Need help with an SWR 115 cab I'm working on!

[dustybottoms]

Hello, I recently became the owner of an old SWR Basic 2-way 1x15 Cab. I decided to plut a 4 ohm speaker (EMINENCE Basslite C2515) in it to get the full power from my head when used as a single cab. (is an 8 ohm cab) After doing the install I have noticed that the tweeter seems to be out of balance with cab. When I turn the tweeter volume all the way up, its still pretty muddy sounding. I talked to a local repairman and he said I probably needed to put a different HF driver in and a different capacitor. Question 1: does this sound correct? Question 2: if so, what would you suggest? I will include all of the cab details below. Thanks!

stock cab description:

Introduced in 1992 (primarily for use as an extension speaker for the Basic Black Combo) the Basic 2-Way enjoyed popularity as part of a modular system that included the Bass 350 and 4x8. The Basic 2-Way was discontinued in 1998.

Impedance: 8 ohms
Power Handling Capacity: 250 watts RMS
One 15" PAS driver
One Piezo tweeter
Weight: 59 lbs
Size: 22"W x 20"H x 16.5"D

jack plate/AT knob: AT AT-50H violet L-8 ohm


Capacitor: TI 4.oj. 250vdc/160 9604



tweeter:



Stock photo:

[dustybottoms]

Bump

[RickenBoogie]

Yes, it sounds correct. What you did was change the impedance of the speaker, without regard to the crossover and horn. First, it's a bad idea to "throw a speaker in a box" that it wasn't modeled for, and 2nd, a bad idea to "squeeze out all the amps wattage" into a single speaker. There's way more science to all this than you've allotted for.

[Bass_Pounder]

Originally Posted by RickenBoogie

Yes, it sounds correct. What you did was change the impedance of the speaker, without regard to the crossover and horn. First, it's a bad idea to "throw a speaker in a box" that it wasn't modeled for, and 2nd, a bad idea to "squeeze out all the amps wattage" into a single speaker. There's way more science to all this than you've allotted for.

/\/\/\/\
This


Above is an example of why people are told that just changing speakers without proper research is a crap shoot at best.

[David1234]

Seriously, put the PAS speaker back in!

It's brilliant, and matches the tweeter and cabinet tuning very nicely.

[dustybottoms]

I did ask. I did do research. Clearly I was told wrong and am finding out the hard way. Is my only option to put an 8 ohm woofer back in it? I don't ever want to couple this cab with anything else. (I don't understand the point a single 8 ohm cab. Any I have ever used in a single cab configuration have been virtually worthless to me.) I sold the speaker that was in it. (which wasn't the original speaker anyway) It didn't sound great at all. I think the 15 in it now sounds good, just not the right balance of high end. I guess at this point my question is there a way to correct the problem as it is or just put another 8 ohm speaker back in it. I didn't pay for the cab. I was just trying to make it work best as it is to have an extra stand alone cab. Sorry for my ignorance. That's why I'm asking.

[dustybottoms]

Originally Posted by David1234

Seriously, put the PAS speaker back in!

It's brilliant, and matches the tweeter and cabinet tuning very nicely.

any lead on where to find the original type speaker that was in this?

[greenboy]

dustybottoms,

I swore I'd no longer put myself in the position to argue with people about cab design stuff here on talkbass. But here I go again, because people are just not giving any real info here...

1) There's no reason to worry about the crossover in relation to a 4-ohm or 8-ohm woofer, because there IS NO TRUE CROSSOVER HERE ANYWAY. A single capacitor hardly qualifies as a crossover and is barely a high-pass section anyway. So you've done nothing wrong per se by using 4-ohm instead of 8-ohm.

2) The Basslite you've used is kinda boomy anyway, in most enclosure sizes and tunings. It's going to bury a single Le Son piezo tweeter which are very easy to bury anyway. In truth they only can hang with a single woofer if one doesn't want much above the woofer response anyway. They are the cheap way to look like one actually has a tweeter without actually having one.

You need to decide if you want something decent in there before proceeding further. That will require a better high-pass filter, some rewiring, a compression driver/flare - perhaps a cheap but decent one like the Eminence APT80.

