| Big Kev ! |
Hey guys,
Its been a long time coming but I'm finally getting around to putting a sub in my room. I've had a look all around the internet and keep getting mixed opinions and unfortunatly I can't hear these subs before purchasing. My primary use is music but I also watch movies every so often something loud and smooth would be nice preferably +100dB @ 20Hz.
To run the sub I'm going to use a Behringer A500 which is 500W @ 8 Ohms and a Jaycar sub processor.
One of the biggest problems I'm facing is driver avalibility, shipping from parts express is more than the driver over here. I've had a serious look at the Peerless range, specifically the 830500 and thought about going that with a PR although I've had conflicting opinions on the Peerless range with some calling them overatted and other praising them. I've also had a look into some of the higher end "car audio" drivers in particular the Phoenix Gold Xenon series subs caught my eye as in a moderatly sized sealed box they had a very low smooth output (-3dB @ 29Hz in WinISD) and can be had in Aus for a bit more than the Peerless driver mentioned. I've emailed the distributor for Adire over here but I don't think they've had any stock of Adire products for some time.
Any suggestions or experiences would be greatly appreciated - I can't wait to get in the shed and start building :)
Cheers |
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| beppe61 |
Dear Sir,
please excuse me if I ask you a question off-topic.
First of all I cannot give you any useful advice.
By the way I see that you use a Behringer A500.
I am very interested in this amp for a stereo system.
I understand that you use it bridged.
Have you had the opportunity to try it as a stereo power amp?
Whit which speakers ?
What do you think of its sound ?
Sorry again and kind regards,
beppe
Italy |
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| Big Kev ! |
No problems, although I'm still waiting for the amp to come in, hopefully I'll be able to pick it up before the end of the week. I have a few speakers and I play to try it out as a stereo amp as well and see how it goes, I will post up my findings on here when I do :)
Still searching for a suitable driver, so any opinions or suggestions (there must be some ;)) would be great. I'll have the chance to try out the Xenon sub soon so that will be interesting, I would really love to try out the Peerless subs but I don't know anyone with any. A question on the side, is it true in saying that adding a PR will give you a greater increase in SPL than just a vented box?
Cheers
Kev |
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| beppe61 |
| quote: | Originally posted by Big Kev !
No problems, ... I will post up my findings on here when I do :)
...
Cheers
Kev |
Thank you so much Mr. Kev.
I wait for your opinions.
I am interested about the bass response over all.
I like amps that have a good solid bass.
Kind regards,
beppe |
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| johngalt47 |
| Can you tell me which brands are readily available there? |
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| xstephanx |
vented and pr give the same SPL, there is no diference.
if you told us what was available over there we could help more.
peerless drivers however, from what measurements ive seen over the years, are very low distortion drivers, although they are by no means a "super woofer" anymore, and their excursion is somewhat average, maybe even a bit below(12.5mm one way linear i believe), they are very good sounding drivers and still get use in many highly regarded designs(mr linkwitz there is a big fan of em).
try doing some simulations for an XLS or XXLS in vented or pr systems, remember that you will gain 3db from predicted spl in the program(i reccomend winISD) by putting it on the flor, another 3db with floor and a wall, and ANOTHER 3db if you shove it in a corner. And plan with a bit of headroom too! watch those excursion graphs!
you also never told us how large your room was!
bottom line is i would be VERY suprised if a properly powered 12" XLS in a properly designed PR design couldnt crack 100db at 20hz in room. worst comes to worst you coudl always build a pair! |
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| Big Kev ! |
| quote: | Originally posted by johngalt47
Can you tell me which brands are readily available there? |
Over here I can get the Response drivers, Peerless drivers, just about all the highend "car audio" drivers although while some of them model quite similar to some renouned home drivers they often cost a fair bit more. I've contacted the supplier for Adire because for the past year there hasnt been any stock of them and he currently has the Shiva 10" and 15", Tempest 10" 12" and 15" and Tumult 12" and 15". I am now going to contact him with regards to pricing. And that pretty much sums it up :( Any other drivers people use down here are generally shipped in.
| quote: | Originally posted by xstephanx
vented and pr give the same SPL, there is no diference.
if you told us what was available over there we could help more.
peerless drivers however, from what measurements ive seen over the years, are very low distortion drivers, although they are by no means a "super woofer" anymore, and their excursion is somewhat average, maybe even a bit below(12.5mm one way linear i believe), they are very good sounding drivers and still get use in many highly regarded designs(mr linkwitz there is a big fan of em).
try doing some simulations for an XLS or XXLS in vented or pr systems, remember that you will gain 3db from predicted spl in the program(i reccomend winISD) by putting it on the flor, another 3db with floor and a wall, and ANOTHER 3db if you shove it in a corner. And plan with a bit of headroom too! watch those excursion graphs!
you also never told us how large your room was!
bottom line is i would be VERY suprised if a properly powered 12" XLS in a properly designed PR design couldnt crack 100db at 20hz in room. worst comes to worst you coudl always build a pair! |
My room is about 4x4meters. 100dB was just a ballpark I basically want a nice sounding sub that can go loud :D but my main obstical is I dont have the resources to try out a lot of combinations. The 830500 + PR seems to be pretty good but everyone seems to have different sized weights for their PR's and I don't really know how to setup a PR properly.
Thanks a lot for your replies :)
Kev |
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| xstephanx |
how much weight to add to the pr, tunes it, and is the same thing as adding length to a vent. download winisd and play around with the XLS. i hate to do it, but i have to reccomend against adire, ive heard nothing but complaints for the past year about their warranty service.
BUT there is an elemental designs 15" woofer, that has VERY similar parameters to the older tempest(back when it came as JUST a 15) so see if you guys get eD. |
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| Big Kev ! |
I've played around with the 830500 but the only problem is it behaves very differently to most other drivers I've played around with. Even with Peerless recommended tunings it seems to have a pretty steep roll off.
I understand how you say adding weight tunes it like adding length to a port but how do you know what weight to start with and how to increase it (what increments). I only have WinISD so I can't model excursion which I believe is an issue with PR designs. I will have a 20Hz rumble filter.
Thanks again. :) |
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| xstephanx |
| jsut get winisd pro, its also free and a much better program. |
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| Big Kev ! |
Been playing around with WinISD Pro, very intresting. Went to the shop I ordered the Behringer amp from and they said it will be in next week.
