My experimental speakers :)

[quickshift]

Hello

I'm part way through making some experimental speakers so I thought I'd pop up a couple of pics so you can tell me it's a silly idea and it won't work

It's a sort of T-Line type idea.

I'm using 8 x 5" wharfedale + 1 x Seas H1212 crossed at 3000 - 4th order LR.

If it doesn't work I can use the tweeters and crossover for another project

[quickshift]

The units so far

They stand 1.7 meters high

Excuse the mess, a new kitchen is being fitted although I can't pretend the builders are entirely responsible

P.S. - they do actully stand up straight, the wood they are on is crooked.

[RJ]

Don't be afraid to experiment.
Here's my Snowman 2.5 ways with 2 different midbass drivers in a labyrinth Transmission Line that's about 110" long. They sound absolutely great with the Seas 27TBFC/G tweeter. Kind of high Qts. drivers .58 & .40.....They're fully stuffed so that about makes them Aperiodic. It's nice to know that the backwave is nearly nullified. With 90db output in front they're not even registering 50db out the port.
Still tweeking the crossover.
I really like your design.
What drivers are you using and did you model the length with MJK's worksheet????

[sdclc126]

Very interesting concept. This kind of looks like a line array/T-line/tuning port hybrid. I'm no T-line expert, but this is what comes to mind...

First of all, could you be more specific as to what your goals were when you came up with this design? Certainly enhancing the bass response, but -

What calculations did you do? Did you take into account the parameters of all four drivers in each enclosure when designing the T-line? And is it actually a T-line? It doesn't appear to be tapered throughout its entire length, which is what I'm used to seeing.

Does the T-line/port(?) have a particular tuning?

These are just questions, not criticisms. More details about what you're trying to do will help others here give you advice. When you say you'll try something else if it "doesn't work" you really have to define what it means to you by the speaker working or not. It will certainly "work" of course by emitting sound, but perhaps not the way you had in mind.

So what did you have in mind for this project?

[quickshift]

RJ,

I love experimenting with stuff Probably a bit too much to ever try building a tube amp though

Excellent name for your speakers Good stuff! The Seas 27TBFC/G really are great tweeters

The drivers are some really cheap (under £2 each from Ebay) doped paper wharfedales - I don't know the model number, I measured the FR and got the attached results which I was pleased with to say the least!

I haven't modeled the length properly. TBH, all I really understand about t-line speakers is the length is theoretically 1/4 of the wavelength of fs and usually works out to be 80% to 90% of that in practice - so went for about 1.4 meters as fs is 56Hz. I did look at the mathcad worksheets, well I say looked, I read about them and decided it would take too long to learn what they mean as I only have a short window in which to build the speakers.

It'll be about a week before they are finished enough to listen to, I can't wait

[quickshift]

Originally posted by sdclc126
Very interesting concept. This kind of looks like a line array/T-line/tuning port hybrid. I'm no T-line expert, but this is what comes to mind...

That's what I was trying to build, I haven't seen anything exactly like this before so though I'd give it a go.

[i]First of all, could you be more specific as to what your goals were when you came up with this design? Certainly enhancing the bass response, but - [/B]

To try to build a line array type speaker that didn't absolutely require a sub. Small footprint and to use up some of the box of 5" speakers I bought.

[i]What calculations did you do? Did you take into account the parameters of all four drivers in each enclosure when designing the T-line? And is it actually a T-line? It doesn't appear to be tapered throughout its entire length, which is what I'm used to seeing. [/B]

Err, nearly no calculations I haven't really got to grips with all the maths involved. Now if the nice people who made winisd would do a version for t-lines....

I don't think they have to taper, at least I hope not anyway

Most of the ones I have seen do taper but not all of them.

[i]Does the T-line/port(?) have a particular tuning?[/B]

The length is about 90% of 1/4 of 56Hz which is the fs of the 5" speakers.

[i]These are just questions, not criticisms. More details about what you're trying to do will help others here give you advice. When you say you'll try something else if it "doesn't work" you really have to define what it means to you by the speaker working or not. It will certainly "work" of course by emitting sound, but perhaps not the way you had in mind. [/B]

I didn't feel like they were criticisms I'm sorry I can't provide better (sensible I.E. based on proper research) answers. I'm not sure exactly what I'm expecting but if I can enhance the low end output of the drivers I'll be happy.

It's really just an experiment, I haven't set any criteria as such. I may try mass loading the box and stuff like that just to see how it performs.

[quickshift]

Right, they are built.

They actually sound pretty OK, the bass output isn't too bad and they produce 30Hz at a resonable level which is nice. They pass through 56Hz without any problems. The sound from the port isn't muddy which was a slight worry - bass is quite punchy. I'm happy to listen to them without a sub

They really aren't very subtle. They don't sound at all harsh but the sound really grabs the attention. The sound is massive for want of a better way of putting it.

As there still seems to be a shortage of H1212s so I'm using other tweeters for the moment.

Pics and measurements when the proper tweeters arrive.

Quite a successful experiment I'd actually buy speakers that sounded like these do - If I didn't object to buying speakers

[Relax]

What drivers are in the snowmen?

[RJ]

What drivers are in the snowmen?

MCM 55-2311 - 6 1/2" Which are Discontinued.
MCM 55-1870 5" Stage Monitor
Seas H1212 Tweeter
2.5 crossover

[baggins]

Hi Quick,

SO THATS WHAT YOU WERE BUILDING!!

Ive just spotted the thread --- Nice one
BIll T.