[levis76]

Originally Posted by RickenBoogie

a bad idea to "squeeze out all the amps wattage" into a single speaker. There's way more science to all this than you've allotted for.

How can you call this a "bad idea"? OP has not stated what type of music he plays, the amp he is using, type of venues, his target tone, etc...

For all we know this could be exactly what he wants. Point is, he asked for help and advice, not criticism.

To the OP, Have you tried running it without the tweeter? That drivers freq range runs right up to 2.5KHz, maybe eq out some of the sub lows (<100Hz) to clean it up if it's muddy. A common misconception is that 15s are subwoofers for bass guitar. 15s actually have a stronger midrange voice than sub lowend, especially when it's a neodymium driver, so it will be a bit brighter than the PAS that was in it. Try it, you might like it without the annoying screeching piezo tweeter.

PS - I got similar reactions from people when I gutted my SWR Goliath Sr. 6x10 and loaded it with Eminence Deltalite's I ordered from Avatar. I got all kinds of crap when I asked for advice on here. Everything from "That will sound like crap" and "that cabinet wasn't designed for those drivers" and my favorite "you're destroying the cabs value" blah blah. It sounded great, weighed a lot less, and was easier to sell since it didn't have three blown PAS drivers in it anymore.

[levis76]

Originally Posted by greenboy

dustybottoms,

I swore I'd no longer put myself in the position to argue with people about cab design stuff here on talkbass. But here I go again, because people are just not giving any real info here...

You try to get out, but TB pulls you right back in.

[Petebass]

Originally Posted by greenboy

1) There's no reason to worry about the crossover in relation to a 4-ohm or 8-ohm woofer, because there IS NO TRUE CROSSOVER HERE ANYWAY. A single capacitor hardly qualifies as a crossover and is barely a high-pass section anyway. So you've done nothing wrong per se by using 4-ohm instead of 8-ohm.

The picture of the wiring confirms this is correct. There is no crossover on the woofer at all so swapping from 8 to 4 ohms was no problem - in this case.

All that's happened here is the higher output from the new 15" is now overpowering the tweeter so.....

Originally Posted by greenboy

You need to decide if you want something decent in there before proceeding further. That will require a better high-pass filter, some rewiring, a compression driver/flare - perhaps a cheap but decent one like the Eminence APT80.

+1.

[dustybottoms]

Originally Posted by greenboy

dustybottoms,

I swore I'd no longer put myself in the position to argue with people about cab design stuff here on talkbass. But here I go again, because people are just not giving any real info here...

1) There's no reason to worry about the crossover in relation to a 4-ohm or 8-ohm woofer, because there IS NO TRUE CROSSOVER HERE ANYWAY. A single capacitor hardly qualifies as a crossover and is barely a high-pass section anyway. So you've done nothing wrong per se by using 4-ohm instead of 8-ohm.

2) The Basslite you've used is kinda boomy anyway, in most enclosure sizes and tunings. It's going to bury a single Le Son piezo tweeter which are very easy to bury anyway. In truth they only can hang with a single woofer if one doesn't want much above the woofer response anyway. They are the cheap way to look like one actually has a tweeter without actually having one.

You need to decide if you want something decent in there before proceeding further. That will require a better high-pass filter, some rewiring, a compression driver/flare - perhaps a cheap but decent one like the Eminence APT80.

THIS.... was very helpful. The kind of answer I was looking for. Any suggestion on what capacitor I would need to run with it? Thats where I get a little confused. That and does the attenuator need changed too since it says 8 ohm on it or does that make a difference in this scenario. I'm probably going to check out the eminence driver based on your recommendation. Thanks

[dustybottoms]

Originally Posted by levis76

How can you call this a "bad idea"? OP has not stated what type of music he plays, the amp he is using, type of venues, his target tone, etc...

For all we know this could be exactly what he wants. Point is, he asked for help and advice, not criticism.

