Hello all.
I have a thumping great Fidek/Azatom iBigboy 2AD BTX ICD that I use outside. It's heavy, loud and has phenominal bass. I love it but I've blown one of the speakers and need to replace it. Information about the device is sparse and tech help non-existent, so I've come here in the hope that someone can help me match the speaker to the device.
The audio section includes a Class D Yamaha amp with a 10" woofer and two 5" coaxial speakers. I have blown the tweeter in one of the coaxials so am trying to replace both of them with 5" or 6" coaxials of a similar power rating and quality (or better). But I have no idea what spec they are and no way of finding out.
These are all the specs given for the iBigBoy in the manual:
OUTPUT POWER :
UR CH (Nominal): 30W+30W THD = 1% 8 ohm
SW CH (Nominal): 64W THD = 1% 4 ohm
RMS: 240W. PEAK: 500W
FREQUENCY RESPONSE:
UR CH (200Hz-20KHz at +1 I -2dB)
SW (40Hz-200Hz at +4/-13dB)
SENSITIVITY:
UR:550mV SW:200mV
OVERLOAD SOURCE e.m.f.: >2V
SEPARATION: >55dB
S/N: >70dB
Less authoritative info I've found (so not too sure whether to believe it or not) includes:
Impedence: L/R: 4 ohm, Sub: 4 ohm
Sensitivity: 90dB +/- 3 dB
Frequency Response: L/R: 200 - 20Hz, Subwooder: 20 - 200Hz
The existing speakers do not include a crossover and have four wires (two for main speaker, two for integrated tweeter). I assume the speakers are 'full range' with the 200hz and below filtered off to the 10" bass speaker via another crossover.
So my question is: what power rating and impedence should the replacement coaxial speakers be to get the best and loudest sound out of this beast? (I can adjust the holes in the cabinet as required.)
So far, all I've found are these but have no real idea if they'll do the job (I'm guessing not):
nominal impedance of 4 ohms, a frequency response of 36-20,000 Hz, a sensitivity of 90 dB, and a rated power handling of 40 watts.
https://www.soundimports.eu/en/sb-acoustics-sb16pfcr25-4-coax.html
Thanks for any help with this.
I have a thumping great Fidek/Azatom iBigboy 2AD BTX ICD that I use outside. It's heavy, loud and has phenominal bass. I love it but I've blown one of the speakers and need to replace it. Information about the device is sparse and tech help non-existent, so I've come here in the hope that someone can help me match the speaker to the device.
The audio section includes a Class D Yamaha amp with a 10" woofer and two 5" coaxial speakers. I have blown the tweeter in one of the coaxials so am trying to replace both of them with 5" or 6" coaxials of a similar power rating and quality (or better). But I have no idea what spec they are and no way of finding out.
These are all the specs given for the iBigBoy in the manual:
OUTPUT POWER :
UR CH (Nominal): 30W+30W THD = 1% 8 ohm
SW CH (Nominal): 64W THD = 1% 4 ohm
RMS: 240W. PEAK: 500W
FREQUENCY RESPONSE:
UR CH (200Hz-20KHz at +1 I -2dB)
SW (40Hz-200Hz at +4/-13dB)
SENSITIVITY:
UR:550mV SW:200mV
OVERLOAD SOURCE e.m.f.: >2V
SEPARATION: >55dB
S/N: >70dB
Less authoritative info I've found (so not too sure whether to believe it or not) includes:
Impedence: L/R: 4 ohm, Sub: 4 ohm
Sensitivity: 90dB +/- 3 dB
Frequency Response: L/R: 200 - 20Hz, Subwooder: 20 - 200Hz
The existing speakers do not include a crossover and have four wires (two for main speaker, two for integrated tweeter). I assume the speakers are 'full range' with the 200hz and below filtered off to the 10" bass speaker via another crossover.
So my question is: what power rating and impedence should the replacement coaxial speakers be to get the best and loudest sound out of this beast? (I can adjust the holes in the cabinet as required.)
So far, all I've found are these but have no real idea if they'll do the job (I'm guessing not):
nominal impedance of 4 ohms, a frequency response of 36-20,000 Hz, a sensitivity of 90 dB, and a rated power handling of 40 watts.
https://www.soundimports.eu/en/sb-acoustics-sb16pfcr25-4-coax.html
Thanks for any help with this.
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You'll need to figure out what's going on with the tweeter crossover. There has to be one. It's either active (supplied by a separate amplifier channel) or passive (likely a single capacitor in series with the tweeter somewhere - could be glued onto driver, on the amplifier board, inline in the wire and covered in heat shrink, etc.
