Hi All,
I'm trying to improve my Fiancee's naff old Disco speakers so that we get some better mid-tone, but at minimal cost as we're probably going to build or buy some *real* speakers later this year.
At present there is a Zomax 120W 12" woofer in each cabinet along with an 'anonymous' bullet tweeter horn wired in parallel with no crossover. We're very limited for space in the cabinet, so I really want to replace the tweeter with a horn that is going to provide a better range.
In my CPC catalogue there are Horns which are 8ohms that need a crossover, but there are also a whole load of Horns that are rated as '1000ohms @ 1kHz' - The advert for many of these says that they do not need a crossover and should be wired in parallel with the woofer.
Just to add to my confusion, they have a power rating of things like: "300W max. (4ohm)"
How can it be 4ohm if it's 1000ohms?
What exactly does the 1000ohm impedance imply? Can I still use one of these with a crossover? (The 1000ohm Tweeters with a range of 1.8k -- 27kHz would be ideal (I think the anonymous tweeter only goes down to about 4kHz so an extra 2k lower will probably help the sound) , but I'd feel more comfortable if I had a crossover connected as well)
Please bear in mind that these boxes are years old and were not necessarily 'calculated' when they were built. They've got drain pipe for bass reflex!! I'm not trying towork a miracle with these units - they're crap and always will be, but a few tweaks may help then survive a bit longer.
Can anyone explain this difference in impedance to me a I'm confused and I can't find any DIY sites that mention the idea of *not* using crossovers.
Many Thanks
Jonathan
I'm trying to improve my Fiancee's naff old Disco speakers so that we get some better mid-tone, but at minimal cost as we're probably going to build or buy some *real* speakers later this year.
At present there is a Zomax 120W 12" woofer in each cabinet along with an 'anonymous' bullet tweeter horn wired in parallel with no crossover. We're very limited for space in the cabinet, so I really want to replace the tweeter with a horn that is going to provide a better range.
In my CPC catalogue there are Horns which are 8ohms that need a crossover, but there are also a whole load of Horns that are rated as '1000ohms @ 1kHz' - The advert for many of these says that they do not need a crossover and should be wired in parallel with the woofer.
Just to add to my confusion, they have a power rating of things like: "300W max. (4ohm)"
How can it be 4ohm if it's 1000ohms?
What exactly does the 1000ohm impedance imply? Can I still use one of these with a crossover? (The 1000ohm Tweeters with a range of 1.8k -- 27kHz would be ideal (I think the anonymous tweeter only goes down to about 4kHz so an extra 2k lower will probably help the sound) , but I'd feel more comfortable if I had a crossover connected as well)
Please bear in mind that these boxes are years old and were not necessarily 'calculated' when they were built. They've got drain pipe for bass reflex!! I'm not trying towork a miracle with these units - they're crap and always will be, but a few tweaks may help then survive a bit longer.
Can anyone explain this difference in impedance to me a I'm confused and I can't find any DIY sites that mention the idea of *not* using crossovers.
Many Thanks
Jonathan
Certainly the "1000 Ohm tweeters" are the piezo ones. All of their specifications are confusing usually, as they behave quite different from dynamic, i.e. "low impedance" speakers - their impedance is quite purely capacitive. The don't need the crossover theoretically, as they have a sharp rolloff below 1,5 - 3,5 kHz (depending of type). But they can be destroyed by excessive voltage stress coming from the bass region, if they are connected parallel to the bass (or mid-bass) driver. So it is better to use them with crossover at around 1-2 kHz, but it is necessary to connect a parallel resistor 8 ohm to the tweeter. The resistor should to be dimensioned to 20 watts approx. Without this resistor the crossover is ineffective.
And, don't expect any miracles - the sensitivity of these drivers is about 93-95 dB referred to 8 ohm impedance, if measured conventionally. In turn, they can be connected more piezo-tweeters to get higher sensitivity - 4 pieces no problem.
This is very simplified - you can find more in literature searching about "piezoelectric tweeter".
And, don't expect any miracles - the sensitivity of these drivers is about 93-95 dB referred to 8 ohm impedance, if measured conventionally. In turn, they can be connected more piezo-tweeters to get higher sensitivity - 4 pieces no problem.
