So I decided to wire my parker audio 98's in series to get an 8ohm load instead of the the normal 2ohm load. While doing this I somehow broke one of my ft-17 tweeters. Before I replace the tweeter, are there any alternatives I should be looking at?
Parker no longer makes the 98 kit but you can see some of their products here.
index
http://www.parkeraudio.net/98_&_98_kit.htm
Parker no longer makes the 98 kit but you can see some of their products here.
index
http://www.parkeraudio.net/98_&_98_kit.htm
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FT17 is a good tweeter. I'd put the Fosters out of the Radio Shack pods on-par sonically, but with an edge aesthetically. The next stop is the FT96. There are likely some pro horns that would also fit in that range -- i have obtained some of the lessexpensive, but so far all need work
dave
dave
Those FT96h's are not cheap are they. I would pick up the FT96 if I thought I might use it in another design after I am done with these but they seem like such a niche product.
Have you heard the FT-96h's? Are they worth the extra $250 investment?
I am afraid I may just have to buy another ft-17 and leave with the speakers I have until I can afford to build something new. 🙁
Have you heard the FT-96h's? Are they worth the extra $250 investment?
I am afraid I may just have to buy another ft-17 and leave with the speakers I have until I can afford to build something new. 🙁
Check out B&G Neo3. I have just gone to them from FT17. They are not too expensive. I have only had them running for less than a week, but crossed over lower than my 17s (2500hz) they sound rather good.
Dust
Dust
Yeah $250 for 2 of them since I would have to replace one on each speaker.
I would try the neo3's but their sensitivity is way to low for this application.
I would try the neo3's but their sensitivity is way to low for this application.
Hi,
Might not be, and other tweeters might not be if the speakers are rewired
for 8 ohms. Don't know whats going on there, is there no bass/mid c/o ?
If so 96dB for two 4 ohm units in parallel is no great shakes, 90dB a unit
which is what you'll get for two in series also, plenty of 90dB tweeters,
including the Neo3.
2 ohms impedance for a SET amplifier ? yeah right, that makes sense .....
rgds, sreten.
Correct me if I am wrong as I am good with speakers but not great.
No matter if the drivers are arranged in series or paralel 2 drivers should have 3db more sensitivity then just one driver. Each driver is 93db/w/m efficient and using two of them in an mtm gives me 96/db/watt/meter. The drivers are not 90db units, if they were I would need 4 to reach 96db/watt/meters. As far as I know, and I could be wrong, the sensitivity of two drivers does not depend on if they are wired in series or parallel. Where I start getting confused is when you throw in a tweeter with a different ohm load in the mix. For example, if I used 2X93db/watt/meter drivers in series to make an 8 ohm load and I put in a 4 ohm tweeter, what sensitivity would the tweeter need to be to match the drivers? Is the answer a) a 96db/watt/meter tweeter b)you have to calculate the amount of power being put into the 4 ohm tweeter while the midbasses are receiving 1watt. Then calculate how much spl is being generated by the tweeter receiving that power level c)something else
My set plays just fine at 2 ohms and in fact can play down to one ohm. Just check it out here if you don't believe me.
Audiophile Tube Amps and Tube Gear from DECWARE
I do recognize that this is not the norm for SET amps though.
No matter if the drivers are arranged in series or paralel 2 drivers should have 3db more sensitivity then just one driver. Each driver is 93db/w/m efficient and using two of them in an mtm gives me 96/db/watt/meter. The drivers are not 90db units, if they were I would need 4 to reach 96db/watt/meters. As far as I know, and I could be wrong, the sensitivity of two drivers does not depend on if they are wired in series or parallel. Where I start getting confused is when you throw in a tweeter with a different ohm load in the mix. For example, if I used 2X93db/watt/meter drivers in series to make an 8 ohm load and I put in a 4 ohm tweeter, what sensitivity would the tweeter need to be to match the drivers? Is the answer a) a 96db/watt/meter tweeter b)you have to calculate the amount of power being put into the 4 ohm tweeter while the midbasses are receiving 1watt. Then calculate how much spl is being generated by the tweeter receiving that power level c)something else
My set plays just fine at 2 ohms and in fact can play down to one ohm. Just check it out here if you don't believe me.