Still having trouble deciding on a sub, theres just too many varibles :xeye:
Here are the options so far:
Peerless XXLS 830845
Goes well in a sealed box, avalible in Aus ~$300 + Shipping
Peerless XLS 830500 + PR
Only real issues are it starts getting expensive.
Adire, Shiva and Tempest (waiting for prices)
Hmmm as I write this I'm leaning towards the XXLS, my only concern is output, I will feel limited if I turn it up (on the odd ocassion) and it isnt really loud.
My other options are shipping in a driver from overseas. My only real issue with this is I havent really ordered anything overseas before and so the whole expereince is a little new to me. |
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| Big Kev ! |
I've got updated prices for the Adire drivers.
Shiva
15" $240.00
Tempest
10" $262.80
12" $275.00
15" $305.00
15" would seem to be nice for output although box size starts getting large (and of course 12" is cheaper).
Has anyone built subs with the new Adire range? A Tempest 12D4 in a 60Ltr box tuned low could be nice and would give an extra bit of bass (being vented) while still retaining a smaller box size.
Thoughts?
Cheers :) |
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| Big Kev ! |
Has anyone tried the new Tempests, I'm trying to decide between the XXLS 830845 and the new Tempest as both are around the same price unfortunatly I don't have any chance to try either out before I buy, any opinions? I would like to run it in a sealed box which has me leaning towards the XXLS but the Tempest has 18mm Xmax as opposed to the XXLS's 12.5.
Cheers :) |
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| HipoFutura |
| Are Infinity speakers available in your part of the world? I built a pair of subs using the Kappa Perfect 12.1D drivers. They are fantastic! They practically crack the plaster in the walls and rattle the windows. Very crisp notes and bass you can feel in your gut. They are an inexpensive driver and common on ebay. |
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| Big Kev ! |
We can get Infinity speakers over here although they are not terribly common. At the moment I'm using a the Behringer A500 power amp with a Jaycar Sub Bass Processor which I've just finished building and using it with a Hertz ES driver which is only temporary. The Hertz driver I'm using is alright but has limited excursion and isn't in its ideal box.
Comparing the Tempest to the Peerless driver (both in sealed boxes) would the extra excursion of the Tempest give it more SPL? While SQ is the main priority I would like the be able to crank it on the odd occasion. I'm getting from Mach5Audio a 12" driver (thanks Mark :D) in around a month so I'll be able compare what I get now with it.
Another kind of off topic query, I seem to be getting a 50Hz (I'm guessing) hum through the subwoofer. I've checked thats its not the Sub processor so I'm guessing its caused at the amp stage. My Dad had the same issue with his subwoofer, which used a plate amp and if I recall correctly we were told you can put some sort of filter to stop it. We ended up just cutting the ground cord on the plat amp and it went away, however I can't really do that with my amp. I'm guessing this is some kind of issue with the houses power supply?
Cheers
Kev |
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| leonrocks |
| How big can you make your subwoofer. 2x Peerless XXLS drivers in a sealed sub creates amazing amounts of clean bass. The bigger you can make your box the better they will sound. Around 150L for the 830845 model sounds great. One in a 75L box is good too but not as loud. ;) |
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| Big Kev ! |
| Have you used/got the 830845? What do you think of it compared to other stuff? Hmm I'm thinking I should just bite the bullet and get one and see how it goes. The box I have at the moment is 70L sealed and is a nice compromise between avalible space and volume (for my room). I don't have an issue making another box though (working at a hardware store so MDF is cheaper). 2 would be nice but for now I'll leave myself with room to upgrade. I'm just worried that maybe either going the PR approach or vented or a Tempest or something will give me more SPL that I may want. Unfortunatly I can't listen to a XXLS or whatever first and find what I want :( |
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| paulspencer |
The A500 amp doesn't have a lot of power for a sub. Bridged it will only drive an 8 ohm driver, which counts out most subs! Even the XLS has an impedance which dips down very low, and Stones Sound Studio recommend that a 4 ohm stable amp is required for the XLS rated at 8 ohms nominal.
The A500 amp could be used to drive two 4 ohm drivers with 230w each, or two 8 ohm drivers with 160w each.
A good choice for your amp would be two of the XLS, each in a vented box. They could be push pull mounted, and with the power being a little limited, you would find that the excursion limitation of the drivers should not be an issue, if the rumble filter is switched on. I assume you made the Jaycar kit.
Alternatively, a 15" Tempest should also give you a good result. It would be cheaper, produce a similar SPL, but probably slightly higher distortion. You would want to have an 8 ohm impedance to be able to bridge the amp.
Another alternative is two Shiva 15s.
I would not discount the idea of shipping drivers - better value can sometimes be had this way.
Choosing an amp before choosing the driver isn't a great idea, now you are limiting your choices. Ideally you should buy only after designing the system - driver, amp, box, and how you are going to integrate it with filters. |
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| Big Kev ! |
Yeah I built the Jaycar kit and have it mounted with its own power supply in a box as a stand alone unit. The other alternative to the A500 was getting a Jaycar plate amp and I figured (seeing as though they are similarly priced) it would be better to get the A500 for a bit more grunt. The sub thats running off the A500 now dips to around 5Ohms at points but seems to run fine.
2 Subs would be nice but the money factor holds me back a bit. When you say XLS I assume you mean the 830500? As far as I know the Shiva's and Tempests can be had in dual 4 Ohm models so running one won't be a problem. |
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| paulspencer |
XLS: I don't know the number, but I was referring to the 8 ohm version.
If that is true, then a Shiva or Tempest should work fine.
If it were me I'd be looking at other drivers, like Acoustic Visions CX series, Dayton reference series, TC2+ - all of them more impressive. |
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| tktran303 |
Only a 4x4 metre room? Geez, I reckon any of those 12" subwoofers will do the trick*.
It seems that you are hell bent on getting maximum SPL, and in this respect bigger drivers and longer excursions will always beat the smaller driver with smaller xmax, particularly as you GO DOWN IN FREQUENCY. It's just a matter of physics.
Nothing wrong with locally available Adire or Peerless subwoofers.
The Behringer A500 stereo amp with 160W @8ohms (230W @ 4ohms) is a good amount of power for one or two subwoofers.
* The real trick to get high SPL is in the design. For maximum SPL you want to reach close to the maximum excursions limits with the available power on hand.
It sounds like this is your first subwoofer build- go with the recommended cabinets, either ported or sealed (supplied by Peerless or Adire)
For maximum SPL i'd go with vented or PR, which hits greater maximum SPL than sealed.
