Another good looking design, I wish I had your patience.
I am interested in your opinions of your bass unit. I am planning a 3 way speaker project (with cheaper drivers of course) and was planning to use 2 L26RFX per side in a heavily damped closed 120L enclosure for bass with no subwoofer.
Specifically, Seas has an overall excellent reputation, but scanspeak followers claim they are artificial sounding and generally weak on bass. Did you feel your bass unit lack musicality, being there feeling, or bass extension and spl?
I have not heard these drivers, and I picked them based on overall reputation, overall modeling, and price. The other bass units I considered was the scan 10” which added $250 to my project, increased my box size, had earlier starting resonance and had 1db less spl at 27.4Hz -3dB with Xmax excursion.
Also to play devil’s advocate, did you try your loudspeakers outside, in a different room, etc? What was the Q of your loudspeaker enclosure? Did you try to aperoidically load your woofers, change box volume etc? It’s painfull to give up on such nice looking boxes.
Also how did you settle on the Flex unit, have you heard them or is it based on reputation, Have you considered dipole bass, I listened to a phoenix copy and it was very good. It just did not meet my criteria of what I want/need from a loudspeaker.
I am interested in your opinions of your bass unit. I am planning a 3 way speaker project (with cheaper drivers of course) and was planning to use 2 L26RFX per side in a heavily damped closed 120L enclosure for bass with no subwoofer.
Specifically, Seas has an overall excellent reputation, but scanspeak followers claim they are artificial sounding and generally weak on bass. Did you feel your bass unit lack musicality, being there feeling, or bass extension and spl?
I have not heard these drivers, and I picked them based on overall reputation, overall modeling, and price. The other bass units I considered was the scan 10” which added $250 to my project, increased my box size, had earlier starting resonance and had 1db less spl at 27.4Hz -3dB with Xmax excursion.
Also to play devil’s advocate, did you try your loudspeakers outside, in a different room, etc? What was the Q of your loudspeaker enclosure? Did you try to aperoidically load your woofers, change box volume etc? It’s painfull to give up on such nice looking boxes.
Also how did you settle on the Flex unit, have you heard them or is it based on reputation, Have you considered dipole bass, I listened to a phoenix copy and it was very good. It just did not meet my criteria of what I want/need from a loudspeaker.
Yes, I've also wondered why the Flex unit was chosen for bass duties, as many seem to believe that paper is superior to poly for LF duties.
I'm very happy, by the way, with my Scanspeak 26w8861s.
I'm very happy, by the way, with my Scanspeak 26w8861s.
mbutzkies said:
The reason for getting rid of the Seas L22's isn't because they sounded bad, quite the opposite they actually are decent sounding speakers. Just not what I'm looking for though, my main problem is the fact that they sound slighty muddy over about 150hz and since I cross to the ATC at 400hz, they've got plenty of work to do. They also fail to achieve bottom octave performance that I'd like, no real surprise there since these are only 4 x 8" drivers but I did try a transform to move the response further down, not really a great success, tbe gain really just seemed to increase distortion from 40-20hz. Sure it was quiite deep and went loud but harmonic distortions were evident.
This time I'll not try to get sub bass using 8" or 10" drivers, I really think that to do bass well and do it convincingly you need big drivers with big displacment. So from 40hz(music) or 80hz(HT) down I'll crossover to a 24" Precision Devices PD2450 with LT down to 10hz.
The flex units are a sore point at the moment since I've been told I'll have to wait longer because of a supply problem regarding individual components of the speaker.
I've got the option to either stick in there and wait or cancel.
Disabled Account
Joined 2003
The other SS Revelators, the 5.5" 8530 and 7" 8531 are known to be incredible bass machines.
ShinOBIWAN:
If you're looking for a 10", I think the Revelator 26W series should be on the top of your shopping list. ScanSpeak bass drivers are kwown for their extension, lower distortion with the same SPL (or higher SPL given the same distortion level) than SEAS competition.
Re: the L22RNX/4P, Have you have a look at Troels Gravesen's alignment? From what I know of Troels, he's quite meticulous and will construct a test cabinets and try several actual port tunings before settling on *final* cabs. Lately he's been cheating, by sending the fine-tuned specs off, to be built by professional cabinet maker. 😀
In the Point 75i his target was Vb=30L, Fb=33Hz using port 60 mm ID and a length 190 mm.
He crosses over to open-baffle SEAS Excel W15CY001 midrange, around 400-450Hz.
The muddines you're experiencing may not due to any inherent problems with the L22RNX/4P, but in the chosen bass alignment / LP filter and/or primary port resonance....
