Hello, tell me if i'm mad, but i would like to....

[andreasmaaan]

Sounds like I have two options.....a) turn the towers on their side and blast some music through them to see how they sound, or b) look at getting a set of 6's or 6.5 and maybe a tweeter or smaller full range speaker.

Definitely try (a) first

If you go with (b), I'd recommend getting an off-the-shelf 2-way speaker and "re-boxing" it in your radiogram, or buying the parts for a properly designed kit and building those into it. Just buying off-the-shelf woofers and tweeters and putting them next to each other won't work, and designing an appropriate crossover to make them work is a very involved process (but an immensely satisfying one if it's someone you have the inclination to learn how to do).

 

[3rutu5]

Trying my best to not create a randomogram, feels like it at the moment.

Will have to look at what is available, I don't believe i know anyone who has done the crossover work before, so might need a bit of Doc Google to see whats involved before i make a decision.

 

[andreasmaaan]

Trying my best to not create a randomogram, feels like it at the moment.

Will have to look at what is available, I don't believe i know anyone who has done the crossover work before, so might need a bit of Doc Google to see whats involved before i make a decision.

I/we here can no doubt help if you want to learn how to design a crossover. You’ll need to buy at least a measurement microphone though, and learning how to use some modelling software would also be a good idea. As I said, steep-ish learning curve but very satisfying

 

[Soniclife]

You can buy diy kits with everything you need, including crossover.
E.g. https://iplacoustics.co.uk/ipl_m2_mk2_mini_monitor_13_litre.htm
Lots of options out there. What you really want is something with good vertical dispersion, but I doubt that's easy to find.

 

[andreasmaaan]

You can buy diy kits with everything you need, including crossover.
E.g. https://iplacoustics.co.uk/ipl_m2_mk2_mini_monitor_13_litre.htm
Lots of options out there. What you really want is something with good vertical dispersion, but I doubt that's easy to find.

Why would you say good vertical dispersion is particularly important?

 

[Soniclife]

Why would you say good vertical dispersion is particularly important?

It looks like the drivers will be low down, if they are not then it doesn't matter.

 

[andreasmaaan]

It looks like the drivers will be low down, if they are not then it doesn't matter.

Yep, fair point.

@3rutu5, all the advice I've been giving so far has been based on the presumption that the tweeter in your radiogram will be at about the ear height of a person sitting in front of it.

BTW, if this is not the case, I would stay away from ribbon tweeters and look exclusively at dome tweeters. Ribbon tweeters invariably have more erratic vertical dispersion.

 

[3rutu5]

Unfortunately the tweaters will be about 400-450mm above the ground, so more than likely below the persons ears sitting in front of it. I just turned the speakers 90 degs and pumped some thumpy music through it. I dont know if it is in my head, but i could pick up on some difference to standing them upright, mainly it was clearer when vertical. thinking if it is slightly noticeable to us horizontal, than keeping it predominately vertical is the way to go.

i measured the available area per side and i have 600*450*450mm, so i could almost fit the existing speakers in their current arrangement, just short 50mm. I have noticed online some boxes will slightly offset the tweeter, but dont know if there is something done in the crossover to accommodate this. Ignore the not to scale part, it would appear i didnt draw it to scale originally, only found it out last night, which is a bit embarrassing.

The second would be using https://sites.google.com/site/undefinition/diy/amiga as it is basically the alternative speakers i was wanting, the parts itself would be around the 330-370 AUD and the GST component once it enters the country.

I'm thinking if it is slightly noticeable to myself, but not too bad, i would be considering the recycling option for now, but it they stop working i will be at step 1 all over again, but with a bunch of 6 inch holes i would have to re use.

If i was at work i would have smashed this out in CAD instead of using a circle template and a dodgy drawing, but i guess you use what you can when you can.

 

[3rutu5]

Guys, i know this will sound like a dumb follow on and i could see that having woofers out of vertical alignment is a no no, but what about the tweeter? considering the size of the tweeter and the plastic lip/surround (over double the size) i was thinking i could trim the plastic if it is generally a major issue in order to get it closer to the original vertical arrangement. I have a hard time no up cycling something at the moment, i know i could just order some new gear online, but want to exhaust the options first.

 

[Wombat]

Guys, i know this will sound like a dumb follow on and i could see that having woofers out of vertical alignment is a no no, but what about the tweeter? considering the size of the tweeter and the plastic lip/surround (over double the size) i was thinking i could trim the plastic if it is generally a major issue in order to get it closer to the original vertical arrangement. I have a hard time no up cycling something at the moment, i know i could just order some new gear online, but want to exhaust the options first.

This forum may be worth trying: http://www.diyaudio.com/forums/index.php

Cheers.

 

[andreasmaaan]

Hi again @3rutu5,

Unfortunately it's the tweeter-woofer positioning that is more sensitive to these kinds of changes than the woofer-woofer positioning.

It's not that you can't do it, it's just that it's suboptimal. However, given that the whole thing will be *too low* already for optimal listening, perhaps this is a compromise that you can tolerate?

