xrk971, thanks for the tips.
Its not practical to get a woofer closer to the FR driver so I guess if the strict definition of FAST is cutover at 300Hz then this design isn't FAST (maybe satellite is a better term). It is still an interesting design challenge to cutover around 100Hz and a very common listening scenario that isn't mentioned much around here.
Although I have a dedicated listening room (home theater) with an excellent audio setup (HTPC with DIY Hypex amp and Dunlavy SC-IVa speakers) I do 80% of my listening at my computer, 15% in the car and only 5% in the home theater, so I do want to get the best sound I can from my desktop "satellites".
I'm also a bit surprised that there aren't many decent audiophile desktop satellite speakers - which makes this project even more interesting.
Regarding Xo and 300Hz vs 100Hz, you are right that distortion will be increased the lower the crossover however nearfield needs very little power/SPL which does help. So I will need to find a driver that is a compromise between having a lower Fo, decent Xmax but is still lightweight for good transient response and doesn't beam too badly as I sit close. I also want to stick with sealed if possible (for the transient response). It is an expensive driver though!
Another option for me might be the EAD E60 which is a reworked version of the JXR6HD with a better Xmax (2.1mm) and lower Fo although from the EAD site it seems to be out of production. From memory didn't EJJordan outsource their manufacturing to EAD then pull it back to the UK to make the Elkona so I suppose if I want a smaller Jordan driver the E60 would be it?
Regarding the Jordans and ringing, if I run a frequency sweep on my JXR6's there is definitely ringing at around 8KHz, however I don't hear it with music playing. Another problem is with the spiderless drivers, sometimes the cone gets out of alignment and the voicecoil rubs on the magnet.
Given the above, maybe the Elkona (with its better bass response than the JXR6) is more suitable for my application but I'm still cautious about it beaming and not being as 'sweet' to listen to compared to smaller FR drivers.
Its not practical to get a woofer closer to the FR driver so I guess if the strict definition of FAST is cutover at 300Hz then this design isn't FAST (maybe satellite is a better term). It is still an interesting design challenge to cutover around 100Hz and a very common listening scenario that isn't mentioned much around here.
Although I have a dedicated listening room (home theater) with an excellent audio setup (HTPC with DIY Hypex amp and Dunlavy SC-IVa speakers) I do 80% of my listening at my computer, 15% in the car and only 5% in the home theater, so I do want to get the best sound I can from my desktop "satellites".
I'm also a bit surprised that there aren't many decent audiophile desktop satellite speakers - which makes this project even more interesting.
Regarding Xo and 300Hz vs 100Hz, you are right that distortion will be increased the lower the crossover however nearfield needs very little power/SPL which does help. So I will need to find a driver that is a compromise between having a lower Fo, decent Xmax but is still lightweight for good transient response and doesn't beam too badly as I sit close. I also want to stick with sealed if possible (for the transient response). It is an expensive driver though!
Another option for me might be the EAD E60 which is a reworked version of the JXR6HD with a better Xmax (2.1mm) and lower Fo although from the EAD site it seems to be out of production. From memory didn't EJJordan outsource their manufacturing to EAD then pull it back to the UK to make the Elkona so I suppose if I want a smaller Jordan driver the E60 would be it?
Regarding the Jordans and ringing, if I run a frequency sweep on my JXR6's there is definitely ringing at around 8KHz, however I don't hear it with music playing. Another problem is with the spiderless drivers, sometimes the cone gets out of alignment and the voicecoil rubs on the magnet.
Given the above, maybe the Elkona (with its better bass response than the JXR6) is more suitable for my application but I'm still cautious about it beaming and not being as 'sweet' to listen to compared to smaller FR drivers.
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What to you foresee your desktop listening distance and levels to be? For me it's less 1 meter and well below 90dB, so something like a 3-4" FR driver and gentle EQ from the player software if necessary, and a small class D amp (Topping TP30 in my case) has proven quite adequate.
