I've got to admit I'm a little sceptical of using one 9" driver per side at 'decent' levels. I used to have 2 x 10" scanspeak per side (sealed) and they needed subs below 40Hz. For home theater they needed to be crossed at 80Hz.
Particularly as Ant has said he listens to electronic music....
Rob.
Particularly as Ant has said he listens to electronic music....
Rob.
RobWells said:
I used to get by with high quality two ways featuring 6.5" mid/bass. I can live with some good quality 9's for awhile until I've got my system and priorities in order.
ScottG said:
Hi Scott
I'm trying to strip back to as little as possible I guess. With some cheats I've realised I can get very pleasing if not huge output down to 25-30hz. For music this seems good so far.
I'll no doubt go back to multichannel at some point but for now I'm growing tired of audio for the wrong reasons. I've swapped so much stuff that I'm not exactly sure if what I have is the best it could have been, I'm primarily talking about the amps sifted through; six DIY designs and two commercial ones. Then the raft of soundcards, DAC's, clocks, EQ software, EQ hardware. Not to mention all the drivers for the sub and Perceives.
I need to take timeout, strip things down to bare essentials, go back to re-examine the whole system from top to bottom and retrace my steps aswell as make more thorough comparisons to ensure I've headed off in right direction. And specifically I'm pretty sure the PCXO will offer a good alternative to the DEQX after playing around with Thanau's 'Frequency Allocator' software - which I will make time to post a review of once I've more thoroughly investigated it, so far it looks to be very good though with a couple of issues.
Overall, I've spent far far too much time on this forum and the internet in general over the last couple of years so I'm going to knock it on the head for a month or two as its part of the catalyst for buying components in a frequent manner. Its getting to the point where I'm swapping and building faster than I can fully listen to them. I still haven't fully had time to appreciate the Perceives so that's what I'm going to do... after the room
Cheers for all the help everyone.
RobWells said:
One important thing to note, I think Shin's ATC 9's are sealed as well, but he has an advantage your scan-speaks (which ones btw?) probably don't: DSP.
Shin can make an effective linkwitz transform with his room correction software forcing flatness from his 9" drivers, something you can't accomplish with passive crossovers.
ShinOBIWAN said:
Overall, I've spent far far too much time on this forum and the internet in general over the last couple of years so I'm going to knock it on the head for a month or two as its part of the catalyst for buying components in a frequent manner. Its getting to the point where I'm swapping and building faster than I can fully listen to them. I still haven't fully had time to appreciate the Perceives so that's what I'm going to do... after the room
I know what you mean, *way* to much time here, and for me - not enough time writing my book. (..and its particularly bad when your hobby starts "cutting" into your professional time.)
At this point I've personally gone through several designs and spent some cash (though no where near what you have). I'm even happy with some of my results, but I still have that "Itch" to design. Well, IF I do another design of my own it would have to be for commercial reasons. (..I just can't justfy the time or expense otherwise.)
Good Luck! (..and I hope everything turns out better than expected.) 🙂
m0tion said:
The LT cannot give the driver any more output though, which is the reason I ended up using subs below 40Hz - the 2 x 10's per side couldn't give enough output at 20 - 30Hz.
They used 8565-01 drivers, in a 120L enclosure. I used a dcx for xo so had eq available, but they didn't need it, indeed if I had eq'd them flat to 20Hz they'd have struggled even more with output.
Here's an in room plot - no eq. (with an 80Hz high pass as I was using them as subs while I built my tempests)
http://www.diyaudio.com/forums/attachment.php?s=&postid=366441&stamp=1081328162
The speakers can be seen here:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=5868&perpage=15&highlight=&pagenumber=10
Cheers,
Rob.
I know what you mean about needing a break Ant - I've just finished redecorating my room and am planning a no diy audio period until after Christmas. Am fed up of having things to do after work every day🙁
Rob.
Rob.
My will is weak, I can't resist playing 🙁
I'm looking into the sub thing again after I happened across a pair of XLS10's for virtually nothing on ebay. I decided to go and buy another two of these from BK to bring the total upto 4.
I'm not looking to build anything daft, this time its just a rectangle with holes for the drivers. I'm just wanting to try out another design that's geared a little more to higher SPL's than B&C.
I've looked at two designs, one sealed the other ported. The nice thing about the XLS10's is the fact they work well in small enclosures.
The sealed alignment would be 130ltrs(Q=0.36) with an LT to extend to 20hz and a Q of 0.5. Excellent group delay and phase and half decent SPL output, also less risk of bottoming out. Downside is excursion is pretty high in comparison to the ported alignment and therefor distortion will be a fair amount higher too for a given SPL. The big advantage will be a very well damped alignment which would have similar qualities to the Critical Q sub design shown here:
http://www.customanalogue.com/sub_index.htm
The ported alignment is a non standard EBS with 130ltr enclosure tuned to 19hz. With a large 40cm x 5.6cm port of 135cm length(90 degree folded) for zero port noise even at high SPL's. Phase is overall pretty good, group delay is average. The excursion profile is very good and should hit respectable SPL's of 115dB @ 20hz all day long, obviously distortion will be terrible here but lower down at say 105dB I expect them to be low (<5%). This design is actually similar to the Genelec HTS6 with the exception of 4x10" vs. 4x12" XLS's. More on that here:
http://www.avtalk.co.uk/forum/index.php?t=msg&th=14722&start=0&rid=4491&SQ=1156347385
http://www.ultimateavmag.com/features/604way/index4.html
I suspect the Genelec is tuned a tad higher than 19hz but overall they are similar.