This is very simplified - you can find more in literature searching about "piezoelectric tweeter".
These "1000 ohm" tweeters are most certainly piezotweeters. In fact, their real part impedance is very high - they have a complex impedance and behave very much like a capacitor. This is one of the reasons they do not need any crossover - coz' they already got on "built in". In fact, they usually perform better without any crossover at all.
They are rated as "300 W RMS @ 8 ohm" or something like that. This does NOT mean that they are capable of handling 300 W RMS (which is a hell of a lot of tweeter power BTW). It simply means that in a fullrange system with 8 ohms system impedance driven by 300 W of normal program material they are up to handling the power in the high frequency region. Normally they can take a real beating.
All quality piezotweeters are made by Motorola, formerly CTS and rumors go that CTS have ceased production for now.
Some of these piezotweeters (like the popular but horrible KSN-1005) might need a resistor of say 47 ohms in series to prevent certain amplifiers from oscillating.
Could you post a picture of the tweeter? Zomax made some JBL2402 style bullet tweeters that were electrodynamic and hence require a crossover. Most of their LF drivers were JBL copies (they even used JBL part numbers!) and without touching the originals by any stretch of the imagination some of them were not all that bad. And there is nothing wrong with plastic drain pipe or cardboard pipe as a bassreflex pipe, in fact it is the standard.
You could have a look at the Pi Speakers Forum http://www.audioroundtable.com/PiSpeakers/ for tons of information about piezotweeters since the KSN-1038 is used in the 2 Pi's.
For the money, piezotweeters offer the highest bang for the buck ratio in the entire audio field IMO.
/Magnus
They are rated as "300 W RMS @ 8 ohm" or something like that. This does NOT mean that they are capable of handling 300 W RMS (which is a hell of a lot of tweeter power BTW). It simply means that in a fullrange system with 8 ohms system impedance driven by 300 W of normal program material they are up to handling the power in the high frequency region. Normally they can take a real beating.
All quality piezotweeters are made by Motorola, formerly CTS and rumors go that CTS have ceased production for now.
Some of these piezotweeters (like the popular but horrible KSN-1005) might need a resistor of say 47 ohms in series to prevent certain amplifiers from oscillating.
Could you post a picture of the tweeter? Zomax made some JBL2402 style bullet tweeters that were electrodynamic and hence require a crossover. Most of their LF drivers were JBL copies (they even used JBL part numbers!) and without touching the originals by any stretch of the imagination some of them were not all that bad. And there is nothing wrong with plastic drain pipe or cardboard pipe as a bassreflex pipe, in fact it is the standard.
You could have a look at the Pi Speakers Forum http://www.audioroundtable.com/PiSpeakers/ for tons of information about piezotweeters since the KSN-1038 is used in the 2 Pi's.
For the money, piezotweeters offer the highest bang for the buck ratio in the entire audio field IMO.
/Magnus
Thanks for that update, that's put me in the picture a bit better.
Can you define what you mean by sensitivity? 93-95dB sound like an indication that they're faily loud, but not hugely powerful.
I'm really stuck for space in this cabinet - At the moment we suffer pretty muddy bass, absolutely *no* midtone and tinny treble... I think that one of these horns will be a marginal improvement - Ideally I'd like space for a second 10"-12" cone plus a decent tweeter, but that ain't going to happen. I could try and fit two of these horns in... Can they simply be wired in Parallel?
(Incidentally, the horns I'm looking at have got some kind of burnout protection built in).
Oh, and regarding the muddy bass, the boxes are hollow - I'm just about to buy some cheap acoustic foam for this.
If you've got any better suggestions as to how I can make these boxes sound a bit better I'd be glad to hear them.
Cheers
Jonathan
Can you define what you mean by sensitivity? 93-95dB sound like an indication that they're faily loud, but not hugely powerful.
I'm really stuck for space in this cabinet - At the moment we suffer pretty muddy bass, absolutely *no* midtone and tinny treble... I think that one of these horns will be a marginal improvement - Ideally I'd like space for a second 10"-12" cone plus a decent tweeter, but that ain't going to happen. I could try and fit two of these horns in... Can they simply be wired in Parallel?
(Incidentally, the horns I'm looking at have got some kind of burnout protection built in).
