Er, yeah did I mention I wasn’t electronically minded? It would be 2 x 1.64mH inductors 
With that said, you’d have to weigh up the increased space required.. it would probably be easier to just use much larger gauge wire and build just one, although I found the difference between just handling the 1.25mm and 1.0mm to be quite noticeable! I’m not sure I’d want to use 1.4mm (for example) to do the same again!
How do aircoil only setups work? How else would you achieve it? Are running in parallel or using larger wire are the only options?
With that said, you’d have to weigh up the increased space required.. it would probably be easier to just use much larger gauge wire and build just one, although I found the difference between just handling the 1.25mm and 1.0mm to be quite noticeable! I’m not sure I’d want to use 1.4mm (for example) to do the same again!
How do aircoil only setups work? How else would you achieve it? Are running in parallel or using larger wire are the only options?
A 1.64 mH coil would have a greater resistance than a 0.82 mH one wound with the same wire diameter, so paralleling would not result in the reduced resistance you expected. It would be more or less back to where it started.
Stick to single inductors wound with the appropriate wire diameter to obtain the desired resistance.
Stick to single inductors wound with the appropriate wire diameter to obtain the desired resistance.
Broadly speaking, doubling the number of turns on a coil increases inductance fourfold.
Adding a ferrite core increases inductance fourfold. Er, that's about it!
Where we are now on approx. 50L of 12" bass closed box, 5" mid in 5L and 1" soft dome tweeter:
Allegedly no bass. I don't believe it.
Put the speakers up off the floor near the wall and the bass should be OK in my opinion. OK it's closed box bass which is less in your face than reflex. Maybe the mid and tweeter are too loud? We can fix this. Modelling below. Any little glitches are more driver related than crossover related. I am not responsible for THAT!
An almost exemplary Electrical response!
Adding a ferrite core increases inductance fourfold. Er, that's about it!
Where we are now on approx. 50L of 12" bass closed box, 5" mid in 5L and 1" soft dome tweeter:
Allegedly no bass. I don't believe it.
Put the speakers up off the floor near the wall and the bass should be OK in my opinion. OK it's closed box bass which is less in your face than reflex. Maybe the mid and tweeter are too loud? We can fix this. Modelling below. Any little glitches are more driver related than crossover related. I am not responsible for THAT!
An almost exemplary Electrical response!
Attachments
Yes, it's complicated!
The inductance is proportional to the square of the number of turns.
If the length of wire is multiplied by √2 (and this multiplies the number of turns by √2) then the inductance is multiplied by √2 squared = 2, while the resistance is only multiplied by √2.
(√2 = 1.414 for calculation purposes)
Ok an update:
Room size: 5m x 5m
Position: further most left and right about 30cm from the forward wall
Height: 40cm up
The bass is improved but I still have to crank the bass dial up when in most places in the room - especially when front centre or standing in front of one cabinet.
The only time it is improved is when a standing directly in between the cabinets. When standing in between the cabinets, the bass full and rich with much less of the bass dial (but not no bass dial). This is starting to look more like a limitation of the drivers, and maybe we just positioned ourselves advantageously when we tested them before starting modifications. Not really sure when I would be standing in between them apart from to dust the coving. Would this likely have been solved by replacing the bass driver as you originally suggested Steve?
Room size: 5m x 5m
Position: further most left and right about 30cm from the forward wall
Height: 40cm up
The bass is improved but I still have to crank the bass dial up when in most places in the room - especially when front centre or standing in front of one cabinet.
The only time it is improved is when a standing directly in between the cabinets. When standing in between the cabinets, the bass full and rich with much less of the bass dial (but not no bass dial). This is starting to look more like a limitation of the drivers, and maybe we just positioned ourselves advantageously when we tested them before starting modifications. Not really sure when I would be standing in between them apart from to dust the coving. Would this likely have been solved by replacing the bass driver as you originally suggested Steve?
Your sealed box speakers may benefit from being closer to the rear wall, but you should attempt to position them as far as possible from the side walls.
Try to place them 2 to 3 m apart, symmetrically in relation to the listening position.