Everyone wants a "musical" subwoofer sure, but IMHO most people use their subwoofer for predominantly home theater + music; or music + occasional home theatre.
(I have a Dayton 12" DVC driven by a 240W (4ohm) RMS plate amp with slight EQ, in a 1.5cu ft box. Plenty of SPL for home theatre in 6x9 room. In room measured frequency response (hand-held SPL meter) is 25-100Hz (+0, - 3dB)
Some other interesting subwoofers are the TC Sounds and Dayton RS series, but of course shipping is heavy and time consuming. |
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| paulspencer |
Yes shipping is expensive and involves more waiting, but when you buy local, effectively you have already paid shipping. Often you can get the same driver a little cheaper, even allowing for customs and shipping, although I'd only do it for a driver not available locally.
When I bought my subs I could have got Shiva for $300 but for $320 I got AE speakers AV12 which is a LOT more impressive. Had I bought the Shiva I would have wanted to upgrade long ago. |
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| Big Kev ! |
Thanks for the replies :)
The sub will be primarily for music, I do watch a few movies every now and then but at this stage its very much secondary to the music. I don't really want someone rediculously loud (well I do... :p) but basically I want the volume there if I ever need, even if its only ever to show to mates once every blue moon, I would rather have overkill than not. I've built a few subs before but mainly (in the home anyway) with Jaycar amps. I plan to build this one and get it right and leave it for a long while rather than constantly fiddle with it.
The TC drivers seem pretty intresting and have good xmax figures but the site (o audio) is a bit confusing, I'm not sure if they have the dual 4 Ohm version avalible. Might give them an email and see what the go is. |
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| Big Kev ! |
| Getting the TC2+ over here is around $350ish AUD so its in the XXLS, Tempest etc price range. The only problem is only the 4Ohm models are avalible. Using WinISD running it in a sealed box compared to the XXLS it doesnt seem that different (if anything the XXLS looks better) however the TC2+ has more Xmax or will that not make a difference? An option is to grab 2 TC2+'s... but it starts to get expensive and would it be worth it? |
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| paulspencer |
xmax is definately an advantage. The XLS is a bit limited in that regard.
4 ohms - is that per coil?
To get the most out of the A500 amp you want either a single 8 ohm load which allows you to bridge and get 500w or two 4 ohm loads and get 230w into each. The exception is the XLS which has an impedance which drops abnormally low below its nominal impedance which means extra caution is needed so as not to push the amp beyond its limits. |
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| Big Kev ! |
| The only TC2+ avalible is the 12" SVC 4Ohm model, so running one isnt really an option but I'm wondering if having 2 would be a great advantage but the extra cost makes it a bit pricey. |
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| paulspencer |
It's not a good match to your amp. Yes you could get two of them and then have 230w into each, which isn't that bad. You would have plenty of excursion to spare. You could push pull mount them in one corner loaded box and get more output due to increased efficiency. Effectively you get the same amount of power as when bridging into a single 8 ohm load, however the drivers could easily deal with more power. This is not a bad thing as lower distortion would result from this arrangement. You could buy one first, and buy a second later if you wish.
This isn't ideal however.
A single Shiva 15D4 is a good option when it comes to getting the most out of your amp. Series wire it to get 8 ohms and bridge > 500w or use each channel to power one of the VCs. This is fairly cost effective. Most likely you will have some power to spare this way. Not as sexy as the TC2+ (not even close).
Tempest might be worth considering here, or a pair of 15" shivas for some serious oomph!
This is probably a much better option:
http://www.acoustic-visions.com/~ac...vers/exodus_cx/
Exodus Audio CX Series
Very nice price for a driver with this kind of motor. I'm not aware of any other drivers at this price point which have a motor system that compares that you can get to Australia. Looks far better than Shiva or Tempest in performance, probably better than the TC sounds driver. I'd expect drivers that compare to it in SQ would be some of the new TC sounds flat BL drivers, top of the range RE audio drivers, Adire Tumult, but not that many others. |
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| Big Kev ! |
Thanks a lot for the advice,
By push pull mount you mean that they would share the same enclosure and are wired out of phase? Does enclosure size still have to double? What benifits does this have over having the woofers in identical seperate enclosures?
I checked out the CX's and they look (well the XBL^2 does) but as they are 4Ohms shipping 2 over is around the $600 mark if not more which starts to get a bit extreme.
Hmmm, now I'm thinking of dual woofers and dual TC2+'s isnt a great deal different (in price) to Shiva's at this end. However the Shiva's are 15" as opposed to 12" so I'm guessing there would be a bit of an SPL difference. Dual 10" Shiva's look good from a price perspective but the high Fs doesnt look so good.
Food for thought.
Cheers :) |
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| paulspencer |
Kev,
Push pull means two drivers in the same box (double the volume of one driver), one driver with magnet facing out, polarity reversed on one of the drivers. As one pushes the VC out of the magnet gap, the other pulls the VC in to the magnet gap. 2nd order harmonic distortion is lower, the effect is that some non-linearities are cancelled. Subjectively the bass is a little tighter and more accurate.
Two 12"s have more SD than a single 15" and should have more output, but cost more. 15s usually require a much larger box than 12s.
You really need to choose driver and amp together at the same time Kev! I would tend to prioritise it this way: choose the amp that will give your preferred driver the power it needs. The driver is what you see, it's the most impressive part of a sub, and it is the main factor in getting the best SQ.
The cost effective but unexciting choice is a 15" Shiva or Tempest for your amp. It's probably worth the extra for the Tempest considering you have a decent amount of power for this configuration.
A more sexy and expensive choice is dual TC2+ push pull mounted. More stylish and lower distortion, both due to push pull mounting and because the drivers are most likely better. You don't have to buy both drivers at the same time.
Another option is just get a single CX 15" and it will get 250w which isn't that bad. 500w only gives you 3db more output which isn't that much. Later you could add a second driver to give you that 3db extra, and later again you could get a bigger amp that is suitable to drive them both and find another use for the A500. |
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| Big Kev ! |
I would prefer to do it all in one hit rather than start with one woofer and add another later. I may be going a bit overboard but I'm not how loud loud is if you get my drift, and I would hate to feel the need for something bigger a bit furthar down the track.