Oh, and regarding the muddy bass, the boxes are hollow - I'm just about to buy some cheap acoustic foam for this.
If you've got any better suggestions as to how I can make these boxes sound a bit better I'd be glad to hear them.
Cheers
Jonathan
It looks like I have a choice of several horns given what you've all told me...
(I can stretch to the cost of a few resistors, but I'm trying to avoid buying crossovers as well - given that these *should* work without)...
I've potentially got:
CTS/Motorola - KSN-1141
Power (EIA RS426) 200w nom. 400W protected
Voltage 35v Max
Freq - 1.8k to 30kHz
Impedance 1000ohm @ 1kHz
Sensitivity 92db
Dimsneions 187mmx79mmx108mm
OR
CTS/Motorola "300W Flat Horn Piezo Tweeter":
Freq - 2k to 30kHz
Output SPL 95dB
Dimensions 178mmx95mmx115mm
Power Rating RMS 150W
Max Voltage 35v
Impedance >1000ohm
OR
CTS Piezo Tweeter - Twin Drive
Power 300W max (4ohm)
Freq 3.5k - 20k
Sensitivity 99dB
Max Volts 35v
Dimensions 162x96mm
Any ideas on which may be better??
(I was going to go for the KSN-1141)
Cheers
Jonathan
(I can stretch to the cost of a few resistors, but I'm trying to avoid buying crossovers as well - given that these *should* work without)...
I've potentially got:
CTS/Motorola - KSN-1141
Power (EIA RS426) 200w nom. 400W protected
Voltage 35v Max
Freq - 1.8k to 30kHz
Impedance 1000ohm @ 1kHz
Sensitivity 92db
Dimsneions 187mmx79mmx108mm
OR
CTS/Motorola "300W Flat Horn Piezo Tweeter":
Freq - 2k to 30kHz
Output SPL 95dB
Dimensions 178mmx95mmx115mm
Power Rating RMS 150W
Max Voltage 35v
Impedance >1000ohm
OR
CTS Piezo Tweeter - Twin Drive
Power 300W max (4ohm)
Freq 3.5k - 20k
Sensitivity 99dB
Max Volts 35v
Dimensions 162x96mm
Any ideas on which may be better??
(I was going to go for the KSN-1141)
Cheers
Jonathan
I'm afraid I can't exactly provide a picture of the actual tweeter - it's totally unbranded and my catalogue (CPC, Preston, UK) have several tweeters that all look the same.
An identical one in looks and size is here:
http://custom1.farnell.com/cpc/prod...pc+catalogue&category_name=&product_id=260530
There seem to be both an 8ohm and a 1000ohm version of the above tweeter available. My concern is that the 8ohm version may have been installed in these speakers without a crossover. These speakers have been owned by at least 6 different DJs and have most likely been hammered - I'd guess that the tweeters are pretty tired by now.
The sound could be described right now like thumping a tub full of water while rattling a coke can! Maybe, just maybe, the addition of a bigger and better horn, plus some internal foam may help the sound a little bit.
Incidentally, these boxes are floor standing. I was thinking about the idea of mounting them on tripods - How bad an effect might this have on the sound quality (given that there may be some movement in the speakers).
Cheers
Jonathan
An identical one in looks and size is here:
http://custom1.farnell.com/cpc/prod...pc+catalogue&category_name=&product_id=260530
There seem to be both an 8ohm and a 1000ohm version of the above tweeter available. My concern is that the 8ohm version may have been installed in these speakers without a crossover. These speakers have been owned by at least 6 different DJs and have most likely been hammered - I'd guess that the tweeters are pretty tired by now.
The sound could be described right now like thumping a tub full of water while rattling a coke can! Maybe, just maybe, the addition of a bigger and better horn, plus some internal foam may help the sound a little bit.
Incidentally, these boxes are floor standing. I was thinking about the idea of mounting them on tripods - How bad an effect might this have on the sound quality (given that there may be some movement in the speakers).
Cheers
Jonathan
OH NO! THE HORRIBLE KSN-1005! Get rid of this part! Really.
This driver is extremely popular in sub-quality "pro" systems and I have never figured why. Maybe because of the "long-throw" narrow dispersion pattern. Clusters of 10 or even more of these units per channel is a very common sight in many DJ setups.