I think each has its strengths, one in quality over SPL and the other in SPL and pretty decent quality.
What do you guys think?
I'm looking into the sub thing again after I happened across a pair of XLS10's for virtually nothing on ebay. I decided to go and buy another two of these from BK to bring the total upto 4.
I'm not looking to build anything daft, this time its just a rectangle with holes for the drivers. I'm just wanting to try out another design that's geared a little more to higher SPL's than B&C.
I've looked at two designs, one sealed the other ported. The nice thing about the XLS10's is the fact they work well in small enclosures.
The sealed alignment would be 130ltrs(Q=0.36) with an LT to extend to 20hz and a Q of 0.5. Excellent group delay and phase and half decent SPL output, also less risk of bottoming out. Downside is excursion is pretty high in comparison to the ported alignment and therefor distortion will be a fair amount higher too for a given SPL. The big advantage will be a very well damped alignment which would have similar qualities to the Critical Q sub design shown here:
http://www.customanalogue.com/sub_index.htm
The ported alignment is a non standard EBS with 130ltr enclosure tuned to 19hz. With a large 40cm x 5.6cm port of 135cm length(90 degree folded) for zero port noise even at high SPL's. Phase is overall pretty good, group delay is average. The excursion profile is very good and should hit respectable SPL's of 115dB @ 20hz all day long, obviously distortion will be terrible here but lower down at say 105dB I expect them to be low (<5%). This design is actually similar to the Genelec HTS6 with the exception of 4x10" vs. 4x12" XLS's. More on that here:
http://www.avtalk.co.uk/forum/index.php?t=msg&th=14722&start=0&rid=4491&SQ=1156347385
http://www.ultimateavmag.com/features/604way/index4.html
I suspect the Genelec is tuned a tad higher than 19hz but overall they are similar.
I think each has its strengths, one in quality over SPL and the other in SPL and pretty decent quality.
What do you guys think?
I missed what the problem with the B&C design was, I did skim back through the thread as well 
but you know how this thread is. Can you very briefly recap for me, please?
Regarding your proposed designs, they look good but in a way they also follow what you have done with the B&C drivers, the sealed one moreso. I would be tempted to go for the sealed design purely as a contrast to the vented B&C's.
but you know how this thread is. Can you very briefly recap for me, please?Regarding your proposed designs, they look good but in a way they also follow what you have done with the B&C drivers, the sealed one moreso. I would be tempted to go for the sealed design purely as a contrast to the vented B&C's.
Hi Rich,
No real problem with the BC when driven at average levels but it doesn't go particularly after you've normalised the response to the level at 20hz. Its also lacking tactile response.
So I like what it does but its been driven hard at lower frequencies and with only moderately high SPL's. Two would combat the situation but since I got the pair of XLS10's really cheap and another a pair for £178 I figured try something else before settling down to build the second BC.
I'm trying thing up a good way to allow me to try both ported and sealed options without having to build two cabinets. Since both designs share the common 130ltrs then I figured I could build two bases; one with a slot port running its enitire 85cm length and another without. It would then be a simple case of switching between these two and sealing up the hole in the main 130ltr enclosure that was used to try out the ported alignment.
I was really looking for critique on anything obviously wrong with the designs.
No real problem with the BC when driven at average levels but it doesn't go particularly after you've normalised the response to the level at 20hz. Its also lacking tactile response.
So I like what it does but its been driven hard at lower frequencies and with only moderately high SPL's. Two would combat the situation but since I got the pair of XLS10's really cheap and another a pair for £178 I figured try something else before settling down to build the second BC.
I'm trying thing up a good way to allow me to try both ported and sealed options without having to build two cabinets. Since both designs share the common 130ltrs then I figured I could build two bases; one with a slot port running its enitire 85cm length and another without. It would then be a simple case of switching between these two and sealing up the hole in the main 130ltr enclosure that was used to try out the ported alignment.
I was really looking for critique on anything obviously wrong with the designs.
I'd try stereo subs with the 4 x 10's. 2 per side push push. Sealed boxes. If I liked what I'd heard I'd buy another 4 to do 4 per side to lower distortion. I'd probably have the rear firing pair mounted magnet out too.
Rob.
Ant - how did you get on with that veneer you was playing with a while back ? Did it end up looking nice? (about to do some veneering..) Did you use the car laquer on it ?
Rob.
Ant - how did you get on with that veneer you was playing with a while back ? Did it end up looking nice? (about to do some veneering..) Did you use the car laquer on it ?
