Using 12" guitar element as high efficiency midrange?

[Elias]

Hello,

In seeking of high efficiency midrange for home hifi, how about using some of the guitar elements as midrange somewhere between 200Hz-2kHz? When crossing low enough at 1-2kHz can avoid most of the cone breakup.

For example some of the Celestion seems promising

An externally hosted image should be here but it was not working when we last tested it.

http://professional.celestion.com/guitar/products/classic/detail.asp?ID=4

Claimed efficiency 100dB seems tempting for a small tube amp

Any experience you would like to share?

- Elias

 

[bigwill]

There is a guitar speaker by eminence that makes a good mid range as reported by a few people here, I think it's called the "Lil Buddy"

 

[AdamThorne]

I've heard some people dig the "Tone Tubby" driver in this way, but I have no personal experience with it.

 

[Saturnus]

One should note the high Qts of these drivers. They are best suited for OB purposes.

 

[CLS]

Some professionals seem not like this idea because of such drivers tend to have too short of Xmax and cones with severe breakups, thus bad linearity and poor stop band behaviors (especially when play loud).

I think, choosing the right one and using it under limited bandwidth and SPL, the problems above maybe not so serious. (Be careful with those published frequency response charts. The real breakup peaks may probably be much worse than they look on paper. )

I am experimenting with such setup right now. The driver is Emimence Legend 125 (the wrong one), which I've already owned and used on and off for some years. This model comes with some broad and huge breakup peaks (10dB or the likes) centered around 2.5kHz. So, using it as is is almost unbearable. Some mods to the driver are needed.

These are done to the drivers (for the time being):
1. cut the dust cap and insert a phase plug onto the pole peice.
2. apply PVA glue on both side of the cone.
3. cut the paper surround at some partilcular areas to soften the overall suspension.
4. apply silicon oil on the spider for furthur reducing the stiffness

After these mods, the breakup peaks seem largely tamed. I examined this by impedance scan and simple RTA, and finally, ears. Now they are playing music (other than electric guitar, of course) and quite pleasing.

The cone is folded straight profile with corrugated press. It's light and stiff inherently. Now it's furthur hardened by the PVA glue. Within the range I'm using (160~3kHz, OB'ed), it's dynamics and details are quite good.

It lost some sensitivity on the lower mids because of those cuts on surround (sound waves on front and back of the cone are short circuited here). So I'll do something on it later.

The whole thing is on going and not completed yet. I'll update here if you're interested.

 

[jamikl]

Elias, did you look at the 10" Celestions. I can't remember whether it was guitar series or PA series. The ferrite version was actually flatter on paper than the neo version. Around 97 Db.

I was interested in this one but could not find a price for it in Australia. I am now looking at a 10" PHL, around 100 Db, available here though a bit pricey.
jamikl

 

[ttan98]

Elias, did you look at the 10" Celestions. I can't remember whether it was guitar series or PA series. The ferrite version was actually flatter on paper than the neo version. Around 97 Db.

I was interested in this one but could not find a price for it in Australia. I am now looking at a 10" PHL, around 100 Db, available here though a bit pricey.
jamikl

you can find various Celestion models here:

http://www.svvintageamps.com/

I believe they send overseas as well. Cheaper than PHY.

Cheers.

 

[sreten]

Hi,

PA drivers are far more sensible for midrange than guitar drivers.
Distortion profiles are completely different, you want the former.

/sreten.

 

[Elias]

Hello,

Elias, did you look at the 10" Celestions. I can't remember whether it was guitar series or PA series. The ferrite version was actually flatter on paper than the neo version. Around 97 Db.

You mean 10" truvox?
http://professional.celestion.com/pro/products/tf/detail.asp?ID=7

I've been looking at this too. There seems to be some link to Monacor, however specs are a bit different
http://www.monacor.de/typo3/index.php?id=62&L=1&act=&act_sub=&artid=6064&spr=EN&typ=u

- Elias

 

[Elias]

Hello,

PA drivers are far more sensible for midrange than guitar drivers.
Distortion profiles are completely different, you want the former.

I'm looking for relative big (10-12") cone with very low cone mass, and high sensitivity. PA drivers seems to have heavy cone mass, instead guitar drivers seems to fit in here. Vintage appearance does not hurt either

Propably it's very true that distortion is very different. However, I've never seen any published distortion plots of any guitar drivers, so direct comparison to PA drivers is impossible at this point.

- Elias

 

[Saturnus]

Propably it's very true that distortion is very different. However, I've never seen any published distortion plots of any guitar drivers, so direct comparison to PA drivers is impossible at this point.

That's because guitar drivers are not sold on their technical specifications but on their sound (read: how much and where they distort the most). This is because guitar cabs aren't technically speakers but instruments themselves.

Guitar drivers are made specifically with too low mass and too big a motor so that they distort heavily. If you make the effort of taming these distortions you end up with a normal PA midrange driver.

 

[CLS]

Guitar drivers are made specifically with too low mass and too big a motor so that they distort heavily. If you make the effort of taming these distortions you end up with a normal PA midrange driver.

Maybe or maybe not.