However, it severely lacks in the fidelity department. I did a quick measurement on one unit and it peaks like mad around 5 kHz. You think your ears are being ripped apart as Van Halen hits the cymbals with this one...
KSN-1141 certainly would be an improvement, it is one of the best piezos IMO. The extended frequency response (down to approx 2k) also takes some stress from your 12'' drivers and should clean up a bit in the upper vocal range. I wouldn't run the 12''s above 2k as they will start exhibit breakup distortion if you run them too high. You could connect 2 in parallel to increase the sensitivity a bit (around + 3dB).
Other than that, you could use the glassfibre-wool stuff that you usually use for house insulation to stuff the box with. Not only is it dirt cheap but it is actually one of the very best stuffing materials out there. The only trouble is that some are allergic to it and it is quite nasty to work with. In a DJ setting small amounts might also find its way through the ports when the speakers are pushed hard.
/M
This driver is extremely popular in sub-quality "pro" systems and I have never figured why. Maybe because of the "long-throw" narrow dispersion pattern. Clusters of 10 or even more of these units per channel is a very common sight in many DJ setups.
However, it severely lacks in the fidelity department. I did a quick measurement on one unit and it peaks like mad around 5 kHz. You think your ears are being ripped apart as Van Halen hits the cymbals with this one...
KSN-1141 certainly would be an improvement, it is one of the best piezos IMO. The extended frequency response (down to approx 2k) also takes some stress from your 12'' drivers and should clean up a bit in the upper vocal range. I wouldn't run the 12''s above 2k as they will start exhibit breakup distortion if you run them too high. You could connect 2 in parallel to increase the sensitivity a bit (around + 3dB).
Other than that, you could use the glassfibre-wool stuff that you usually use for house insulation to stuff the box with. Not only is it dirt cheap but it is actually one of the very best stuffing materials out there. The only trouble is that some are allergic to it and it is quite nasty to work with. In a DJ setting small amounts might also find its way through the ports when the speakers are pushed hard.
/M
Regarding the tripods: At the moment we've just got the two speakers providing the full range (although at present there's not much inbetween the bass and the treble).
Incidentally, I've ordered the KSN-1141 Piezos as recommended.
If we decide to build a new set of speakers later this year I suspect we'll make them taller than these (these are only about 20" high by 15" wide).
I'm expecting that I'll go for a 12" - 15" sub, a 10" - 12" Mid and then perhaps a few tweeters to cover multiple directions, AND proper crossovers - I'm certainly open to ideas on this one.
Out of interest, does anyone know if the Zomax 12" 120W cones are any good as we might reuse them if they're really worth the >$100 that people seem to charge for them. (I think the model is P1265).
I'm not totally sure on which cones we'll want yet, but some of the Celestion range look quite reasonable.
When we upgrade the speakers, we'll also do the Amp. At the moment, Jane's got a 'Lyon Forge A120' It seems to do the job, but again I'd be interested to hear any opinions as to whether this is any good. Again, any recommendations of an Amp which is approx 200-300W with a good price/power ratio will be apreciated - We don't need Hi-Fi - It's just a Disco (Sadly, drunk people have no appreciation of Hi-Fi quality lest to suggest I might reduce the volume to a *safe* level )
I'm still at a loss as to the definition of 'sensitivity' - Can anyone explain this to me?
Thanks
Jonathan
Incidentally, I've ordered the KSN-1141 Piezos as recommended.
If we decide to build a new set of speakers later this year I suspect we'll make them taller than these (these are only about 20" high by 15" wide).
I'm expecting that I'll go for a 12" - 15" sub, a 10" - 12" Mid and then perhaps a few tweeters to cover multiple directions, AND proper crossovers - I'm certainly open to ideas on this one.
Out of interest, does anyone know if the Zomax 12" 120W cones are any good as we might reuse them if they're really worth the >$100 that people seem to charge for them. (I think the model is P1265).
I'm not totally sure on which cones we'll want yet, but some of the Celestion range look quite reasonable.
When we upgrade the speakers, we'll also do the Amp. At the moment, Jane's got a 'Lyon Forge A120' It seems to do the job, but again I'd be interested to hear any opinions as to whether this is any good. Again, any recommendations of an Amp which is approx 200-300W with a good price/power ratio will be apreciated - We don't need Hi-Fi - It's just a Disco (Sadly, drunk people have no appreciation of Hi-Fi quality lest to suggest I might reduce the volume to a *safe* level
)I'm still at a loss as to the definition of 'sensitivity' - Can anyone explain this to me?