To the OP, Have you tried running it without the tweeter? That drivers freq range runs right up to 2.5KHz, maybe eq out some of the sub lows (<100Hz) to clean it up if it's muddy. A common misconception is that 15s are subwoofers for bass guitar. 15s actually have a stronger midrange voice than sub lowend, especially when it's a neodymium driver, so it will be a bit brighter than the PAS that was in it. Try it, you might like it without the annoying screeching piezo tweeter.

PS - I got similar reactions from people when I gutted my SWR Goliath Sr. 6x10 and loaded it with Eminence Deltalite's I ordered from Avatar. I got all kinds of crap when I asked for advice on here. Everything from "That will sound like crap" and "that cabinet wasn't designed for those drivers" and my favorite "you're destroying the cabs value" blah blah. It sounded great, weighed a lot less, and was easier to sell since it didn't have three blown PAS drivers in it anymore.

I agree with this too. I like trying new things and experimenting. In my experience I have had things turn out unexpectedly bad or good AND had fun learning about it while doing it. The value of the cab is not that important to me. It isn't worth anything sitting in my living room not getting used.

[BassmanPaul]

Originally Posted by dustybottoms

I agree with this too. I like trying new things and experimenting. In my experience I have had things turn out unexpectedly bad or good AND had fun learning about it while doing it. The value of the cab is not that important to me. It isn't worth anything sitting in my living room not getting used.

What you say is true however you DID ask for help. However you don't seem inclined to accept that help. Isn't it better to work towards something worth while?

The value of the capacitor depends on what crossover frequency you want. The 4µF cap that you have will crossover somewhere in the range of 5K assuming an 8Ω tweeter. The single cap makes a very poor crossover.

[dustybottoms]

Originally Posted by BassmanPaul

What you say is true however you DID ask for help. However you don't seem inclined to accept that help. Isn't it better to work towards something worth while?

The value of the capacitor depends on what crossover frequency you want. The 4µF cap that you have will crossover somewhere in the range of 5K assuming an 8Ω tweeter. The single cap makes a very poor crossover.

I think you misunderstood my point. I'm very accepting of help. Hence the whole reason I am here asking instead of just guessing and doing it myself. I don't understand how I'm not working toward something "worthwhile". I'm trying to build a good cabinet suitable for my needs. I think "worthwhile" is a pretty subjective term.

I appreciate all of the help so far everyone.

[Blues Bass 2]

You could do like Greenboy says and just put in that Eminence APT80 . It's small like the Leeson is and would probably work with the cap that's in there but a better option would be to use this crossover from Eminence .
http://www.parts-express.com/pe/show...number=290-602
http://www.parts-express.com/pe/show...number=290-532

It's a true third order highpass and while not ideal or designed for that specific tweeter it's a big step up from what's in your cab now and with the APT80 will give you the volume you want to match your woofer . That attenuator will work fine with that tweeter also . You will have to do some rewiring to get it done but it will make a difference .

I've edited my post here . I had the full crossover as the one to use but Greenboy has it right . The woofer is a 4 ohm and wouldn't have worked with the crossover I reccomended .

[greenboy]

I'd never put a compression driver on less than a 2 component high-pass, usually a third-order is better yet. Actually the existing variable L-pad/attenuator and jack plate could be wired in with the PXB:3K5 highpass section and the APT80 to keep it cheap but decent. After the Le Son it'll seem like a Cadilllac with a turbocharger.

[will33]

I guessing that cap is there to pass the tweet up around 5k to get a little of the "clackiness" out of the lower end of the piezo's range but it's not near steep enough to use with a real tweeter. Greenboy's suggestion is about the best you could do with that cab without spending a good bit more. If you want to keep it really cheap, you could add 2 or 3 more piezo's to it for about $10. That'd get the high ends SPL more around where the woofer is playing at. Could also take the cap out for a little more snap and see if you like it that way, if not put it back in.

[dustybottoms]

I have been reading all night now based on the info you guys have all provided me. Thanks so much. I feel like a have a better idea in which direction I will be going now. Thanks, Greenboy. I may be hitting you up with a question here again soon.

[dustybottoms]

Just got done with this! Greenboy, took your advice on the eminence crossover and the apt driver. Sounds great and its loud! My favorite part is that you can pick it up with one hand. Thanks for all the help!