Suggestions for driver please.
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Category: General
Forum Name: Newbie Discussion
Forum Description: Newbie Discussion/Questions. Look less stupid here...
URL: https://forum.speakerplans.com/forum_posts.asp?TID=104944
Printed Date: 27 March 2026 at 4:55am
Software Version: Web Wiz Forums 12.08 - https://www.webwizforums.com
Topic: Suggestions for driver please.
Posted By: bin juice24
Subject: Suggestions for driver please.
Date Posted: 04 March 2020 at 8:34am
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Yo. I’ve a couple of eminence 18” 400w pro series, unused I think. Rather than selling them or using them for drain covers, does anyone have any suggestions as to what I could put them in? (Other than a skip etc...) Thanks.
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Replies:
Posted By: Elliot Thompson
Date Posted: 04 March 2020 at 11:46am
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Eminence makes lots of 18-inch drivers. What is the model number of your Emimence 18-inch driver? Best Regards,
------------- Elliot Thompson |
Posted By: bin juice24
Date Posted: 04 March 2020 at 12:32pm
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Ps184008 I’m tarting up 4 super scoops, so if there’s anything suitable that I could plonk on top, with these eminence?
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Posted By: APW
Date Posted: 04 March 2020 at 1:18pm
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Here are the specs... Power rating: 400w resonance: 33hz usable frequency range: 30hz to 800hz
average sensitivity mailto:1w@1m" rel="nofollow - 1w@1m : 98db magnet weight: 95oz
magnet gap depth: 0.375",9.53mm
voice coil diameter: 3",76.2mm fs: 34.50hz re: 6.6 ohm
le: 1.63mH
qes: 0.41
qms: 7.32
qts: 0.39
vas: 374.72 litres
vd: 457.90cc cms: 0.2053 bl: 19.06T-M
Mms: 103.68grams rms: 3.0699N*sec/M
ebp: 84.5
xmax: 4.5mm sd: 1140.09cm2 zmax: 124.9 |
Posted By: bin juice24
Date Posted: 04 March 2020 at 1:49pm
| That’s great and thanks but I have no idea what half of that means. |
Posted By: APW
Date Posted: 04 March 2020 at 1:58pm
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These will help:
https://www.speakerplans.com/index.php?id=faq1" rel="nofollow - https://www.speakerplans.com/index.php?id=faq1 https://www.speakerplans.com/index.php?id=faq6" rel="nofollow - https://www.speakerplans.com/index.php?id=faq6 The specs I posted above will dictate the best cabinet type for your drivers. |
Posted By: cravings
Date Posted: 04 March 2020 at 2:08pm
| knowing what half of it means is probably enough heh. |
Posted By: bin juice24
Date Posted: 04 March 2020 at 2:28pm
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Okay thanks for that, I’ll have a look when back in the office. Is there a breakdown somewhere of what all these measurements and units are? And how they relate to eachother? And how they affect sound? Please excuse my ignorance. Cheers
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Posted By: studio45
Date Posted: 04 March 2020 at 2:30pm
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Well, they are old Emmies so....: 400 watts is optimistic, the motor structure isn't particularly strong, the coil former is Kapton so not great at withstanding heat, the cone isn't very thick. Generally they're just sort of....not very good, compared to modern 18" drivers. From a time when the strategy was deploying many low-powered bins, rather than a few high-power ones. A scoop bin is probably the best way of getting the most bass out of them per watt, but you'll have to be careful. 4.5mm Xmax is not a lot and you will probably be able to exceed that with less than a hundred watts input at the sub-bass end. But, don't be tempted to raise your highpass filter to get the Xmax down too much - or you'll run into issues with not enough cone movement to properly circulate cooling air through the magnetic gap. Available Xmax when mounted in the scoop, will absolutely dictate how loud you can run them. If you try to push them, they will just hit the backplate and burn out, quick style. The suggested application is probably a very large reflex box with a big port. But again, you would have to watch out for over-excursion. ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: Elliot Thompson
Date Posted: 04 March 2020 at 3:51pm
There are more Parameters broken down clicking on the below link... https://en.wikipedia.org/wiki/Thiele/Small_parameters" rel="nofollow - https://en.wikipedia.org/wiki/Thiele/Small_parameters There is also a book in which that breaks down all the figures but, the name escapes me. If I can find it, I will post the name and Author. Eminence is an American Loudspeaker Manufacture. In the United States, the Reflex cabinet is the standard (most dominating) design in which, the parameters offered by your loudspeaker reflects being more suitable for a Reflex enclosure. You could use the drivers in Scoops however, the performance level will be adequate compared to putting them in a reflex cabinet. Sound is subjective so, no parameter will tell you how it will sound. The TS Parameters are there to guide you on the necessary requirements needed in order to attain the best performance from the loudspeaker. Once you create a means of compromise, the performance level is hindered. There are those that can predict a sound by looking at the TS Parameters of a loudspeaker however, that requires years of experience of evaluating lots of speakers offering all types of TS Parameter figures. If it does not sound simple, its not. The TS Parameters of a loudspeaker is like the DNA structure of a Human Being. Best Regards,
------------- Elliot Thompson |
bin juice24 wrote:Posted By: bin juice24
Date Posted: 04 March 2020 at 4:44pm
Guess I’m naive to think they’d run happily if fed 400w then? What would be the ideal frequency range to get the most out of them? Thanks all for your replies.