Thanks
Jonathan
OK, here is a short one on "sensitivity"
Usually you specify the sensitivity of a speaker by running it with a 1 kHz pure sine wave and a power of 1 W and measure the generated sound pressure level at 1 m from the speaker cone. For an 8-ohm speaker this translates to an applied voltage of 2.83 V RMS.
There is some confusion added to this when wiring drivers in paralell. The efficiency of a speaker (as for any other transducer) is the ratio of emitted acoustic power divided by applied electric power, for most raw drivers this fall into the 1-5% category. Horn loading can raise the efficiency considerably.
Sensitivity on the other hand usually means the SPL @ 1 m when the applied voltage is being kept at 2.83 V RMS. For two drivers wired in paralell this means that the applied power is doubled. Feel free to correct me on this one but AFAIK this is the "definition" on sensitivity.
The trouble with sensitivity is that it is pretty useless if stated like "the XXX woofer has a sensitivity of 99 dB @ 1W, 1m". The sensitivity is a function of frequency and although it should ideally be flat in practice it is everything but flat. Sensitivity should thus always be presented as a graph or at least a table with measurements at multiple frequencies.
Another issue is that manufacturers tend to use the most optimistic figures when stating sensitivity. Take the Eminence Kappa 15LF as an example: http://editweb.iglou.com/eminence/eminence/pages/products02/speakers/kap15lf.htm
The maximum sensitivity is about 104 dB @ 1.8 kHz but stating this would be pretty misleading. This peak is due to a breakup mode of the cone (where the driver exhibits lots of distortion) and outside the range where this driver should be operated (this is a bass driver) where sensitivity is around 96-97 dB.
Take a look at the stuff from Eminence http://www.eminence.com and P. Audio http://www.paudio-europe.com for good "bang for the buck" drivers for your upcoming upgrade.
Keep us informed what you think of the KSN-1141 when it arrives!
/M
Usually you specify the sensitivity of a speaker by running it with a 1 kHz pure sine wave and a power of 1 W and measure the generated sound pressure level at 1 m from the speaker cone. For an 8-ohm speaker this translates to an applied voltage of 2.83 V RMS.
There is some confusion added to this when wiring drivers in paralell. The efficiency of a speaker (as for any other transducer) is the ratio of emitted acoustic power divided by applied electric power, for most raw drivers this fall into the 1-5% category. Horn loading can raise the efficiency considerably.
Sensitivity on the other hand usually means the SPL @ 1 m when the applied voltage is being kept at 2.83 V RMS. For two drivers wired in paralell this means that the applied power is doubled. Feel free to correct me on this one but AFAIK this is the "definition" on sensitivity.
The trouble with sensitivity is that it is pretty useless if stated like "the XXX woofer has a sensitivity of 99 dB @ 1W, 1m". The sensitivity is a function of frequency and although it should ideally be flat in practice it is everything but flat. Sensitivity should thus always be presented as a graph or at least a table with measurements at multiple frequencies.
Another issue is that manufacturers tend to use the most optimistic figures when stating sensitivity. Take the Eminence Kappa 15LF as an example: http://editweb.iglou.com/eminence/eminence/pages/products02/speakers/kap15lf.htm
The maximum sensitivity is about 104 dB @ 1.8 kHz but stating this would be pretty misleading. This peak is due to a breakup mode of the cone (where the driver exhibits lots of distortion) and outside the range where this driver should be operated (this is a bass driver) where sensitivity is around 96-97 dB.
Take a look at the stuff from Eminence http://www.eminence.com and P. Audio http://www.paudio-europe.com for good "bang for the buck" drivers for your upcoming upgrade.
Keep us informed what you think of the KSN-1141 when it arrives!
/M
Oh my god - I can't believe it!!! We've managed to turn a really horrid pair of speakers into something quite acceptable!
