18" + WAVEGUIDE - 2 Way Bass Reflex 'THE VERSATILE' Loudspeaker.

[Charles Darwin]

Have you found it for sale somewhere?

Reason I'm asking is that I've been told that Volt stopped making pressed steel chassis and their site has not been updated for at least 5 years.

 

[The Space Egg Corp]

No.

Have you found it for sale somewhere?

Reason I'm asking is that I've been told that Volt stopped making pressed steel chassis and their site has not been updated for at least 5 years.

Hi CD

In a word, I haven't

I checked the Sabre PA link you gave me.
They do the Volt studio range, but not PS18/300, which I thought was odd.

Your probably right, not available.
Looks like Volt update themselves even less often than I do !

I don't know if I'm being unjustly prejudiced about this,
but I was keen to avoid steel chassis anyhow, as it always seems to be the sign of a 'cheapie' driver.
I was interested in the dual coil feature however.

Did you see the 21" Precision Devices spec. a few posts ago ?...

Cheers

Simon

 

[pinkmouse]

The PD is a very nice driver, and I'm very familiar with the Turbosound variant, (tweaked for horn loading). IIRC, they're not that expensive for what you get, about £350, ( but that could well be a trade price ). However it would mean a three way, they really get a bit ragged over about 250Hz. But you have the power handling and excursion to use an ELF type eq, so you could get the box size down a bit, perhaps with something like the recently re-introduced Audax PR170 for the mids.

 

[The Space Egg Corp]

Hi pinkmouse

The PD is a very nice driver, and I'm very familiar with the Turbosound variant, (tweaked for horn loading). IIRC, they're not that expensive for what you get, about £350, ( but that could well be a trade price ). However it would mean a three way, they really get a bit ragged over about 250Hz. But you have the power handling and excursion to use an ELF type eq, so you could get the box size down a bit, perhaps with something like the recently re-introduced Audax PR170 for the mids.

Hi pinkmouse

Just as your post came through, I was drooling, and getting a price for the PD 21"
Driver £480
Recone £208

I can't deal with a 21" really, just a brief fantasy !

I don't know if you've read some of the other posts ?
But I have been looking at drivers for a while now,
and the only serious contender for the overall spec. in my view is the Eminence Sigma Pro 18A-2.

I have however looked seriously at the Precision Devices PD 186 18" as the only realistic other contender so far.
Any experience of that ? or the Sigma Pro ?

I know some will say an 18" two way is just not cricket, but a three way is simply not what I want to do.
I would like to X @ 2K if possible, I would at a pinch stretch to 1.2K, but 2k is what I want.
I would like to solve any issues, and make a 2 way work.

Any thoughts most welcome.

Cheers

Simon

 

[pinkmouse]

Frankly, you may be pushing beyond the bounds of practicality here, sorry to say. I haven't heard any 18" that will do what you want with that crossover frequency. You might just about get away with a 15" running to 1.2K, but not an 18, I wouldn't take one above about 800Hz. But, there are 3" compression drivers that will go down to 800Hz.

 

[Antripodean]

If you cross at below 1K then an 18" driver will work. Need the right flare and CD, at least a 1.4" CD. AE TD18H+ will do the bottom end.(Just more of what pinkmouse wrote )

 

[The Space Egg Corp]

Frankly, you may be pushing beyond the bounds of practicality here, sorry to say. I haven't heard any 18" that will do what you want with that crossover frequency. You might just about get away with a 15" running to 1.2K, but not an 18, I wouldn't take one above about 800Hz. But, there are 3" compression drivers that will go down to 800Hz.

Hi again pinkmouse

The power input to this speaker will be only 100W max. (200 abs.max.max)
The intention is not to use an 18" for its absolute power handling.
What interests me about an 18, is it's very low resonance.
Sigma Pro 28Hz
PD 186 - 25Hz
I have looked at 15's, but haven't found resonance below, say 33Hz
I know we're only talking about a couple of digits or so here, but my aim was to have this figure bellow 30Hz.
Also I am not looking to make a large enclosure to create a big bass hump or anything like that, but to have a 2 port reflex of about 5 cu ft.
My thinking is that without massive power and cone excursion an 18 might handle the highs alot better than in it's typical 'bass bin' situation.

?

Simon

Yes...the pain of scientific truth

 

[The Space Egg Corp]

If you cross at below 1K then an 18" driver will work. Need the right flare and CD, at least a 1.4" CD. AE TD18H+ will do the bottom end.(Just more of what pinkmouse wrote )

Hi Antripodean

Thanks for putting me on to the AE TD18H+ It's resonace is similar to the Sigma Pro.
Also on the AE line up is the 'Dipole 18', not efficient @ 92dB, but resonance at a very impressive 22.9 Hz.
The Sigma Pro frequency runs to 2.4K Hz
The PD 186 frequency runs to 2.0K Hz
AE claim the response of their drivers also runs into the mid-range, but they don't provide any plots on their website to check this.
I may well e-mail them as I have done with Precision Devices to get better details of the units.

Thanks for the pointer to them.

Cheers

Simon

 

[pinkmouse]

Have you looked at SB Acoustics?