Do you have a DVM that you can use to measure the resistance of the remaining good speaker? Generally in an application like this, the speakers will be 4 ohm in order to get the most out of a modestly sized amplifier. Resistance typically reads about 3/4 of driver impedance.
The SB coaxials will probably work, but again you need to figure out the crossover situation.
Car coaxials are another possible approach. They will typically cost less, but have the crossover built into the speaker (again, typically a single capacitor on the tweeter on the cheaper ones). Sometimes that's easily removed.
Do you have a DVM that you can use to measure the resistance of the remaining good speaker? Generally in an application like this, the speakers will be 4 ohm in order to get the most out of a modestly sized amplifier. Resistance typically reads about 3/4 of driver impedance.
The SB coaxials will probably work, but again you need to figure out the crossover situation.
Car coaxials are another possible approach. They will typically cost less, but have the crossover built into the speaker (again, typically a single capacitor on the tweeter on the cheaper ones). Sometimes that's easily removed.
Thanks very much for your reply. I didn't realise the crossover was important so didn't detail it. But here's a photo of one of them.
Both coaxials measure 5.9 ohm over the full range speaker and the remaining working tweeter measured 6.8 ohm. Can't vouch for the accuracy of my (very old) multimeter though!
I'm a bit suprised you say that the coaxial speaker I linked to may be OK as it's only rated at 40W and the iBigBoy seems to be rated at 240W RMS (this is where I really lose the plot with this stuff!).
Both coaxials measure 5.9 ohm over the full range speaker and the remaining working tweeter measured 6.8 ohm. Can't vouch for the accuracy of my (very old) multimeter though!
I'm a bit suprised you say that the coaxial speaker I linked to may be OK as it's only rated at 40W and the iBigBoy seems to be rated at 240W RMS (this is where I really lose the plot with this stuff!).
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That sounds more like an 8 ohm coaxial, assuming we can trust your meter (and we probably can).
From your previous descriptions, it sounds like you have 30 watts left and 30 watts right for the range above 200 Hz (UR CH (Nominal): 30W+30W THD = 1% 8 ohm). And now that I read that more carefully, it also implies that is 8 ohm, which seems in line with your resistance measurements. Though your later, less reliable information contradicts that.
The wattage rating on the speaker doesn't worry me much. In typical applications they are pretty dependent on how the speaker is being used. Since it seems like your midranges are only playing down to 200 Hz, that makes their life easier. The 240 watts is likely an optimistic number for the entire speaker's power (subwoofer, plus left upper range, plus right upper range)
Does that crossover have one input (the red/black on the right) and then two outputs (the red, black, black, and yellow on the left) that go to one side's tweeter and midrange? And is there another one in the box for the other channel?
And by any chance, does the text next to the inductor have a value for those? Capacitors normally have their values printed right on them, but inductors often don't, which makes it harder to work out the details.
The crossover point shifts when you change impedance, so it's best to get the details right if we can. If you need an 8-ohm coaxial, that'll change your options.
From your previous descriptions, it sounds like you have 30 watts left and 30 watts right for the range above 200 Hz (UR CH (Nominal): 30W+30W THD = 1% 8 ohm). And now that I read that more carefully, it also implies that is 8 ohm, which seems in line with your resistance measurements. Though your later, less reliable information contradicts that.
The wattage rating on the speaker doesn't worry me much. In typical applications they are pretty dependent on how the speaker is being used. Since it seems like your midranges are only playing down to 200 Hz, that makes their life easier. The 240 watts is likely an optimistic number for the entire speaker's power (subwoofer, plus left upper range, plus right upper range)
Does that crossover have one input (the red/black on the right) and then two outputs (the red, black, black, and yellow on the left) that go to one side's tweeter and midrange? And is there another one in the box for the other channel?
And by any chance, does the text next to the inductor have a value for those? Capacitors normally have their values printed right on them, but inductors often don't, which makes it harder to work out the details.
The crossover point shifts when you change impedance, so it's best to get the details right if we can. If you need an 8-ohm coaxial, that'll change your options.
I am very grateful for this Matt. It is much more than I could have expected.
You are right about the crossover. There are two, one for each channel (left, right). From each crossover two wires come from the amp (left in photo) and four go to the coaxial speaker (two to the main speaker and two to the integrated tweeter).
The text next to the inductor you refer to is obscured:
But the number printed on the crossover board by the side of the inductors is E256792
I can only see useful numbers on the smaller of the two capacitors on the crossover board (the one not near the white block things): Bipolar 3,3uF 100WF
There is text on the white block things too: HKR 5M3RJ, and on the board next to them: 21179BG1
Interesting you call the main speaker 'midrange'. I'm not sure if you are using this to refer to the type of speaker or it's function within the unit. Assuming type.... If there is one issue with this unit it's that the high/mid(?) bass is not 'there' enough. This equates to a lack of lower end punch and a certain 'sogginess' at low/mid volumes (it's fine at high volume though). One of the reasons I am not averse to increasing the size of the speaker from 5" to 6" is to see if I can improve the sound in this area. I'd also wondered if a 'full range' speaker would help too... or at least not do any harm, seeing as how the very high and very low frequencies are filtered off by the crossover.