I've heard the old Shiva and was quite pleased with the SQ so I don't know if its worth going for something more higher end or not. I've narrowed my options down a bit now and this is what I'm thinking:
Peerless XXLS 830845 in a small sealed box. -Simple, compact, reasonably good by all reports. ~$320
15" Dual 4Ohm Tempest in a sealed box. ~$325
2* 15" Dual 8Ohm Shiva's in a big sealed box. ~$480
2* TC2+'s in a sealed box. ~$520
Is it worth the extra cash for the TC2+'s? Would maybe a 12" or (space permitting) a 15" Tempest is a vented box make a better more cost effective combo? I'm kinda leaning more towards the sealed box because its primarily for music, not because a vented box would sound bad but with the woofers I'm looking at it doesnt seem like the best option.
Thanks :) |
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| tktran303 |
Big Kev!
As you're probably finding, when max SPL is a concern, there's more than one way to skin a cat.
If you are familiar with using basic T/S parameters, I think you should download a good box modelling program, like Unibox and start modelling some of those drivers.
I politefully disagree with Paul on this one. I think 2x 230W in 4 ohms is plenty. Here's why.
If you design your box carefully, you can hit the excursion limits of your driver before you run out of amplifier power. So you'll be getting the max SPL out of the woofers, with your current amplifier, without ever reaching the subwoofer's maximum power handling (thermal (voice coil) power handling) |
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| paulspencer |
Kev, I use two 12" AV12 subs driven by an amp that can put 650w into each. I have had them in a sealed box each, they have 23mm xmax (twice that of XLS). They are more than enough to keep up with my mains. In my medium room (4x5m) I have measured a peak of 108db on a movie from the subs. The mains at listening position can handle not much more than 90 dB, with some changes I'd be lucky to squeeze 95 dB out of them, and you will find this the same with any hifi speaker with two 6.5" drivers. The subs can go louder than I've measured, but the mains won't keep up. In vented boxes with this amp they simulate up to about 120 dB @ 1m but you won't measure that in room.
One XLS in a sealed box won't impress. I'd say two of them in sealed boxes is a minimum. My subs can go quite loud and keep up with the mains with about an inch of excursion.
A single Tempest 15" will most likely satisfy you. Where having more excursion and cone area will help is when you want to get deeper, or reduce distortion by having the drivers not be pushed as hard. I rarely push my drivers beyond half their excursion.
I think you will find the TC2+ is the best of those you mentioned, slightly better than XLS but with more excursion. The Shiva and Tempest would come next, but they are good value for money. It depends on whether you are willing to pay a little more for better performance or better looks.
For music, two sealed subs will give more output than a single vented, but for home theatre their ultimate output down low will be about the same. Put a typical sub in a sealed box and F3 is about 40 Hz, but vented it will get down to 20 Hz, excluding the impact of the room.
Keep in mind it's a good idea to allow for some eq for the bass room modes, like BFD or Ultracurve which I use.
It all comes down to what you decide is important for you, and what you prefer. Are you going to cover the driver with a grille and leave it on? If so, go with Tempest 15" and with the money saved buy at least BFD if not Ultracurve to eq the whole system flat. If you want it sexy, go TC2+ and ideally add on some eq to it later. XLS is good but TC2+ is better in looks, performance and output and worth the extra. If you want to blow your pants off, then get a pair of Shiva 15s put them in a tall box in the corner, vented and push pull mounted - design it well and integrate it well with eq and it will go low for HT and be musical at the same time. |
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| paulspencer |
| quote: | | I politefully disagree with Paul on this one. I think 2x 230W in 4 ohms is plenty. Here's why. |
That would depend on the driver in question. My drivers would be underpowered with 230w, but 650w is just about right. Many drivers will perform adequately with 230w or less.
I recall hearing a sealed 15" Tempest powered by a 250w plate amp, then by a pro 550w amp. The plate amp would have enough power by the estimation of most, however, the pro amp clearly was far superior in punch and authority - it was not a subtle difference. I suspect the difference was that the higher power amp was able to handle transients where the plate amp was probably clipping. The difference in this case was easily noticeable, not the kind that you need a blind AB test to prove - our jaws dropped.
Now is a good time to do some sims with WinISD pro and this will give an idea of how the options compare in terms of SPL and extension. |
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| Big Kev ! |
Once again thanks for all the help :)
I'd previously only modelled the DVC TC2+ in WinISD but I've just plugged in the standard TC2+ and the results arn't all that great comparitivly (-3dB at 56Hz) in a sealed box although it seems to perform better in a vented box and the boxes don't require much space. I could be completely off the mark but they seem to be more like "car subs". However that said I've spent a fair bit of time fiddling with WinISD in the past and have built a few subs and what looks good on the graph isnt exactly what sounds the best in the real world.
On the grille issue, no way! Half the fun is seeing the driver move :D I'm only a uni student so at this stage I don't have to worry about the whole Spouce Approval Factor ;)
Early today I was leaning towards the whole dual TC2+'s but after playing with WinISD it seems to show that SPL would be on par with a single Tempest which while I definatly agree does not look as cool as dual TC2+'s there is the cost factor. WinISD only seems to calculate SPL by Power and the SPL figure though?? I'm guessing there are other factors here that influence SPL in the real world (given the same enviromental conditions)? I have a sub which is 97dB (at 2.83V mind you) however the xmax is only 9mm and other subs I've heard with greatly more xmax but far less SPL perform much louder.
I'm tossing up between the single Tempest and the dual TC2+'s at the moment (dual 15 Shivas would be awesome but I don't know if I'm ready for a 250L+ box) unless someone wants to suggest something entirely different and confuse me again ;)
Thanks a lot,
Kev |
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| paulspencer |
| Kev, when I get the chance I will do some sims, but have to enter in driver parameters properly first. There more I learn, the more I find you can get a driver to do what you want with a few tricks that aren't obvious with the first box you model. Also keep in mind that with a sealed box you can use the one band of parametric eq you have - experiment also with the Q since you can change that with a resistor. |
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| paulspencer |
This is a quickie ... Tempest vs TC2+, sealed vs vented, each with rumble filter and low pass @ 70 Hz.
Tempest sealed 100L
Tempest vented 200L @ 20 Hz
TC sealed 75L
TC vented 120L @ 20 Hz
Not necessarily optimal designs, but an indication. Eq used for the sealed subs to get a similar response.
Two TC12" subs are almost identical with this setup to a single Tempest.
Chart shows max SPL as limited either by xmax or amp power. Aargh, just remembered that the TC is 4 ohms hence for one driver there will be 3db less output for the vented version, but the sealed version won't be affected.
