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Danielr View Drop Down
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    Posted: 30 December 2016 at 11:49pm
Hello,

I have in my mind an idea to build some tweeter boxes for a PA "rig" I have.

Budget wise it's a bit shoe string, so I'm probably going to build the boxes and load them with the cheap black plastic kind of tweeter to start, and maybe upgrade later, enlarging the holes and putting some decent bullet tweeters into them.

I'm not worried about crossovers inside them as they are going to be driven after an active crossover.

But I've got a couple of questions, specifically about those tweeters.

Those cheap black plastic tweeters generally seem to come with a nominal impedance of 1000ohms, 
Does anyone know if that is across the range? 

Is that is across the range, it would seem I could take say 8 and put them all in parallel without thinking too much, but if that nominal 1000ohm, drops to 8 when they are in a certain range, then that's just going to cook my amp...

second question:
What sort of power (as in wattage) amplifier should I be looking for in an amplifier driving these?
(assume that all the other components are 500W per side, should I also look to drive these at 500W (i.e load 8 35W tweeters in a box and have two boxes.) per side also?

I guess more specifically, that question is, should I be balancing the system giving the same sort of power to all components. or would a set of tweeters like that be happy (and not lost) being driven by a 500W (250 per side) amp?


Final question:
whilst I believe that I don't need any filtering inside the box as I've got an active crossover before the power amp. Am I correct? or should I be looking at some sort of simple capacitor based high pass filter also? (and if so is that 1 per box or 1 per driver in the box?)
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Post Options Post Options   Thanks (0) Thanks(0)   Quote kronborg Quote  Post ReplyReply Direct Link To This Post Posted: 31 December 2016 at 8:48am
Ooooh, piezo tweeters are probably the ones you are refering to. They are small, cheap, play loud and generally (in my personal opinion) sound horrible.
With piezo tweeters, it is generally not the impedance you should worry about, but the capacitive loading of your amplifier. That's why you often see people recommend adding a series resistor (in the 30-70 ohm range) to each unit. Strictly the do not need a seperate crossover, but they do work better with one.
Most of them also works from 4 or 5kHz and up, requiring a midrange driver in the system to cover the upper midrange. (15" + piezo will not be optimal)

Piezo-tweeters are usually not rated for how much power (watts) they can dissipate (as this is minimal) but what maximal voltage they can take, and what this equals in a 4 or 8 ohm system. One example I have seen is 30VAC max. If your amplifier is rated at 500Watts into 8 Ohms, it will output around 63VAC at full power. This will require AT LEAST two piezo tweeters in series (multiple pairs in parallel to get the sensitivity up), to handle the full voltage swing (and that just barely)

Have you considered finding a pair of good compression drivers and horns instead? You might be able to find a pair for the same price or slightly more than 16 piezo's and resistors. It might make sense since you are already talking about upgrading.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Danielr Quote  Post ReplyReply Direct Link To This Post Posted: 31 December 2016 at 12:58pm
Yes, piezo teeters, couldn't remember what they were called. But cheap, horrible black plastic thing was the most descriptive I could be...

Mid range is ok (or should be)

The complete system is a live band miked to a 24 channel desk feeding into a behringer fbq6200, the "sub" is taken from this, the remaining signal is then going into an active 3-way stereo crossover,

"Sub" is being fed to some tuned reflex cabinets. (To be built)
Then the "low" will be handled by a couple of 12" cabs (to be built)
"Mid" by a set of 10inch "disco style" speakers that have a crossover and piezo.
And highs to a box that is the subject of this thread...

Amp are rated into 4ohm. At the moment there is a single pair of full range cabs that do not handle either highs or lows fantastically well. Those are 8 ohm cabs. (All cabs are or will be 8ohm) that will let me double up the cabs and run in parallel before I need to add more amps! (Flexibility is key here!)