In that weight range there are numerous FR driver candidates by makers such as Jordan, Mark Audio, Fostex, TangBand, Dayton, the Tymphany consortium. As mentioned earlier, I quite like the little FF85 &105 WKs, and have also used several of the MA / Alpair family in boxes from approx 3 - 5 liters. Most of those have happened to be vented.
If your computer sound card supports 2.1 output, then adding a small powered sub to any desktop monitor build should more than suffice if deemed essential.
There are tons of commercial computer speaker sub/sat systems by folks like Logitech, and while they certainly benefit from economy of scale, to describe the performance of any that I've heard as anything more than mediocre would be a gross misstatement. Forum decorum prevents my honest opinion, as sometimes the only words that work are unprintable here.
Several of the more prestigious commercial brands B&W, Focal, Eclipse, KEF to name the first few I can recall have products in their line-ups that would qualify as audiophile priced computer speakers - I've never heard any, perhaps their prices could be justified.
Yes, the long term durability of spiderless designs without the benefit of ferrofluild in the motor assembly has yet to be proven. I hope they work
In that weight range there are numerous FR driver candidates by makers such as Jordan, Mark Audio, Fostex, TangBand, Dayton, the Tymphany consortium. As mentioned earlier, I quite like the little FF85 &105 WKs, and have also used several of the MA / Alpair family in boxes from approx 3 - 5 liters. Most of those have happened to be vented.
If your computer sound card supports 2.1 output, then adding a small powered sub to any desktop monitor build should more than suffice if deemed essential.
There are tons of commercial computer speaker sub/sat systems by folks like Logitech, and while they certainly benefit from economy of scale, to describe the performance of any that I've heard as anything more than mediocre would be a gross misstatement. Forum decorum prevents my honest opinion, as sometimes the only words that work are unprintable here.
Several of the more prestigious commercial brands B&W, Focal, Eclipse, KEF to name the first few I can recall have products in their line-ups that would qualify as audiophile priced computer speakers - I've never heard any, perhaps their prices could be justified.
Yes, the long term durability of spiderless designs without the benefit of ferrofluild in the motor assembly has yet to be proven. I hope they work
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Thanks Chris, yes this will be a 2.1 system with less than 1 meter distance and low SPL listening. To get decent treble the driver needs to be smaller and to get decent bass a woofer/subwoofer is needed. It's all about selecting the right compromises with a sound that I'll find pleasing.
As its not practical to buy all the drivers recommended in this thread and run up listening tests, I'll have to look closely at the excellent subjective listening threads.
As its not practical to buy all the drivers recommended in this thread and run up listening tests, I'll have to look closely at the excellent subjective listening threads.
If the Eikona is too large for your needs, I can recommend the Scanspeak 3" driver mentioned earlier. I haven't listened to it but it tests very well.
Attacking it from a different angle, what about using a pair of mid-bass drivers with the JXR6HDs? You'll get an increase in clarity rolling the 6 off below 300Hz and using it without EQ. At the relatively low SPLs you're talking about, you may be able to boost the right drivers and do without a sub. Somewhat similar to Linkwitz's approach with the Pluto / LXmini designs.
Just to give you some more homework
Attacking it from a different angle, what about using a pair of mid-bass drivers with the JXR6HDs? You'll get an increase in clarity rolling the 6 off below 300Hz and using it without EQ. At the relatively low SPLs you're talking about, you may be able to boost the right drivers and do without a sub. Somewhat similar to Linkwitz's approach with the Pluto / LXmini designs.
Just to give you some more homework
If Colin is referencing the 10F, yes it is very smooth and neutral. My only experience with them is the tiniest vented box they can fit in, and IIRC a close to aperiodic short pipe TL - in either of which, even for nearfield, I personally find them lacking at the bottom end compared to Fostex FF85 or 15WK, and several of the Mark Audio & Alpair models mentioned.
