Eminence Delta 10b

[Chienmortbb]

Very wise. The team at Ashdown know their stuff and would have considered this in the design. I am just repairing my 15 year old After Eight combo and the thing that impressed me was how well the cooling has been thought out. No fans but a really well thought out design where the heatsink is bolted to the rear of the chassis. It not only has cooling vents, but the chassis is mounted on two spacers so that air can flow behind the chassis. There is also thermal compound between the heat sink and the chassis to improve heatflow between the two. 

Edited March 31, 2020 by Chienmortbb

[fleabag]

Likewise, the heatsinks on the amp are at the back of the chassis

 

 

Edited June 1, 2020 by fleabag

[Dan Dare]

On 30/03/2020 at 22:25, Bill Fitzmaurice said:

My preference is blowing out. Blowing in can result in dust accumulation on the heatsink, reducing its effectiveness over time. I've seen fans with filters to prevent dust from ending up inside, on computers, but not on amps. They're not a panacea either, you have to periodically clean the filters. Pro-sound rack mount power amps can be either in or out flowing, with the fans on either the front or back. With those I've seen occasions where an out flow from one amp can get pulled into the in flow of another amp, leading to a very uncool result.

Bill's absolutely right. If you have a fan-cooled amp, it's remarkable how much dust can be drawn into it, especially if it has no filter. I try to remember to clean my PA power amps regularly. There cab be a fine coating of what looks like fur (which is accumulated dust) inside and on the output trannies. It must have an insulating effect and prevent them from keeping cool. If you have never cleaned a fan-cooled amp, take the top off and take a look. You may be in for a surprise. It's simple enough to brush off the dust and fluff with a soft paintbrush and vacuum it up.

[fleabag]

Yep, DD  have already done the cleaning, hence the photo above, and there was some dust on the sink fins on the fan side, but not a great deal.

[fleabag]

Fans arrived and now mounted. Dear cliff these things are  quiet.  I had to put my ear right up to them to hear them working. What a difference.  The originals could wake a house of lords member.

Not  totally in love with the speakers, now the originals are back in.

 

Edited May 13, 2020 by fleabag

[fleabag]

On 29/03/2020 at 10:32, BassBunny said:

If Ashdown are still working, contact them. They'll tell you what the original speakers are.

I'm still getting emails from them, so suspect someone is around.

I eventually contacted Ashdown and got a reply the next day, but they didnt tell me what the original drivers were and what the TSP's were, and i did ask. Probably too old to keep such info

All i got was a short message saying that the best replacement was the Eminence Beta 10  but that has Bill's absolute minimum xmax of 3mm.

The beyma CMV2 suggested seems to be more apt

 

Edited April 8, 2020 by fleabag

[Lozz196]

Ashdown seem to like the Beta 10, that’s what they recommended and fitted for me in my RM210 cabs. And I’m very glad they did, I liked the sound of the cabs before, absolutely love them now. 

[fleabag]

I've gone for @Phil Starr  's  recommendation and ordered the Beyma CMV2's.  I've used Beymas before , though it was the SN/110,  and they were awesome.

CMV2 drivers are £15 each cheaper than the betas, so have saved £30

 

[Phil Starr]

Hope you like them

The Beta's have a really prominent peak between 1kHz and 4k. they are also slightly underdamped so will give you a prominent peak around 100hz in most practical sized boxes, so will end up with a bit of a smiley faced eq baked in. the Beymas are similar but it won't be so exaggerated and you'll get a little more deep bass at power with the extra excursion. It's the kind of response I like in both cases but £15 per speaker makes it a no brainer.

[fleabag]

23 minutes ago, Phil Starr said:

Hope you like them

The Beta's have a really prominent peak between 1kHz and 4k. they are also slightly underdamped so will give you a prominent peak around 100hz in most practical sized boxes, so will end up with a bit of a smiley faced eq baked in. the Beymas are similar but it won't be so exaggerated and you'll get a little more deep bass at power with the extra excursion. It's the kind of response I like in both cases but £15 per speaker makes it a no brainer.

Thanks Phil

One thing with the original ports, is that they're  2.75"   I.D.  at the outside but as they dive into the cab, they taper to 2.25"

They may have been fine for the  OEM  drivers but i'm wondering if they should be bigger, so i've ordered a pair of 100mm ports from CPC , and they're 114mm long.

Roughly,  ( very roughly ) the combo is  2.47ft Cube, or 0.07M cube.  If that equates to about 70 litres, then the Beymas should be fine as they need 30 litres each.  Of course the back of the drivers use up some litreage, so it wont be quite 70 litres

[fleabag]

The Beymas arrived yesterday,  so Bluelines de-mounted, and now just waiting for the 4" MBR ports to arrive, as  i need to widen the port holes, and its way easier without drivers mounted.

One thing that puzzles me.  There always seems to be foam rubber seal on the front of the driver mounting flange of every driver i've bought in the past, including these Beymas, suggesting they should be mounted from behind ( oooer ) the baffle, yet this would involve destroying the cab.

You simply cannot get the drivers in otherwise.  It would make more sense to have the foam seal on the back of the mounting flange, since they will be mounted on the front of the baffle

 

 

Edited May 13, 2020 by fleabag

[Bill Fitzmaurice]

The gasket on the front is so you can rear mount them, though that's seldom done today other than in horn loaded cabs. They should have a gasket on the rear of the flange as well, 'tis puzzlement why they all don't. They can be sourced.