That voltage rating is exactly what I'm looking for.
So at 30vac max I should be looking to something like an amp rated maximum 200w (per side) (realistic 100-150w) into 4 ohms. (Maybe less) then I can feed them in parallel. (That's actually good I have an amp around that rating)


Yes, I have thought about getting some decent compression drivers, but it comes down to cost....

At the moment I've got these little 10" "full" range speakers.
To complete working with what I've got amp wise I need to build..
4 Sub boxes (have drivers)
4 Low boxes (have 2 of the drivers)
high boxes (don't have drivers)
another set of 10" drivers, + the piezo tweeters in that box,
another set of 12" , (As above I have 2)
Then the fixings and coverings to put them all together!)

So whilst I'd prefere a decent set if horn loaded compression drivers... Whilst you can get 10 for £10 of those plastic piezo tweeters... They are going to have to be used. (Even if that's just a stop gap whilst I save money.)

When I say "sub" I don't really mean sub frequencies that are heavily used in dub styles) so the cross over for this would be set quite high)... This live band is a jazz band, the lowest instruments are Bari sax, (80hz) bass trombone, (60hz) double bass (40hz) and piano (28hz but not used this low). (obviously piano rates as one of the highest instruments too.) (4khz) and the flute is a little higher... so my lowest frequencies will be handled by 15" drivers. (I may go HD15 instead of reflex cab, going to need to spend some time with software and figure out use, response and how much space these take up!) all I'm needing from these things is to pick up around 4khz, and handle the very top end of the piano and occasional flute, plus transients from cymbals. (Frequency response you quoted makes me think that the little round piezo tweeters may not cut it, which probably means I need to look for the next cheapest option (those piezo tweeters with rectangular horn attached.)

(I'm building the cabs individually so that I can have a fully modular system)
Either just a single full range set 1amp (250w per side)
Or 2sets of full range speaker from 1 amp (500w per side)
Or a full range set and "sub" set split with the sub out from the 6200 (2 amps @250 in 8ohm cabs)
Or double the cabs on that.
Or three way cross over and three amps (with either 1 or 2 cabs per amp)
Or 4 way with either 1 or 2 cabs per amp...

This gives me all options from a small 500w indoor setup
To a 4kW outdoor setup.

Of course building boxes with a view to be able to stack them and benefit from a line effect.
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Conanski View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Conanski Quote  Post ReplyReply Direct Link To This Post Posted: 31 December 2016 at 4:35pm
Piezos bullets will not work well for a live band PA as there is typically quite a bit more energy in the vocal range(compared to recorded tracks) where these things would be required to operate given your proposed system layout.  And IMO your system plan is more complicated that it needs to be.. there is no need for anything more than a 3-way system covering 40hz-15khz give or take, you don't need the super highend sparkle these piezos deliver but you do need serious output in the mids and highs. I suppose if you used a hugh stack of piezo bullets like 12-16 a side or something they wouldn't instantly die in the first 30 seconds of your first performance but then you're spending enough money to buy some decent 1" compression drivers. Been there and done that. Piezo bullets are super tweeters, they really don't produce any meaningful output below 8-10khz, there are peizo loaded compression drivers though which may suite your purposes better.. allow a simplification of your system to dual 12+CD over subs for example, something you can upgrade with much better CDs as money becomes available without having to change any of the cabinets.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Danielr Quote  Post ReplyReply Direct Link To This Post Posted: 31 December 2016 at 8:33pm
Many thanks for replies.

Do the replies apply equally to the small square piezo tweeters (little ones marked as 6-20khz) and to those types that are moulded with an attached rectangular flare? (Generally rated with higher power handling and a frequency response from 2 - 20khz -but lower sensativity)? And a little more expensive per unit.

Price of the 85mm square piezo is ~£1 each, ~£3 for the ones with a flare attached. Compression drivers look to start in the £15-£30 range, then added expense is needed to either buy of make flares, and maybe get thread adapters etc...

So, if I abandon the cheap piezo tweeter idea all together...