Colin's suggestion is a good one, provided you have space on your desktop for a larger T-M 2-way- generally the sub would get stashed on the floor, but in the case of a 2-way with appropriate mid-bass drivers, might not be required after all.
Colin's suggestion is a good one, provided you have space on your desktop for a larger T-M 2-way- generally the sub would get stashed on the floor, but in the case of a 2-way with appropriate mid-bass drivers, might not be required after all.
We put the 10F into an optimum miniOnken style box to extend the bass response. With a tail wind in might get to 120-130 Hz. It does sound good, and shows how little bass one can get away with. In comparison to similarily priced FF85wKeN (EnABLed & matched) it lacked top & DDR/low level detail.
I need to get them back from Chris so we can compare them to A5.2 and A5.2eN. Also need to compare A5.2eN to FF85wKeN.
dave
Well I had a quick listening session last night - starting with Monty Alexander & Delfeayo Marsalis "No More Trouble" Holy smokes can that guy slide the bone, and Monty - well else is there to say? - excellent demo track . Then some Maceo Parker to spark things up a bit - "Uptown Up"
James: "I don't care what you play man, as long as it's FUNKAY"
Mr Parker never fails there .
Listening distance was 10 ft in a 320ft room, so perhaps not a valid test of near-field performance, but at the end of the day, I just wanted to relax in the lazy boy, sip a dry Vodka martini or two and escape into the music.
Anyway, in the specific little box that Dave mentioned, the 10F was clean and neutral from upper mid-bass on up (my guess would have been a bit higher than Dave suggests) , but lacked the top end extension, detail and "air" of the A5.2, and in a Woden designed Baby-Lab, that little Alpair is surprisingly solid well into the lower mid-bass. Don't ask for measures from me, but there may be some modeling of that.
Yah, I quite like the 5.2
James: "I don't care what you play man, as long as it's FUNKAY"
Mr Parker never fails there .
Listening distance was 10 ft in a 320ft room, so perhaps not a valid test of near-field performance, but at the end of the day, I just wanted to relax in the lazy boy, sip a dry Vodka martini or two and escape into the music.
Anyway, in the specific little box that Dave mentioned, the 10F was clean and neutral from upper mid-bass on up (my guess would have been a bit higher than Dave suggests) , but lacked the top end extension, detail and "air" of the A5.2, and in a Woden designed Baby-Lab, that little Alpair is surprisingly solid well into the lower mid-bass. Don't ask for measures from me, but there may be some modeling of that.
Yah, I quite like the 5.2
deandob,
Here my view based at post 42 sounds as you care having quality near field soundstage, and attacking project at angle as Colin suggested and if you agree/trust drivers based on good objective data leads to HQ speaker.
FAST system 10F/8424 4-500Hz and up with a SATORI MW16P-8 below. MW16P-8 in sealed Qtc 0.7 reach a f3 62Hz and needs only around 9ltr when stuffed, has 6mm Xmax so plenty headroom for a near field setup to extend low end reach with a Linkwitz transform or ordinary LF EQ filters. Have no subjective experience woofer other than via diyA friends but 10F is very good driver and can back it up with nice objective data and subjective info. Out of box with no correction these drivers have nice nearly flat response and will ensure best quality transients from a IRR band pass speaker system. Being feed from your computer you can later see if system up quality adding FIR filters and or more IRR correction and can make system able to reproduce even better transients in acoustic square waves from lows to 4-5kHz area. Admit SATORI woofer is costly, SS have one at better cost 18W/8434 that calls for nearly same low box volume but f3 will raise to 82Hz and Xmax headroom is less but okay maybe enough to your near field listening. Also JXR6 could be combined those woofers as FAST system.
If interested links to real world in room data these drivers other than normal datasheets post a request and will get back.
Here my view based at post 42 sounds as you care having quality near field soundstage, and attacking project at angle as Colin suggested and if you agree/trust drivers based on good objective data leads to HQ speaker.