The DIY Amiga speakers you linked look ok. However, the frequency response graph they've posted is confusing. For one, it's entitled "modelled response", which gives me cause for concern (did they actually measure anything??), and secondly, I can't work out which trace is supposed to be the bass response. On one reading, the bass will be very, very lean - if that's the case, I wouldn't use these without a sub personally, or unless you prefer almost no bass.

Anyway, if you're set on recycling your current speakers, then my hunch without hearing or measuring them would be that offsetting the tweeter as you suggested would be a better compromise than rotating the whole thing 90°.

If you're open to buying a DIY kit and then building it into the cabinet yourself, let me know and I can recommend something to you for a similar price to the Amigas but with reliable measurements / a fuller bass response. There's probably some good stuff available in Australia without needing to import from the US, although I'm not sure.

A

EDIT: ok, I've looked at the manual, and the bass response doesn't seem to be lacking, but I'm still a little concerned about the "modelled response" thing.

EDIT 2: one thing I forgot to mention is that if you take any narrow speaker like the ones you own or the various kits you're looking at and put it into a much wider box like the one you're building, it will boost the bass and lower midrange frequencies. Not necessarily a bad thing, just something to be aware of.

 

[3rutu5]

guys, just to give a progress report on the radiogram ....we have hit a dozen hurdles along the way which prevented me having enough disposable income to spend on my 2 way speakers, which mean having to be creative on the run. I know this may infuriate most audiophiles, but i matched the volume of the original towers and offset the tweeter around 150mm in order to accommodate the height. Gave it a first run today with the amp and it sounds ok which will be perfect for the needs at the moment. Still need to put the centre channel in and the openings for the amp and install the HTPC, plus of course the prep and finishing work, but it is quite different since June/July. This thing is solid and still a bit to go, sourced some further 30mm ply to create the vertical members for the speaker enclosures. Will have to find some of that speaker stuffing to line the inside of the boxes as well. I'm not sure the original towers were actually "tuned" for anything in particular as there was a 100mm port. Also there is zero information available on these drivers and woofers, so couldnt even think of a way to redesign the box and go a sealed or transmission line option.

I would have loved to go down the orignal option, but as my little one decided to smash my 50inch tv and use my pioneer amp as a trampoline, i had to basically spend money where it wasn't originally needed. You can see the replacement receiver on top of the box for the trial run today.

 

[3rutu5]

hey guys, haven't really closed this one out have i since posting and starting this build i have built a powered T Line and Bluetooth box, both experimenting with random styles and techniques, which has been fun. Utilising some of the skills from a 180deg kerfing project on the BT, i went back to the drawing board and redid the front upskilling in the use of a router. Honestly i intend to close out the radiogram this week and will post some pictures of the finished project (as well as the TV guard i had to build due to my 3 year old(.

this thing weighs a ton with all that 30mm ply.

 

[3rutu5]

All done....as mentioned further in the post, this was a recycling job with my 15 year old 2/3 way towers, center channel being made into this bookshelf/radiogram thing to use as a home entertainment setup. My son broke another tv so I made a screen protector with 6,mm perspex as well. In this cabinet I might repurpose an active sub, but definitely the receiver and raspberry pi.

Good learning experience, even through I did the cardnal sin of messing with the MTM arrangement.

Made with 30mm ply with kerfed (curved) edges, this is not a veneer, but yes you guess it bent wood (also there isn't a massive gouge in the close up, just the light reflecting off the surface)

 

[Blumlein 88]

On a transmission line you'd like to keep the area of the line equal to the area of the woofer. Basic polyester pillow stuffing can be used at .5 to .75 pounds per cubit foot density. I've used this Acousta_stuff and it is much better.

https://www.amazon.com/Acousta-Stuf-Polyfill-Speaker-Cabinet-Material/dp/B0002ZPLDY

The above will slow the speed of sound thru it to nearly half of normal. Making the effective length of the line twice as long tuned to half the frequency while also damping any resonance modes. You needed to know the frequency of resonance of your woofer to determine all of this up front, but hopefully it will be close as you appear to already have the cabinet built.

 

[3rutu5]

Thanks, that cabinet isn't actually the t line, my PC speakers are and I can still add to it as the length is technically a bit short. I bought a box of acoustic squares for this.big sound bar thing

 

[Thomas savage]

Great work, it’s been fun seeing the progress of these projects so thanks for sharing it.

 

[3rutu5]

I'm thinking of repurposing my old 2.5" satellite speakers that came with my Logitech z-2300 2.1 setup. Was thinking of doing a small t line or horn, but struggling to find any t)s parameters for them. Will definitely use the stuffing for that one. Each one of these builds I seem to pick something unique with the build, ie this one 4 kerfed corners using 30mm ply, the Bluetooth was 1 piece of timber with 180deg kerfed edges and joined back to itself and the t line was nothing special lol....with this 2.5" I want to use a router and make layers verically and glue the sections together, seems like a bit of fun

 

[andreasmaaan]

Really great cabinet work