What is the "cheapest" driver that will do the job (either with a flare already attached or that can be made in wood -but then it really needs to be bolt mounted).

And what is (really subjective question) the "best" driver/cab combination for my (live sound) needs. (Because I may just save and do it right the first time.)

Would the "tweeter" (be that piezo/titanium bullet/compression + horn) be enough on its own, or should I be considering something like a 6 or 8 inch driver to handle some frequencies and then a dedicated "tweeter" to handle what that won't produce through to what can't be heard?

How many drivers am I likely to need per box?

(Focus is sound production for a jazz band, (I.e wood wind + brass, some guitar/bass/piano. Vocals and occasional need to put drums through PA. -but at the same time this may be used for other live bands eg standard rock 4 piece stuff.)

Yes, it is crazy/complicated/over kill. -but there is a reason.
My idea is to have a "single" system for all occasions. And not end up (as we were earlier this year) doing some outside gig with a couple of full range speakers being driven from a single mono amp (my bass amp) because we thought the venue (who were having multiple groups) would have sorted that... (And they though that as the only band strictly requiring amplification that would be our job... (We were saved from a complete washout sound wise by calm sunny weather and well maintained box hedges!) But at the same time not end up in a situation (where we were at a different gig) where a friendly sound guy brings his "festival rig" to play the back room of a pub... (Unfortunately cannot just hire him all the time - can't afford that. And he can't afford to turn down fully paid work to help this band with a cheap sound guy.

I would honestly doubt that I'll ever use that 4 way 4K system described because I honestly doubt that we'd organise our own outdoor music event, and would expect if just appearing on a billing) all that stuff to be sorted... (But you never know when you'll get that call for a wedding where you do need everything.) Standard outings are likely to be taking a 250hz low pass into 12" cabs and putting the rest to a 2-way full range cab. -it'd need to be a special occasion to even bring out the cross over far a proper 3-way system. Amps/cross overs/monitor amplifiers/outboard effects/eq unit and recording gear are all grouped and racked to flight cases such that the least amount of lifting would be done at any one show (and everything is ready to go. -no multiple effects because I want them in the big gig flight case as well as the small gig one. No carrying 2 amps if I only have to use one, no (more) dismantling my friends studio because we desperately need something!
Small gig, take the small desk, effects rack, amp1 rack. And some speakers.
Big gig that we're also recording live. -grab every box... (Somewhere in the middle do something in the middle)

The only exception to this is an old "traffic light" system I have. Because you never know when a venue is going to tell you that they have noise restrictions. So best to just be prepared.

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Conanski Quote  Post ReplyReply Direct Link To This Post Posted: 31 December 2016 at 11:47pm
Originally posted by Danielr Danielr wrote:

And what is (really subjective question) the "best" driver/cab combination for my (live sound) needs. (Because I may just save and do it right the first time.)


OK that is the smartest question you have asked so far, it's always best to figure out what you need first and then determine if you can afford it or how close you get to it.

IMO a proper live sound PA cab will include a 2" exit CD which is actively crossed to 12" or 15" drivers really low.. like at 800hz or so. These big CDs are expensive but they deliver outstanding clarity and output in the all critical vocal range, be sure you're sitting down when you do a search for a B&C DE750 or RCF N850 because you might fall over from sticker shock. LOL.

That is the gold standard, yes each driver is more expensive but you only need a pair to start and you can eliminate separate mid and high cabs if you like and make the system easier to move and quicker to setup.

The next step down from those beasts are 1.4" exit drivers, these don't go as low as the bigger drivers but they generally sound much cleaner through the vocal range than 1" exit drivers. Typical crossover frequencies are around 1.2khz to 1.6khz so you can build a respectable live sound PA with them. Examples of these are the B&C DE610 or Radian 745.