FAST system 10F/8424 4-500Hz and up with a SATORI MW16P-8 below. MW16P-8 in sealed Qtc 0.7 reach a f3 62Hz and needs only around 9ltr when stuffed, has 6mm Xmax so plenty headroom for a near field setup to extend low end reach with a Linkwitz transform or ordinary LF EQ filters. Have no subjective experience woofer other than via diyA friends but 10F is very good driver and can back it up with nice objective data and subjective info. Out of box with no correction these drivers have nice nearly flat response and will ensure best quality transients from a IRR band pass speaker system. Being feed from your computer you can later see if system up quality adding FIR filters and or more IRR correction and can make system able to reproduce even better transients in acoustic square waves from lows to 4-5kHz area. Admit SATORI woofer is costly, SS have one at better cost 18W/8434 that calls for nearly same low box volume but f3 will raise to 82Hz and Xmax headroom is less but okay maybe enough to your near field listening. Also JXR6 could be combined those woofers as FAST system.
If interested links to real world in room data these drivers other than normal datasheets post a request and will get back.
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The A5.2 Chris has are stock production units. The ones i have are EnABLed pre-production.
dave
Thanks ChrisB, Byrtt, Dave, Colin for all the suggestions.
I'd really like to keep the desktop with one driver per speaker (this is a full range forum after all ) supplemented by a separate subwoofer for below 150Hz (to reduce bass directionality), sealed (to help reduce distortion caused by LF excursion and better transient response) and metal cone (transient response, imaging). Treble is important especially as I sit so close to the driver. The idea of smaller drivers on the desktop and a separate small subwoofer but still giving audiophile sound is what I'm looking for. The box size can be up to 6L which isn't too small and helps get a little more bass out of the small driver running sealed.
The main tradeoffs here will be the quality of the treble (smaller drivers better) versus ability to go low enough to use 1 subwoofer and not introduce too much extra distortion by pushing a small driver to reproduce too much bass excursion.
To run a small driver down to 150Hz, xmax > 1mm and Fo < 100Hz are important to avoid too much distortion from the bass although nearfield helps because the speakers only need to driven with low power levels. I will be using a software HP higher order filter to roll off the lower frequencies quickly to avoid undue driver excursion. So I think a combination of all these factors will make it practical to use a smaller driver without too much introduced distortion from LF excursions.
So looking at the various drivers recommended here:
SS 10F. 4" Paper cone, xmax 2.3mm, Fo 100Hz, suitable for 2L sealed cabinet F3 180Hz in a 5L box.
=> Not low enough F3 and reports of missing top end 'air'.
Fostex FF85W. 3" Paper cone with metal cap, xmax 0.35mm, Fo 115Hz, suitable for vented 3.5L cabinets
=> doesn't sound too suitable.
Elkona. Metal cone 5" driver, xmax 5mm, Fo 43Hz, ample low end to run in a small box
=> possible but concerns about size, treble quality and expensive
Alpair 5.2. 3" metal cone, F0 100Hz, F3 180Hz
=> Seems suitable and a more modern version of the JXR6. Initial feedback on this new model is positive but F3 isn't low enough
EAD E60 2" metal cone. F0 94Hz, xmax 2.1mm, 130Hz F3 in a 5L sealed box
=> Seems to be out of production and a close clone of the JXR6 - is it any better though?
JXR6. 2" metal cone, xmax 3mm, F0 86Hz, F3 100Hz in 5L sealed box.
=> I use this driver currently and it works well except for some mechanical voicecoil scraping. This is an older driver so I'm looking for something newer and better.
Daytona PS95 3.5" paper cone, xmax 2.5mm, Fo 115Hz, F3 130Hz
=> possible but not a metal cone so not sure about transient response & treble.
