Testing crossovers

[Covenant]

I have just built a pair of crossovers for IPL kit speakers. Is there a way of testing them with a meter as I am nervous about connecting to the expensive drivers.

[Reffc]

Depends what you mean by testing...is it the filter function you want to test or just the physical connections? If the latter, a visual check with a continuity test (multi-meter set on minimum Ohms) is usually all that is needed if concerned. The filter function is more difficult (and involved!). I am assuming that this is an established crossover design for the speakers and you've constructed the circuit.

[Covenant]

I just want to make sure they don't have anything fundamentally wrong. Hopefully the parts are all in the right place. Photos attached.1419014191

[Reffc]

Impossible to tell from that photo Jerry. The circuit diagram plus clearer photos in terms of what is connected to what would be necessary to provide a confidence check, but in terms of working with the space available, it doesn't look too bad and seems neatly done. My only observation is that the little white bobbin inductor could do with rotating 45 degrees clockwise to avoid coupling issues with the adjacent air core and is a little close for an air core really.

[Covenant]

Impossible to tell from that photo Jerry. The circuit diagram plus clearer photos in terms of what is connected to what would be necessary to provide a confidence check, but in terms of working with the space available, it doesn't look too bad and seems neatly done. My only observation is that the little white bobbin inductor could do with rotating 45 degrees clockwise to avoid coupling issues with the adjacent air core and is a little close for an air core really.

Thanks Paul,
I will borrow a decent camera from my son to do a better photo. The positions of all components were dictated by IPL including orientation. Would a screen between the two inductors help?

[Reffc]

Thanks Paul,
I will borrow a decent camera from my son to do a better photo. The positions of all components were dictated by IPL including orientation. Would a screen between the two inductors help?

Hi Jerry

No. Rotating such that axis are placed at 90 degrees is fine and you can have even air cores fairly closely placed like this. I'd look to have the small one rotated a little more and if space allows, moved slightly further away. May not make a lot of difference but my OCD kicks in with things like this!

[Covenant]

Ok, no problem. I like messing about with the hot glue gun!

[walpurgis]

I like a bit of space between crossover components myself. There's no rule saying crossovers need to be small. A larger board gives more room to work and lay things out in a good fashion, avoiding interaction issues.

[Desmo]

I like a bit of space between crossover components myself. There's no rule saying crossovers need to be small. A larger board gives more room to work and lay things out in a good fashion, avoiding interaction issues.

As long as you can get the board back in the box.... :)

[The Alchemist]

If is of any help I have made a number of IPL kits. I understand your concerns that if the tweeters receive low frequencies the will never work again but in reallity that is most unlikely to happen. If any thing is amiss the likelyhood is that you will get nothing rather than do permanent damage. It would probably suffice to do a basic continuity check on all the joints but be aware the you won't get anything downsteam of the capacitors. As a brief aside I mount all the components on a 3mm paxolin board which is then attached to the 6 legs provided on the connection panel. This method gives a little more room and enables me to use solder tags at all the joints and also to use cable ties on all the components as well as the hot melt glue. This method requires the gold plated tags on the connection panel to be relocated on to paxolin board and attached with short flying leads. When I can get my head round it I will try to post a photograph..........

[Covenant]

Thanks Richard,
That's a relief, I would hate to damage those ribbon tweeters. What speakers do you use now?

[Audio Advent]

Could you connect the tweeter side up to the mid-range? That way you'd hear that the lower frequencies were definately filtered out and playing high frequencies to the lower drivers won't cause damage as the other way around might. Or simply connect it to a some spare, cheap drivers first to check for basic functionality, no box needed..

If it's any consolation, I get the same fears, especially if I've got a new power amp.. so always have some cheap Gale speakers to hand to sacrifice.

[Covenant]

I will probably try it with some cheap drivers. Might need to go to the tip and have a sneaky look around.......

[Reffc]

If you're using the circuit provided with the kit and have wired it accordingly, I would simply fit to your drivers and forget. The circuit will be correct as supplied with the kit. No damage can arise as long as this is the case.

[Audio Advent]

I will probably try it with some cheap drivers. Might need to go to the tip and have a sneaky look around.......

A skip is where my Gales came from! Can't sell those Gale Golds even on ebay at £5... they're not actually bad for what they are.

[The Alchemist]

Hi Jerry,
In answer to your question I have a pair of S2tlp's which I am very fond of. I am just finishing a pair S2tlK's for another member at the moment. They are similar to mine but have a new Kevlar Bass Driver which goes down to 25 Hz....... I might get them running tomorrow and will let you know how they sound. What speakers are you building?

[Covenant]

Hi Jerry,
In answer to your question I have a pair of S2tlp's which I am very fond of. I am just finishing a pair S2tlK's for another member at the moment. They are similar to mine but have a new Kevlar Bass Driver which goes down to 25 Hz....... I might get them running tomorrow and will let you know how they sound. What speakers are you building?

The ones you are building are the same ones as mine I think. S2TLK CD3 Ribbon. I would be very interested in your initial listening results. If I get stuck is it ok for me to PM you? I have the help of my father in law with the cabinets, he is a retired joiner but I don't want to tire him too much. Nervous about the veneering but that will be in a few weeks I think.

[The Alchemist]

Hi Jerry,
Feel free to send me a PM. I understand your reservations about veneering and I would be very happy to help. I am on my 3rd pair of veneered cabinets so can provide first hand experience of the process. I always use paper backed veneer stuck on with Scotchweld 30. It is an excellent adhesive but you only get one shot at it!

[struth]

Hi Jerry,
Feel free to send me a PM. I understand your reservations about veneering and I would be very happy to help. I am on my 3rd pair of veneered cabinets so can provide first hand experience of the process. I always use paper backed veneer stuck on with Scotchweld 30. It is an excellent adhesive but you only get one shot at it!

Richard,you should do a step by step with pics in drawing board. sure plenty of folk would enjoy reading it :)

[Reffc]

Could you connect the tweeter side up to the mid-range? That way you'd hear that the lower frequencies were definately filtered out and playing high frequencies to the lower drivers won't cause damage as the other way around might. Or simply connect it to a some spare, cheap drivers first to check for basic functionality, no box needed..

If it's any consolation, I get the same fears, especially if I've got a new power amp.. so always have some cheap Gale speakers to hand to sacrifice.

Just noticed this comment...note...it doesn't hold water ;) Filters are not absolute shelves in response. If it's a 2 pole filter, there will be a 12 dB/octave roll off. If a single pole filter, it'll be a 6dB/octave roll off (electrical). Therefore, you will hear some higher frequencies (ie above crossover point) albeit at lower volumes by passing a signal via the tweeter filter to a midrange unit. It isn't a test of anything tbh.

All you need to ensure is that the tweeter has a capacitor in series with it from the input and that the cap is part of the HF filter (ie you haven't mixed your filter connections up). Nothing else is required.

[awkwardbydesign]

And start with no music playing. You should get a hiss from the tweeters. Unless your amp is totally silent!