Here's a photo of the speaker connections:
Again, thanks very much for this.
You are right about the crossover. There are two, one for each channel (left, right). From each crossover two wires come from the amp (left in photo) and four go to the coaxial speaker (two to the main speaker and two to the integrated tweeter).
The text next to the inductor you refer to is obscured:
But the number printed on the crossover board by the side of the inductors is E256792
I can only see useful numbers on the smaller of the two capacitors on the crossover board (the one not near the white block things): Bipolar 3,3uF 100WF
There is text on the white block things too: HKR 5M3RJ, and on the board next to them: 21179BG1
Interesting you call the main speaker 'midrange'. I'm not sure if you are using this to refer to the type of speaker or it's function within the unit. Assuming type.... If there is one issue with this unit it's that the high/mid(?) bass is not 'there' enough. This equates to a lack of lower end punch and a certain 'sogginess' at low/mid volumes (it's fine at high volume though). One of the reasons I am not averse to increasing the size of the speaker from 5" to 6" is to see if I can improve the sound in this area. I'd also wondered if a 'full range' speaker would help too... or at least not do any harm, seeing as how the very high and very low frequencies are filtered off by the crossover.
Here's a photo of the speaker connections:
Again, thanks very much for this.
Glad to help.
The text under the one inductor is just L1 (which stands for inductor 1) and ROHS (which is for Restriction of Hazardous Substances - this is primarily an indication of lead-free solder on parts and the board in cases like this). Unfortunately it looks like you have a typical board with no value indicated for the inductor.
If I had to guess, it looks like a 12 dB/octave crossover at 3 kHz (assuming a Linkwitz-Riley crossover, which is common). The component values may be the same for the midrange and tweeter, they just swap spots for high-pass and low-pass when the impedance is the same. At 8 ohms, standard crossover values are 3.3 µF and 0.85 mH.
The white blocks are resistors. 5WR3 would typically be a 5 watt 3 ohm resistor. Those most likely are an L-pad on the tweeter to decrease its level. It's normal for tweeters to have more output than a woofer for the same drive voltage, so the L-pad is used to decrease the tweeter level. That also brings up another possibility: are you sure your tweeter is damaged? Have you tried plugging the bad speaker into the opposite side's crossover to make sure there's not an issue in the crossover? Or measured the resistance of the tweeter on the bad one to see if it's open?
The text under the one inductor is just L1 (which stands for inductor 1) and ROHS (which is for Restriction of Hazardous Substances - this is primarily an indication of lead-free solder on parts and the board in cases like this). Unfortunately it looks like you have a typical board with no value indicated for the inductor.
If I had to guess, it looks like a 12 dB/octave crossover at 3 kHz (assuming a Linkwitz-Riley crossover, which is common). The component values may be the same for the midrange and tweeter, they just swap spots for high-pass and low-pass when the impedance is the same. At 8 ohms, standard crossover values are 3.3 µF and 0.85 mH.
The white blocks are resistors. 5WR3 would typically be a 5 watt 3 ohm resistor. Those most likely are an L-pad on the tweeter to decrease its level. It's normal for tweeters to have more output than a woofer for the same drive voltage, so the L-pad is used to decrease the tweeter level. That also brings up another possibility: are you sure your tweeter is damaged? Have you tried plugging the bad speaker into the opposite side's crossover to make sure there's not an issue in the crossover? Or measured the resistance of the tweeter on the bad one to see if it's open?
In this case, its mostly function. Though things get blurred a bit between midranges, woofers, and midbasses in this frequency range.
A full-range could work if you are OK with limited dispersion at higher frequencies. That would not need a crossover. There could be an active high-pass crossover on the feed that goes into the passive crossover, which then goes to the midrange (or midbass if you prefer) and tweeter. So that would make it 40 Hz-200 Hz on the subwoofer, 200 Hz to 3 kHz on the midbass/midrange, and 3 kHz and up on the tweeter. That could limit what you can do to improve the midbass. But a bigger midrange/midbass may help some.
The Lavoce CSF061.21 looks like a decent option for an 8 ohm coaxial. It has an integrated crossover for the tweeter, so that would remove the question of the old crossover values. Looks like it has a bump in the midbass/low midrange too, so that might help.
Sensitivity may be a little high. Does the device have a subwoofer level control or some other means of adjusting the balance between the sub and upper range speakers?