SB65. 2.5" metal cone, xmax 2.6mm, F0 115Hz, F3 in a 5L box is 130Hz
=> Looks suitable, rated well in the listening tests
Peerless TG9FD10. Fiverglass 3.5", xmax 2.5mm, F0 105Hz, F3 105Hz
=> Response looks to taper off significantly above 14Khz but good low end.
WinISD plots for all these drivers in a 5L sealed box attached. The Elkona obviously goes the lowest but the JXR6 looks to be most suitable for 150Hz cutoff, although the SB65, PS95 and E60, the others make the -3dB between 150Hz and 200Hz so will struggle.
Haven't really looked at the subwoofer but it won't be as critical (thinking about a lighter metal cone one as well - with linkwitz transform and corner loaded). This weekend I'm designing the amp for these speakers TPA3251D2 in 2.1 configuration, 20w for desktop, 150W for subwoofer (which with a linkwitz transform in a small box it will need the power).
Dave, I'm interested in the tweaks you do to the drivers - are these suitable for metal cones? Do you sell the drivers tweaked or is it DIY?
Colin - will the EAD E60 be an improvement over my JXR6? I'll consider the Elkona although concerned about its treble (versus JXR6 as it is larger & will beam), size and price.
I'd really like to keep the desktop with one driver per speaker (this is a full range forum after all
) supplemented by a separate subwoofer for below 150Hz (to reduce bass directionality), sealed (to help reduce distortion caused by LF excursion and better transient response) and metal cone (transient response, imaging). Treble is important especially as I sit so close to the driver. The idea of smaller drivers on the desktop and a separate small subwoofer but still giving audiophile sound is what I'm looking for. The box size can be up to 6L which isn't too small and helps get a little more bass out of the small driver running sealed. The main tradeoffs here will be the quality of the treble (smaller drivers better) versus ability to go low enough to use 1 subwoofer and not introduce too much extra distortion by pushing a small driver to reproduce too much bass excursion.
To run a small driver down to 150Hz, xmax > 1mm and Fo < 100Hz are important to avoid too much distortion from the bass although nearfield helps because the speakers only need to driven with low power levels. I will be using a software HP higher order filter to roll off the lower frequencies quickly to avoid undue driver excursion. So I think a combination of all these factors will make it practical to use a smaller driver without too much introduced distortion from LF excursions.
So looking at the various drivers recommended here:
SS 10F. 4" Paper cone, xmax 2.3mm, Fo 100Hz, suitable for 2L sealed cabinet F3 180Hz in a 5L box.
=> Not low enough F3 and reports of missing top end 'air'.
Fostex FF85W. 3" Paper cone with metal cap, xmax 0.35mm, Fo 115Hz, suitable for vented 3.5L cabinets
=> doesn't sound too suitable.
Elkona. Metal cone 5" driver, xmax 5mm, Fo 43Hz, ample low end to run in a small box
=> possible but concerns about size, treble quality and expensive
Alpair 5.2. 3" metal cone, F0 100Hz, F3 180Hz
=> Seems suitable and a more modern version of the JXR6. Initial feedback on this new model is positive but F3 isn't low enough
EAD E60 2" metal cone. F0 94Hz, xmax 2.1mm, 130Hz F3 in a 5L sealed box
=> Seems to be out of production and a close clone of the JXR6 - is it any better though?
JXR6. 2" metal cone, xmax 3mm, F0 86Hz, F3 100Hz in 5L sealed box.
=> I use this driver currently and it works well except for some mechanical voicecoil scraping. This is an older driver so I'm looking for something newer and better.
Daytona PS95 3.5" paper cone, xmax 2.5mm, Fo 115Hz, F3 130Hz
=> possible but not a metal cone so not sure about transient response & treble.
SB65. 2.5" metal cone, xmax 2.6mm, F0 115Hz, F3 in a 5L box is 130Hz
=> Looks suitable, rated well in the listening tests
Peerless TG9FD10. Fiverglass 3.5", xmax 2.5mm, F0 105Hz, F3 105Hz
=> Response looks to taper off significantly above 14Khz but good low end.