SB Acoustics :: 15" SB42FHC75-6

 

[Arty]

my choice for many many projects that need a larger woofer is since 2006 is the following driver:

nominal impedance 4 Ohm
(IEC 268-5) power handling 70 VA
AVG. Spl 93 dBL
linear excursion ±2,5
mechanical excursion ±6,0


Re 3,0 Ohm
B*l 8,248
Sd 510 cm^2
Cms 1,382
Mms 57,749 g
Rms 3,369
Fs 17,813 Hz
Vas 510,644 L
Qms 1,918
Qes 0,285
Qts 0,248

The price is around 26 euro.

This is a reply actualy for the first few posts, there is no problem with cheapoo drivers, till you know what to look for, and purchase the "right stuff".

I made back to back isobaric subbox for car use using this driver.
And made a few HT subs too, allso is part of at least 3 pairs of 3 way systems i made over the years.

Actualy as a back to back isobaric this thing is quite space-and cost efficient.
I consider it to be in the top 10 12" bass units i would ever purchase.
Moving mass could be less, might not do so well for guitars i never did attempt it.
It covers quite well till 2Khz, but using this driver higher than 1 or maybe 1.5 Khz is not realy advised by me.

 

[Charles Darwin]

Hi CD

Did you see the 21" Precision Devices spec. a few posts ago ?...

Cheers

Simon

I came across that one a few years ago. A friend of mine was thinking of using the cellar below his living room as a subwoofer enclosure by just fitting a couple of them into the floor but he eventually moved to South Africa instead.

How about a Fostex FW405 16"? Fs 20Hz and 96dB @1w but no idea about price or availability.

 

[The Space Egg Corp]

my choice for many many projects that need a larger woofer is since 2006 is the following driver:

nominal impedance 4 Ohm
(IEC 268-5) power handling 70 VA
AVG. Spl 93 dBL
linear excursion ±2,5
mechanical excursion ±6,0


Re 3,0 Ohm
B*l 8,248
Sd 510 cm^2
Cms 1,382
Mms 57,749 g
Rms 3,369
Fs 17,813 Hz
Vas 510,644 L
Qms 1,918
Qes 0,285
Qts 0,248

The price is around 26 euro.

This is a reply actualy for the first few posts, there is no problem with cheapoo drivers, till you know what to look for, and purchase the "right stuff".

I made back to back isobaric subbox for car use using this driver.
And made a few HT subs too, allso is part of at least 3 pairs of 3 way systems i made over the years.

Actualy as a back to back isobaric this thing is quite space-and cost efficient.
I consider it to be in the top 10 12" bass units i would ever purchase.
Moving mass could be less, might not do so well for guitars i never did attempt it.
It covers quite well till 2Khz, but using this driver higher than 1 or maybe 1.5 Khz is not realy advised by me.

Hi Arty

Thanks for your interest in the thread.
Moving mass for a 12" seems about normal.
Must say though the resonance seems strange at 17 Hz.

There seem to be loads of people making bass guitar cabinets on the net using drivers with high resonance & not enough low frequency extension.

People seem to think there's no fundamental energy in a 30 Hz bass guitar string, well that's a load of nonsense, just cause the speaker won't reproduce it doesn't mean it's not there.

These cabinets having said that are pretty much what the average commercial company such as 'Ampeg' knock out.
But at £1000 for a 1 x 15" cab with probably not that greater tweeter in it, you wouldn't catch me going that way even if 'Ampeg' wanted to let me have one for £250.

You said it, fitness for purpose is everything.
Throwing cash at problems to find the solution rarely works (except in Formula 1 of course, and even they get it wrong half the time).

I saw on the site somewhere a member who's motto is a Henry Ford quote:-

"If you've always been doing it like that, your probably wrong"

I'm sure Henry was probably a real pain to work for, but he did get the job done.

I'm not realy trying to make a 'guitar cab' as such, but rather some thing that will reveal what is not being reproduced by some speakers.
I would like the speaker to be fairly 'Hi-Fi' and at the same time cope well with an instrument low end.
The piano afterall goes even lower to 27.5 Hz, and with a synth, the bottom limit is endless.

Glad the iso. sub was a winner, I have a pair of 8.5"ers hear I was thinking of doing something similar with.

Cheers

Simon

 

[The Space Egg Corp]

Have you looked at SB Acoustics?

SB Acoustics :: 15" SB42FHC75-6

Hi pinkmouse

Thanks for the pointer.
Yes. Looks very interesting for a 15".
Lowest resonance by far that I've seen, seems like quite a unique driver.
The AE 'Dipole 18' was also at about 22/23 Hz.

One of the other problems of the driver selection for this project is that a friend of mine wants to make speakers, and is about to emigrate to NYC.
Some of the drivers such as PD, AE & SB, only have distribution on one side of the 'Pond' or other, not both.

The omnipresent 'Eminence' however seems to have global distribution nailed.
Eminence also do recone kits for a measily £25, where with PD it's more like the best part of a Ton.

I don't think my friend or I fancy importing & exporting 20 Kg drivers buy USPS and The Post Office.
It is a very frustrating situation indeed.

