92 replies to this topic

[peaandham]

Hey guys, its now time for me to Upgrade my Focal 165v2 midbass to a standard that can compete with my new front stage. My front stage is a Scanspeak Revalator RR Tweeter and a Fountek FR89ex.

Im looking for something in the eight inch region and like the look of the following two.

http://www.madisound...8-woofer-4-ohm/

http://www.madisound...ex-cone-woofer/

I was thinking the peerless because it keeps getting recommended to me, but I like the design of the Scanspeak a little bit better and am more familiar with their gear. The scanspeak woofer is also a 4ohm driver which makes me even happier.

I am open to suggestion, but these are around the price range I am looking at unless I can spend a little more to get something alot better. The midbass will have about 240wrms on tap @4ohm, it will be playing from 71/80hz to 280/315 so I don't think I need something to extraordinary.

Thanks in advance.

[syd-monster]

How muah air/volume of an enclosure (or can you even go IB) have you got to play with?

Edited by syd-monster, 01 April 2012 - 11:36 AM.

[268669♫]

If you can get true IB to the outside then some HAT L8's would be ideal.

Ant

[peaandham]

These will be going into the doors of my magna so I would have to say about 30/40Litres?

[syd-monster]

really! sealed 30 to 40 litres or leaky door 30/40 litres?

[peaandham]

really! sealed 30 to 40 litres or leaky door 30/40 litres?

Ummm well all service hole sealing is done but the Magna's doors arent the best so probably leaky somewhere, but id like to say sealed.

Im not to familiar with how to run IB either, I have the basic idea of what it is, but dont have it down pat.

[scraverX]

even with the service holes sealed/covered a door will be leaky.
a) you have drain holes for moisture
b) window seals aren't great

[peaandham]

Just thinking, if 30/40L is a decent approximation for a car door cavity? They are still rather large.

Edit: Also looking at the FS/QTS of the Scanspeak compared to the Peerless it looks like the Scanspeak would be the better of the two in a car door application.

[muzzy66]

Consider that the Scanspeak Discovery line is mostly made up of re-engineered Vifa and Peerless models, so don't get too caught up in the fact that it has a Scanspeak name. In this case I believe that driver is a reengineered version of the Vifa

My first question is, what is your budget? If you're restricted to that <$100 per driver price point, then I would ditch both of those models in favour of the Seas L18.

If you're willing to spend a little more, I would ditch all of above and move on to the Scanspeak 21W/8555. This is the 8" version of the 18W/8535, which is one of the better 7" bass drivers going around. It should thoroughly outperform either of the two models you have listed, and probably the Seas as well.

[2LOUD2OLD]

from the reviews I have read the Peerless dont do very well in a door. they really need a proper sealed enclosure

one driver I was tempted by before I decided to build sealed pods was the CSS SDX7, though not actually an 8" it reportedly works quite well in a car door

[peaandham]

Muzzy, firstly thanks for the response but I would rather stay around the $100 as im only looking for something that will bring back that nice midbass my system is missing, higher freq detail isnt really needed, I was thinking an 8inch woofer but your belief is that the SeasL18 would out perform both of those I already listed?

Also, how about the 8inch version over the 6.5? http://www.madisound...um-cone-woofer/

[2LOUD2OLD]

Also, how about the 8inch version over the 6.5? http://www.madisound...um-cone-woofer/

with a Qts of 0.27 I don't see it working very well in a car door IMO

[bobo333]

Dont be soft like AJ and build a sealed pod, you should be able to get around 20-25 litres with some careful molding...

[peaandham]

Bobo: I would rather keep them behind the trim for the time being until I know im entirely happy with them.

With that said then if most speakers have a QTS of say between 0.2 and 0.8 alot of the ones listed wall fall short since they are sitting around the 0.3 mark?

The Scanspeak Discovery 4ohm woofer I listed before has a FS/QTS Ratio of 88hz, can I get lower than this fairly easy or is this a good rating?

How do you actually work out the FS/QTS Ratio?? It will take some guess work out of it for me.

Thanks.