WinISD plots for all these drivers in a 5L sealed box attached. The Elkona obviously goes the lowest but the JXR6 looks to be most suitable for 150Hz cutoff, although the SB65, PS95 and E60, the others make the -3dB between 150Hz and 200Hz so will struggle.
Haven't really looked at the subwoofer but it won't be as critical (thinking about a lighter metal cone one as well - with linkwitz transform and corner loaded). This weekend I'm designing the amp for these speakers TPA3251D2 in 2.1 configuration, 20w for desktop, 150W for subwoofer (which with a linkwitz transform in a small box it will need the power).
Dave, I'm interested in the tweaks you do to the drivers - are these suitable for metal cones? Do you sell the drivers tweaked or is it DIY?
Colin - will the EAD E60 be an improvement over my JXR6? I'll consider the Elkona although concerned about its treble (versus JXR6 as it is larger & will beam), size and price.
zman01, thanks for the tip.
You are correct that the alpair 6 is probably a better suited driver because its a little bigger than the other drivers at 4" with better xmax and Fo.
WinISD modelling this driver gives a surprisingly high F3 in a 5L sealed box at 130Hz for a driver of this size, however the driver freq response has a bump from 100Hz to 500Hz that would help reinforce the bass and make up for the higher box F3. It is also a second generation driver so should sound decent. Would be useful to see some distortion data as the frequency response of this driver isn't very flat (but not necessarily a problem).
You are correct that the alpair 6 is probably a better suited driver because its a little bigger than the other drivers at 4" with better xmax and Fo.
WinISD modelling this driver gives a surprisingly high F3 in a 5L sealed box at 130Hz for a driver of this size, however the driver freq response has a bump from 100Hz to 500Hz that would help reinforce the bass and make up for the higher box F3. It is also a second generation driver so should sound decent. Would be useful to see some distortion data as the frequency response of this driver isn't very flat (but not necessarily a problem).
Just a quick note that the SS 10F is a fiberglass coned driver, not a paper cone.
Cone size is the same as Vifa's TG9 (3.5") and it's x-max is reported as ~2.6 mm.
http://www.scan-speak.dk/datasheet/pdf/10f-8424g00.pdf
Cone size is the same as Vifa's TG9 (3.5") and it's x-max is reported as ~2.6 mm.
http://www.scan-speak.dk/datasheet/pdf/10f-8424g00.pdf
deandob
Regarding sealed box not shure you have good transient response argument right when full ranger is XO'ed to a sub. Because sealed verse ported has better transient response is because filter roll of is a softer lower order 12dB/oct verse ported 24dB/oct. But at same you add a sub there be a acoustic IRR XO no matter any electric XO is present and ruin transients and especially because you write "will add a software HP higher order filter to roll off the lower frequencies quickly" for the full ranger this brings you into higher order ported territory or worse roll off seen in acoustic domain. A way to improve on transient response ruined by XO is use FIR filters somewhere or IRR XO type HARSCH which has a thread here on diyA.
Below are 4 more drivers that is as Elkona driver inside your 150Hz f3 slope reach running sealed and if stuffed to damp backwave reflection and box resonance they all go under 6 liter, Xmax data is there too and not bad.
Seems you warm on a metal cone therefor FR88EX would be hard to beat in it have smooth response in datasheet and 20kHz reach and confirmed at xrk971 comparison thread plus very low HD too. Be aware when FR88EX is measured above 20kHz some high Q peaks occurs and think also B 80 and A7.3m have such signature. Such signature can be reason why chrisb categories 10F lacked the top end extension, detail and "air" and planet10 talks lack of low level detail, because it roll off with softer low order and no nasty high Q peak/dips. By the objective book a 10F will show much better true transient response than high Q peaks/dips/roll offs and is clear when looking impulse and step response at xrk971 comparison threads. Have no real world subjective experience FR88EX/B 80/RS100-4 else than sound clips shared by xrk971 and lets leave that, know A7.3m and say if played as out of box with no IRR/DSP EQ correction it has a wrong pleasing signature never heard before that needs heavy correction in the long run, looking real world measurements A7.3m think backs up need for correction.