Cheers

Simon

 

[The Space Egg Corp]

I came across that one a few years ago. A friend of mine was thinking of using the cellar below his living room as a subwoofer enclosure by just fitting a couple of them into the floor but he eventually moved to South Africa instead.

How about a Fostex FW405 16"? Fs 20Hz and 96dB @1w but no idea about price or availability.

Hi CD

Leaving the country due to sub-woofer stress seems a bit drastic.

Yes...If this emergency speaker project hadn't come up, I thought my next speaker build might be a pair of Fostex full rangers.

I have done 6.5" & 8" full rangers in the past, and they were both suprisingly successful.

The 8" ones rocked some pretty LOUD partys for years, but now reside in a barn just outside of Amsterdam due to foam fatigue !

Cheers

Simon

 

[Charles Darwin]

Well he left because somebody offered him a better paid job than he had.
Last time I spoke to him he had enough space in his new house to build the things into regular boxes but I don't know if he ever did.

The first speakers I ever build at the ripe old age of 16 were some 10" Fostex extended range drivers in a back-loaded horn, I think they were FP253s. They did party well but all in all not a patch on the active Tannoy/Volts I use now. Well made drivers though I seem to remember, 'twas a long time ago!

 

[The Space Egg Corp]

Well he left because somebody offered him a better paid job than he had.
Last time I spoke to him he had enough space in his new house to build the things into regular boxes but I don't know if he ever did.

The first speakers I ever build at the ripe old age of 16 were some 10" Fostex extended range drivers in a back-loaded horn, I think they were FP253s. They did party well but all in all not a patch on the active Tannoy/Volts I use now. Well made drivers though I seem to remember, 'twas a long time ago!

Just noticed some dirt cheap compression drivers CPC are banging out.
Could be good for 'basic' crossover testing to avoid costly meltdowns !
You never know they may even sound golden.

Whats on the top of your record pile at the moment CD ?

 

[DougL]

I found a chart indicating power response as a function of driver diameter in a thread in another forum.
B200 a bit shouty
Scroll down to the middle of the page for the chart.

If you cross over above 500 Hz, your drivers will be increasingly directional. At 2 kHz, the driver will be 6 db down around 40 degrees off axis. Good luck with that crossover

You need to address the issues of a compression driver operating below 1 kHz, or you need to go 3 way. Or you can put on your rose colored glasses and produce scrap.

Your choice.

 

[Arty]

I attached the drivers mesurement graphs.
(edit * for some reason only 1 pic shows up in attachments, i'm linking the otherone right now.
diyAudio

The 17 hz resonance is for real.

I can only agree, region of 20-30 Hz IS important, only problem when doing a speaker design is room gain. If You tune even this cheapoo "communist leftover" driver too low, and the room gain kicks in, it will sound wobbly/goofy.

My usual xover point for this driver in 3 way setups is less than 300 hz.
Verrrrry expensive to make a passive xover for this unit, as You can see the impedance curve demands compensation.

Other than that, in this price range I bet it will be hard to show anything that can come near to its potential.

On must not attempt to do a DIY speaker with the approach of getting the most expensive midbass as a start as he/she can pay for.
Simply not worth it.

I think a better solution is to clarify design goals, and seek a driver that can do the job right. Once found, ask around from others whom had the luck to use the selected driver(s), then decide what to do.

Btw, for 2 way systems a 40hz -3 dBL point is not a bad start.

 

[Charles Darwin]

Whats on the top of your record pile at the moment CD ?

Right now it's 'Rockstone - Natives adventures with lee perry at the black ark' (Pressure Sounds 56) but the vast majority of the time I just have my entire iTunes library on shuffle.

That said my top 3 bands are The Clash, Booker T & The MGs and Funkadelic.
Mixed with a liberal dose of Ween, The Eels, Oliver Mtukudzi, Johnny Cash, Primal Scream, Seasick Steve, Stax/Volt stuff and lots of dub and african stuff.

Whats on yours?

 

[The Space Egg Corp]

I found a chart indicating power response as a function of driver diameter in a thread in another forum.
B200 a bit shouty
Scroll down to the middle of the page for the chart.

If you cross over above 500 Hz, your drivers will be increasingly directional. At 2 kHz, the driver will be 6 db down around 40 degrees off axis. Good luck with that crossover

You need to address the issues of a compression driver operating below 1 kHz, or you need to go 3 way. Or you can put on your rose colored glasses and produce scrap.

Your choice.

Hi DougL

I looked at the graph you linked to, I normaly read charts just fine, but...

If I have a 1" tweeter, tweeting at 10K Hz, the chart indicates a 6dB point at 180 deg.

That makes no sense to me at all, at 180 deg. it must be way more down than that surely ?

Also the piston size bit seems to read X Y + find result, but I can't for the life of me figure out what your supposed to do with, or workout from the baffle perimeter bit ?
Anyone got any idea ?

I would not think myself that 6dB at 40 deg. is too much of an issue personaly, but maybe thats just me ?

Simon

(oh...is it a nomograph type thing)