Jane bought some new chipboard and had it cut to size to replace the old speaker fronts. She's painted it in a nice black instead of mock metallic grey, and we have this evening transferred the Zomax 1265 Cone across onto the new board and installed the new bass ports. The 12" woofers in the old speaker were held in place with silicone sealant and little plastic wire grips! Now the speakers are sealed with foam strips and are bolted solidly to the front panel.
Then we also added some Sheep Wool+Polyester damping (there simply wasn't any in the old design), and instaled the new KSN-1141 Tweeters.
We've only finished one speaker so far, but we played a few various tracks from classical to whomping bass through the old speaker and the new and the difference is incredible.
Jane's taken some photos so I'll post one here once she's uploaded them.
The speakers now look and sound good - Not hi-fi obviously (I'll keep my KEF 105s for that but they look more professional (no silicone sealant around the drain-pipe ports) and by-christ they sound better. Those missing middle tones have returned!!!
I haven't as yet put any form of resistor on the KSN-1141s, can anyone tell me how I can tell if I need one and if so how to judge the value??
Many Thanks
Jonathan
Jane bought some new chipboard and had it cut to size to replace the old speaker fronts. She's painted it in a nice black instead of mock metallic grey, and we have this evening transferred the Zomax 1265 Cone across onto the new board and installed the new bass ports. The 12" woofers in the old speaker were held in place with silicone sealant and little plastic wire grips! Now the speakers are sealed with foam strips and are bolted solidly to the front panel.
Then we also added some Sheep Wool+Polyester damping (there simply wasn't any in the old design), and instaled the new KSN-1141 Tweeters.
We've only finished one speaker so far, but we played a few various tracks from classical to whomping bass through the old speaker and the new and the difference is incredible.
Jane's taken some photos so I'll post one here once she's uploaded them.
The speakers now look and sound good - Not hi-fi obviously (I'll keep my KEF 105s for that
but they look more professional (no silicone sealant around the drain-pipe ports) and by-christ they sound better. Those missing middle tones have returned!!!I haven't as yet put any form of resistor on the KSN-1141s, can anyone tell me how I can tell if I need one and if so how to judge the value??
Many Thanks
Jonathan
No, you do not need any resistor for the KSN-1141. It already has a resistor built in. Good to hear about the improvements!
It might be worth the effort to use a crossover for the Zomax 12'' depending on your crossover design skills. I only have the T/S parameters for that driver and not the graph. Generally you do not want to run a 12'' too high (breakup distortion). But designing a crossover requires a bit of work and also the equipment to measure it (spectrum analyser). In this case it would probably not be worth the hazzle.
As for your next project, state the amount of cash you are willing to spend. You might end up with a really good system for a lot less than what you thought!
In the meantime, take a look at http://www.speakerplans.com for some nice horn-loaded designs. Horn-loading will both increase efficiency and lower distortion. A properly designed horn system with pro drivers will give you high SPL with a sound quality unparalelled by any so-called "hifi" or "high-end" or whatever systems!
/Magnus
It might be worth the effort to use a crossover for the Zomax 12'' depending on your crossover design skills. I only have the T/S parameters for that driver and not the graph. Generally you do not want to run a 12'' too high (breakup distortion). But designing a crossover requires a bit of work and also the equipment to measure it (spectrum analyser). In this case it would probably not be worth the hazzle.
As for your next project, state the amount of cash you are willing to spend. You might end up with a really good system for a lot less than what you thought!
In the meantime, take a look at http://www.speakerplans.com for some nice horn-loaded designs. Horn-loading will both increase efficiency and lower distortion. A properly designed horn system with pro drivers will give you high SPL with a sound quality unparalelled by any so-called "hifi" or "high-end" or whatever systems!
/Magnus
Regarding music type the answer is: General Disco Trash
We've really noticed the terrible quality of these speakers when we got booked to play at a Greek restaurant - Before starting up the 'party' we have to play some background music including 'Bouzouki' (litlle guitar like thing) music and it sounded like an elehant being sick
Normally the speakers get hammered with Pop music and disco oldies like 'Y.M.C.A.' and 'Agadoo' (yeuch, but the patrons like it and don't care about quality)
Thanks Swedish Chef for the info about resistors - I've never made a crossover and don't understand inductance. To be honest I think these boxes sound fine without one.