[muzzy66]

Muzzy, firstly thanks for the response but I would rather stay around the $100 as im only looking for something that will bring back that nice midbass my system is missing, higher freq detail isnt really needed, I was thinking an 8inch woofer but your belief is that the SeasL18 would out perform both of those I already listed?

Also, how about the 8inch version over the 6.5? http://www.madisound...um-cone-woofer/

Oh, my bad - wrong driver!! I was thinking of the 8" model, the L22RN4X/P

What are you aiming for from your midbass? Is your preference more towards good low end extension, or low distortion? If low distortion is the aim, then the 8's are generally going to be cleaner then the 7" drivers...however if you want good low end extension, then you can get some 7" drivers or even 5.75" drivers (Seas L16RN) that are going to play lower then the 8" Peerless.

The L22 however from what I recall plays nice and low, and should also have good low end distortion - all for the same price as the Peerless, and it also has 25% more excursion then the other two drivers. If I could fit an 8" and had a $100/driver budget, that's what I'd go for, assuming you limited depth. I

For those who don't have limited depth, there is the 8" Peerless 830667 SLS. This thing has low end capabities that will embarass the others on this. How good is it down low? Well it's actually not a midbass driver...it's a low distortion 8" subwoofer that just happens to ahve a flat response out to 800hz! It also has a high Q (0.66), a low fs (42hz), a large cone area (204cm^2) and 8.5mm of one way xmax. That's 20% more xmax then the Seas and 50% more then the both the Scanspeak Discovery and the Peerless HDS. If you dont plan on crossing much above 300hz, I'd take a seriously look at these babies. Oh, and did I mention they are only $66/pair at Madisound and probably even cheaper locally?

The Scanspeak Discovery 4ohm woofer I listed before has a FS/QTS Ratio of 88hz, can I get lower than this fairly easy or is this a good rating?

How do you actually work out the FS/QTS Ratio?? It will take some guess work out of it for me.

The Peerless SLS 8" above has an FS/qts ratio of 64

How do you work out the FS/QTS Ratio? You quite literally divide the FS by the QTS

Edited by muzzy66, 01 April 2012 - 10:05 PM.

[peaandham]

Hard to say what I want because I dont really understand the technical side of drivers or sq's for that fact.

I want some nice snappy midbass's that can keep up with the rest of the system, like I said they will only be playing 71/80hz through to 315hz max, and I have a Morel SC12 playing anything from 71/80 down.

So as you can tell im not too savvy with this stuff so im purely looking at recommendations and learning something along the way.

But as 2loud2old has said Pete with a QTS of 0.27 that wouldn't make it very suitable for a door would it? Or does the FS/QTS Ratio work out much better?

Edit: The peerless does look good, but I won't really need it playing to low, 71hz would probably be the lowest it would go.

[muzzy66]

If it helps visualise for you, here is a simulated IB response of the 830667 infinite baffle, with an approximate cabin gain effect factored in - note the flat extended response down to 22hz (the -3dB point is at 16hz). This is due to a combination of the low FS (good extension) and the high Q (helps maintain cone control).

Now the other graph simulates cone displacement (i.e. excursion, or how much the cone moves) at various frequencies for a given input power. This driver's thermal power handling (how much power it can take before the voice coil overheats) is 90w RMS, so I've modelled displacement off 90w input power. Off this input power the SLS doesn't reach it's rated 8.5mm of excursion until it gets down to 50hz, which means crossing over at 71hz would be an absolute walk in the park for this baby. You could seriously cross it at 50hz withotu a worry in the world.

The lower power handling andlower xmax of the other three drivers means they will run out of excursion sooner, and so crossed at 70hz there is a greater risk of them bottoming out - especially the Peerless and Scanspeak Discovery (with only 5.5mm xmax apiece). With the Scan and the other Peerless you'll likely find that they would be very close to their xmax limits at 70hz - the Seas would take it a little better, but still would run out sooner then the SLS. This essentially means they will bottom out sooner (especially with the lower Q limiting control of the cone). Wih the SLS would theoretically take 220w to push it to 8.5mm xmax @ 70hz, meaning it runs into it's 90w thermal power handling limits long before you'd have any chance of it bottoming out (if you crossed it at 70hz as intended).