Are the coaxials in their own separate enclosures?
Sensitivity may be a little high. Does the device have a subwoofer level control or some other means of adjusting the balance between the sub and upper range speakers?
Are the coaxials in their own separate enclosures?
This really is an education and I'm beginning to recall stuff from studying electronics in my early twenties that has been long forgotten.
The tweeter is definitely non-functional. I did swap the two speakers over, which was pretty conclusive, but also checked with a multimeter. No reading.
The speakers are in their own enclosed compartment. The bass woofer is separated into its own bass reflex compartment.
Your definition of 'full range' differs from my (probably incorrect) definition. For me the definition includes a coaxial speaker, with or without integrated crossover.
If 'limited dispersion at higher frequencies' means the treble is not as good no, I want to avoid this. I like clear, defined and precise treble.
There is no separate volume control for the bass woofer sadly. I'm not averse to adding one though. Maybe I could fit the one below into the two wires feeding the woofer? I'd mount it on the back of the unit, cutting into the bass reflex compartment. Simple job. There are bound to be others easily available.
https://www.thomann.co.uk/monacor_lp1008.htm
The Lavoc looks good. Good find (I've not had much luck sourcing a replacement 8 ohm speaker). I'd have to check if I could actually fit 6.5" speakers in though. The price is low too (is it a good quality speaker?). I see it's rated at 100W into 8 ohm. Noting your question about distinct woofer volume control.... the bass from the subwoofer is already dominant (esp at higher volumes). Reducing the volume of the coaxial speakers would be quite bad. Increasing it a bit would not matter though.
My options seem to be these:
1) Replace coaxial speakers with same type.
Adv: Chance to improve sound
Disad: Risky. Might degrade sound (with no going back if cabinet has been re-drilled)
2) Keep existing speakers but bypass tweeters and wire in new distinct tweeters (eg: D19TD-05).
Adv: Lower risk than 1).
Disad: Might unbalance treble, lots of cutting of cabinet, cost (those tweeters are hard to get hold of in UK). Won't improve overall sound.
3) Get existing broken tweeter repaired.
Adv: V low risk.
Disad: No increase in sound quality. Might not (probably not?) be possible.
1) Is definitely favourite as I'd like to improve the sound quality if I can (top end clarity and punch esp). But I do understand the risk and would need to be as certain as I could be that it was going to work (due to cutting the cabinet)
Again, thanks a lot for your help. It's invaluable.
The tweeter is definitely non-functional. I did swap the two speakers over, which was pretty conclusive, but also checked with a multimeter. No reading.
The speakers are in their own enclosed compartment. The bass woofer is separated into its own bass reflex compartment.
Your definition of 'full range' differs from my (probably incorrect) definition. For me the definition includes a coaxial speaker, with or without integrated crossover.
If 'limited dispersion at higher frequencies' means the treble is not as good no, I want to avoid this. I like clear, defined and precise treble.
There is no separate volume control for the bass woofer sadly. I'm not averse to adding one though. Maybe I could fit the one below into the two wires feeding the woofer? I'd mount it on the back of the unit, cutting into the bass reflex compartment. Simple job. There are bound to be others easily available.
https://www.thomann.co.uk/monacor_lp1008.htm
The Lavoc looks good. Good find (I've not had much luck sourcing a replacement 8 ohm speaker). I'd have to check if I could actually fit 6.5" speakers in though. The price is low too (is it a good quality speaker?). I see it's rated at 100W into 8 ohm. Noting your question about distinct woofer volume control.... the bass from the subwoofer is already dominant (esp at higher volumes). Reducing the volume of the coaxial speakers would be quite bad. Increasing it a bit would not matter though.
My options seem to be these:
1) Replace coaxial speakers with same type.
Adv: Chance to improve sound
Disad: Risky. Might degrade sound (with no going back if cabinet has been re-drilled)
2) Keep existing speakers but bypass tweeters and wire in new distinct tweeters (eg: D19TD-05).
Adv: Lower risk than 1).
Disad: Might unbalance treble, lots of cutting of cabinet, cost (those tweeters are hard to get hold of in UK). Won't improve overall sound.
3) Get existing broken tweeter repaired.
Adv: V low risk.
Disad: No increase in sound quality. Might not (probably not?) be possible.
1) Is definitely favourite as I'd like to improve the sound quality if I can (top end clarity and punch esp). But I do understand the risk and would need to be as certain as I could be that it was going to work (due to cutting the cabinet)
Again, thanks a lot for your help. It's invaluable.