The boxes are pretty sturdy and well braced inside - that's one thing they do have going for them
I found a spec sheet for the Zomax P1265A (Ours is just P1265). According to their specs on all 10" and 12" cones, the top frequency is 5kHz. Given that these have been driven hard in the past they may have lost a bit at the top end (?!? am I right that this *is* possible), and then we had a nasty small tweeter that seems to start at ~4kHz, there wasn't really much of an overlap between the 12" Cone's highest limit and the tweeter's lowest limit (and it too was probably quite tired).
Now we've got a more powerfull tweeter that handles down to 1.8kHz, so that's ~2kHz that the 12" cone hasn't got to squeeze out. It sounds so much better.
We're only running a 100watt system anyway - this isn't deafening nightclub material - We run it as quite as our audience will allow:
I haven't yet established whether a Lyon Forge A120 amp is >100W per channel, of >100W total and hence about 50W per channel - nevertheless it's loud enough for now.
I think when we upgrade, we are going to be looking at £200-£300 max for speakers, then hopefully a not too pricey amp on top of that. I'd probably go for about 250W/per channel which would be louder that we'll ever need.
My reckoning is to design the speaker around a premade crossover, all in one tall case with a 12"-15" Sub crossing @800Hz to a 10-12" Mid crossing at 4kHz (ish) to a tweeter(s).
If there are any serious pitfalls to aviod with this please do warn me - I'm guessing that as we've just exchanged contracts on a house today, we're unlikely to start this project until Dec/Jan.
Thank you to all of you for your help - especially Swedish Chef (your explaination of Sensitivity was really helpful).
I'm thinking about making a centre channel surround speaker next, but I'll start a new thread for that
Other next project - Make Jane some speaker cables with some heavy multicore copper 'speaker cable' so she stops trying to use: Co-Ax Guitar Leads !!!!!! and Three-Core Mains cable. Sheesh! Some people!
Cheers
Jonathan
We've really noticed the terrible quality of these speakers when we got booked to play at a Greek restaurant - Before starting up the 'party' we have to play some background music including 'Bouzouki' (litlle guitar like thing) music and it sounded like an elehant being sick
Normally the speakers get hammered with Pop music and disco oldies like 'Y.M.C.A.' and 'Agadoo' (yeuch, but the patrons like it and don't care about quality)
Thanks Swedish Chef for the info about resistors - I've never made a crossover and don't understand inductance. To be honest I think these boxes sound fine without one.
The boxes are pretty sturdy and well braced inside - that's one thing they do have going for them
I found a spec sheet for the Zomax P1265A (Ours is just P1265). According to their specs on all 10" and 12" cones, the top frequency is 5kHz. Given that these have been driven hard in the past they may have lost a bit at the top end (?!? am I right that this *is* possible), and then we had a nasty small tweeter that seems to start at ~4kHz, there wasn't really much of an overlap between the 12" Cone's highest limit and the tweeter's lowest limit (and it too was probably quite tired).
Now we've got a more powerfull tweeter that handles down to 1.8kHz, so that's ~2kHz that the 12" cone hasn't got to squeeze out. It sounds so much better.
We're only running a 100watt system anyway - this isn't deafening nightclub material - We run it as quite as our audience will allow:
I haven't yet established whether a Lyon Forge A120 amp is >100W per channel, of >100W total and hence about 50W per channel - nevertheless it's loud enough for now.
I think when we upgrade, we are going to be looking at £200-£300 max for speakers, then hopefully a not too pricey amp on top of that. I'd probably go for about 250W/per channel which would be louder that we'll ever need.
My reckoning is to design the speaker around a premade crossover, all in one tall case with a 12"-15" Sub crossing @800Hz to a 10-12" Mid crossing at 4kHz (ish) to a tweeter(s).
If there are any serious pitfalls to aviod with this please do warn me - I'm guessing that as we've just exchanged contracts on a house today, we're unlikely to start this project until Dec/Jan.
Thank you to all of you for your help - especially Swedish Chef (your explaination of Sensitivity was really helpful).
I'm thinking about making a centre channel surround speaker next, but I'll start a new thread for that
Other next project - Make Jane some speaker cables with some heavy multicore copper 'speaker cable' so she stops trying to use: Co-Ax Guitar Leads !!!!!! and Three-Core Mains cable. Sheesh! Some people!
Cheers
Jonathan
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