Audiophile Tube Amps and Tube Gear from DECWARE
I do recognize that this is not the norm for SET amps though.
Hi,
I've been there before with the nonsense pedalled on the DECWARE site.
No SET amplifier can do 2 ohms without being severely limited
into 8 ohm, or do 8 ohms properly without 2 ohms being a no-no.
Your right two drivers are 3dB more efficient. Not sensitive, that only
depends on drive voltage. However a real 96dB/W at 2 ohms implies a
voltage sensitivity of 102dB/2.83v/1m, and whatever your efficiency is,
wiring two drivers in series as opposed to parallel will reduce sensitivity
by 6dB, and consequently the sensitivity needed of the matching tweeter.
That is assuming you don't have large issues with amplifier output
impedance, which to be fair you probably do, an unknown factor.
Its the very poor output impedance that means a near dead
short won't blow it up, but no SET ever likes low impedances.
All single ended amplifiers have to be optimised to a given
load, its that simple, but its something SD is quite happy
to mislead his customers about, sadly his site is full of
similarly misleading BS, overegging the pudding severely.
Given the drivel spouted on the DECWARE site about their own
products its impossible to work out whether you'd be better off
with 2 ohm or 8 ohm loading, to me that is quite insulting.
rgds, sreten.
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From our experience with a pair of these, the Decware is much happier driving 2 ohms.
The 2 ohm Parker's were specifically designed for this amp.
dave
Assuming each driver is 4 ohms and has a sensitivity of 93/db/w/m
I agree that 96db/w/m is 102db/2.83v/1m but it should be considering that at 2 ohms with 2.83V the speakers would be receiving 4wrms. I don't quite see what you are getting at.
From what I understand if I wire the drivers in series I would be at 96db/2.83v/m. Which is 1 watt at 8 ohms.
This means that I would need a tweeter that is 96db/2.83v/m at 8 ohms. What about if I use a 4 ohm tweeter in parallel with the other drivers though? What is the right sensitivity to match the drivers? This is where I get a bit confused. My guess is I would need a tweeter that is 93/db/w/m or higher but I am not confident in that number.
As for the Decware site being a bit vague on details, they are far from the only site which choses to keep the details to their products a mystery. A quick search shows that their zen amplifier has an output impedance of less then 1 ohm (.8 ohms to be exact). They are the only company who makes an affordable entry into the SET style amps and I have greatly enjoyed my amp for the past 8 years. You may not be a fan but I think they are a great entry into the high end stereo market.
I also want to say that the speakers work great with the F5 I built as well, while setup for 2 ohms. I wouldn't want to try that with less efficient speakers though as I think it would run out of current pretty quick. I have been listening to the f5 a lot more lately, which is why I wanted to try the speakers setup for 8 ohms.
I agree that 96db/w/m is 102db/2.83v/1m but it should be considering that at 2 ohms with 2.83V the speakers would be receiving 4wrms. I don't quite see what you are getting at.
From what I understand if I wire the drivers in series I would be at 96db/2.83v/m. Which is 1 watt at 8 ohms.
This means that I would need a tweeter that is 96db/2.83v/m at 8 ohms. What about if I use a 4 ohm tweeter in parallel with the other drivers though? What is the right sensitivity to match the drivers? This is where I get a bit confused. My guess is I would need a tweeter that is 93/db/w/m or higher but I am not confident in that number.
As for the Decware site being a bit vague on details, they are far from the only site which choses to keep the details to their products a mystery. A quick search shows that their zen amplifier has an output impedance of less then 1 ohm (.8 ohms to be exact). They are the only company who makes an affordable entry into the SET style amps and I have greatly enjoyed my amp for the past 8 years. You may not be a fan but I think they are a great entry into the high end stereo market.
I also want to say that the speakers work great with the F5 I built as well, while setup for 2 ohms. I wouldn't want to try that with less efficient speakers though as I think it would run out of current pretty quick. I have been listening to the f5 a lot more lately, which is why I wanted to try the speakers setup for 8 ohms.
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I think you need a 90dB 1W/1M 8 ohms tweeter and it is correct to use a 93dB/2.86V for a 4 ohms tweeter. As said you have a lot of choices.
It is a good idea to go to 8 ohms. They are much amplifiers which supports this impedance.
It is a good idea to go to 8 ohms. They are much amplifiers which supports this impedance.