If you'd like me to model out the other three drivers just let me know - I have to hit the sack at the moment (5am wakeup) but I'd be happy to put them up after work if you think they are helpful to you.

Attached Files

•  830667-FR.JPG   105.57K   10 downloads
•  830667-Displacement.JPG   105.41K   5 downloads

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[muzzy66]

Just for fun, here are the graphs of the Seas L22RN4X/P

It has 1.5mm less xmax then the SLS, but still handles power very nicely down low. Off it's rated thermal power handling (125w rms) it doesn't reach it's 7mm xmax until 55hz. That means that like the SLS, it's nowhere near it's lmits if crossed @ 70hz. It plays as low as the SLS in this application. Looking very good as a dedicated midbass. It has a very low FS (21hz) but also a very low Qts (0.27) - but the latter doesn't seem to have too dramatic an effect on how it models in this case. Still might be worthy of concern though.

Attached Files

•  L22-FR.JPG   108.74K   2 downloads
•  L22-Displacement.JPG   106.4K   1 downloads

Edited by muzzy66, 01 April 2012 - 10:46 PM.

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[peaandham]

Wow thanks for the info so far, I will need to have a proper read once I finish work but if I have enough room looks like I might be looking at the Peerless SLS, I mean the depth between the two drivers is only 10mm difference, so I will do some measurements and see where that puts me.

[2LOUD2OLD]

one question, why are you only limiting yourself to an 80Hz crossover point, one of the big benefits of a larger midbass driver is the ability to cross them over lower.
My Trio8's are currently crossed at 63Hz, but I have had them crossed as low as 40Hz in the past

[muzzy66]

To be honest, I even had my Seas L16's crossed at 40hz when they were in my MX-5...and that's a 5 inch (albeit not your regular 5 inch)!

On a 5" or 6" driver power handling (in terms of cone displacement especially) limits how low you can cross, with drivers often reaching xmax off as little as 20W when crossed at 40hz in a car door. But with 8" drivers like these, you don't have those limitations - as 2LOUD2OLD said above, something like that Seas L22 or the Peerless SLS could cross at 50hz with ease, and clossing low opens up your subwoofer options becaue you no longer need one that can play clean up high to achieve smooth integration.

If I could fit an 8" driver in my stock locations, I'd definately be crossing between 40hz-50hz.

[peaandham]

OK thanks guy, I will probably be crossing them lower, the main reason why I didnt want to was because I thought my Morel SC12 sounded so nice that i thought it would do a better job around the 80hz mark, but I have been swayed.

[BMWTurbo]

Maybe try some overlap. I run my 8's down to 63 and the sub from 80 down. I find the overlap helps with seemless blending - providing you have you TA etc set correctly.

[shizzle]

What crossover slope do you use BMWturbo?

[peaandham]

OK so based on some of the info ive read im still happy with the SLS for my first option but I have looked at some other options if I dont have 100mm of mounting depth.

Obviously this is my first choice.
http://www.madisound...er-cone-woofer/

2nd choice, im not to familiar with this woofer, it has a nice price tag, power handling is 80wrms, sensitivity is 88db so it could probably be a bit higher and the FS/QTS ratio is about 75, but the mounting depth of 90mm looks good.
http://www.madisound...oy-cone-woofer/

Then if those 2 are still too large then I will be looking at the following SB Acoustics Driver.
http://www.madisound...s45-8-8-woofer/

I will be getting outside to measure them tomorrow at some point then I can look at orders some.

[~Samuel~]

Have you measured the depth that you have to play with?

[peaandham]

Have you measured the depth that you have to play with?

I will be tomorrow morning hopefully.

[ryzaa]

Stop being soft and buy Scan Revelators

No further discussion necessary.

[peaandham]

I don't see myself benefiting that much from Revalators so it'll be a waste of money.

[peaandham]

Ok not very happy with todays measurements. At the moment I am using a 12mm ring ontop of a 12mm baffle, so it 22mm baffle in a sense, however it rubber from the Focal 165v2 Mid at the moment is very very close to hitting the back of the door trim, so If I use an 18mm baffle I only have 76mm clearance so i can put it easily behind the trim.

I will start looking now but if anyone can recommend me a driver with a mounting depth of no more than 76mm that would be great thanks.