It's a beauty and the best comparison. Clearly from a bang for buck comparison point of view, the Tempest wins easily. The TC has shorting rings and almost certainly lower distortion, although this is offset by the Tempest being a larger driver. The TC is going to be a lot prettier to watch move. |
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| tktran303 |
You miss my point Paul. I'm not talking about desired amplifier power, voltage or current limits, nor non-linear distortion characteristics near clipping. I'm not talking about a specific driver's Pe (voice coil's thermal power handling) rating.
I'm talking about a driver's maximum in-box, excursion limited maximum SPL.
Linkwitz provided a better explanation than I could ever do, when he describe his Thor subwoofer design.
http://www.linkwitzlab.com/thor_splmax.htm
There is a way that you can maximise your SPL with your current available amplifier. You don't always need a bigger driver, more xmax or more amplifier power.
Here's an example of choosing a 10" over a 12" to get MORE maximum SPL, when using a fixed amplifier and desired box size- http://www.linkwitzlab.com/Pluto/subwoofer.htm
Since Big Kev already has chosen his amplifiers, I strongly recommend he use Unibox or Closedbox.xls to explore this further. |
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| paulspencer |
| quote: | | You miss my point Paul. I'm not talking about desired amplifier power, voltage or current limits, nor non-linear distortion characteristics near clipping. I'm not talking about a specific driver's Pe (voice coil's thermal power handling) rating. |
I'm not interested in having a debate here, or discussing whether or not I have missed your point. I'm only interested in helping Kev make an informed decision he will be happy with. You're probably not interested in a debate either.
Linkwitz was talking about a sealed box which would tend to limit power required and SPL capability. For a fixed box size, sealed box and a given amplifier, the bigger driver won't necessarily have more SPL.
However, the only fixed entity is the amplifier. He may choose sealed or vented, one or two drivers, a small or large box. A vented box will most likely benefit from more power, not that this is relevant now since amp is already chosen. For a given amount of power, a bigger driver and bigger box will most likely mean more SPL, although of course, it depends ...
| quote: | | I'm talking about a driver's maximum in-box, excursion limited maximum SPL. |
So am I since this is what counts - the only max SPL that counts is what you have considering thermal and xmax limited power, as well as amplifier power.
I'll go back to the point at which we seem to disagree ...
| quote: | | I politefully disagree with Paul on this one. I think 2x 230W in 4 ohms is plenty. Here's why. |
My main point is that this depends. He has not chosen a driver yet. If this is enough depends on the driver, the box and the design. As you say, there is more than one way. Linkwitz also states in more elaborate terms that "it depends." This is what I'm saying.
I know from theory and practice that 230w will sometimes be enough, and at other times, quite a bit less than optimum. I know this both from simulations and from experience with different subs. I'm sure you will agree that a blanket statement can't be made, and that you must consider the driver, the box and the design.
So if we are going to disagree, then let's have a specific driver, box and design to agree or disagree on. That can then be helpful for Kev, rather than discussing theory and getting caught up in one of those debates. He can choose which view sounds most suitable or come up with his own version.
One more point to consider is that it's not only about SPL but also SQ. In my earlier comparison of a plate amp and a pro amp driving a Tempest sealed sub, I found the improvement was not about SPL but about the pro amp having far more authority and punch - it was more dynamic. |
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| paulspencer |
For max SPL and depth, a Tempest 200L vented box does it well. Use a 6" vent (PVC) and it will keep turbulence down without being too long. The box could be approx 450 x 450mm footprint and 1.4m or so tall. Yes quite large, but it doesn't occupy too much floorspace.
With the rumble filter the air velocity peaks at around 19m/s - ok if you have decent vent flares.
You can achieve 115db in the midbass and exceed 110db @ 20 Hz, 113 db @ 25 Hz.
If you go with the TC2+ in a 100L vented box, you can reach 109 db in the midbass and 103 db @ 20 Hz, 107 db @ 25 Hz.
Vent velocity is quite low with a 6" vent, lower than the Tempest which requires more attention to the aerodynamics to avoid chuffing. 6" vent must be 1m which is long, but possible.
If you go with two of the TC2+, then the size will be the same as the Tumult, and you will reach 115 db in the midbass, 109 db @ 100 Hz and 113 dB @ 25 Hz - essentially identical to the Tempest response (almost). |
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| Big Kev ! |
Thanks a lot for the continuing help Paul :)
The extra money for the TC2+'s plus the waiting for them to be shipped over isnt make them that attractive. As far as SQ goes I know vented doesn't mean bad SQ but I would like something pretty tight, I hate sloppy bass and having the double kicks on drums blurring into each other. I don't really know much about the SQ difference between the TC2+ and the Tempest, would it be a slight difference or something highly noticable? As you can tell I was leaning towards sealed boxes before as its easier to eq (with what I've got) and its pretty safe in terms of group delay and the like. The vented tempest looks pretty cool but I would have to seriously consider the size of the box.
:xeye:
I would love to run 2 TC2+'s (one inverted) purely for asthetics but its a lot extra to pay just for looks. Seeing as my budget seems to have crept up slightly is there anything like the Tempest but perhaps with better SQ (and better looking :p)? I'm guessing as I start to get higher up amplifier power is going to start being an issue.
Edit: Sorry I was typing as you posted above! |
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| Big Kev ! |
| Oh I just realised, is that graph for only one TC2+? |
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| paulspencer |
Kev, yes I only showed with ONE TC2+. The only decent sub drivers that I'm aware of locally available are Adire and Peerless.
Vented subs are not necessarily more difficult to eq. In fact, where a sealed sub needs eq to get down low, vented does not and in that way it is most likely easier. The exception is rooms more typical in the US where room gain is such that a sealed box needs no eq, and a vented box needs eq to reduce the effect of room gain. Both vented and sealed subs need eq to deal with room modes, neither is easier in that regard.
Sloppy bass does not necessarily come from a vented box. I've heard sloppy sealed and tight vented. For home theatre, vented subs are more appropriate in Australia than they are in the US. Here, a sub should be designed to reach the target F3 in anechoic conditions, since room gain will not extend in room response much if at all.
I'm inclined to think that with your current amp, a single vented Tempest 15" is the most sensible choice.
The thing to keep in mind with GD is that it's related to response. If you eq a sealed box to exactly the same response, then you get the same GD. How much GD is audible is debatable, and has not been established for subwoofers. Low GD goes with a higher F3.