Due to room acoustics, it is normal for the bass level to vary according to position in the room.
Here's a good source of information: Loudspeaker Placement Part 2: Fix The Bass And Define Your Sonic Space by David Smith, President And Chief Engineer For Snell Acoustics
Wait… somethings different. I’ve just listened to nothing else matters (original) and false flags and it was pretty damn good. I listened to nothing else matters when I first moved them and it wasn’t the same.
Edit: sorry I hadn’t refreshed so I didn’t see your post above. Thanks got the info. I can move them in a bit but not a lot due to the other furniture and fire place in this room. They definitely sound different. The detail in the mids is improving.
Edit: sorry I hadn’t refreshed so I didn’t see your post above. Thanks got the info. I can move them in a bit but not a lot due to the other furniture and fire place in this room. They definitely sound different. The detail in the mids is improving.
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Having now compared them directly to the Roth Oli’s again, the gap has closed. I know you don’t subscribe to the cap run in time Galu, but I’m not sure how else to explain how they sound better today than 3 days ago? We’re currently at ~30 hours run time. Maybe I should get cracking and fit the spikes and built the stands!
We’ll agree to disagree on that one then
Fwiw, I have quite keen hearing. The Mrs does not. I realised the sound was changing when she commented on something - a noise she hadn’t noticed - I listened, and there did indeed seem to be more detail.
Anyway, since it looks like we are done from a technical POV (thanks everyone for all your help, patience, everything!) I will continue on the grilles and spikes this week and post final photos as soon as I am done!
Fwiw, I have quite keen hearing. The Mrs does not. I realised the sound was changing when she commented on something - a noise she hadn’t noticed - I listened, and there did indeed seem to be more detail.
Anyway, since it looks like we are done from a technical POV (thanks everyone for all your help, patience, everything!) I will continue on the grilles and spikes this week and post final photos as soon as I am done!
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Spikes are overrated, IMO. I just use 4 rubber feet to protect the woodwork. Cheapest lace I know is Poundland's "Skid Protectors" for furniture at a, er. Pound!
B&Q charge £5 for four, which tests my credulity!
You have done tremendously well here, David. A big project really.
I usually design for a bit of easy adjustment to the overall sound, but assume generic sorts of drivers.
The tweeter filter is pure Celestion Ditton 44:
Some influence from Troels Gravesen too:
SEAS-3-Way-Classic
You usually use a few favourite test disks to judge if the balance is right. 3 ways have a quiet sort of sound. It's the lack of distortion when you play them loud that marks them out.
B&Q charge £5 for four, which tests my credulity!
You have done tremendously well here, David. A big project really.
I usually design for a bit of easy adjustment to the overall sound, but assume generic sorts of drivers.
The tweeter filter is pure Celestion Ditton 44:
Some influence from Troels Gravesen too:
SEAS-3-Way-Classic
You usually use a few favourite test disks to judge if the balance is right. 3 ways have a quiet sort of sound. It's the lack of distortion when you play them loud that marks them out.
Thanks Steve that means a lot. I know I ask a lot of [potentially stupid] questions, but I do retain and learn.
Another good option for the feet is those IKEA soft fuzzy things. They do packs of god knows how many for a couple of quid. Lower profile too if that’s what you’re going for. As it happens, I already had these spikes. I bought them as a replacement for the Roth’s ages ago but the seller sent the wrong ones and didn’t want them back. I think the colour will work well with the new dark veneer.
Here’s a pic of them [carefully placed] on a cabinet:
Galu, a sneak peek of the veneer there… the grain has come out so nicely. We love them. The darker wood will suit the spikes and new badges.
Here’s what I have been doing this morning:
We’ll have no reflections here!
Those 44’s look lovely Steve, I’d love for some of those to come up on Freecycle. I’m always on the lookout for stuff like that. Even rarer than speakers of that caliber is a decent amp. Plenty of LED-tastic 5CD changer Aiwa happy hardcore systems, though!