Hi,
Again you cannot state sensitivity as dB/W/m, that is "efficiency".
What I'm getting at is the matching tweeter for 102dB/2.83V/1m
needs to have a sensitivity of around 102dB/2.83V/1m whatever
its impedance, 2, 4, 8 or 16 ohm, the higher its impedance the
more "efficient" it needs to be in terms of dB/W/m.
A matching 8 ohm tweeter would be around 102dB/W/1m.
With the drivers in series, "efficiency" remains the same but
the sensitivity drops to 96dB/2.83V/1m and a matching
tweeter needs to be around 96dB/2.83V/1m. For a 4ohm
tweeter that would mean 93dB/W/1m, but the sensitivity
required is still 96dB/2.83V/1m, that doesn't change.
I'm not knocking the DECWARE products, just the sites
habit of overegging the pudding when it comes to the
product descriptions, his site, his marketing I guess.
Not a site to get a good handle on the real technical
details, and I agree there are many others like that.
rgds, sreten.
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Back to the original question - if you were happy enough with the Parkers /Zen combination before the damage, I'd just replace the single FT17H and be done with it - at $42 a bargain AFAIC.
Now, if you're looking to upgrade them, that's a different story, and no doubt there are countless opinions to be shared - I nominate the newly available Heil AMT - from personal experience with the Zen C, an stunning combination.
Yes, Steve does tend to egg the pudding, and some of the technical prose is certainly a fun read - sometimes I think he missed his true calling on Madison Avenue.
.
Now, if you're looking to upgrade them, that's a different story, and no doubt there are countless opinions to be shared - I nominate the newly available Heil AMT - from personal experience with the Zen C, an stunning combination.
Yes, Steve does tend to egg the pudding, and some of the technical prose is certainly a fun read - sometimes I think he missed his true calling on Madison Avenue.
.
I might just order a ft17h and be done with it as that is the easiest and most cost effective option. I just wanted to see what my other options were before I went and ordered it. Since the FT17H is sort of a niche item I wanted to know if there was an alternative I could reuse for when I want to build another pair of high efficiency speakers. The only alternative that I think I like so far is the Beyma T2030 but since I have never heard one in person I am not sure it is worth the investment. Unless someone here told me it was worth the money for a pair of Beyma's or the like, which will only be used on 5khz and up I think the FT17h is it.
Thanks for you help guys I appreciate your input.
sreten do you know of a good link that lays out the math and theory behind the differences between efficiency and sensitivity? The next time I want to build a set of speakers I would really like to have that down 100%.
Thanks for you help guys I appreciate your input.
sreten do you know of a good link that lays out the math and theory behind the differences between efficiency and sensitivity? The next time I want to build a set of speakers I would really like to have that down 100%.
Efficiency is the output in dB when you feed the DUT 1watt of power
Sensitivity is the output in dB when you feed the DUT 2.83V.
There should also be a frequency (or frequency range) at which the number is valid.
into 8 ohms 2.83V = 1W
into 4 ohms 2.83V = 2W
into 2 ohms 2.83V = 4W
So a sensitivity of 96 dB with a 2 ohm speaker implies 90 dB efficient, which is where your Parkers end up with drivers wired in series or parallel, but now at 8 ohms, they are also nominally 90 dB sensitivity.
dave
It is a bit more complex into a real loudspeaker.
dave
Sensitivity is the output in dB when you feed the DUT 2.83V.
There should also be a frequency (or frequency range) at which the number is valid.
into 8 ohms 2.83V = 1W
into 4 ohms 2.83V = 2W
into 2 ohms 2.83V = 4W
So a sensitivity of 96 dB with a 2 ohm speaker implies 90 dB efficient, which is where your Parkers end up with drivers wired in series or parallel, but now at 8 ohms, they are also nominally 90 dB sensitivity.
dave
It is a bit more complex into a real loudspeaker.
dave
Planet10 that sounds easier then it is for me to process. Now I understand why everyone just uses 8 ohm drivers to keep things simple. Let me see if I am starting to get this.
Efficiency is the output in dB at 1 meter when 1 watt is given to the driver, regardless of what Re the driver has.
