1 x 15" 4 ohm Cabs. Are they a myth?

[38bass]

Check the DR.BASS website. I'm sure the have 1 x 15 cabs that can be 4 OHMS.

Perfect! Thanx for the tip!

 

[Bassmec]

The heavier the moving mass vs the motor strength than the less midrange and highs the speaker will produce. It won't make the response any slower though.

Alex

A 15" speaker that needs crossing out at less than 100 Hz because its dragging that much copper about, feels fairly slow to me if its the only driver doing my frequency response. (whatever slow actually means in electrical or Talk Bass terms).
Its the equivalent of removing the mag alloys off a race car and fitting railway wheels in unsprung weight terms.
The wheel just wont follow the pavement with the available damping.
happens to amps at very low impedance too. Insufficient damping!.
I remember when amps proudly announced these important figures. Damping factor 1000 at eight ohms etc.
What happens about back EMF today or have the sales staff conveniently un-invented it along with watts RMS and the need to damp it.

 

[MNAirHead]

Bassmec..

Technically you're right - street level is a bit different.

I'm taking this directly from the product managers at a fewer of the higher volume companies.

The overall public market prefers more quantity of lower quality cabinets.. most heads are designed for a 4 ohm minimum. The market requests an 8 ohm cabinet so they can series them.

I called and called on the quest to find a 1-15..

We could go on about speaker physics.. the reality is that speaker cabinets are dogs for a music vendor.. 4 ohms are St. Bernard size dogs.

All of my cabinets are 4 ohm... I have everything 6s, 8s, 10s, 12s, 15s.. some were found diamonds.. some were engineered from the theil specs.

T.

Sorry!, a lower power rating has nothing to do with quality, although in this day and age it may have more than a little to do with honesty.
What does a loudspeaker sound like at its maximum thermal rating?.
Also how long will it last?.
If this amp is run at near maximum power and you love good fifteens the ideal new cabinet is probably something like a sealed 4 X 15 with light weight cones and voice coils, Very agile 15's that produce good midrange tone.
Or get something to absorb the power safely, it will however be the worst bass guitar sound you ever heard but as its ohms are very very low (2) and its power handling is very very high 5000 peak and so must be the quality?.
not! it would sound like mud.
15" independently tested at 6050 watts peak to peak for one hour 37 mins before thermal failure.

In physics the problems of trying to throw a large amount of thick copper wire and some cardboard back and forth a long way, tends to have a limiting factor on how often per second you can actually make it do it.
Therefore as a general rule, the higher the real thermal handling of a fifteen inch the muddier and slower the response.

 

[agedhorse]

From a practical point of view, damping factor is one ofthe least important specs. in modern amplifiers. As soon as you add say a 6 foot speaker cable aloong with internal speaker wiring, your amp's damping factor becomes insignificant compared with the loss (R factor) of in circuit damping factor from these external components.

In practice, for bass guitar, anything greater than say 250-300 is meaningless due to the outside factors that come into play.

Also, 4 ohm drivers do not necessicarily have to have heavier moving mass, for the same power rating. There are many factors that can be adjusted to end up very close. The difference in a coil's moving mass between 4 and 8 ohms is generally only a VERY small factor compared with the mass of the cone, surround and spider.

There is nothing wrong with 2 ohm loads provided the amp is designed to drive 2 ohms and that the reactive conditions and sub-nominal conditions are anticipated and accounted for in the design. It's not rocket science. In fact, it's pretty trivial for a competant designer.

 

[JMDT]

It's not rocket science. In fact, it's pretty trivial for a competant designer.

As a chemical engineer, I never though rocket science was that hard. Those electrical schematics on the other hand blew my brain when I tried to figure them out, lol.

 

[38bass]

You guys are a fountain of information. Seriously!






+2

 

[anyonefortennis]

The mesa scout radiator is available in 4ohm iirc.

 

[Lia_G]

The mesa scout radiator is available in 4ohm iirc.

I just remembered this as well. Also, the other Mesa 15's (Powerhouse and Vintage Powerhouse) are available in both 4 and 8 ohms.

 

[pfschim]

The mesa scout radiator is available in 4ohm iirc.

yep, I have one in the practice room right down the hall ... hmm maybe its time to take a playing break from all this tedious work

 

[alexclaber]

A 15" speaker that needs crossing out at less than 100 Hz because its dragging that much copper about, feels fairly slow to me if its the only driver doing my frequency response.

But that is a result of the frequency response, not the 'speed' of the driver. Cross that 15" sub to a midrange speaker and it'll then sound as fast as anything.

My concern with hunting for a 4 ohm 15" is that is that 4 ohm 15" as well developed as the bigger selling 8 ohm variant? Changing the voice coil impedance isn't a trivial job.

IMO 4 ohm vs 8 ohm is predominantly a marketing issue, not an engineering issue. And although it's interesting to see that Epifani are attempting to produce a cab that is switchable impedance there are a whole host of other issues that need to be addressed with dual voice coils which seem rather unnecessary. But if it's anything like the comedy specs usually quoted then marketing usually wins out over engineering...

Alex

 

[greenboy]

A fair number of 4-ohm versions derived from 8 ohm designs are also reduced in capabilities. Quickies to the market, they often have less voice coil winding, less excursion, among other things. Not too many I've modeled can keep up with their 8-ohm cousins.

 

[Michael Vee]

"1 x 15" 4 ohm Cabs. Are they a myth?"

No. But Hip-hop bass lines do not exsist.

 

[agedhorse]

A fair number of 4-ohm versions derived from 8 ohm designs are also reduced in capabilities. Quickies to the market, they often have less voice coil winding, less excursion, among other things. Not too many I've modeled can keep up with their 8-ohm cousins.

But they do not have to be, if the transduecr engineers know what they are doing.

 

[steamthief]

I think Eden makes the D115XLT in 4 ohm.

 

[euronymous]

I have a carvin 4ohm rated at 600 watts

 

[euronymous]

"1 x 15" 4 ohm Cabs. Are they a myth?"

No. But Hip-hop bass lines do not exsist.

Hiphop ha! Good call

 

[bassman10096]

Check the DR.BASS website. I'm sure the have 1 x 15 cabs that can be 4 OHMS.

I have a DrBass 4 ohm 115. If not listed on the site, Marc was happy to take it as a "no big deal" variation from standard when I got mine. The reason I got a 4 was because so I could pair it when needed with another 4 to get a lot of power out of one amp channel (at 2 ohms). The other channel was dedicated to a BagEnd ELF sub. Turns out I almost never need both cabs on that channel, but no harm done.

 

[John Webb]

I have a DRB115 4 Ohm as well. I use it on the low side of my 800RB with a 210 on the high side.

I'm trading it for a 4 Ohm 410.

 

[eastcoasteddie]

I'm sure Carvin 4-ohm 15's are still available. Probably just have to call.

 

[Eight_Stringer]

But they do not have to be, if the transduecr engineers know what they are doing.

Me too, GB has the exposure to speakers and operational parameters so will defer to his experience, however like agedhorse my experience says the matter of impedence does not or ought not dictate overall electrical and mechanical limitations ( within normal bounds of say 2-8 or maybe 16 ohms ). Designed many products over the years, though a speaker is not one of them so maybe i have something to learn yet....Regards to all.