Now we come to 1" exit drivers, some of these are very cheap but you really do get what you pay for and most of these drivers will need at least a 2khz crossover which stretches the range of a 12" driver never mind a 15. Really you say? Yes some 12" and 15" drivers do produce lots of output at these frequencies and beyond but that is mostly on axis, play a 2.5khz tone through these drivers and then walk off axis, what you will find is output drops of rapidly as soon as you move away from directly in front of the driver. That is why such low crossover frequencies are used with the bigger compression drivers, you get better coverage at all frequencies along with cleaner more detailed output.

So you can build boxes with 1" exit drivers that will make noise and not blow up but at least you now know you can do much better. Examples of some good 1" exit drivers would be the B&C DE250 or Selenium D220ti, on a very tight budget go with the Selenium DH200E.. it doesn't have the highend response of the others but these things can take some serious abuse.


Edited by Conanski - 01 January 2017 at 12:19am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Danielr Quote  Post ReplyReply Direct Link To This Post Posted: 01 January 2017 at 1:51am
Originally posted by Conanski Conanski wrote:

 you might fall over from sticker shock. LOL.
$350 (sale price) N850s are well outside what I can spend! - the thread started with me saying I might get a handful of £1 each piezos!

I guess my question now is:
are 2" compression drivers just better than smaller ones? - and is this true even if you're fishing in the ultra cheap end of the market? (e.g a £150 2" driver of no name brand, vs a 1.4" or 1" decent brand driver at the same price?)


Originally posted by Conanski Conanski wrote:

The next step down from those beasts are 1.4" exit drivers, these don't go as low as the bigger drivers but they generally sound much cleaner through the vocal range than 1" exit drivers. Typical crossover frequencies are around 1.2khz to 1.6khz so you can build a respectable live sound PA with them. Examples of these are the B&C DE610 or Radian 745.

I thought I'd found a cheap set I could afford, - turns out it was just replacement diaphragms!

Originally posted by Conanski Conanski wrote:

Now we come to 1" exit drivers, some of these are very cheap but you really do get what you pay for and most of these drivers will need at least a 2khz crossover which stretches the range of a 12" driver never mind a 15.
So, with 1" drivers, these are back to being top end duty only (which is what I was originally thinking of building), they would have to be pair with a mid range cabinet (like the one I have with 10" drivers in it.)...

Originally posted by Conanski Conanski wrote:

Some 12" and 15" drivers do produce lots of output at these frequencies and beyond but that is mostly on axis,[quote]
Sadly in the price range I'm shopping in, sometimes you feel blessed if you get thiele small numbers, asking for a polar pattern is pointless... 

[QUOTE=Conanski]So you can build boxes with 1" exit drivers that will make noise and not blow up but at least you now know you can do much better. Examples of some good 1" exit drivers would be the B&C DE250 or Selenium D220ti, on a very tight budget go with the Selenium DH200E.. it doesn't have the highend response of the others but these things can take some serious abuse. 

now these are in my price range...
but you have me wondering... is it worth spending £50 on a driver, and £15 on a horn flare... in the 1" range... when I know I want to change them anyway... (and I can't imagine them holding their value for resale!)
and changing them will mean a different flare, that may mean a new/different box... and so on... it's the save now, or buy cheap buy twice problem...
this is especially true if the answer to the question above is 2" is just better no matter what, Blue Aran are advertising some Celestion 2" compression drivers at £139... (CDX20-3020)

As I've no immediate call for these right now, I may just save...



More generic wiring / powering questions...

Can I treat the compression driver like a normal loudspeaker? - Do I need any electronics in the cabinet? or can I just feed it from an active crossover before the and and with the compression driver directly to the back plate?

Are these (like regular loud speakers) happy being wired in series of parallel?

Second question, I did ask this in my first. what sort of power amplifier do I need to power these?

I'm very used to thinking that bass end spreads and dissipates a lot so bass needs a lot of power and high sounds are like green light, humans just perceive them better, so there is not the need for as much power...