Efficiency is the output in dB at 1 meter when 1 watt is given to the speaker as a whole, regardless of it's total ohm load
Sensitivity is the output in dB at 1 meter when 2.83V is given to the the driver, so depending on the Re of the driver it may be receiving more then 1 watt (2ohm-4watts, 4ohms-2watts,8ohms-1watt)
Sensitivity is the output in dB at 1 meter when 2.83V is given to the the speaker as a whole, so depending on the Re of the driver it may be receiving more then 1 watt (2ohm-4watts, 4ohms-2watts,8ohms-1watt)
When discussing 8 ohm drivers Sensitivity = Efficiency so that is why there is so much confusion.
If I am understanding this correctly. Efficiency seems like a better measurement system as the amount of power is held as a constant, not the voltage. In fact I have always looked at efficiency and not sensitivity, you put 1 watt in you get X dB out.
I believe that the drivers for the parker audio 98 are 93dB/watt/meter and 4 ohms (efficiency). I could be wrong on that but lets assume that is correct. Wouldn't that make them 96db/2.83V/m (sensitivity). Am I on the right track here?
Ok so what about this, you have a speaker with two drivers which you want to have the same level output from. One is a 4ohm driver with an efficiency of 90dB/watt/meter. The second is an 8ohm driver with an efficiency/sensitivity of 93dB/2.83V/meter. All things being equal these two drivers should play at the same level when the speaker receives 1 watt. Can you check my math? If I am right, I get it, if not it's back to hitting the books 🙂
BTW I do understand that these measurements are an average over a range.
It looks like the mounting terminal broke inside the tweeter while I was trying to put it back into the enclosure. There is no apparent way to disassemble it without damage so I think I will just have to replace it.
Efficiency is the output in dB at 1 meter when 1 watt is given to the driver, regardless of what Re the driver has.
Efficiency is the output in dB at 1 meter when 1 watt is given to the speaker as a whole, regardless of it's total ohm load
Sensitivity is the output in dB at 1 meter when 2.83V is given to the the driver, so depending on the Re of the driver it may be receiving more then 1 watt (2ohm-4watts, 4ohms-2watts,8ohms-1watt)
Sensitivity is the output in dB at 1 meter when 2.83V is given to the the speaker as a whole, so depending on the Re of the driver it may be receiving more then 1 watt (2ohm-4watts, 4ohms-2watts,8ohms-1watt)
When discussing 8 ohm drivers Sensitivity = Efficiency so that is why there is so much confusion.
If I am understanding this correctly. Efficiency seems like a better measurement system as the amount of power is held as a constant, not the voltage. In fact I have always looked at efficiency and not sensitivity, you put 1 watt in you get X dB out.
I believe that the drivers for the parker audio 98 are 93dB/watt/meter and 4 ohms (efficiency). I could be wrong on that but lets assume that is correct. Wouldn't that make them 96db/2.83V/m (sensitivity). Am I on the right track here?
Ok so what about this, you have a speaker with two drivers which you want to have the same level output from. One is a 4ohm driver with an efficiency of 90dB/watt/meter. The second is an 8ohm driver with an efficiency/sensitivity of 93dB/2.83V/meter. All things being equal these two drivers should play at the same level when the speaker receives 1 watt. Can you check my math? If I am right, I get it, if not it's back to hitting the books 🙂
BTW I do understand that these measurements are an average over a range.
It looks like the mounting terminal broke inside the tweeter while I was trying to put it back into the enclosure. There is no apparent way to disassemble it without damage so I think I will just have to replace it.
DJNUBZ, the only problem I see with your logic is the part about holding the power constant.
Since most amplifiers are more or less voltage sources, then if you change nothing else
and connect an 8ohm speaker and a 4ohm speaker to an amplifier they will both receive the same voltage but the 4ohm will dissipate twice as many watts.
So the dB/W/2.83V rating may be easier to understand...
Most driver manufacturers seem to use this convention, although if you know the Znom of the driver it's easy enough to jump from one to the other.
John
Since most amplifiers are more or less voltage sources, then if you change nothing else
and connect an 8ohm speaker and a 4ohm speaker to an amplifier they will both receive the same voltage but the 4ohm will dissipate twice as many watts.
So the dB/W/2.83V rating may be easier to understand...
Most driver manufacturers seem to use this convention, although if you know the Znom of the driver it's easy enough to jump from one to the other.
John
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