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
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
Attachments
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????
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????
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?
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?
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
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
Attachments
sdclc126 said:
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.
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.
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.
The length is about 90% of 1/4 of 56Hz which is the fs of the 5" speakers.
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.
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
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 
Well I finally got these finished. Well, finished to prototype standards anyway
They don't sound too bad at all, I'm quite happy listening to them anyway I'm pleased with the presentation.
I've ended up lightly stuffing the top and bottom openings with acoustic wadding.
I guess the next stage would be to find a load of cheap tweeters to build a tweeter array from as a single tweeter in the middle of each speaker means my head needs to be more or less at tweeter height to get the best from them.
I can't measure them ATM because I've managed to break my mic preamp, they sound like they play reasonably low and although there isn't a lot of punch to bass but I don't usually bother with the subs.
I connected them to a frequency generator and loosened the front baffle a bit - I guess the TL is doing it's job because the front tried to detach itself between 52 and 57 Hz - with the front tight, they are fairly even down to about 40 Hz but tail off fast below that.
They really are big
Well, finished to prototype standards anyway They don't sound too bad at all, I'm quite happy listening to them anyway
I'm pleased with the presentation. I've ended up lightly stuffing the top and bottom openings with acoustic wadding.
I guess the next stage would be to find a load of cheap tweeters to build a tweeter array from as a single tweeter in the middle of each speaker means my head needs to be more or less at tweeter height to get the best from them.
I can't measure them ATM because I've managed to break my mic preamp, they sound like they play reasonably low and although there isn't a lot of punch to bass but I don't usually bother with the subs.
I connected them to a frequency generator and loosened the front baffle a bit - I guess the TL is doing it's job because the front tried to detach itself between 52 and 57 Hz - with the front tight, they are fairly even down to about 40 Hz but tail off fast below that.
They really are big
Attachments
They must sound awesome! Ive only got 2 of these 5" in small boxes
with piezos and they are the best most analytical speakers Ive ever built. I,m still wading through my old records listening to things Ive never heard before .
O.K. I probably only had very bad speakers before and Ive never measured these but its all about enjoyment at the end of the day and if someones looking to build some competent units cheaply, I thoroughly recommend trying these old wharfedale units.
Well Done!
with piezos and they are the best most analytical speakers Ive ever built. I,m still wading through my old records listening to things Ive never heard before .
O.K. I probably only had very bad speakers before and Ive never measured these but its all about enjoyment at the end of the day and if someones looking to build some competent units cheaply, I thoroughly recommend trying these old wharfedale units.
Well Done!
I forgot to mention ,
I use the other pair I bought in aluminium boxes on the backwall
of the house ,again with piezos -as garden speakers -- A glass of wine
and some Puccini under the grape vine and the world seems a much nicer place. the grapes are edible too - must be global warming !
Baggins.
I use the other pair I bought in aluminium boxes on the backwall
of the house ,again with piezos -as garden speakers -- A glass of wine
and some Puccini under the grape vine and the world seems a much nicer place. the grapes are edible too - must be global warming !
Baggins.
Good to see someone else experimenting. Sometimes it's just quicker to do it than design it. See my thread on plastic TLs. I did those to see what all the fuss was about. Learnt how to tune the pipe length with my ears. And realised the transient response that TLs can provide.
Did some measuring on the weekend. Those poles were an inch long.
I fixed that, new pictures soon.
How do you find the vertical spread on your array? I have found with 4 drivers a very wide dispersion, and about 10 degrees vertical.
Keep up the experiments.
Did some measuring on the weekend. Those poles were an inch long.
I fixed that, new pictures soon.
How do you find the vertical spread on your array? I have found with 4 drivers a very wide dispersion, and about 10 degrees vertical.
Keep up the experiments.
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