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It's a common issue, since "full range" means multiple things depending on how it's used. On an individual driver basis, full range most often refers to a single driver (no crossover) that's trying to cover a wider range than is typical (preferably enough to make it pleasing on its own without additional drivers to help it). Something like the classic Lowthers is a good example.
Even this definition gets stretched a bit, since 2- and 3-inch drivers can also be called full range, when they obviously struggle with much bass at all. They can run lower into the midrange/midbass than expected for their size and all the way up without a tweeter though, so it makes sense from that angle.
And of course you can use a full-range driver as a midrange or mid/treble speaker with other drivers to assist it in a mult-way speaker.
Many larger full range drivers have poorer off-axis behavior at significant angles. They can still sound fine at reasonable angles, but if you want to cover a large listening area evenly, a co-axial is probably a better approach. An example:
First we have a 7-inch full range from Seas with a whizzer. Above 1 kHz, the deviation between on- and off-axis behavior is pretty large (>10 dB above 6 kHz in particular). The heavy line is on-axis, and the other two are 30º and 60º off-axis.
https://www.madisoundspeakerstore.com/approx-6-fullrange/seas-h1794-fea18rcz-7-full-range/
And here's a 7 inch Seas coaxial measured at the same angles. The purple lines for the tweeter are much closer together, so off-axis frequency response is more similar to on-axis at high frequencies.
https://www.madisoundspeakerstore.com/coaxial/seas-prestige-t18rex/xfc-h1353-7-coaxial-clear-cone/
It's typically a better idea to put an attenuator on the upper range speakers, since power is lower for them given typical music. You can get ganged adjustable L-pads to handle left and right simultaneously. Of course you need to be in a spot where you have more midrange/treble than you need to make this work the way you'd typically want. I'd start without it, just to keep things simple, then add it if necessary after you get a feel for what you have. Given the limited power on the subwoofer in this case, you can probably get away with a mono adjustable L-pad on it if necessary.
https://www.parts-express.com/L-Pad-100W-Stereo-1-Shaft-8-Ohm-260-264?quantity=1
I don't have direct experience with that one, but LaVoce is a pretty big manufacturer with a good reputation.
Overall, your options list seems to cover the reasonable approaches to your problem.
You might be able to use an adapter ring or plate to get the new co-axial speaker temporarily installed without any cabinet modification. This can be nearly anything you can work with and tape to to get a good enough seal to give a quick listen. Fome-Cor, plastic, cardboard tube, insulation board - whatever works for you is OK. I use a lot of masking tape to seal up very temporary prototypes like this. It might have some resonances or other issues, but it will give you a feel for the frequency balance and loudness. It's how I would approach something like this - starting with one of whatever driver I was considering and getting it up and running as quickly as possible with no major or permanent work.
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Thanks again for your detailed reply. Better higher frequency dispertion sounds good. Another reason to go with coaxial speakers. I'll give the attenuator a miss and revisit when speakers are installed.
I've been looking at the Lavoce CSF061.21 6.5" Coaxial Drivers (50W 8 Ohm). I can fit them in but it only leaves about 9mm of enclosure and faceplate each side of the hole.
Two things worry me:
I've been looking at the Lavoce CSF061.21 6.5" Coaxial Drivers (50W 8 Ohm). I can fit them in but it only leaves about 9mm of enclosure and faceplate each side of the hole.
Two things worry me:
- The recommended enclosure size for the Lavoces is 6.21 litres. I only have 3.64 litres per speaker (17.5cm x 16cm x 13cm)*
- The speakers have three terminals. That seems like one more than I'd need.
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Sealed enclosures are pretty forgiving when it comes to their volume. At 6.2 liters, the Qtc of the speaker/enclosure is 0.861, with an F3 of 110 Hz. Theoretical response at rated power looks like this:
Decreasing the cabinet volume to 3.5 liters moves the Qtc to 0.975 and F3 to 120 Hz. Neither of these are large moves or a problem in my opinion given the use scenario here. You're only losing about 2 dB at 100 Hz.
I'm not sure what you are describing here, given what I see in the overall image of your speaker.
I noticed that as well. I think the extra terminal may just be a ground for the frame of the driver. It wasn't common in the past, but I've seen it a couple of times recently. A quick e-mail to whoever you may order them from can probably get you an answer on that topic.
That's actually better from a general design standpoint.
9mm refers to how much cabinet facia I am left with at each side of the speaker after I've drilled the larger hole for the 6.5" Lavoce
I'm surprised the size of the enclosure makes so little difference, especially when optimum QTC seems to 0.707 and the QTC here is 0.975. Also, I'd assumed the issues would not be so much with volume but with resonance and maintaining an even frequency response.
Any changes in volume beneath 200hz are immaterial anyway as those frequencies are filtered off to the bass woofer.
Anyway. I shall buy the speakers and report back after I installing them.