Quick question about this:
The centre of this cone is just a dust cap, right? Can it be very carefully and lightly coated in PVA to turn it black? Or is that a really bad idea? It’s just aesthetics but I have a totally black front apart from the grey of the centre of the bass cones and some of the screws which I will eventually change. Any ideas on blacking those out would be appreciated.
Edit:
I wasn’t sure about that foam, heat wise. Yes it was in direct contact with the original goodmans crossover, but that was a different animal. I have placed some of the foam directly over the new crossover, but not touching the coils. To make sure it was suitable I put a small chunk on a paving slab and heated it with a heat gun in one hand and with an IR thermometer in the other hand checked the temperature of the surface. It got to just over 200C before scorching. So I am happy.
that means a lot. I know I ask a lot of [potentially stupid] questions, but I do retain and learn. Another good option for the feet is those IKEA soft fuzzy things. They do packs of god knows how many for a couple of quid. Lower profile too if that’s what you’re going for. As it happens, I already had these spikes. I bought them as a replacement for the Roth’s ages ago but the seller sent the wrong ones and didn’t want them back. I think the colour will work well with the new dark veneer.
Here’s a pic of them [carefully placed] on a cabinet:
Galu, a sneak peek of the veneer there… the grain has come out so nicely. We love them. The darker wood will suit the spikes and new badges.
Here’s what I have been doing this morning:
We’ll have no reflections here!
Those 44’s look lovely Steve, I’d love for some of those to come up on Freecycle. I’m always on the lookout for stuff like that. Even rarer than speakers of that caliber is a decent amp. Plenty of LED-tastic 5CD changer Aiwa happy hardcore systems, though!
Quick question about this:
The centre of this cone is just a dust cap, right? Can it be very carefully and lightly coated in PVA to turn it black? Or is that a really bad idea? It’s just aesthetics but I have a totally black front apart from the grey of the centre of the bass cones and some of the screws which I will eventually change. Any ideas on blacking those out would be appreciated.
Edit:
I wasn’t sure about that foam, heat wise. Yes it was in direct contact with the original goodmans crossover, but that was a different animal. I have placed some of the foam directly over the new crossover, but not touching the coils. To make sure it was suitable I put a small chunk on a paving slab and heated it with a heat gun in one hand and with an IR thermometer in the other hand checked the temperature of the surface. It got to just over 200C before scorching. So I am happy.
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The centre of the woofer cone is a dust cap If it is porous and intended to 'breathe' it would be a bad idea to seal it. If it is solid, I would give it a light spray with acrylic matt black paint from an aerosol can, after masking off the cone of course.
I'm not sure that placing the foam so close to the woofer cone is a good idea as it may overdamp the woofer and reduce its Q, making the bass less prominant. Some experimentation may be required here.
Edit: Paint the screws matt black too!
I'm not sure that placing the foam so close to the woofer cone is a good idea as it may overdamp the woofer and reduce its Q, making the bass less prominant. Some experimentation may be required here.
Edit: Paint the screws matt black too!
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The centre of the woofer cone is definitely paper. I’ll leave it well alone. I wouldn’t want to get this far then break the woofer because of appearance!
I’ll test and experiment with the woofer foam. There was quite a considerable amount in the cabinet before. Not all of it has gone back in due to the position of the mid enclosure. So far I haven’t noticed any negatives but I’ll do as you suggest and give it a good caning over the next few days one with and one without to check.
I could paint the screws, It’s easy to fill in a Phillips though (yes I’ve done in before and then they’re a b**** to undo!) I’ll have to be careful.
Edit:
Interesting fact: these cabinets now weigh 18.3kg each.
I’ll test and experiment with the woofer foam. There was quite a considerable amount in the cabinet before. Not all of it has gone back in due to the position of the mid enclosure. So far I haven’t noticed any negatives but I’ll do as you suggest and give it a good caning over the next few days one with and one without to check.
I could paint the screws, It’s easy to fill in a Phillips though (yes I’ve done in before and then they’re a b**** to undo!) I’ll have to be careful.
Edit:
Interesting fact: these cabinets now weigh 18.3kg each.
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