SEAS Exotic X1-08

[johnsonad]

PJ had posted that he had some interest in this speaker over at the HE asylum.  I too have been looking at this speaker for the last year but hadn't pulled the trigger as my Altec Model 19's are great.  I had a pair of Madisound BLH's with Fostex 165's in them and this put the full range taste in my mouth.  The WAF is also much higher with the SEAS if I'm being honest

If the 8 Ohm driver was used and implimented in the suggested sealed enclosure, given the posted numbers (as i'm not good with these) how well would they mate with a pair of 300B Paramounts taking into consideration dampening and such? 
 
For finished or near finished speakers I see two out there without looking too hard. 
1.  John at KCS (http://www.kcsloudspeakers.com/) has a finished sealed box pair
2.  Madisound (https://www.madisound.com/store/product_info.php?manufacturers_id=177&products_id=8504) offeres an enclosure for the speaker.
Any thoughts or comments on these?  Nelson Pass wrote that this is a pretty amazing little speaker and so have others but it seems it hasn't been implimented in many commercial offerings yet. 


Aaron

[edfallon]

They should work great with Paramount 300b amps in most listening environments.  I built a Tangband W1808 clone that is much less $$ and works in the same 2cu' sealed box.   Either driver will need a simple BSC type filter to tame a mild rising repsponse which ulitimately reduces the advertised efficiency but are still plenty loud with 8watts.  Mine also needed a sub to fill in the bottom octave but the combo works very well.  This is a very easy system to build if you have even limited woodworking skills.  I'll try and demo them the next time the local bottleheads get together. http://www.parts-express.com/pe/showdetl.cfm?Partnumber=264-894

[johnsonad]

Hi Ed, thanks for the recommendation.  My experience with Fostex 166's has steered me away from whizzer cone speakers.  One of the reasons I was looking at the SEAS was the lack of shout often associated with whizzer cones.  Can you elaborate on your experience with the Tangband's?  My 19's can be powerful but I prefer the top end of these to the shouty 166's.

John commented that the filter network caused a lack of imaging with the SEAS driver.  Haven't read anything else about it.  Did you try yours' with and without the network?  They are well prices when compared to the SEAS drivers.  Being stationed overseas you would be surprised how difficult it is to get decent lumber.... 

In reading the comments on the Tangband it seems some people are using them in OB's with good results.  Don't know if I can trust their ears but it may be worth a shot...

[edfallon]

Well, first off let me say that I do not care for mid range shoutiness which has turned me off of lowther and fostex systems I've heard.  The Tangbands in comparision are well controlled in the midrange and are easy to listen to for extended periods.  I don't consider them giant killers but they are easy, fun, work with tube amps, and are not too expensive.  I ran them on OB at first just to evaluate them and surprisingly they sounded very good but a little bass shy as expected and need a sub or helper woofer.  I wanted something more compact and went with a sealed box instead and the sound didn't seem to suffer.  The frequency response is fairly flat with a little bit of rise on the top and the expected bass roll off.   I prefer them with a BSC filter to extend the bass down low enough to hand off to the sub below 60hz or so.  The xmax is 5mm so they can tolerate some bass boost.  The Z plot is also well controlled so a Zobel filter if desired is very mild.  I found both filters benign to imagining although some might perceive a peaked midrange as beneficial to imaging but I would consider it just an artifact.   

[johnsonad]

Thanks Ed.  So you are running them in a sealed 2 cubic foot enclosure, would you mind sharing the dimensions?  Also would you mind sharing the values of the filters that worked well for you as a starting point?  My heart isn't set on the SEAS predominantly due to cost.  I too would use a pair of subs for the lower octave.  There is too much music to loose down there. 

This could be a fun winter project. I've got access to a nice wood shop on base; all that is needed is the wood.

[Maxwell_E]

Ok, I've been watching this from the sidelines and now I'd like to jump in. Would the Tang Band 8" be able to run off of a SEX amp? I hope to get a Stereomour in the next couple of months as soon as I sell some old belongings and I have been looking also at good full-range drivers for a single speaker system accompanied by a powered sub. I saw the posted efficiency at 93dB, which is still better than the 86 I have now, but the Fostex offerings have 95-97 usually. I'd be listening in a small room, probably not more than 8 feet from the speakers (apartments aren't known for they're roomy interior).

