The Driver/Enclosure relationship

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Lindsayt
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Re: The Driver/Enclosure relationship

Unread post by Lindsayt »

How's the bass extension? Any filtering out of bass drums, or reggae style bass guitars?

I've been looking at getting 18" drivers. When I've looked at online calculators, they've predicted bass roll-off at higher frequencies than I'd like. Although of course that's all Thiele Small calculated stuff - which I take with a huge pinch of salt.

But yeah, sealed box all the way - whenever possible.

I also think that light coloured cabinets look more cheerful than black ones.
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karatestu (Fri Jun 05, 2020 8:44 pm)

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Re: The Driver/Enclosure relationship

Unread post by Docfoster »

Lindsayt wrote: Sun May 31, 2020 9:47 pm How's the bass extension? Any filtering out of bass drums, or reggae style bass guitars?

I've been looking at getting 18" drivers. When I've looked at online calculators, they've predicted bass roll-off at higher frequencies than I'd like. Although of course that's all Thiele Small calculated stuff - which I take with a huge pinch of salt.

But yeah, sealed box all the way - whenever possible.

I also think that light coloured cabinets look more cheerful than black ones.
Thanks. "Cheerful". Yes, that's a good word. :-)
I'll want to switch back and forth a few times more between the two cabinets before making any definitive comparative pronouncements.
Though I'm not sitting here thinking "the bass is lacking".

My big DIY speakers have old Goodmans 18P 18 inch drivers. They do provide huge scale.
They crossover to the 5 1/4 inch sealed back Monacor mids at 800Hz. I chose that simply because it was the frequency that Goodmans used to use for their mids back in the 1970s, and my design plan was to build supercharged Goodmans Magisters. But, I think 800Hz is too high for the 18P for my ears. It can cope easily with that frequency, but I think they lack a bit of clarity as they get up there. If I were to do it again I'd have the crossover much lower (<90Hz) and use a larger mid unit to get down to meet that. Possibly even a dual concentric like the Tannoy 295 I've got now!
I doubt if I'll dismantle the big DIY Goodmans 18P. They do sound awesome to me and I am proud of them. They push that old Goodmans envelope as far as my abilities will allow. More likely is that one day I'll build a new pair using all modern drivers. And plywood cabinets!
System 1: JRiver MC24 > Dell Latitude 7270 > Asus Xonar Essence One Muses Edition DAC & pre- > One4 Class A power amp (with Dynamic PSU boards) > DIY Monacor SP-310CX speakers & DIY Dayton Audio SD315A-88 bass cab.
LC Audio Technology mains DC filter > Sovereign MTBPS balanced power supply
TQ (Wonfor) Ultra Black cables.

System 2: Anything with a headphone socket > Inca Tech Claymore > DIY Monacor SP-308CX speakers

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Re: The Driver/Enclosure relationship

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I've had a chance to play about it.
Maybe this conveys my thoughts...
(Even though I'm not at all into F1, I seem to have filmed this with a pit-stop theme...)



A couple of asides...
The Tannoy drivers are not very well matched (possibly due to age...?). One has a far more lively top end. I tried to remedy this by cleaning the magnet gap in both HF units, but it didn't make any difference. That sort of thing irritates me, although there is an upside. The acoustic balance in my living room is terribly asymmetrical, so having one speaker that pulls the sound in one direction can actually be quite corrective!

Also during the work I discovered something of an anomaly.
The label on the original Eaton cabinets clearly states that the units are 295A. But, on the back of the units themselves the label is "295/8" (/8 for "8 ohms" I think). I understand that these were the previous model, and that the original run of Tannoy Eatons did have the 295/8 instead. But the plot thickens. The 295/8 had a foam surround. The ones I have are definitely rubber. Maybe they have been replaced. If so, it was a very good job. There's no evidence of replacement.
Anyway. No biggie.

Certainly the best sounding 70s HF drivers I've heard. Very good all round in fact.
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Ithilstone (Fri Jun 05, 2020 10:15 am) • Toontrev (Fri Jun 05, 2020 11:47 am)
System 1: JRiver MC24 > Dell Latitude 7270 > Asus Xonar Essence One Muses Edition DAC & pre- > One4 Class A power amp (with Dynamic PSU boards) > DIY Monacor SP-310CX speakers & DIY Dayton Audio SD315A-88 bass cab.
LC Audio Technology mains DC filter > Sovereign MTBPS balanced power supply
TQ (Wonfor) Ultra Black cables.

System 2: Anything with a headphone socket > Inca Tech Claymore > DIY Monacor SP-308CX speakers

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Re: The Driver/Enclosure relationship

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Finishing touches...
Managed to source some funky retro Tannoy badges... 8-)

Image
System 1: JRiver MC24 > Dell Latitude 7270 > Asus Xonar Essence One Muses Edition DAC & pre- > One4 Class A power amp (with Dynamic PSU boards) > DIY Monacor SP-310CX speakers & DIY Dayton Audio SD315A-88 bass cab.
LC Audio Technology mains DC filter > Sovereign MTBPS balanced power supply
TQ (Wonfor) Ultra Black cables.

System 2: Anything with a headphone socket > Inca Tech Claymore > DIY Monacor SP-308CX speakers

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