I modelled a pair of Shiva 15s in a 200L sealed box, and the output with your amp was still less than the single Tempest when I managed to eq the response the same. The GD was pretty much the same as well. You could squeeze out maybe 2 db more SPL from the dual sealed for music but not for HT since xmax is the limitation. To actually get the same response you would need to modify your parametric eq since you need the gain at 20 Hz, not at 30 Hz which is the minimum on that Jaycar unit.
I doubt you will find a driver that will match the advantages of the Tempest 15 with your amp, although if you do insist on a sealed sub and accept the disadvantages there may be some you might want to consider. They will be more like the TC2+ than the Tempest.
My suggestion is make this a value for money sub. Go with a venteed Tempest 15D4, be a little creative about the shape of the box and how it fits in the room, and if later you want something more sexy, more impressive then choose both the driver and amp together and count on spending a fair bit more. If you do then insist on buying the amp before choosing the driver, then get a pro amp like Behringer EP2500 which is very flexible since it can drive two 2 ohm loads, or be bridged to put 2.4kw into 4 ohms - in other words it will power any driver you are likely to choose, and its not much more expensive than a plate amp, but then you will have fan noise to deal with! |
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| paulspencer |
Here's an alternative thrown in for interest. Two of the Peerless SLS 15" in a large 400L vented box. The excursion isn't that high at 8mm but in a vented box tuned to 20 Hz you can exceed the output of all other options considered, probably with lower distortion than all of them. These drivers would also have more top end, so you could cross them higher than typical sub drivers, and if you wish use them in stereo configuration.
In the midbass you get 116db but below about 23 Hz the max SPL is the same as the single vented Tempest with the rumble filter on.
How much does it cost? I'm not sure but knowing Peerless it would be very reasonable.
Not as sexy, very large and not as much fun to watch the cones moving at high excursion, but it does show that there are many ways to reach a target. |
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| Big Kev ! |
Thanks Paul,
I think I will go with the Tempest after all of that. I'll go with vented but preferably I would like to make it as small as is practical. My only other issue (with vented subs) is the vent chuffing issue. A few years ago I had an 8" small vented sub that hardly went below 60Hz and had rediculous chuffing from the vent, I think it put me off vented boxes a bit :p For the ports should I get some ports from Jaycar, make a slot port or something else?
I am also curious why rooms in the US have so much room gain? I didn't realise they were built differently to our houses.
Hmmm part of me still wants to go with the two TC2+'s but it seems like a fair bit of money just to have something that looks cool. Going by your previous graph does that mean that 2 TC's vented would be very similar to one Tempest vented but better sounding, or does the push pull configuration only apply to sealed boxes?
Yeah it was the no fan that drew me towards the A500 as opposed to the higher model Behringers and it was a cheaper price for me than the Jaycar plate amp I was previously going to buy. When I finally build the sub it will (should) be louder than anything I've had/heard (in home) before so once I've heard it it will be easier to decide when and if I need to upgrade. :D I'm talking about upgrading already :p |
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| Big Kev ! |
| quote: | Originally posted by paulspencer
Here's an alternative thrown in for interest. Two of the Peerless SLS 15" in a large 400L vented box. The excursion isn't that high at 8mm but in a vented box tuned to 20 Hz you can exceed the output of all other options considered, probably with lower distortion than all of them. These drivers would also have more top end, so you could cross them higher than typical sub drivers, and if you wish use them in stereo configuration.
In the midbass you get 116db but below about 23 Hz the max SPL is the same as the single vented Tempest with the rumble filter on.
How much does it cost? I'm not sure but knowing Peerless it would be very reasonable.
Not as sexy, very large and not as much fun to watch the cones moving at high excursion, but it does show that there are many ways to reach a target. |
Intresting... I don't know how much the SLS's are but I'll try and find out. 400L is pushing it a bit for avalible space. Where I am now space isnt a huge issue but I may be moving early next year and I don't yet know what I'm up against for space. |
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| Big Kev ! |
:( Just to make life really difficult... I emailed John at Aranmar Acoustics, the prices of the drivers has gone up and..... they have no dual 4 Ohm Tempests only Dual 2's! :bawling: Only the Shiva's in dual 4 Ohms.
Argh! |
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| paulspencer |
Forget Jaycar ports!
What you want is one of two options:
1. PVC vents - either 90, 100 or 150mm with flares on each end. Flares can be made in a number of ways and for high excursion drivers you will need a fairly large radius. Collo on this forum has actually done some experiments to determine the flare radius you need to avoid chuffing.
2. Rectangular vents (shelf vents) are useful in that they allow you to make vents which are very good aerodynamically since you can taper the ends out to get the kind of flare radius not possible on a circular vent.
As a general rule, aim to keep vent velocity 17m/s - 34m/s. The higher speed is the absolute limit and is a compromise, requiring special attention to aerodynamics, the lower end of the range will require smaller flares which will be easier to construct.
It is some extra effort to get this right, however, at 20 Hz a single vented sub matches two sealed subs. Some would say just spend more money on drivers, but if you have the money, then why not buy a better driver?
Kev, how much extra are those drivers now?
The SLS driver idea is probably not the best considering the size, but I showed it for interest.
As I understand, US houses more commonly have construction that is more solid than a single 10mm plasterboard layer on studs with particleboard flooring on joists. Such construction moves a lot with bass, and the whole room acts as a bass absorber. The result is that room modes are less severe, and room gain helps us out a lot less, if at all. My listening room is 4m wide x 5m deep x 3m ceiling, with double glass internal doors and three fairly normal sized windows. My measurments seem to indicate no room gain at all, and two room modes, the most significant one adding boost @ 35 Hz which is easily tamed with eq. Subjectively, this room mode adds some artificial midbass punch, and makes any speaker that can get down to 40 Hz seem like it has a lower F3 - my TLs or my sealed subs get down to about 23 Hz with the only eq being that which is used to cut out the room mode. Below the effect of this mode, response drops off to the extent that not even 15db of boost @ 20 Hz can get my system flat down that low. I accept this and allow my speakers to go to about 23 Hz without any boost and the room mode actually gives me a little free extension and SPL.
If I were to listen to the comments of many from the US about how room gain would affect in room response, then I'd think the extra extension were due to room gain, and would be confused about why the response drops off just before 20 Hz.
As a general rule, in Australia your anechoic F3 should be considered the same as in room F3, unless you have measurements showing otherwise.