ShinOBIWAN:
If you're looking for a 10", I think the Revelator 26W series should be on the top of your shopping list. ScanSpeak bass drivers are kwown for their extension, lower distortion with the same SPL (or higher SPL given the same distortion level) than SEAS competition.
Re: the L22RNX/4P, Have you have a look at Troels Gravesen's alignment? From what I know of Troels, he's quite meticulous and will construct a test cabinets and try several actual port tunings before settling on *final* cabs. Lately he's been cheating, by sending the fine-tuned specs off, to be built by professional cabinet maker. 😀
In the Point 75i his target was Vb=30L, Fb=33Hz using port 60 mm ID and a length 190 mm.
He crosses over to open-baffle SEAS Excel W15CY001 midrange, around 400-450Hz.
The muddines you're experiencing may not due to any inherent problems with the L22RNX/4P, but in the chosen bass alignment / LP filter and/or primary port resonance....
The PD2450 is an awesome looking driver, but what sort of enclosure are you planning on using? Side mounting?
tktran said:
Alignment could be the issue.
2x woofer was Vb: 40L Qtc: 0.62
It could be a number of things such as alignment, box construction, room, incompatibilities between the ATC and seas such as cone materials.
I'd like to think that cabinet construction was up to scratch since I did extensively brace and double wall. Alignment was investigated well before construction as shown earlier in this thread.
Frequency plot look nice and flat throughout the operating range of the L22's with care being taken to kill the cone break up resonances. So hopefully the room isn't the problem.
Which really leaves just the fact that the ATC and Seas don't work well together, one is a doped woven fabric dome and the other is an alu cone. The XO point is in the critical 400hz area meaning any incompatiblility problems will be noticable.
Personally I think I just cocked up on driver choice for the bass, not a good match for the ATC.
I may even go with ATC bass drivers.
BTW I have done a small amount of testing outside but the weather here in the UK is a little temperamental and its a pain to lug all the equpment up and downstairs. No serious stereo listening has taken place outside, just sweeps and measurements.
Vil said:
I've had a couple of Volts in the past for sub use. First one was the B2500.1, good driver with great sound and the other was a 15" RV3863 excellent bass from this one.
David Gatti said:
If I went with a transform to 10hz, which models extremely nicely in WinISD BTW, it would be 150L sealed.
This driver looks well ported too though, box size goes through the roof though and I'm not sure if a transform would be the best idea with ported and high SPL.
Dipole is another option but I'm unsure of the suitability of the PD2450.
Disabled Account
Joined 2003
I joined this discussion a bit late, but did you measure the woofer's actual T/S parameters, final in-box Qtc, quasi-anechoic F3 post equalization or Linkwitz transform etc?
How's the room FR response?
In a sealed alignment, 20L each or a sealed enclosures seem too small to me. This is another SEAS woofers that works best vented...
How's the room FR response?
In a sealed alignment, 20L each or a sealed enclosures seem too small to me. This is another SEAS woofers that works best vented...
Attachments
Ant,
Your experiences tie in with mine - I used 2 x 10" s-speak 8565-01's per side (sealed) and found them excellent between 40 and 300, with 'regular' subs below. If you pushed them too low they lost dynamics, but still sounded clean. The trouble is running the subs up to 80 made the setup sound worse, but dynamically better...
Rob.
(4x 8565-01's for sale at the moment 😀 )
Your experiences tie in with mine - I used 2 x 10" s-speak 8565-01's per side (sealed) and found them excellent between 40 and 300, with 'regular' subs below. If you pushed them too low they lost dynamics, but still sounded clean. The trouble is running the subs up to 80 made the setup sound worse, but dynamically better...
Rob.
(4x 8565-01's for sale at the moment 😀 )
RobWells said:Ant,
Your experiences tie in with mine - I used 2 x 10" s-speak 8565-01's per side (sealed) and found them excellent between 40 and 300, with 'regular' subs below. If you pushed them too low they lost dynamics, but still sounded clean. The trouble is running the subs up to 80 made the setup sound worse, but dynamically better...
Rob.
(4x 8565-01's for sale at the moment 😀 )
I suspect mine actually sounds worst since at least you were using 2 x 10" instead of 2 x 8"
Its good that you mention dynamics as that's exactly what these lack, after the initial impressive 'look what I've built' is over you start to notice whats really wrong with the sound. Compared to the mid and treble they sound dynamically challenged, muffled, muted and coloured. Especially when you push the whole thing hard - they run out of steam very quickly with that 20hz transform.
tktran said:
Actually tried it vented early on before the main ones were built, it sounded worst.