Thanks very much for your help Matt.
I'm surprised the size of the enclosure makes so little difference, especially when optimum QTC seems to 0.707 and the QTC here is 0.975. Also, I'd assumed the issues would not be so much with volume but with resonance and maintaining an even frequency response.
Any changes in volume beneath 200hz are immaterial anyway as those frequencies are filtered off to the bass woofer.
Anyway. I shall buy the speakers and report back after I installing them.
Thanks very much for your help Matt.
Because the driver inherently has a relatively high Qts (0.68), at Qtc 0.707 the required box volume is much larger, at 27 liters. The overall response is pretty similar though, which is part of the tradeoff of picking a sealed enclosure volume. If you get nearly the same performance in a smaller box, you typically use the smaller box. If Qtc was much higher (like 2) it would be a different story, but for this driver a modest increase in Qtc allows a much smaller enclosure to be used.
27 liter, Qtc 0.707 model of frequency response
One thing you get with larger boxes is higher excursion at low frequencies, which exceeds the Xmax of the driver at full power. Maximum power handling is typically at Qtc 1.1.
Excursion plot for 27 liters
At your 3.5 liters, excursion is kept in check
Fb at 27 liters is 99 Hz. Fb at 3.5 liters is 151 Hz. This and the previous models all had "heavy fill" turned on, so the peak at resonance was a little lower and a little more blunted in each case. With no fill, the 3.5 liter Fb is 161 Hz, f3 is 120 Hz. Given the use case here, I still think it's a reasonable alignment even with no fill. Many commercial speakers have Qtc's up around 1 to make them sound more "full." Since that was one of your desires for the midrange, a Qtc in the upper range of normal is probably desirable in this case.
Please do report back on the results, and let me know if you have any other questions along the way.
27 liter, Qtc 0.707 model of frequency response
One thing you get with larger boxes is higher excursion at low frequencies, which exceeds the Xmax of the driver at full power. Maximum power handling is typically at Qtc 1.1.
Excursion plot for 27 liters
At your 3.5 liters, excursion is kept in check
Fb at 27 liters is 99 Hz. Fb at 3.5 liters is 151 Hz. This and the previous models all had "heavy fill" turned on, so the peak at resonance was a little lower and a little more blunted in each case. With no fill, the 3.5 liter Fb is 161 Hz, f3 is 120 Hz. Given the use case here, I still think it's a reasonable alignment even with no fill. Many commercial speakers have Qtc's up around 1 to make them sound more "full." Since that was one of your desires for the midrange, a Qtc in the upper range of normal is probably desirable in this case.
Please do report back on the results, and let me know if you have any other questions along the way.
Well this is a bummer. I can only find a single Lavoce CSF061.21 in the UK and next restock is half way through October. So either I wait, buy abroad (practically doubles the price) or look for an equivalent...
Whilst looking for the speaker I came across this thread on this forum though.....
https://www.diyaudio.com/community/threads/lavoce-csf051-21-coaxial.386138/
@profiguy has experience of the the Lavoce co-axials and thinks the tweeters are cheap and makes the high frequencies harsh and dominant. He suggests two other makes, SICA and SEAS. SEAS are far too expensive but I can find SICA at not too overblown prices. They do a 6" coaxial too, which would fit the cabinet better than the 6.5" Lavoce. However, it is rated at 400W, has a QTS of 0.24 and the spec mentions a vented box... so I guess it's a no-goer....
Till October then. :-(
Whilst looking for the speaker I came across this thread on this forum though.....
https://www.diyaudio.com/community/threads/lavoce-csf051-21-coaxial.386138/
@profiguy has experience of the the Lavoce co-axials and thinks the tweeters are cheap and makes the high frequencies harsh and dominant. He suggests two other makes, SICA and SEAS. SEAS are far too expensive but I can find SICA at not too overblown prices. They do a 6" coaxial too, which would fit the cabinet better than the 6.5" Lavoce. However, it is rated at 400W, has a QTS of 0.24 and the spec mentions a vented box... so I guess it's a no-goer....
Till October then. :-(
Keep in mind that many tweeters cost more than the price of the LaVoce co-ax, and some much more. Many users on this site are audiophiles that are looking for high performance, and many comments reflect that slant. I try to give advice based on where people are and what they probably want. It involves some guesswork, naturally.
I'm not sure which Sica you were looking at. The 6.5C1.5CP will do OK in 3.5 liters sealed also, given your use case. If you were trying to get the best performance at low frequencies, a larger vented enclosure would provide significant benefits. Since you're just using the driver as a midrange/midbass, you have more leeway.
With no fill and 3.5 liters sealed, Fb is 119 Hz, F3 is 99 Hz, and Qtc is 0.89. At 50 watts, performance is similar to the LaVoce.
