-40cm from the closed end of the line - this measure is also accounted for in the alignment tables. Work backwards and get the Fs of the needed driver. Choose a Xover and HF driver to match and you're set.

I don't know about the IPL speakers, but I've had a chance to demo M&K and heard good reports about PMC. Check here for links.

http://www.t-linespeakers.org/linx/linx.html#Commercial

:)ensen.

[VvvvvV]

These are definitely two-way cabinets, made from 20 millimetre MDF, and 76 centimetres high.
The beginning of the transmission line starts horizontal with the low edge of the bass driver, within 15 centimetres. The lower half of the enclosure is divided so that two thirds of the lower half is a bass reflex box directly under the bass driver, and round the back of the bass reflex is a transmission line. Like in the link on the first post. This means that the transmission line is 60 centimetres maximum.
These are well reviewed speakers, but the drivers were never top-quality, and has all sorts of strange things about it, for example the shortness of the line, the giant integrated bass reflex, and a lack of padding fibre in a line that normally provides viscous resistance. I don't know what all this means!

This is my first DIY project, I just wanted some well-suited replacement drivers, but everywhere I find 41 page 16 term function laden articles about phase Characteristics. I thought I read on some article you could get some good drivers and some special kind of DIY crossover where you could vary a knob on the crossover to get the perfect setting. Three forwards and then three forwards and then one back until it hits the spot. That's what I heard about IPL speakers.

[planet10]

It all depends on how you interperet it... in the pic below the line length is roughly the red line.... this is a stepped cross-section line with offset driver...

dave