The graph you've got for the vented option also looks slightly peaky which would be exagerated after room gain resulting in just what I found, boomyness.
Sealed was the most natural sound and 20L each is actually quite generous with a Qtc of 0.62. Consider that Troels used 30L ported and your looking at similar volumes.
I think the top and bottom is that the Seas isn't as capable a performer as the mid and treble and by someway.
Since you are doing room corection and digital xovers, why don't you look into what TacT is doing regarding woofers.
They actually cross their W210 subwoofers rather high.
The special Vifa drivers and sub plans can be had for DIY.
More info on some of the Tact user groups on yahoo groups and on the tact dk site.
They actually cross their W210 subwoofers rather high.
The special Vifa drivers and sub plans can be had for DIY.
More info on some of the Tact user groups on yahoo groups and on the tact dk site.
ShinOBIWAN said:
I should have added, I only really noticed the lack of steam on 5.1 film stuff. If my setup was music only I'd have kept them (with subs below 40). Only changed them due to my habit of watching films at reference level.
I've started cutting the wood for some labhorns for 30Hz - 80Hz, and will be keeping my tempests for 15 - 30... Hopefully that will end my subwoofer building days for a long time..😀
If you've still got the speakers in their cabs maybe give them a go with a sub below - It should really clean them up.., and poss save you shelling out time and money on a new bass unit project.
Cheers,
Rob.
cph2000 said:
Do you know how high exactly?
These are crossed at 400hz currently with 3rd order acoustic slopes.
RobWells said:
I've had the linkwitz circuit out of the loop and the integration doesn't improve unfortunately power handling does of course.
Like you I watch plenty of films so they've really got to be up to scratch with the latest 5.1 mixes.
I route the LFE channel back through the mains at the moment and skip the sub.
Whichever way I go I'm not entirely pleased. With music integration isn't what I'd like and with movies the depth, slam and low distortion aren't there in the quality I'd like.
I've kinda made the L22 sound like its no good when in actual fact its rather nice. I think in the right system most folks would be pleased.
Nothing beats large woofer with huge xmas. Try to get one or even two avalanche 18 that is on clearance right now. You can pump 800W each into the woofer and it will shake the house.
ShinOBIWAN said:
You'll have a hard time finding a dynamic ("subjectivly") driver that can handle high excursion levels (for the L. transform) that doesn't have a large sd. Even an AT driver with the proper T/S *AND* non-standard cone material (i.e. NOT a mineral loaded poly mixture) will need a larger sd. This was something that I tried to convey early-on (see pg. 2 of this thread), but.. well.. the rest is "history" as they say. In fact IF you still desire a truely dynamic driver that is 8 inches with greater "transparency" - then you'll be hard pressed to better the Supravox 215 GMF.. the only thing you would lack then would be "headroom" with a L. Transform - (or better yet create a true subwoofer* and forget L. transforming (below fs) the 8 inch drivers and just operate them "normally" in a sealed enclosure with laminar "ducting" around the drivers and perhaps with aperiodic "venting").
*as to a true subwoofer.. most of the subjective sense of "dynamics" have nothing to do with real dynamic capabitlity - at least as it involves just changes in sound pressure level. Moreover the subjective sense of dynamics really have little to do with freq.s below 40 Hz (and typically 50 Hz), simply because few instruments fundamentally operate in this range (or even in the case of organs - are rarely played in this range). So then what IS important with the "sub" freq.s? Beyond moderate linearity (+/- 5 db), distortion is "king" (..contrary to what many have written). The reason again is fairly simple but usually overlooked - most of these freq.s do NOT represent the fundamental of the "event" (or instruments, singers, etc.) but rather the "hallsound" of the event. We can detect direct sound rather easily even if it is distorted (i.e. a singer or an instrument), but detecting the "nature" (or quality) of hallsound is rather difficult because it in itself is a distortion (and a very complex one at that), and is not direct sound. So with regard to what you should be looking for in these sub freq.s - low distortion is EXTRMELY important ..and its why Wilson Audio still manages to sell a subwoofer with speakers like the X-1 and the MAXX - note the subjective impressions of doing so here (though some of these impressions relate to decreased distortion above 50 Hz due to bandwidth limiting the focal drivers on the X-1 via the subs crossover):
http://www.arduman.com/aa/Sayfalar/elgiz/elgiz.htm
The problem is that low distortion below 40 Hz is very difficult to come by. Even the best HiFi drivers have rather substantial 2nd order distortion below this freq. (and it increases as freq.s decrease - often to the point of "doubling"). Typically then this freq. range requires the use of really good pro drivers that can operate below their fs with relativly low distortion. Some of the better drivers in this regard are the JBL pro drivers (and the Beyma knock-offs). Moreover using them in multiples (decreasing VC heating and excursion) provides gains for these drivers that traditional HiFi drivers often do NOT provide (..at least to the same extent). (In particular note the Beyma LX60's performance.. a superb driver for use in multiples in a sub configuration.)