Keep in mind that with this Sica you're going to have to make a crossover or buy theirs. Using the stock crossover in your current speaker may or may not produce reasonable results. If you can't do acoustical measurements, it makes things like trying alternate crossovers more difficult.
Manufacturer suggested crossover is on page 3 of this PDF.
https://sica.it/wp-content/uploads/2023/12/Z004102.pdf
Looks like they have some other co-ax's with integrated crossovers, but I don't know what you have access to.
I'm not sure which Sica you were looking at. The 6.5C1.5CP will do OK in 3.5 liters sealed also, given your use case. If you were trying to get the best performance at low frequencies, a larger vented enclosure would provide significant benefits. Since you're just using the driver as a midrange/midbass, you have more leeway.
With no fill and 3.5 liters sealed, Fb is 119 Hz, F3 is 99 Hz, and Qtc is 0.89. At 50 watts, performance is similar to the LaVoce.
Keep in mind that with this Sica you're going to have to make a crossover or buy theirs. Using the stock crossover in your current speaker may or may not produce reasonable results. If you can't do acoustical measurements, it makes things like trying alternate crossovers more difficult.
Manufacturer suggested crossover is on page 3 of this PDF.
https://sica.it/wp-content/uploads/2023/12/Z004102.pdf
Looks like they have some other co-ax's with integrated crossovers, but I don't know what you have access to.
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I did wonder whether @profiguy's comment was relevant to my user case.. which is mostly blasting out electronic music at volume whilst working outside the house.
This was the speaker I had in mind (6" is a better fit for the cabinet than 6.5").
https://sica.it/prodotto/6-cx-2-pl/
I don't want to start messing around with crossovers though and prefer to keep costs low so I'll stick out for the Lavoce CSF061.21. :-(
This was the speaker I had in mind (6" is a better fit for the cabinet than 6.5").
https://sica.it/prodotto/6-cx-2-pl/
I don't want to start messing around with crossovers though and prefer to keep costs low so I'll stick out for the Lavoce CSF061.21. :-(
Hello again.
It looks ages for the Lavoce speakers to be restocked in the UK and then a while before my brother was able to rout the new speaker holes and depressions for the rims (included using a 3D scanner to make a super long bit).
So this morning I stuck them in the iBigBoy and spent a couple of hours listening to a variety of music at various volumes.
Overall the set up is improved. It's louder for a start... quite a bit louder. Before the bass could be overwhelming but now it seems more balanced and what's more it's got much more punch which makes for a more engaging sound (before at lower volumes the mid bass could be a bit flaccid making the overall sound a touch stodgy). Obviously the treble is better than it was before as a tweeter had blown but I think think the electronic hihats of house music are more 'there' than they were even before the tweeter was blown.
So overall I'm really impressed. Despite losing the dedicated crossover these Lavoces are an improvement on the stock iBigBoy drivers. They are now louder and sound better at lower volumes.
There are two very small downsides. I'm not too sure the mids and lower mids are as clear as they were before. The sound may be slightly less focussed. But this is only at volume and may well be my imagination. Another is resonance. Out of the thirty or so tracks I played I noticed what I thought was a small resonance on two of them (one of them on some of the organ notes on Zero 7's 'In the Waiting Line'). Not huge but definitely there, again at some volume.
So Matt. Thank you very much for all your help. I am extremely grateful to you. I don't know what I'd have done If you hadn't stepped in. As well as your help you gave me an education. I knew nothing about speaker design before this and you opened up a world to me. If you come to Southern England message me and I'll stand you a beer, or three. Thanks again.. hopefully the iBigBoy will live on for some decades more (that's if my neighbours don't destroy it first!).
Here's a photo of it with the larger Lavoces installed.
Simon
It looks ages for the Lavoce speakers to be restocked in the UK and then a while before my brother was able to rout the new speaker holes and depressions for the rims (included using a 3D scanner to make a super long bit).
So this morning I stuck them in the iBigBoy and spent a couple of hours listening to a variety of music at various volumes.
Overall the set up is improved. It's louder for a start... quite a bit louder. Before the bass could be overwhelming but now it seems more balanced and what's more it's got much more punch which makes for a more engaging sound (before at lower volumes the mid bass could be a bit flaccid making the overall sound a touch stodgy). Obviously the treble is better than it was before as a tweeter had blown but I think think the electronic hihats of house music are more 'there' than they were even before the tweeter was blown.
So overall I'm really impressed. Despite losing the dedicated crossover these Lavoces are an improvement on the stock iBigBoy drivers. They are now louder and sound better at lower volumes.