(then there is the fact that my 10" drivers are only 97db on sensitivity, whilst those DH200E as an example are 105db...)

the question is, should I match the power levels to the same as other frequencies?
in which case (ignoring differences in sensativity that mean they might not need as much power), with 500W per side (250W @8ohm) cabinets at other frequencies... these 75W compression drivers start to become expensive, that kind of power handing would need 4 of them per cabinet...


Last question (hopefully) are there particular horn flares that work better than others?
Is it ok to make these out of wood?
What about Fibre glass, or carbon fiber as materials?

with flares starting at £10 for little 90x40mm ones is it just silly not to get an off the shelf horn?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Conanski Quote  Post ReplyReply Direct Link To This Post Posted: 01 January 2017 at 4:46am
Originally posted by Danielr Danielr wrote:

I guess my question now is:
are 2" compression drivers just better than smaller ones? - and is this true even if you're fishing in the ultra cheap end of the market? (e.g a £150 2" driver of no name brand, vs a 1.4" or 1" decent brand driver at the same price?)
Yes a 2" driver is generally better. Celestion isn't a no name company so it is quite possible that driver is a better performer than a smaller driver from another company, the big question is.. is it built with sufficient quality to last because that is part of being better too.

Originally posted by Danielr Danielr wrote:

Sadly in the price range I'm shopping in, sometimes you feel blessed if you get thiele small numbers, asking for a polar pattern is pointless...
You don't need polar plots here this is about physics, when the wavelength of the sound being produced is equal to or less than the diameter of the driver the output polar pattern narrows to a beam directly in front of the driver. So that means a 15" drivers should be crossed no higher than 900-1khz, a 12" at 1.2-1.4khz, a 10" at 1.4-1.6khz. That is the hard theory, in practice this rule is often fudged a little or a lot because even the big name manufacturers produce 15+1 cabs with 2.5khz a crossover.

Originally posted by Danielr Danielr wrote:

but you have me wondering... is it worth spending £50 on a driver, and £15 on a horn flare... in the 1" range... when I know I want to change them anyway... (and I can't imagine them holding their value for resale!)
A quality brand name driver of any size will retain resale value, chinese junk not so much.

Originally posted by Danielr Danielr wrote:

and changing them will mean a different flare, that may mean a new/different box... and so on... it's the save now, or buy cheap buy twice problem...
That is why you plan ahead, if you know you want to get 2" drivers eventually you build the cabs with room for the bigger flare but only cut a hole big enough for the smaller 1" flare now.

More generic wiring / powering questions...

Originally posted by Danielr Danielr wrote:

Can I treat the compression driver like a normal loudspeaker? - Do I need any electronics in the cabinet? or can I just feed it from an active crossover before the amp and with the compression driver directly to the back plate?
Yes any dynamic compression driver can be treated like any other driver, you can power it directly from an amplifier. With 2" drivers this is often how it is done mainly because building a passive crossover for the required crossover frequency and power level is quite expensive, but with a 1" driver it can be done with $10-$20 in parts so using a separate amp channel could be considered a waste of resources.

Originally posted by Danielr Danielr wrote:

Are these (like regular loud speakers) happy being wired in series of parallel?
Yes no problem but using multiples effectively is more complicated and probably not necessary because these drivers are often much more sensitive than the cone mids they are paired with.

Originally posted by Danielr Danielr wrote:

Second question, I did ask this in my first. what sort of power amplifier do I need to power these?
Nothing big, a 100-150w amp would do it and even with that you may never use more than about 25w.

Originally posted by Danielr Danielr wrote:

(then there is the fact that my 10" drivers are only 97db on sensitivity, whilst those DH200E as an example are 105db...)
Yes exactly.. so even with a 2x10+1" config you would have to turn the CD down 5db.