Now if you consider that in many US residences a sealed sub will use room gain to get down to 20 Hz due to room gain, you will understand why vented subs are considered boomy - room gain gives you too much bottom end. In this situation a sealed sub or an EBS is more appropriate.
Might be worth asking John when the dual 4s come in. |
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| davidrees |
Here's some food for thought-I'm running two Altronics 15s(C3033) in parallel in a 360 litre common chamber box tuned to 35hz using two 6"I.D. x 3.5"L. ports, powered by a Jaycar 350W sub amp.Very adequete in a12 x 6m room.I know this sounds a bit over the top,but it rattles walls and scares the dog quite easily at the quarter volume setting.
If this sounds a bit too insane for you,they can be compound isobaric loaded into a 200 litre reflex box tuned to 30 hz with an f3 of 28hz.Or two Jaycar Venom 10s compound isobaric in 115 litres tuned to 30 hz for an f3 of 27hz.
Both subs are reasonabely priced and are usually on special every few months |
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| Big Kev ! |
| As I type this the Dual 8 Ohm Tempest is $345 (plus GST and shipping so looking at a bit over $400), while the 15" Shiva's which are in Dual 4Ohms are $260 and so would end up around $325. I've sent off an email asking about the other Tempests. |
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| paulspencer |
| I don't want to shoot down your post, but I find those Venom drivers to sound terrible. I have used a cheap Jaycar driver for a sub for my dad, got it on special for $50, a 10" driver with 9mm xmax which is quite reasonable considering it is a cheapie used to add some bass to TV speakers. For serious use I would not consider any Jaycar subs. Even if they qualified as hifi, I have yet to find one that offers a good displacement/$ ratio. Those that are cheap are not so cheap when you consider the low xmax. |
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| tktran303 |
I didn't want to argue with Paul, but I do want to provide a second opinion.
But now Paul's gone off and done it-
| quote: |
As a general rule, in Australia your anechoic F3 should be considered the same as in room F3, unless you have measurements showing otherwise. |
What the..?
As a general rule?
and in Australia??
Room size, listening position, and speaker placement is consideration that must be made. I can not predict room interaction, and it is a decision that Big Kev ! will have to make.
I've built 3 sets of mains and 2 different subwoofers and at one stage or another, I've dragged my speakers into different room or different homes to do comparative listening. (6 rooms, in 4 homes but who's counting? :D ).
All speakers sounded different in the bass in the different rooms.
Aiming for anechoic 20Hz, using with dual 12" or 15" subwoofers in huge 200L cabinets?
Big Kev's room is 4x4m!
Do you want subwoofers to augment bottom octaves in music, or do just want bragging rights, or to shake off the plaster?
I think you should consider 18" horn loaded subwoofers...
Build this and be done with it, start listening. |
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| paulspencer |
| quote: | | But now Paul's gone off and done it- |
I think everything I have said is reasonable and logical given certain parameters.
Yes, what I am saying is that you should not count on room gain being there to lower in room F3 in a typical Australian listening room. In a more solid room there will be more room gain, however, in the absense of measurements, you shouldn't rely on it.
| quote: | | Aiming for anechoic 20Hz, using with dual 12" or 15" subwoofers in huge 200L cabinets? |
To some that would be over the top, to others that would be inadequate.
tkt, perhaps you are right - an XLS is a good place to start, and from there to get a good idea of just how much SPL he does want. |
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| Big Kev ! |
tktran, In all honesty I am probably never going to need the sort of SPL's I'm aiming for but its more for the fact that they are there if I even decide I do feel like using it. Being able to get the thump in your chest would be nice even if I only ever turn it up that much once in a while. I would rather have something thats a bit of an overkill. That said theres no point being loud if it sounds bad.
I have found though like you said that the room can make a bit of a difference or rather the placement of the sub in the room. My room is mostly square except for a little entrance at the doorway and this is where I find (if I put the sub there) where I get the most room gain, either that or the cupboard. Apart from that there is seemingly very little difference.
At this stage the Peerless drivers seem the way to go (;) seems like I've done a full circle here). I've always found it weird modelling the drivers though (the 830500 inparticular), it seems that everyone that builds one has a different way of doing it with very different response graphs. I'm not quite sure what I'm looking for. I wouldn't mind going with a PR approach to save trying to make complicated ports and to keep volume down a bit. Would it be worth going 2 of the drivers and running them in series? At worst senario the amp would see 9.4 Ohm which should be well within its limits. But would the sound suffer from the lack of power? If 2 drivers worked well it may be worth sorting out the vent and instead of a PR just vent two XLS's.
The only other idea I was thinking of was a Peerless 830845 in a large vented box. I know Peerless recommend them for small sealed boxes but in a big 160L box tuned at 20Hz it seems to extend very deep and doesn't require huge ports. |
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| paulspencer |
With the XLS you need a PR for a small box, like say 40L, since the required vent would be huge, and would not fit inside the box. You would trade some extension, since for low frequencies, the box size relates to efficiency.
Try this. In WinISD make a vented box. Keep the tuning the same and double the box size. Notice how you get a peak at tuning when the box is too big? This means the box is "too efficient" at the point of tuning. You then make it smaller until the response is relatively flat. If there is a dip between the tuning point and the response higher up then you effectively have an EBS where the box is too big or the tuning is too high. Going back to the previous example, where you have the peak at tuning, keep the box size the same and lower tuning until you get it flat. You can enter the numbers or you can click and drag with the mouse on the box diagram under the Box tab.
A quick sim in WinISD finds that a single XLS with two PRs can get an F3 of 29 Hz in a 40L box. Make it a 60L box and I can get it down to 21 Hz. What is interesting is that the PR boxes have more midbass, however at 20 Hz they are not able to exceed the output of the vented box. The small 40L box hits 110db in the midbass, but is lacking in depth. Keep in mind this is with TWO PRs, which will in themselves cost more than the driver itself, although you could probably get away with just one PR.
160L for one XLS is DEFINATELY too big. You would have to tune it at 10 Hz to avoid the tuning peak, and this reduces max SPL to about 98db in the midbass. Sure you get an F3 around 10 Hz, but the output there is only about 95 db which isn't enough to make any real impact. There isn't much reason to make the box bigger than 70L per driver, except to reduce the size of the vent. |
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| Big Kev ! |
Back again :)
I've finally narrowed down my choices and I'm pretty sure I will go with the Peerless 830500 in a vented box. I looked at a few PR designs with WinISD but it seems that unless you use 2 there are no real advantages aside from ease of construction and slight volume reduction than going ported. So its a bit extra to spend.