[Paul Joppa]

At 93dB I would normally recommend 8 watts, i.e. a 300B amp. But in a small room you could cut that in half with little risk, i.e. 4 watts or a 2A3 amp (such as the Stereomour you are contemplating). A SEX amp at 2 watts might work but I'd be less confident of that even in a small room unless you also listen at moderate levels as well.

Note that for 86dB I would normally recommend 40 watts.

[Maxwell_E]

The 86dB are bookshelf speakers that are practically in my face next to my computer monitor.

[Maxwell_E]

I found the same Tang Band but in a 95dB version.

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=264-893

This would work quite nice....wouldn't it?

[Doc B.]

The one that Ed recommends will work, Max. We have used a S.E.X. amp on the lab bench with some 87 dB monitors. You can't rock the house, but in the nearfield they work OK. So 93 dB speakers would get plenty loud if you are using them as nearfield monitors and probably be decent for all but the really demanding stuff when listening at a distance. If you feel the need for more beans down the road you could also consider strapping the S.E.X. amp that you have into mono for twice the power and then adding a second one for the other channel. I haven't listened to Ed's Tang Bands yet, but I think Ed and I feel the same way about the Fostex sound and I trust Ed's ear. He's quite picky, as are most of the Bottlehead OGs. ;^)>

[Paul Joppa]

I found the same Tang Band but in a 95dB version.

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=264-893

This would work quite nice....wouldn't it?

A great illustration of speaker design tradeoffs. The higher efficiency one has a shorter linear excursion (xmax) of 3mm vs. 5mm and a lower QE. It is clearly intended for ported boxes, while the other is intended for sealed boxes. The ported box would be larger (maybe 3 cubic feet instead of 2) but would go deeper.

They appear to be identical except for the thickness of the top plate. The higher efficiency one has a shorter top plate (you can tell because the excursion is 4mm less peak to peak, and the overall depth of the driver is also 4mm less). With the same magnet and voice coil, the field strength is more concentrated giving the improved efficiency at the price of reduced displacement. This way the cone and voice coil mass is not altered so the sound will be basically the same. Very clever bit of engineering, IMHO.

If it were me, I'd go sealed box if I was planning on a sub, because you can control excursion better, they are easier to integrate with a sub, and the box design is less critical. If I knew I would never use a sub, then I'd probably do the ported box.

[Maxwell_E]

I love how much I learn each time I read one of PJ's posts. Thanks.

[edfallon]

would you mind sharing the dimensions?  Also would you mind sharing the values of the filters that worked well for you as a starting point? 

I actually built a 2.5 cu' box but I think they would be better in a 2 cu'.  It's not really critical with a sealed box as long as you are close.  I attached a pic showing one of the unfinished plywood boxes.  They turned into sort of a funky art project and I added short legs that are splayed out like furniture from the 50's to get them to the right height.  After I cover them in some mahogany Formica they should go well with my 1957 Karlson sub!

For the very simple passive correction filter, I used a 3.3mH inductor in series with the driver and an 8 ohm 10w resistor shunting across the inductor.  This allows for about 6db of added bass around 200hz or so.  You can adjust the resistor value depending on how much bass boost you need.   PJ has a line level BSC filter calculator published somewhere that would work even better. 

My thoughts on these is that they sound better than expected.  I'm a little dissappointed that they didn't have stronger bass without the need for BSC.  With the BSC and sub barely running at 60hz they are fine.  They are easy for the DIY since there is only one driver and no complicated crossover to tweak.  8 watts seems to drive them fine in a fairly large space.

[Grainger49]

Ed,

Your speaker stands made me smile.  My kind of engineering!

[johnsonad]

Thanks Ed.  They look great!  I like the 50's furniture look and will probably do something similar.  I'm going to give these guys a shot this winter.  Cheap project and will be my first attempt at speaker building.

For PJ, would you mind giving a link to your BSC filter calculator? 

For anyone, what tools do you use in cabinet design as far as getting the dimensions right?  I've heard of some online calculators but not sure how it applies to a sealed box.  Probably doesn't