Originally posted by Danielr Danielr wrote:

the question is, should I match the power levels to the same as other frequencies? in which case (ignoring differences in sensativity that mean they might not need as much power), with 500W per side (250W @8ohm) cabinets at other frequencies... these 75W compression drivers start to become expensive, that kind of power handing would need 4 of them per cabinet...
No you don't match power levels only sound output level. My big system consists of dual 18 reflex subs with 1000w/driver, dual 15 bass/mids with 500w/driver, and a single 2" exit CD on top that will never use more than about 150w peak. This produces balanced sound believe it or not.


Originally posted by Danielr Danielr wrote:

Last question (hopefully) are there particular horn flares that work better than others?Is it ok to make these out of wood?
What about Fibre glass, or carbon fiber as materials?
There is a lot of science in horn flares, there are various flare rates and coverage patterns you can pick from depending what you want to do. Various materials can be used including wood but you'll be hard pressed to better the performance of what you can buy off the shelf especially at the entry level.




Edited by Conanski - 01 January 2017 at 4:58am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote kronborg Quote  Post ReplyReply Direct Link To This Post Posted: 01 January 2017 at 9:18am
Very good information you get here Danielr. A few things I would like to add to the post above (of which I completely agree) is that even though a compression driver is happy to work directly on a power amplifier output in an active system, I would still recommend installing a series capacitor (filtering lower than the crossover frequency to avoid phase issues), to protect the driver from amplifier "thumps", incorrect wiring/signal and other faults that may occur. Many manufacturers of bi-amped speaker systems do this for extra protection.

While 15"+1" compression driver is certainly not optimal, it has been done many times and with acceptable quality quite often. I have 10 stage monitors in my rig that are all 15" + 1" compression driver, these are all crossed at 1.2kHz (both active and passive) as the compression driver (Beyma CD10Fe) has no problems working this low. Since you already have a mid cabinet with 10" you might just be happy with 1" CD and an appropriate horn.

You could perhaps find a set of speakers with horns and CD's in them in the classifieds but with blown bass drivers for example. That could be a very cheap deal, and give you a pair of usable tweeters for your system. I have done this quite a few times, buying partially broken speaker systems for next to nothing, just to scavenge the parts. For example, I got two big 2x15"+2" horn speakers (Beyma 15G400 and Beyma CP650) for $350. Sold the horns and CD for $200 and gave away the cabinet, so I got 4 powerful 15" bass woofers for $150. Couldn't even get one of those woofers new for that price.
If putting time and labour into the project is "less expensive" to you than spending the extra cash, I think this could be a way forward. Lots of good speaker components out there on the used market.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Mark James Quote  Post ReplyReply Direct Link To This Post Posted: 01 January 2017 at 2:20pm
persoinaly if it was choice of piezos or??? id just get some bms 4524 stick em on a horn that fits dispersion/freq range requirements etc far better than a piezo arrange ment and can cross directly from the 10" mids at about 2/2.5khz [on right horn] or for not much more [ie not alot more than what 8 piezos cost] you could probably get the next model up to get lower/more output. not saying its the best route but surely better than piezos?
also there are some half decent budget 1.4/2" horns out there that will suit better than piezos above a double ten box tbh
If you want people to feel the bass then a reflex design is probably best as you get the most air movement per decibel from those.      errrrr yes wtf?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote kronborg Quote  Post ReplyReply Direct Link To This Post Posted: 02 January 2017 at 5:39pm
I know you say you are on a budget, but wouldn't it be possible for the band members to chip in some cash to buy the equipment? It surely must be in everyones interest to sound as good as possible for the given budget. Especially if You are a jazz band, I would never recommend piezos as they IMO are not suitable for reproducing music of any decent quality.
As said earlier, I think you could do good with a used pair of speakers or compression drivers. It should be possible to find a pair of used but functional drivers for less than £100.