There are all kinds of guitar drivers and PA midbass. Regarding the ratio of cone mass and motor strength, guitar drivers are not always lighter and stronger...

I think the major 'problems' of guitar drivers are those not-so-controlled (or specifically controlled) cone breakups in the mid-high frequencies. With the not-low-enough voice coil inductance, rising impedance, and the cone full of breakups, the sound in this frenquency range is almost produced by cone breakups and not properly driven by motor!

But on the other hand, PA drivers also do not always perform good enough in this problematic mid-high region which "bothers" guitar drivers. 12" PA midbass drivers are usually not used up to 3~5kHz where the same size guitar drivers usually show their 'tones'.

Simply put, many PA drivers also show severe breakups above 2kHz which should be filtered out by xover. If these breakup region of guitar drivers were also filtered out, they can perform very well (or at least fair) -- of course you need inherently smooth ones.

I'm looking for relative big (10-12") cone with very low cone mass, and high sensitivity. PA drivers seems to have heavy cone mass, instead guitar drivers seems to fit in here. Vintage appearance does not hurt either
...

"Playing" with guitar drivers is great fun, but they are definitely not a good choice at the start of a speaker system plan. There are many things can and should be done to the drivers themselves -- this may or may not be a good thing.

If you already had some on hand or can get some with very little cost, feel free to try them (and be prepared for all the mess). If not, guitar driver is indeed not a good choice.

It's not and shouldn't be a clear yes or no. It's how you see it with the whole thing.

Right now my speakers (with 12" guitar drivers as mids) are playing classical music -- piano solo now and chamber music a few minutes earlier. With helps from xover, tweeters and woofers, as a mid on OB, it's not bad at all -- a very vivid and dynamic sound, with not so pronouced colorations sometimes.

But to be honest, I'm playing with these drivers because they are laying around, not used for some time, and very cheap. So I can do some experientments without hesitation. I did not expect much, and it turns out very good -- it's just a bonus to me.

This definitely won't be my ultimate midrange, but great fun for a while.

 

[tinitus]

A German company list a very nice looking special Eminence Legend 122 /20watt, alnico with paper voice coil former...interesting

 

[tinitus]

They also have a Legend 1o2 /20watt, alnico with paper voice coil former

 

[Le Basseur]

One should note the high Qts of these drivers. They are best suited for OB purposes.

There's a guy,Robert Bastani http://www.bastanis.com/ who uses some "custom-made" Celestions in OBs for the exact purpose of the original thread's question.Nothing spectacular about these 12's since they're some variation of a certain mass-produced guitar driver model,though Bastani's followers swear about it
Some 12-15 years ago I tried a wide plethora of guitar/PA 12's for the same reason:to get a great 12' mid in my system.Nothing worked as I wanted to,mainly because no such driver unit "coped" with the tweeters I wanted to use (some great bullets,I cannot remember wich ones).
Of course,time has passed and the guitar drivers' industry grew constantly.Though,I'm still kinda skeptical about a guitar/PA 12'...ANY such 12' used in a 3-way home system,no matter how high the Bastanis are praised by their followers.

Guitar drivers are made specifically with too low mass and too big a motor so that they distort heavily.

Hmmmm...according to your statement,Lowther drivers (8',membranes weightning a few grams AND a HUGE magnetic field in theirs' gaps) should distort heavily....but they don't.
Regards,

 

[Saturnus]

Hmmmm...according to your statement,Lowther drivers (8',membranes weightning a few grams AND a HUGE magnetic field in theirs' gaps) should distort heavily....but they don't.
Regards,

Actually I would postulate that they do, just as my own Fostex 206e's does. It's more the manor in which they distort and how it's attempted tamed that marks a great driver from a bad driver. And practically any driver regardless of cost has some use, it might not be in hi-fi, though.

Remember all music is always distorted sound. Always!

 

[Geek]

Here, won't empty your wallet either:
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-402
and
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-409

PE has a nice chooser

Cheers!

 

[MisterTwister]

P10-100MB is on sale.
http://www.loudspeakersplus.com/html/paudio_8-10_mid.html
did anyone have experience with this beast?
some parameters are wrong, get info from P.audio website.

 

[GM]

Actually I would postulate that they do, just as my own Fostex 206e's does.

No need to postulate, they (Lowthers) do. Like all minimal Xmax 'FR' drivers they quickly go into a ~euphonic distortion due to a rising effective Qts as it leaves the gap and then the ugly distortion of suspension non-linearity hammers you on wide BW transients.

GM

 

[Elias]

Hello,

They also have a Legend 1o2 /20watt, alnico with paper voice coil former

I find Legend 102 very interesting when looking at the specs

An externally hosted image should be here but it was not working when we last tested it.

I just love that looks

http://www.eminence.com/pdf/legend-1028k.pdf

10" cone and only 15g of moving mass.. yummy! This is the same mass per area as in Supravox drivers which have very light cones.


AlNiCo magnet is a legendary material itself, although I'm not sure how it's characteristics will show up when listening at 'normal' level well below heavy distortion. I'm not a guitarist but I understand that magnet material will show some tone when signal level is very high in the coil. In home listening things may be different.

- Elias