In any event.. I hope all is well for you, just saw the news that another A-Hole (or set of A-Holes, have again managed to make the world, and in particular the UK, a lesser place).
The linkwitz transform isn't happening on the mains now, though I'd use some EQ on the sub.to get what I wanted.
This free's up the mains to do the stuff down to 40hz without stretching itself too much.
TBH I really don't care too much how low they go, what I want is a good integration into the ATC mid.
Wish I had listened to you earlier on but you live and learn. These supravox, they look like the cheapest drivers on earth, I know that's shallow and ignorant but its just my initial feelings.
As you may have read above I'm having some problem on the AT Flex drivers so I'm almost certainly going to cancel those and do a complete re-assessment before I make any more mistakes.
Would you be so kind as to provide details on possible loading for the supravox 215 or 285 GMF. What do you think would work best here? Forget LT's, that's out the window, I'll augment with a sub later on. My primary concern is 40-40Khz range at the moment.
I was thinking go big with something like a 24" pro driver such as Precision Devices PD2450 sealed with EQ.
Other than that commercial offerings such as the Velodyne HGS18 and DD18 perform well with less than 5% distortion down to 20hz at three figure SPL's.
Thanks, they botched it up thank god though, next time I doubt we'll be so lucky. Personally I think its time to take more drastic measures and start shipping 'these' ****s out the country en masse.
Disabled Account
Joined 2003
Measurements aren't everything, but it's a start...
L22RNX4P is a woofer. Ideal use is ported, as indicated by SEAS (26-31L QB3 alignment) to maximise efficiency, power handling and reduce excursion, which affects non-linear distortion.
When I started DIY audio I thought, absolutely, sealed is ALWAYS better, But I've learnt that a properly tuned ported system can sound very good.
I haven't heard the L22RNX4P sealed, but I can share a story about the time I experimented with the SS 7" 8535 midwoofer (that Troels uses in the Point 75A). When put in a closed box, apart from losing all it's bass, the mids sounded closed-in, muted, and the sound generally lacked any kind of dynamics or slam. This was a very surprising result, because all the computer simulations had predicted was a loss of bass!
On the other hand, when T/S parameters are right, a woofer can sound can be entirely satisfying in a sealed system. The 7" the SS 8545K midwoofer was remarkable in a sealed 0.5cu ft cabinet, with F3 of 60Hz, both in the mids AND midbass. I'm talking about an experience with Dan Wesnor's Ella. Yes for the dinostaur stomps and rocket explosions it fell over, but augmented with a pair of 12" subwoofers crossed low solves this, without muddling the mids. The system has liquid mids, sweet highs and all the bass I could want. More importantly, the sound was cohesive.
As you know, for home theatre or nightclub sensations, an exaggerated response is the norm, and with any sort of EQ or Linkwitz transform, when sealed, you'll quickly run out of excursion and into non-linear distortion, so it doesn't sound as clean as you'd expect it to be, when it's ported, you'll run into power handling issues ("drop like a rock" below tuning), so you'd be better careful on how you tune it and how much power you can send it.
For a true 20-20K Hz full range system, the L22RNX4P should be the 3- part of a 4-way system. On SPL predictions alone, I think the absolute minimum for the bottom octave would be a pair fo 12" subwoofers with at least 1" x-max. You could probably get away with a pair of 10" subwoofers if you needed 30Hz.
Like ScottG I'm confident that what you're reporting and the lack of sensations is not about the bottom octave. (If it was, you'd you'd want true subwoofers anyhow. 🙂 ) It's in the critical 40Hz to 320Hz area. It might also be related to your W-M crossover. It's amazing how a woofer can affect the perceived midrange response, and vice-versa.
Many of us believe that in the in commercial audio world, pricing has little to do with quality. So why then, do we still hold on to these beliefs when playing with our own DIY audio? Not an attack on you ShinOBIWAN- I am often guilty of this.
AT's claim to fame is their incredible mids. If you look at what the commercial manufacturers and 'amateur' DIYers (with their 20+ years of DIY experience) are doing, it's with AT's mids.
If you can reassess the source of the problems, perhaps it will be easier to remedy them. Throwing money at uber-expensive drivers like the AT will likely not solve your issues.
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