A vented box of 68L tuned to 19Hz seems to be about what I'm seeking which gives (theoretically) 103dB @ 20Hz peaking to about 108 @ 50Hz. One of my concerns is the dip in impedance - its above 8Ohms from 25-55Hz but outside of that range can dip to 4Ohms. I think if I'm careful everything should be fine but I really don't want it cutting out all the time.
Another other idea was to use 2 of the drivers in a 150L box tuned to 20Hz which seems to give very similar results to above but with an extra 6dB across the board. Also I could run them in series and wouldn't have any impedance issues and it should hopefully satisfy my SPL needs (if not I need to start saving!).
Is there any advantage to going straight for 2 drivers in the one box? If I made another one later (twin 70L subs), I would only get an extra 3dB right? Is there something to do with having both drivers together which gives the extra SPL? At the price the 830500's are I'm thinking it may be the way to go, but if one will be enough then I could always upgrade I suppose - but I would prefer not to build a whole new box.
With the port I'm thinking of using 90mm stormwater pipe (because I have easy access to it), is it just a simple case of putting in a length of it that fits anywhere and flaring the ends? Or should I be mounting it in a specific spot?
Cheers
Btw, thanks Paul for all your help via email :) |
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| paulspencer |
Regarding impedance, it will not be a problem with one channel to each driver. It is only if you bridge the amp to power one driver that the amp will effectively see the impedance drop down to 2 ohms. Either drive each sub with a channel, or bridge and wire the drivers in series - hence you are then connecting a 16 ohm load which will drop down to 8 ohms which is safe. Note that when you bridge and connect an 8 ohm load, the amp effectively sees a 4 ohm load.
If you use one driver then just use one channel of the amp, or if you bridge into one XLS be careful.
Two drivers in one box means better coupling. Two subs can in theory get 6db more output than one, but this is less likely to occur the further apart they are. 3db comes from twice the input power and 3db comes from twice the SD.
Two drivers in one box also allows push pull for lower distortion. According to Linkwitz, for push pull, one should have both drivers on the same baffle.
100mm is better and easy to get - just go to Bunnings, it is cheap. 90mm is a compromise and should only be used where you can't possibly fit in a 100mm vent due to the required length.
To choose a vent that will work without chuffing, you must juggle the following:
- vent diameter
- vent tuning
- vent flare radius
- box size
The vent velocity that won't chuff depends on the vent diameter and flare radius. Lower tuning means longer vent. Larger diameter means longer vent. Smaller diameter means larger vent flare and higher vent velocity. It's not complicated, its just a juggling match. |
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| badman |
| quote: | Originally posted by Big Kev !
Back again :)
I've finally narrowed down my choices and I'm pretty sure I will go with the Peerless 830500 in a vented box. I looked at a few PR designs with WinISD but it seems that unless you use 2 there are no real advantages aside from ease of construction and slight volume reduction than going ported. So its a bit extra to spend.
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Passive radiators don't unload beneath tuning. BIG advantage. Nobody likes an acoustic short circuit, except those dipole types :) |
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| paulspencer |
Interesting. If this is true, then it is not shown in simulations in WinISD. Assuming it shows what actually happens, I have not found any advantage here over a vented box. I note that in the old Adire Shiva PR applications paper, it is said that some driver protection is provided below tuning and that the PR does not fully unload.
I'd be interested to see more information on this if anyone knows of any. WinISD shows the same excursion below tuning as a vented box, given the same tuning point and box size.
Logic would suggest that the PR box will give a level of protection somewhere in between a sealed and vented box. Below tuning the difference to a sealed box is that the PR allows less pressure build up to restrict driver excursion. If the PR reaches its Xmech, the box will then behave more like a sealed box. However, I'd expect the driver will reach xmax before this occurs.
Does WinISD fail to model what actually occurs with excrusion in PR boxes?
As a result, the sub will still need a highpass filter (rumble filter). |
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| Big Kev ! |
| Going the PR approach is still an option, and the smaller box size in the long run would be very useful. I just figured that if I'm buying 2 passive radiators I may as well just buy another driver (for the price) and build something big but ultimatly a lot better. If I could get away with one PR it may actually be not so bad an idea - no dealing with ports, still not super expensive, and later I can build another sub with a PR if I feel the need for more, or just get another driver and go ported... see how it goes. When you say it doesnt unload below the tuning you mean it doesnt over-exurt it self?? The reason I thought 2 PR would be a lot better than one was because 1 (from memory) reaches xmax more quickly. What do you think? |
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| paulspencer |
This will be of interest:
http://www.bamberglab.com/xls.shtml
You will find an answer there.
In general, a 12" driver is used with dual 15" PRs. The driver in front, PRs on the sides. If you use just one XLS 12" PR then you should use it probably with the 10" XLS driver. The conventional 12 plus 2x15PR makes sense due to the forces involved, and due to using less of the excursion of the PRs, which will mean they are more linear. Suspension linearity of the PR will become worse with higher excursion, and will affect distortion performance.
The XLS has a fairly low xmax, but a high Xmech so there will be less problems here.
But still, it only costs $10 for a length of PVC! Two PRs will cost more than a second driver. |
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| Big Kev ! |
Well after a lot of playing with WinISD and using a few bits of cardboard to see how much room this box could end up taking I've decided to go with the 12" XLS and a PR in a 60L box with 110grams added to the PR. It seems to model pretty closely to the vented solution and volume is down a bit which is good. I've resigned myself to the fact that this will not be my only subwoofer and so its become more of a build it and see how it goes and then at the very least I will have gained some actual expereince and have a fairer idea of what I'm actually looking for in the real world rather than dealing with figures.
Using 2 PR would be nice but cost starts to get in the way, at least this way I can in the future experiment with vented/more drivers/radiators if I want to. The huge ports kind of put me off, that and my ability to make huge flares. I modelled the 10" XLS with one PR which everyone seems to be fond of and it looks pretty much exactly like mine but with a bit less SPL so hopefully I'll be pretty happy with it.
If I'm doing something horribly wrong let me know!
I take it WinISD works out the inital mass of the PR via the Qms/Fs/Vas etc? Ie where you choose the "added mass" it is actually the added mass and not the net mass of the radiator?
Thanks for all your help though guys :) |
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