If you insist on using piezo tweeters, I can only recommend you to use them as I wrote in the first reply, with a 50 Ohm resistor in series with each one. You say you are going to use active crossover and amp, that will probably improve sound quality, as long as you set the crossover above the lowest usable frequency (typically in the 3-4 kHz range) as they have a tendency to "whistle" in that critical frequency area.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Danielr Quote  Post ReplyReply Direct Link To This Post Posted: 03 January 2017 at 5:19pm
Awesome, thanks very much guys,

After a few days thinking about it, I think this is going to be a back burner thing for a little bit. 
(decided that some 2" drivers (i.e those Celestion ones would probably be great for me -if they never come back in stock, or at least some cheaper ones to tide me over) are inside my price range. (sure it's not the £1 starter shoe string budget I originally thought) but it looks like 1" drivers start around the £15 - £30 mark, (well within budget) but 2" drivers start in the £30 - £60 at the very cheapest end of the market...

For an extra £30 - £60, if seems silly not to just start with the 2" drivers, simply put, it seems like pairing a 1" compression expecting it to go down to frequencies it's not good at doing, with whatever other drivers I had up to frequencies they aren't really suited for either would just lead to a poor overall sound... 

So this will be a case of wanting to stop and save up a little now, to get a better result later, (if the difference was hundreds, then I'd probably go with cheaper 1" drivers now, but realistically, it's such a small difference it's silly to half arse it after putting time/money into box building)

Quote You could perhaps find a set of speakers with horns and CD's in them in the classifieds but with blown bass drivers for example.
I'm not against doing something like this, in fact that's how the 10" speakers came my way, I bought the set from ebay for £20, (actually fully working) cheap chinese speakers... (couldn't get the wood for that price)
then pulled out the drivers. (fully working) and put them on ebay for £20 each.
Quote Celestion isn't a no name company
and replaced the drivers with a set of Celestion Trevox drivers (at £40 each).
Thus total cost £60 after selling the original drivers (a little more after replacing the jack/binding post plate with speakon) loaded with brand new celestions, for cheaper than the cost of the speakers...
(and ended up with better sounding more sensitive drivers than the original junk ones)


Quote ... is that even though a compression driver is happy to work directly on a power amplifier output in an active system, I would still recommend installing a series capacitor (filtering lower than the crossover frequency to avoid phase issues),
Using Conanski's suggested cross over frequencies above.
can you confirm my calculations for blocking capacitor, (i've calculated for 8ohm drivers, a match of an 8ohm reactance in the capacitor, should give a 3db roll off at the crossover frequency.)

2" exit CD ...crossed ... really low.. like at 800hz ~24uF
1.4" exit drivers,  around 1.2khz to 1.6khz ~16uF - 12uF
1" exit drivers, least a 2khz crossover ~9uF

and on specific type of capacitor is polyester film ok?
(i.e https://www.rapidonline.com/wima-mks4d052206f00ks-mks4-22uf-10-100v-radial-polyester-film-capacitor-64-2440)


Quote If you insist on using piezo tweeters
whilst I was clearly very biased towards these due to cost, there is no point in throwing money away on devices to create poor representations of noise in frequencies that simply don't exist in the ranges we're playing in... so no, giving up on piezos and doing it properly...


Quote but wouldn't it be possible for the band members to chip in some cash to buy the equipment?
you'd have thought, but the reality is that it's a little more complicated than that...
Quote surely must be in everyones interest to sound as good as possible
until (very recently) the band were happy with no amplification (except for guitar and bass amp and the PA being one of those single speaker personal almost a guitar amp) systems...

It's only since a new musical director who knows a little more about the technology aspect came on board that technology wise things have started to move on... now, whilst the band are happy to get on board with miking sections, etc... the paying for it part is a little more tricky... 

It's (at the moment) in a tough spot where the mindset is still that a lot of members are of the mind set that this sort of stuff simply isn't needed. no worth paying for. etc... or there are (unrealistic) limits to how much this stuff should cost etc.

(whilst I've been fairly quick to listen and turn my ideas around regarding parts of equipment to get best results in this thread... other may not have been...)
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