There are two very small downsides. I'm not too sure the mids and lower mids are as clear as they were before. The sound may be slightly less focussed. But this is only at volume and may well be my imagination. Another is resonance. Out of the thirty or so tracks I played I noticed what I thought was a small resonance on two of them (one of them on some of the organ notes on Zero 7's 'In the Waiting Line'). Not huge but definitely there, again at some volume.
So Matt. Thank you very much for all your help. I am extremely grateful to you. I don't know what I'd have done If you hadn't stepped in. As well as your help you gave me an education. I knew nothing about speaker design before this and you opened up a world to me. If you come to Southern England message me and I'll stand you a beer, or three. Thanks again.. hopefully the iBigBoy will live on for some decades more (that's if my neighbours don't destroy it first!).
Here's a photo of it with the larger Lavoces installed.
Simon
Glad to hear that everything came together, that you took the time to report the results, and that you found the process enjoyable.
Cosmetically they look as good as the originals, so nice work there.
If the former, you could try adding some damping to the enclosure for the co-ax's. 1/16 of a 1 pound bag of this is about the right amount for each of your midrange boxes (1/8 bag total used since you have 2 individual boxes for the mids). You want to loosely fill the whole enclosure volume, but not add so much that it's up against the baskets, magnets, or cones.
https://www.parts-express.com/Acousta-Stuf-Polyfill-1-lb.-Bag-260-317?quantity=1
For a rattle, my first suspects would be a poor seal between the driver and enclosure or a wire that's loosely running right against a panel. If the LaVoce's didn't come with a gasket, you can add one. They sell gasket material for speakers:
https://www.parts-express.com/Speaker-Gasketing-Tape-1-8-x-3-8-x-50-ft.-Roll-260-540?quantity=1
But you can also use easily compressed foam weatherstripping if you have that handy. You want that kind where you can easily squish it down to almost nothing with a little finger pressure.
M-D Building Products 02253 is one I use. It's 3/16 inch thick and 3/8 inch wide.
https://www.homedepot.com/p/M-D-Bui...-Small-Gaps-Weatherstrip-Roll-02253/100353460
There are other options for problems, of course, but that's where I'd start looking. For rattles, those can often be more easily diagnosed with pure test tones. If you can get your hands on an old analog sine wave generator, those are handy since you can quickly sweep through areas of interest and you get infinite resolution to dial right into a problematic frequency.
One final thought: check the excursion of the midranges during the problematic passages. If it's extreme, that could be addressed with a simple crossover addition. I made some assumptions about how the active crossover was being handled.
Cosmetically they look as good as the originals, so nice work there.
Are you talking about an elevated area in the frequency response or something that sounds like a rattle?
If the former, you could try adding some damping to the enclosure for the co-ax's. 1/16 of a 1 pound bag of this is about the right amount for each of your midrange boxes (1/8 bag total used since you have 2 individual boxes for the mids). You want to loosely fill the whole enclosure volume, but not add so much that it's up against the baskets, magnets, or cones.
https://www.parts-express.com/Acousta-Stuf-Polyfill-1-lb.-Bag-260-317?quantity=1
For a rattle, my first suspects would be a poor seal between the driver and enclosure or a wire that's loosely running right against a panel. If the LaVoce's didn't come with a gasket, you can add one. They sell gasket material for speakers:
https://www.parts-express.com/Speaker-Gasketing-Tape-1-8-x-3-8-x-50-ft.-Roll-260-540?quantity=1
But you can also use easily compressed foam weatherstripping if you have that handy. You want that kind where you can easily squish it down to almost nothing with a little finger pressure.
M-D Building Products 02253 is one I use. It's 3/16 inch thick and 3/8 inch wide.
https://www.homedepot.com/p/M-D-Bui...-Small-Gaps-Weatherstrip-Roll-02253/100353460
There are other options for problems, of course, but that's where I'd start looking. For rattles, those can often be more easily diagnosed with pure test tones. If you can get your hands on an old analog sine wave generator, those are handy since you can quickly sweep through areas of interest and you get infinite resolution to dial right into a problematic frequency.
One final thought: check the excursion of the midranges during the problematic passages. If it's extreme, that could be addressed with a simple crossover addition. I made some assumptions about how the active crossover was being handled.
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Thanks Matt. By resonance I mean the sort of artificial increase of a certain frequency/sound. It's not a rattle. It's a bit like a mild feedback for a very narrow frequency. I was pretty careful with the wires so I don't think it's that.
I did wonder about the lack of gasket. I shall add some.
Now you mention foam.... I remember there was some originally.... now where did I put it.....
I'll check back.
I did wonder about the lack of gasket. I shall add some.
Now you mention foam.... I remember there was some originally.... now where did I put it.....
I'll check back.