Regarding sealed box not shure you have good transient response argument right when full ranger is XO'ed to a sub. Because sealed verse ported has better transient response is because filter roll of is a softer lower order 12dB/oct verse ported 24dB/oct. But at same you add a sub there be a acoustic IRR XO no matter any electric XO is present and ruin transients and especially because you write "will add a software HP higher order filter to roll off the lower frequencies quickly" for the full ranger this brings you into higher order ported territory or worse roll off seen in acoustic domain. A way to improve on transient response ruined by XO is use FIR filters somewhere or IRR XO type HARSCH which has a thread here on diyA.
Below are 4 more drivers that is as Elkona driver inside your 150Hz f3 slope reach running sealed and if stuffed to damp backwave reflection and box resonance they all go under 6 liter, Xmax data is there too and not bad.
Seems you warm on a metal cone therefor FR88EX would be hard to beat in it have smooth response in datasheet and 20kHz reach and confirmed at xrk971 comparison thread plus very low HD too. Be aware when FR88EX is measured above 20kHz some high Q peaks occurs and think also B 80 and A7.3m have such signature. Such signature can be reason why chrisb categories 10F lacked the top end extension, detail and "air" and planet10 talks lack of low level detail, because it roll off with softer low order and no nasty high Q peak/dips. By the objective book a 10F will show much better true transient response than high Q peaks/dips/roll offs and is clear when looking impulse and step response at xrk971 comparison threads. Have no real world subjective experience FR88EX/B 80/RS100-4 else than sound clips shared by xrk971 and lets leave that, know A7.3m and say if played as out of box with no IRR/DSP EQ correction it has a wrong pleasing signature never heard before that needs heavy correction in the long run, looking real world measurements A7.3m think backs up need for correction.
Attachments
You have some good points Byrtt. Even a small 5in woofer like a 5FE120 (or AC130F1 if budget allows) and an FR88EX / B80 / 10F as a FAST to get down to 90Hz with sealed is a good choice and let sub take over from there for omni bass. If going with AC130F1, it has such a wide bandwidth you can even use 1st order XO.
Classified as a 3" driver, it is really closer to 3 ½".
Alpair 7.x is the 4" driver.
Your restriction of a sealed enclosure is really limiting you. A fully aperiodic box can have better transient response than sealed, and a highR vent on a vented enclosure comes close. Everything in a speaker is a selection of compromises. Sticking with sealed is causing you to make compromises that hinder your XO goal (not allowing you to consider many good FRs touse as midTweeter)
dave
You are trying to put a square peg in a round hole. Low level detail (there/not there information) has nothing to do with FR.
dave
The distortion spectra of the TPA3251D2 is excellent, the higher order harmonics are basically all significantly below the theshold of audility and at lower power levels, all distortion products are essentiall hidden in the noise floor.
If the amplifier is used with a suitable power supply the dominant distortion product is third order anyway when driven at higher power levels. 5th order creeps in at higher frequencies. With a less than perfect power supply 2nd order distortion dominates at low frequencies. A perfect power supply in this case is very difficult to realise for any realistic Hifi application and is a design issue with the chip itself. Going single ended worsens the 2nd order issue and using the amplifier in balanced, BTL mode is highly recommended.
Still it is a very nice chip and it's distortion spectra is not going to be detrimental to the overall sound quality. The only time it might become anything other than acoustically transparent is if you're driving it at very high levels, but this could be said for lots of amplifiers on the planet.