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Posted By: Elliot Thompson
Date Posted: 04 March 2020 at 5:28pm
You can run those speakers anywhere from 600 - 800 watts. Eminence rates their wattage based on RMS so 1.5 - 2 times the RMS is not a problem with Eminence Loudspeakers. Best Regards, ------------- Elliot Thompson |
Posted By: studio45
Date Posted: 05 March 2020 at 6:16pm
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Sorry, just read your post properly - you want to use these above scoops as mid-bass? That will be OK, and you're going to want a reflex box for that application. A quick look at Hornresp tells me that if you build a 150 litre box, with a 500cm2 port 30cm long (for a tuning frequency of 42Hz) it will work well for mid-bass. If you cut it at 87Hz with a 24dB/oct filter, you should be able to put 400 watts into it without exceeding Xmax. It will then play from about 95Hz upwards, flat to about 300Hz. Max output about 124dB. ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: bin juice24
Date Posted: 05 March 2020 at 9:32pm
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A 500mm x 500mm x600mm type thing? And just whack a hole in the front for the driver? Should a port be round or any shape? Does it matter wheee it is? Any chance of a fag packet sketch? Thanks
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Posted By: studio45
Date Posted: 06 March 2020 at 12:03pm
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Something like that but you would need to add the port volume on, it's not part of the chamber volume. So actually 500wx600Hx600D would do it. Doesn't really matter where port goes but conventionally, under the driver on the front baffle is the place. A nice fat round over on the port edges (interior and exterior) helps with port noise. Use a router with circle jig or compass attachment to "whack" that hole in there, and add plenty of bracing on the interior walls, or indeed right across the inside of the cabinet. Also add fibreglass or polyester stuffing to taste. 100mm or so over four interior surfaces is a good start. ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: Bams
Date Posted: 06 March 2020 at 12:30pm
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If you’re really interested in all the magic behind the numbers.. https://www.amazon.com/Loudspeaker-Design-Cookbook-Vance-Dickason/dp/1882580338" rel="nofollow - https://www.amazon.com/Loudspeaker-Design-Cookbook-Vance-Dickason/dp/1882580338 Just started reading in it and blown away.. steep learning curve ahead but worth it
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Posted By: bin juice24
Date Posted: 06 March 2020 at 2:21pm
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Cheers guys, For the port, is there any specific material to use? 3 inch down pipe?
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Posted By: studio45
Date Posted: 06 March 2020 at 2:45pm
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Just make the port part of the box. So your front speaker baffle could be 500x500, leaving a 500x100mm gap underneath. This is the 500cm2 port exit. Then you put a 30cm long board extending back inside the box, at the bottom of the baffle. This forms the 30cm port length. Put a couple of vertical braces inside the port and the job is a good one.
edit: That might seem like a big port, but really, for PA work, the bigger the better. Smaller ports have more problems with air movement noise and excessive velocity. If the air in the port moves so much that the entire "slug" is actually expelled/withdrawn from the port, they stop working as acoustic springs and you will suddenly get problems with driver over-excursion. A big port containing a lot of air, mitigates this. ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: bin juice24
Date Posted: 06 March 2020 at 4:16pm
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Thanks, that sounds much less complicated. I can visualise it now, just a shelf, effectively, with vertical supports. Cheers!
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Posted By: bin juice24
Date Posted: 01 April 2020 at 2:15pm
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Update, first one nearly finished. Quite excited to hear it. Thanks guys.  |