[fleabag]

I'm just surprised that speaker manufacturers have not changed that config

Still, like you said Bill, i've sourced some foam seal already.  In the post , as they say

[Bill Fitzmaurice]

It's strange. I've only come across one driver, the Dayton RSS 390-HF-4 subwoofer, that has a rear gasket but not a front gasket. Of course the cab that I specify it in is a horn, so a gasket has to be added. 🙄

 

[fleabag]

@Bill Fitzmaurice

Bill,  what are the symptoms of a 4" diameter 4" long port that could be either too short or too long ?   Currently, the new ports are here, but until the foam seal  has arrivied,  i'm not going to fit the drivers.

When the cab is assembled, i'd like to know what to listen out for.  E.G. if the port is too short, i will hear xxxx  and if the port is too long, i will hear xxxx

Edit

I have some  4"  ducting here if the ports need more length

 

 

 

Edited April 11, 2020 by fleabag

[Bill Fitzmaurice]

If the port is too short it will make for a boomier tone, if too long you lose midbass sensitivity. You should use speaker modeling software to determine the correct length.

[fleabag]

Cheers -  yes, i did use software, but i just wanted to be sure, as i'm not that good with these software progs

I used ajvented,  as WinISD seems too complicated

https://www.ajdesigner.com/speaker/ajvented.php

If you look to the right of  parameters, you will see alignment  SBB4,  QB3 and SC4

I tried each one and they give different port lengths depending on what i want, but i dont know what those alignments  mean in the great scheme of things

Edited April 11, 2020 by fleabag

[Bill Fitzmaurice]

Alignments are obsolete. Back in the Dark Ages before the PC, when speakers were designed with slide rules and scientific calculators, alignments were devised, to reduce the innumerable possible permutations to just a few, for the sake of simplicity. WinISD still has them listed in the initial calculation stages as starting point, but once you've got to the results page you can change the box volume and tuning frequency at will and it will recalculate the result, with each recalculation being a new alignment. This gives you the ability to try all of those innumerable possible permutations. With slide rule or scientific calculator that was impractical, as each new calculation could take fifteen to thirty minutes to do the calc, and then another thirty minutes to manually chart the result.  With a PC and modeling software it's very practical, with each new calculation and chart taking no more than fifteen to thirty seconds, unless you decide to overlay the charts for each new calculation. Then it can take maybe a minute or two for each additional.

[Stub Mandrel]

On 29/03/2020 at 13:58, Bill Fitzmaurice said:

There's more than one Delta 10. The A version, 8 ohms, has 3.5mm xmax, which is adequate. The B version, 16 ohms, has 1.8mm xmax, which is not adequate. 1.8 mm versus 3.5mm xmax means the B will only take half the voltage, one quarter the power, before heavy distortion occurs. Even the A is no prize, with a resonant frequency (Fs) of 66Hz it's best employed as a PA midbass, with separate subs handling the lows. Both the Alpha 10 and Beta 10, with Fs of  50 and 53Hz respectively, are better for electric bass.

My Trace Elliot 1110 has four Alpha 10s in it. Not sure if they were put in by someone with the slightest clue as one was wired out of phase.

Swapped that speaker over, sounds great, very loud and clear and doesn't fart even when pushed hard.

Theoretically I think it would be better with beta 10s, but I'm happy to leave it as it is.

[Bill Fitzmaurice]

By and large the Alpha is better in a sealed cab, the Beta better in a ported cab, but it also depends on the cab particulars.

[Balcro]

Hello Fleabag,

You did the right thing in getting some new port material.

Two Beyma 10 CMV"'s in 70 litres is perfect. Using two 100mm i/d ports you need the following:-

For 57Hz tuning you need a length of 13.3cm.

For 56Hz tuning you need a length of 14cm. For 55Hz tuning - 14.9cm long etc,. and on and on .....

I hope you have the space behind the new drivers.

 

[Matt P]

@fleabagas the fans are blowing into the amp you might want to consider a couple of dust filters to help keep it nice and clean (as you have gone to the effort of cleaning it) most computer places sell very cheap magnetic dust filters, i think they are a couple of quid each, might be worth it (or for anyone else with a inward facing fan)

https://www.google.com/search?q=magnetic+dust+filter

 

Matt

[Stub Mandrel]

On 08/04/2020 at 12:28, fleabag said:

All i got was a short message saying that the best replacement was the Eminence Beta 10  but that has Bill's absolute minimum xmax of 3mm.

Talking crap about alpha's looking at wrong  number it's 3.2...

Edited April 12, 2020 by Stub Mandrel

[fleabag]

4 hours ago, Balcro said:

Hello Fleabag,

You did the right thing in getting some new port material.

Two Beyma 10 CMV"'s in 70 litres is perfect. Using two 100mm i/d ports you need the following:-

For 57Hz tuning you need a length of 13.3cm.

For 56Hz tuning you need a length of 14cm. For 55Hz tuning - 14.9cm long etc,. and on and on .....

I hope you have the space behind the new drivers.

 

Thanks B.   I've been extending the ports today, from  10cm  to  16.5 cm so i will cut some off

[fleabag]

3 hours ago, Matt P said:

@fleabagas the fans are blowing into the amp you might want to consider a couple of dust filters to help keep it nice and clean (as you have gone to the effort of cleaning it) most computer places sell very cheap magnetic dust filters, i think they are a couple of quid each, might be worth it (or for anyone else with a inward facing fan)

https://www.google.com/search?q=magnetic+dust+filter

 

Matt

The dust build up isnt huge, judging by what i cleaned off the heatsinks.  I could leave it for a couple of years and clean it out manually