I guessed your aim with the box was something like that. I don't see anything fundamentally wrong with either design. What do you have available to power the subs? They will take some driving.
How do the SPL vs freq models for these two boxes come up against what the model for the B&C predicted? I think you will be needing to see at least 6dB above the B&C from 18Hz up to get much gain.
How do the SPL vs freq models for these two boxes come up against what the model for the B&C predicted? I think you will be needing to see at least 6dB above the B&C from 18Hz up to get much gain.
RobWells said:
That had crossed my mind but I feel going for a sub with four drivers is the way to go for now. Mainly because its less work 🙂
Terrible would be the best word to describe it. The laquer was pretty hardcore 2pack and just disolved the veneer glue and it fell to pieces 😀 Looked great for a couple of days though, problem was the veneer wasn't backed otherwise this might not have happened.
The veneer peeled off very easily and the cabinet are just back to MDF. Will have another go with veneer again but not in the near future and I've also got a hell of lot more to learn so for now I'll stick with spraying as its soooo much easier.
richie00boy said:
Here's the figures:
Designs are:
RED = 1 x B&C (Vented)
YELLOW = 4 x XLS (Vented)
ORANGE = 4 x XLS (Sealed with LT)
This is the SPL normalized to 105dB @ 20hz:
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Excursion @ 105dB/20hz
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Amp load @ 105dB/20hz
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Port Velocity @ 105dB/20hz
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Phase
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Group Delay
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Max SPL:
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An important note here is that the B&C absolutely doesn't get anywhere near 110dB max SPL at 20hz. Not even in-room. So the model is way off on that one. I think this is because the model considers the max power handling to be 2000w at that frequency, where as the driver impedance turns that figure into more like 200w max power handling at that frequency which would tally with around the 102dB I managed to achieve in room.
I've also got reservations about the accuracy of the XLS models. Modelling a single sealed XLS10 in a 20-30ltr enclosure shows it to be near useless for low stuff - this is just plain wrong, real world experience has shown me that it stretches down flat to 25hz inroom with an F3 of 20hz, this is in an 18ltr sealed enclosure without EQ. WinISD would have you believe that this was impossible. So the validity of the above modelling for the XLS's is in question and realworld figures are likely to actually be better in some regards.
From those graphs the vented XLS would look to be snapping at the heels of the B&C in many respects for music. I'd be interested to see how reality turns out.
The model should work out max SPL vs frequency by considering both voicecoil thermal handling and excursion. I would expect the B&C to be limited in the low end by excursion, so I'm not sure that the impedance matters quite so much. I do agree though that theoretical models can be different from practical application.
The issue is, if you take the experience with the B&C as the benchmark, does that mean that all the max SPL predictions are wildly optimistic? In which case you have little choice but to go for the vented XLS. Or is it down to the specific model for the B&C, and so the sealed XLS may be a surprise winner for both music and film?
The model should work out max SPL vs frequency by considering both voicecoil thermal handling and excursion. I would expect the B&C to be limited in the low end by excursion, so I'm not sure that the impedance matters quite so much. I do agree though that theoretical models can be different from practical application.
The issue is, if you take the experience with the B&C as the benchmark, does that mean that all the max SPL predictions are wildly optimistic? In which case you have little choice but to go for the vented XLS. Or is it down to the specific model for the B&C, and so the sealed XLS may be a surprise winner for both music and film?
richie00boy said:
Excellently put Rich. Those are exactly my concerns. I know that modelling the XLS *is* inaccurate and doesn't tally with real world results, at least for sealed. My memory is good and I distinctly remember the BK XLS200 going flat down to 25hz in my room, even considering room gain, there's no way there could be anything other than an inaccurate model.
And no 12inch driver with 20mm peak-to-peak xmax was going to hit 110dB at 20hz in a ported alignment. I considered the figures optimistic when first modelled but I was surprised to find how much difference there was in reality; 102dB(in-room) vs. 110dB(supposed anechoic model prediction) I'd hoped for better figures.
So there's two examples of inaccurate modelling and fairly gross errors at that; one is overly optimistic and the other is selling the reality of a design short.
I guess all this is pointing to the fact that its best not to read a whole lot into the models and just go ahead and build. This being the case, where would folks start? Sealed LT or vented?
pinkmouse said:
I used the ones from Viks webpage. Since they tie in very closely with the manufacturer's spec's it doesn't make much difference between the two sets.
Well the models for phase, group delay etc should be the ones that are more reliable. With the nicer results of these compared to the vented XLS and B&C, and the fact that you found an XLS promising in the past, I would be keen to vote for the sealed XLS.
Going for the sealed XLS would also give you the opportunity to tweak the sound a bit simply by changing the LT. You wouldn't have this level/ease of flexibility IMO with the vented box. But I guess I'm more of an electronics man than a woodwork man 🙂
Going for the sealed XLS would also give you the opportunity to tweak the sound a bit simply by changing the LT. You wouldn't have this level/ease of flexibility IMO with the vented box. But I guess I'm more of an electronics man than a woodwork man 🙂
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