For a nearfield, single driver, set up I would be looking at the SB65 myself. Unlike most of the other full range drivers with metal cones, the SBs is very rigid. It even has those little ribs moulded into the shape to give the cone extra ridigity. It is pistonic throughout all of the audible band and only starts going through breakup in the last octave. I have used this driver myself and its treble performance is sublime, it's as smooth as silk and very transparent. The Vifa TG9 in comparison lacked and for my listening pleasure required a tweeter.
The SB65 also has an inherent rising uppper end, so gives you the ability to modify the treble balance by altering the amount of toe in.
It has a very well designed motor, lots of xmax and very low distortion. For what it does, and the price at which it does it, I cannot praise this driver highly enough. Its only caveat is its low sensitivity and obviously limited bass, but if you're using these nearfield and with bass reinforcement then you should be fine.
If the amplifier is used with a suitable power supply the dominant distortion product is third order anyway when driven at higher power levels. 5th order creeps in at higher frequencies. With a less than perfect power supply 2nd order distortion dominates at low frequencies. A perfect power supply in this case is very difficult to realise for any realistic Hifi application and is a design issue with the chip itself. Going single ended worsens the 2nd order issue and using the amplifier in balanced, BTL mode is highly recommended.
Still it is a very nice chip and it's distortion spectra is not going to be detrimental to the overall sound quality. The only time it might become anything other than acoustically transparent is if you're driving it at very high levels, but this could be said for lots of amplifiers on the planet.
For a nearfield, single driver, set up I would be looking at the SB65 myself. Unlike most of the other full range drivers with metal cones, the SBs is very rigid. It even has those little ribs moulded into the shape to give the cone extra ridigity. It is pistonic throughout all of the audible band and only starts going through breakup in the last octave. I have used this driver myself and its treble performance is sublime, it's as smooth as silk and very transparent. The Vifa TG9 in comparison lacked and for my listening pleasure required a tweeter.
The SB65 also has an inherent rising uppper end, so gives you the ability to modify the treble balance by altering the amount of toe in.
It has a very well designed motor, lots of xmax and very low distortion. For what it does, and the price at which it does it, I cannot praise this driver highly enough. Its only caveat is its low sensitivity and obviously limited bass, but if you're using these nearfield and with bass reinforcement then you should be fine.
Guys, all good points and thank you for offering insights into alternatives that I haven't thought of (or had experience with). I appreciate the schooling
I still want to keep with a single driver on the desktop and a satellite single sub as multiple drivers on the desktop with a higher XO will have trouble integrating with such near field listening. However the points about sealed enclosures versus vented are good and I should reconsider, especially as I am limiting options for selecting FR drivers as Dave mentions (eg. selecting a driver with smoother frequency response).
Regarding transient response and the acoustic crossover is also a good point and another reason why doing the XO as low as possible helps the mismatch between sub and the FR desktop (won't be as noticeable). But it also means I should probably consider having a similar box type and XO for the LP filter for the sub for a best match.
Is there any recommended reading on aperiodic and specifically why it has equal transient response to sealed? After a couple of 'net searches it seems the aperiodic is the same as a high R vent? Also any software available to model an aperiodic box (winISD doesn't have that option).
I still want to keep with a single driver on the desktop and a satellite single sub as multiple drivers on the desktop with a higher XO will have trouble integrating with such near field listening. However the points about sealed enclosures versus vented are good and I should reconsider, especially as I am limiting options for selecting FR drivers as Dave mentions (eg. selecting a driver with smoother frequency response).
Regarding transient response and the acoustic crossover is also a good point and another reason why doing the XO as low as possible helps the mismatch between sub and the FR desktop (won't be as noticeable). But it also means I should probably consider having a similar box type and XO for the LP filter for the sub for a best match.
Is there any recommended reading on aperiodic and specifically why it has equal transient response to sealed? After a couple of 'net searches it seems the aperiodic is the same as a high R vent? Also any software available to model an aperiodic box (winISD doesn't have that option).
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